1
|
DeMeritt J, Khan AA, Wattamwar A, Litkouhi B, Vaidya A, Sbarra M, Zamudio S, Pozzi RA, Canning A, Woytanowski J. Serial uterine artery embolizations for the treatment of placenta percreta in the first trimester: Recurrent vascular recanalization and recruitment. J Vasc Interv Radiol 2017. [DOI: 10.1016/j.jvir.2016.12.1027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
2
|
Timor-Tritsch IE, Monteagudo A, Cali G, Vintzileos A, Viscarello R, Al-Khan A, Zamudio S, Mayberry P, Cordoba MM, Dar P. Cesarean scar pregnancy is a precursor of morbidly adherent placenta. Ultrasound Obstet Gynecol 2014; 44:346-353. [PMID: 24890256 DOI: 10.1002/uog.13426] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 05/06/2014] [Accepted: 05/23/2014] [Indexed: 06/03/2023]
Abstract
OBJECTIVE To provide further sonographic, clinical and histological evidence that Cesarean scar pregnancy (CSP) is a precursor to and an early form of second- and third-trimester morbidly adherent placenta (MAP). METHODS This is a report of 10 cases of CSP identified early, in which the patients decided to continue the pregnancy, following counseling that emphasized the possibility of both significant pregnancy complications and a need for hysterectomy. Pregnancies were followed at 2-4-week intervals with ultrasound scans and customary monitoring. The aim was for patients to reach near term or term and then undergo elective Cesarean delivery and, if necessary, hysterectomy. Charts, ultrasound images, operative reports and histopathological examinations of the placentae were reviewed. RESULTS The ultrasound diagnosis of CSP was made before 10 weeks. By the second trimester, all patients exhibited sonographic signs of MAP. Nine of the 10 patients delivered liveborn neonates between 32 and 37 weeks. In the tenth pregnancy, progressive shortening of the cervix and intractable vaginal bleeding prompted termination, with hysterectomy, at 20 weeks. Two other patients in the cohort had antepartum complications (bleeding at 33 weeks in one case and contractions at 32 weeks in the other). All patients underwent hysterectomy at the time of Cesarean delivery, with total blood loss ranging from 300 to 6000 mL. Placenta percreta was the histopathological diagnosis in all 10 cases. CONCLUSION The cases in this series validate the hypothesis that CSP is a precursor of MAP, both sharing the same histopathology. Our findings provide evidence that can be used to counsel patients with CSP, to enable them to make an informed choice between first-trimester termination and continuation of the pregnancy, with its risk of premature delivery and loss of uterus and fertility.
Collapse
Affiliation(s)
- I E Timor-Tritsch
- NYU School of Medicine, Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, New York, NY, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
3
|
Zamudio S, Kovalenko O, Echalar L, Torricos T, Al-Khan A, Alvarez M, Illsley NP. Evidence for extraplacental sources of circulating angiogenic growth effectors in human pregnancy. Placenta 2013; 34:1170-6. [PMID: 24161217 DOI: 10.1016/j.placenta.2013.09.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 09/03/2013] [Accepted: 09/24/2013] [Indexed: 12/24/2022]
Abstract
Pregnancy complications such as preeclampsia (PE) and intrauterine growth restriction (IUGR) are associated with reduced blood flow, contributing to placental and fetal hypoxia. Placental hypoxia is thought to cause altered production of angiogenic growth effectors (AGEs), reflected in the circulation of mother and fetus. Vascular endothelial growth factor (VEGF), placental growth factor (PlGF) and their soluble binding protein (sFlt-1) are, in turn, postulated as being causally involved in PE via induction of systemic endothelial cell dysfunction. To dissect the role of AGEs, accurate measurement is of great importance. However, the values of AGEs are highly variable, contributing to heterogeneity in their association (or lack thereof) with preeclampsia. To test the hypothesis that variability may be due to peripheral cell release of AGEs we obtained blood samples from normal healthy pregnant women (n = 90) and the cord blood of a subset of their neonates using standard serum separation and compared results obtained in parallel samples collected into reagents designed to inhibit peripheral cell activation (sodium citrate, theophylline, adenosine and dipyridamole-CTAD). AGEs were measured by ELISA. CTAD collection reduced maternal and fetal free VEGF by 83%, and 98%, respectively. Free PlGF was decreased by 29%, maternal sFlt-1 by >20% and fetal sFlt-1 by 59% in the CTAD-treated vs. serum sample (p < 0.0001). In summary blood collection techniques can profoundly alter measured concentrations of AGEs in mother and fetus. This process is highly variable, contributes to variation reported in the literature, and renders questionable the true impact of alteration in AGEs on pregnancy pathologies.
Collapse
Affiliation(s)
- S Zamudio
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine and Surgery and the Center for Abnormal Placentation, Hackensack University Medical Center, Hackensack, NJ, USA.
| | | | | | | | | | | | | |
Collapse
|
4
|
Williams SF, Fik E, Zamudio S, Illsley NP. Global protein synthesis in human trophoblast is resistant to inhibition by hypoxia. Placenta 2011; 33:31-8. [PMID: 22077987 DOI: 10.1016/j.placenta.2011.09.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 09/27/2011] [Accepted: 09/29/2011] [Indexed: 12/27/2022]
Abstract
Placental growth and function depend on syncytial cell processes which require the continuing synthesis of cellular proteins. The substantial energy demands of protein synthesis are met primarily from oxidative metabolism. Although the responses of individual proteins produced by the syncytiotrophoblast to oxygen deprivation have been investigated previously, there is no information available on global protein synthesis in syncytiotrophoblast under conditions of hypoxia. These studies were designed to test the hypothesis that syncytial protein synthesis is decreased in a dose-dependent manner by hypoxia. Experiments were performed to measure amino acid incorporation into proteins in primary syncytiotrophoblast cells exposed to oxygen concentrations ranging from 0 to 10%. Compared to cells exposed to normoxia (10% O₂), no changes were observed following exposure to 5% or 3% O₂, but after exposure to 1% O₂, protein synthesis after 24 and 48 h decreased by 24% and 23% and with exposure to 0% O₂, by 65% and 50%. As a consequence of these results, we hypothesized that global protein synthesis in conditions of severe hypoxia was being supported by glucose metabolism. Additional experiments were performed therefore to examine the role of glucose in supporting protein synthesis. These demonstrated that at each oxygen concentration there was a significant, decreasing linear trend in protein synthesis as glucose concentration was reduced. Under conditions of near-anoxia and in the absence of glucose, protein synthesis was reduced by >85%. Even under normoxic conditions (defined as 10% O₂) and in the presence of oxidative substrates, reductions in glucose were accompanied by decreases in protein synthesis. These experiments demonstrate that syncytiotrophoblast cells are resistant to reductions in protein synthesis at O₂ concentrations greater than 1%. This could be explained by our finding that a significant fraction of protein synthesis in the syncytiotrophoblast is sustained by glycolytic metabolism. This suggests that with increasing degrees of chronic hypoxia there is a shift from oxidative to glycolytic pathways, allowing a substantial degree of protein synthesis to be maintained.
Collapse
Affiliation(s)
- S F Williams
- Department of Obstetrics, Gynecology and Women's Health, UMDNJ-New Jersey Medical School, 185 South Orange Ave, MSB E506, Newark, NJ 07103, USA.
| | | | | | | |
Collapse
|
5
|
Brown K, Heller DS, Zamudio S, Illsley NP. Glucose transporter 3 (GLUT3) protein expression in human placenta across gestation. Placenta 2011; 32:1041-9. [PMID: 22000473 DOI: 10.1016/j.placenta.2011.09.014] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 09/02/2011] [Accepted: 09/22/2011] [Indexed: 01/14/2023]
Abstract
Conflicting information regarding expression of GLUT3 protein in the human placenta has been reported and the localization and pattern of expression of GLUT3 protein across gestation has not been clearly defined. The objective of this study was characterization of syncytial GLUT3 protein expression across gestation. We hypothesized that GLUT3 protein is present in the syncytial microvillous membrane and that its expression decreases over gestation. GLUT3 protein was measured in samples from a range of gestational ages (first to third trimester), with human brain and human bowel used as a positive and negative control respectively. As an additional measure of specificity, we transfected BeWo choriocarcinoma cells, a trophoblast cell line expressing GLUT3, with siRNA directed against GLUT3 and analyzed expression by Western blotting. GLUT3 was detected in the syncytiotrophoblast at all gestational ages by immunohistochemistry. Using Western blotting GLUT3 was detected as an integral membrane protein at a molecular weight of ∼50 kDa in microvillous membranes from all trimesters but not in syncytial basal membranes. The identity of the primary antibody target was confirmed by demonstrating that expression of the immunoblotting signal in GLUT3 siRNA-treated BeWo was decreased to 18 ± 6% (mean ± SEM) of that seen in cells transfected with a non-targeting siRNA. GLUT3 expression in microvillous membranes detected by Western blot decreased through the trimesters such that expression in the second trimester (wks 14-26) was 48 ± 7% of that in the first trimester and by the third trimester (wks 31-40) only 34 ± 10% of first trimester expression. In addition, glucose uptake into BeWo cells treated with GLUT3 siRNA was reduced to 60% of that measured in cells treated with the non-targeting siRNA. This suggests that GLUT3-mediated uptake comprises approximately 50% of glucose uptake into BeWo cells. These results confirm the hypothesis that GLUT3 is present in the syncytial microvillous membrane early in gestation and decreases thereafter, supporting the idea that GLUT3 is of greater importance for glucose uptake early in gestation.
Collapse
Affiliation(s)
- K Brown
- Department of Obstetrics, Gynecology and Women's Health, UMDNJ-New Jersey Medical School, 185 South Orange Ave, Newark, NJ 07101-1709, USA
| | | | | | | |
Collapse
|
6
|
Al-Khan A, Aye IL, Barsoum I, Borbely A, Cebral E, Cerchi G, Clifton VL, Collins S, Cotechini T, Davey A, Flores-Martin J, Fournier T, Franchi AM, Fretes RE, Graham CH, Godbole G, Hansson SR, Headley PL, Ibarra C, Jawerbaum A, Kemmerling U, Kudo Y, Lala PK, Lassance L, Lewis RM, Menkhorst E, Morris C, Nobuzane T, Ramos G, Rote N, Saffery R, Salafia C, Sarr D, Schneider H, Sibley C, Singh AT, Sivasubramaniyam TS, Soares MJ, Vaughan O, Zamudio S, Lash GE. IFPA Meeting 2010 Workshops Report II: Placental pathology; trophoblast invasion; fetal sex; parasites and the placenta; decidua and embryonic or fetal loss; trophoblast differentiation and syncytialisation. Placenta 2011; 32 Suppl 2:S90-9. [PMID: 21236487 DOI: 10.1016/j.placenta.2010.12.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 12/21/2010] [Accepted: 12/21/2010] [Indexed: 11/29/2022]
Abstract
Workshops are an important part of the IFPA annual meeting. At IFPA Meeting 2010 diverse topics were discussed in twelve themed workshops, six of which are summarized in this report. 1. The placental pathology workshop focused on clinical correlates of placenta accreta/percreta. 2. Mechanisms of regulation of trophoblast invasion and spiral artery remodeling were discussed in the trophoblast invasion workshop. 3. The fetal sex and intrauterine stress workshop explored recent work on placental sex differences and discussed them in the context of whether boys live dangerously in the womb.4. The workshop on parasites addressed inflammatory responses as a sign of interaction between placental tissue and parasites. 5. The decidua and embryonic/fetal loss workshop focused on key regulatory mediators in the decidua, embryo and fetus and how alterations in expression may contribute to different diseases and adverse conditions of pregnancy. 6. The trophoblast differentiation and syncytialisation workshop addressed the regulation of villous cytotrophoblast differentiation and how variations may lead to placental dysfunction and pregnancy complications.
Collapse
Affiliation(s)
- A Al-Khan
- Department of Obstetrics and Gynaecology, University of California San Diego, San Diego, CA, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Zamudio S, Kovalenko O, Vanderlelie J, Illsley NP, Heller D, Belliappa S, Perkins AV. Chronic hypoxia in vivo reduces placental oxidative stress. Placenta 2007; 28:846-53. [PMID: 17292468 PMCID: PMC2001273 DOI: 10.1016/j.placenta.2006.11.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Revised: 11/29/2006] [Accepted: 11/30/2006] [Indexed: 10/23/2022]
Abstract
Decreased placental oxygenation and increased oxidative stress are implicated in the development of preeclampsia. Oxidative stress arises from imbalance between pro-versus anti-oxidants and can lead to biological oxidation and apoptosis. Because pregnant women living at high altitude (3100 m, HA) have lowered arterial PO2 and an increased incidence of preeclampsia, we hypothesized that HA placentas would have decreased anti-oxidant enzyme activity, increased oxidative stress (lipid peroxidation, protein oxidation and nitration) and greater trophoblast apoptosis than low-altitude (LA) placentas. We measured enzymatic activities, lipid and protein oxidation and co-factor concentrations by spectrophotometric techniques and ELISA in 12 LA and 18 HA placentas. Immunohistochemistry (IHC) was used to evaluate nitrated proteins and specific markers of apoptosis (activated caspase 3 and M30). Superoxide dismutase activity was marginally lower (p=0.05), while glutathione peroxidase activity (p<0.05), thioredoxin concentrations (p<0.005) and thioredoxin reductase activity p<0.01 were all reduced in HA placentas. Decreased anti-oxidant activity was not associated with increased oxidative stress: lipid peroxide content and protein carbonyl formation were lower at HA (p<0.01). We found greater nitrotyrosine residues in the syncytiotrophoblast at 3100 m (p<0.05), but apoptosis did not differ between altitudes. Our data suggest that hypoxia does not increase placental oxidative stress in vivo. Nitrative stress may be a consequence of hypoxia but does not appear to contribute to increased apoptosis. Lowered placental concentrations of anti-oxidants may contribute to the susceptibility of women living at HA to the development of preeclampsia, but are unlikely to be etiological.
Collapse
Affiliation(s)
- S Zamudio
- Department of Obstetrics, Gynecology and Women's Health, UMD-New Jersey Medical School, 185 South Orange Avenue, MSB E-506, Newark, NJ 07103-2714, USA.
| | | | | | | | | | | | | |
Collapse
|
8
|
Brimacombe M, Heller D, Zamudio S. Health Disparities in Relation to Potential Causes of Stillbirth. Am J Epidemiol 2006. [DOI: 10.1093/aje/163.suppl_11.s57-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
9
|
Zamudio S, Baumann MU, Illsley NP. Effects of chronic hypoxia in vivo on the expression of human placental glucose transporters. Placenta 2006; 27:49-55. [PMID: 16310037 PMCID: PMC4497571 DOI: 10.1016/j.placenta.2004.12.010] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2004] [Revised: 12/17/2004] [Accepted: 12/20/2004] [Indexed: 11/26/2022]
Abstract
Birth weight is reduced and the risk of preeclampsia is increased in human high altitude pregnancies. There has been little work to determine whether hypoxia acts directly to reduce fetal growth (e.g. reduced blood flow and oxygen delivery), or via changes in functional capacities such as nutrient transport. We therefore investigated the expression of a primary nutrient transporter, the GLUT1 glucose transporter and two in vitro markers of hypoxia (erythropoietin receptor, EPO-R, and transferrin receptor, TfR) in the syncytial microvillous (MVM) and basal membrane fractions (BMF) of 13 high (3100 m) and 12 low (1600 m) altitude placentas from normal term pregnancies. Birth weight was lower at 3100 m than at 1600 m despite similar gestational age, but none of the infants were clinically designated as fetal growth restriction. EPO-R, TfR and GLUT1 were examined by immunoblotting and maternal circulating erythropoietin and transferrin by ELISA. EPO-R was greater on the MVM (+75%) and BMF (+25%) at 3100 m. TfR was 32% lower on the MVM at 3100 m. GLUT1 was 40% lower in the BMF at 3100 m. Circulating EPO was greater at high altitude, while transferrin was similar, and neither correlated with their membrane receptors. BMF GLUT1 was positively correlated with birth weight at high, but not low altitude. In this in vivo model of chronic placental hypoxia, syncytial EPO-R increased as expected, while nutrient transporters decreased, opposite to what has been observed in vitro. Therefore, hypoxia acts to reduce fetal growth not simply by reducing oxygen delivery, but also by decreasing the density of nutrient transporters.
Collapse
Affiliation(s)
- S Zamudio
- Department of Obstetrics, Gynecology and Women's Health, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103-2714, USA.
| | | | | |
Collapse
|
10
|
Tissot van Patot M, Grilli A, Chapman P, Broad E, Tyson W, Heller DS, Zwerdlinger L, Zamudio S. Remodelling of uteroplacental arteries is decreased in high altitude placentae. Placenta 2003; 24:326-35. [PMID: 12657505 DOI: 10.1053/plac.2002.0899] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Uterine blood flow and birth weight are reduced and the risk of pre-eclampsia is increased in high-altitude pregnancies. Since IUGR and pre-eclampsia are associated with reduced invasion and remodelling of maternal spiral arteries we asked whether the terminal ends of uteroplacental arteries located at the maternal-foetal decidual interface evidenced less remodelling in 19 high (3100 m) compared with 13 moderate (1600 m) altitude placentae from normal pregnancies. Previous work has demonstrated marked villous angiogenesis in high altitude placentae. We asked whether such changes are compensatory for reduced modelling and/or whether they contribute to increased birth weight. Placentae were randomly sampled and examined with immunohistochemistry to evaluate vessel remodelling and foetal capillary density. The decidual ends of uteroplacental arteries were 8-fold more likely to be remodelled at 1600 vs. 3100 m (OR=8.1; CI 2.4, 27.0,P< 0.001). There were more than twice as many uteroplacental arteries observed in the high vs. moderate altitude placentae (OR=2.1; CI: 1.3, 3.5, P=0.006). Foetal capillary density was greater at 3100 vs. 1600 m (P< 0.001), but did not relate to remodelling nor to birth weight. In this in vivo model for chronic hypoxia, remodelling is reduced, and villous angiogenesis is not fully compensatory for reduced PO(2).
Collapse
Affiliation(s)
- M Tissot van Patot
- Department of Anesthesiology, University of Colorado Health Sciences Center, Denver, CO 80262, USA
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Fregoso-Aguilar T, Urióstegui T, Zamudio S, De la Cruz F. The differential effect of haloperidol and repetitive induction on four immobility responses in mouse and guinea pig. Behav Pharmacol 2002; 13:253-60. [PMID: 12218505 DOI: 10.1097/00008877-200207000-00001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The modification by haloperidol and repetitive induction on four immobility responses -- tonic immobility, cataleptic immobility, immobility by clamping the neck and dorsal immobility -- were compared in mice and guinea pigs. Without drug, three out of four responses (cataleptic, neck clamp and dorsal immobility) were induced in mice; guinea pigs displayed all four responses. Haloperidol (5 mg/kg i.p.) potentiated the three responses shown by mice, but did not potentiate the four responses in guinea pigs. In both undrugged and haloperidol-treated mice, only the cataleptic immobility response was potentiated by repetition. In guinea pigs, none of the four immobility responses was affected due to repetition, haloperidol or a combination of both. These data are discussed, considering that, although these immobility responses could be mediated by the same neurotransmitters (e.g. dopamine), they are possibly expressed in a differential manner as a function of the kind of stimulus used to trigger the response, characteristics of the species and, in some immobility responses such as cataleptic immobility, as a function of their interaction with habituation or another learning-like process.
Collapse
Affiliation(s)
- T Fregoso-Aguilar
- Department of Physiology, National School of Biological Sciences, National Polytechnic Institute, Mexico
| | | | | | | |
Collapse
|
12
|
Zamudio S, Douglas M, Mazzeo RS, Wolfel EE, Young DA, Rock PB, Braun B, Muza SR, Butterfield GE, Moore LG. Women at altitude: forearm hemodynamics during acclimatization to 4,300 m with alpha(1)-adrenergic blockade. Am J Physiol Heart Circ Physiol 2001; 281:H2636-44. [PMID: 11709433 DOI: 10.1152/ajpheart.2001.281.6.h2636] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We hypothesized that blockade of alpha(1)-adrenergic receptors would prevent the rise in peripheral vascular resistance that normally occurs during acclimatization. Sixteen eumenorrheic women were studied at sea level (SL) and at 4,300 m (days 3 and 10). Volunteers were randomly assigned to take the selective alpha(1)-blocker prazosin or placebo. Venous compliance, forearm vascular resistance, and blood flow were measured using plethysmography. Venous compliance fell by day 3 in all subjects (1.39 +/- 0.30 vs. 1.62 +/- 0.43 ml. Delta 30 mmHg(-1) x 100 ml tissue(-1) x min(-1) at SL, means +/- SD). Altitude interacted with prazosin treatment (P < 0.0001) such that compliance returned to SL values by day 10 in the prazosin-treated group (1.68 +/- 0.19) but not in the placebo-treated group (1.20 +/- 0.10, P < 0.05). By day 3 at 4,300 m, all women had significant falls in resistance (35.2 +/- 13.2 vs. 54.5 +/- 16.1 mmHg x ml(-1) x min(-1) at SL) and rises in blood flow (2.5 +/- 1.0 vs. 1.6 +/- 0.5 ml. 100 ml tissue(-1) x min(-1) at SL). By day 10, resistance and flow returned toward SL, but this return was less in the prazosin-treated group (resistance: 39.8 +/- 4.6 mmHg x ml(-1) x min(-1) with prazosin vs. 58.5 +/- 9.8 mmHg x ml(-1) x min(-1) with placebo; flow: 1.9 +/- 0.7 ml. 100 ml tissue(-1) x min(-1) with prazosin vs. 2.3 +/- 0.3 ml x 100 ml tissue(-1) x min(-1) with placebo, P < 0.05). Lower resistance related to higher circulating epinephrine in both groups (r = -0.50, P < 0.0001). Higher circulating norepinephrine related to lower venous compliance in the placebo-treated group (r = -0.42, P < 0.05). We conclude that alpha(1)-adrenergic stimulation modulates peripheral vascular changes during acclimatization.
Collapse
Affiliation(s)
- S Zamudio
- Women's Health Research Center, University of Colorado Health Sciences Center, Denver, 80262, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Reeves JT, Zamudio S, Dahms TE, Asmus I, Braun B, Butterfield GE, McCullough RG, Muza SR, Rock PB, Moore LG. Erythropoiesis in women during 11 days at 4,300 m is not affected by menstrual cycle phase. J Appl Physiol (1985) 2001; 91:2579-86. [PMID: 11717222 DOI: 10.1152/jappl.2001.91.6.2579] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Because the ovarian steroid hormones, progesterone and estrogen, have higher blood levels in the luteal (L) than in the follicular (F) phase of the menstrual cycle, and because of their known effects on ventilation and hematopoiesis, we hypothesized that less hypoxemia and less erythropoiesis would occur in the L than the F phase of the cycle after arrival at altitude. We examined erythropoiesis with menstrual cycle phase in 16 women (age 22.6 +/- 0.6 yr). At sea level, 11 of 16 women were studied during both menstrual cycle phases, and, where comparison within women was available, cycle phase did not alter erythropoietin (n = 5), reticulocyte count (n = 10), and red cell volume (n = 9). When all 16 women were taken for 11 days to 4,300-m altitude (barometric pressure = 462 mmHg), paired comparisons within women showed no differences in ovarian hormone concentrations at sea level vs. altitude on menstrual cycle day 3 or 10 for either the F (n = 11) or the L (n = 5) phase groups. Arterial oxygen saturation did not differ between the F and L groups at altitude. There were no differences by cycle phase on day 11 at 4,300 m for erythropoietin [22.9 +/- 4.7 (L) vs. 18.8 +/- 3.4 mU/ml (F)], percent reticulocytes [1.9 +/- 0.1 (L) vs. 2.1 +/- 0.3% (F)], hemoglobin [13.5 +/- 0.3 (L) vs. 13.7 +/- 0.3 g/100 ml (F)], percent hematocrit [40.6 +/- 1.4 (L) vs. 40.7 +/- 1.0% (F)], red cell volume [31.1 +/- 3.6 (L) vs. 33.0 +/- 1.6 ml/kg (F)], and blood ferritin [8.9 +/- 1.7 (L) vs. 10.2 +/- 0.9 microg/l (F)]. Blood level of erythropoietin was related (r = 0.77) to arterial oxygen saturation but not to the levels of progesterone or estradiol. We conclude that erythropoiesis was not altered by menstrual cycle phase during the first days at 4,300-m altitude.
Collapse
Affiliation(s)
- J T Reeves
- University of Colorado Health Sciences Center, Denver, CO 80262, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Mazzeo RS, Donovan D, Fleshner M, Butterfield GE, Zamudio S, Wolfel EE, Moore LG. Interleukin-6 response to exercise and high-altitude exposure: influence of alpha-adrenergic blockade. J Appl Physiol (1985) 2001; 91:2143-9. [PMID: 11641355 DOI: 10.1152/jappl.2001.91.5.2143] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Interleukin-6 (IL-6), an important cytokine involved in a number of biological processes, is consistently elevated during periods of stress. The mechanisms responsible for the induction of IL-6 under these conditions remain uncertain. This study examined the effect of alpha-adrenergic blockade on the IL-6 response to acute and chronic high-altitude exposure in women both at rest and during exercise. Sixteen healthy, eumenorrheic women (aged 23.2 +/- 1.4 yr) participated in the study. Subjects received either alpha-adrenergic blockade (prazosin, 3 mg/day) or a placebo in a double-blinded, randomized fashion. Subjects participated in submaximal exercise tests at sea level and on days 1 and 12 at altitude (4,300 m). Resting plasma and 24-h urine samples were collected throughout the duration of the study. At sea level, no differences were found at rest for plasma IL-6 between groups (1.5 +/- 0.2 and 1.2 +/- 0.3 pg/ml for placebo and blocked groups, respectively). On acute ascent to altitude, IL-6 levels increased significantly in both groups compared with sea-level values (57 and 84% for placebo and blocked groups, respectively). After 12 days of acclimatization, IL-6 levels remained elevated for placebo subjects; however, they returned to sea-level values in the blocked group. alpha-Adrenergic blockade significantly lowered the IL-6 response to exercise both at sea level (46%) and at altitude (42%) compared with placebo. A significant correlation (P = 0.004) between resting IL-6 and urinary norepinephrine excretion rates was found over the course of time while at altitude. In conclusion, the results indicate a role for alpha-adrenergic regulation of the IL-6 response to the stress of both short-term moderate-intensity exercise and hypoxia.
Collapse
Affiliation(s)
- R S Mazzeo
- Department of Kinesiology and Applied Physiology, University of Colorado, Boulder, Colorado 80309, USA.
| | | | | | | | | | | | | |
Collapse
|
15
|
Muza SR, Rock PB, Fulco CS, Zamudio S, Braun B, Cymerman A, Butterfield GE, Moore LG. Women at altitude: ventilatory acclimatization at 4,300 m. J Appl Physiol (1985) 2001; 91:1791-9. [PMID: 11568164 DOI: 10.1152/jappl.2001.91.4.1791] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Women living at low altitudes or acclimatized to high altitudes have greater effective ventilation in the luteal (L) compared with follicular (F) menstrual cycle phase and compared with men. We hypothesized that ventilatory acclimatization to high altitude would occur more quickly and to a greater degree in 1) women in their L compared with women in their F menstrual cycle phase, and 2) in women compared with men. Studies were conducted on 22 eumenorrheic, unacclimatized, sea-level (SL) residents. Indexes of ventilatory acclimatization [resting ventilatory parameters, hypoxic ventilatory response, hypercapnic ventilatory response (HCVR)] were measured in 14 women in the F phase and in 8 other women in the L phase of their menstrual cycle, both at SL and again during a 12-day residence at 4,300 m. At SL only, ventilatory studies were also completed in both menstrual cycle phases in 12 subjects (i.e., within-subject comparison). In these subjects, SL alveolar ventilation (expressed as end-tidal PCO(2)) was greater in the L vs. F phase. Yet the comparison between L- and F-phase groups found similar levels of resting end-tidal PCO(2), hypoxic ventilatory response parameter A, HCVR slope, and HCVR parameter B, both at SL and 4,300 m. Moreover, these indexes of ventilatory acclimatization were not significantly different from those previously measured in men. Thus female lowlanders rapidly ascending to 4,300 m in either the L or F menstrual cycle phase have similar levels of alveolar ventilation and a time course for ventilatory acclimatization that is nearly identical to that reported in male lowlanders.
Collapse
Affiliation(s)
- S R Muza
- United States Army Research Institute of Environmental Medicine, Natick, MA 01760-5007, USA.
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Moore LG, Young D, McCullough RE, Droma T, Zamudio S. Tibetan protection from intrauterine growth restriction (IUGR) and reproductive loss at high altitude. Am J Hum Biol 2001; 13:635-44. [PMID: 11505472 DOI: 10.1002/ajhb.1102] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Chronic hypoxia at high altitude restricts fetal growth, reducing birth weight and increasing infant mortality. We asked whether Tibetans, a long-resident high-altitude population, exhibit less altitude-associated intrauterine growth restriction (IUGR) and prenatal or postnatal reproductive loss than Han (ethnic Chinese), a group that has lived there for a shorter period of time. A population sample was obtained, comprising 485 deliveries to Tibetan or Han women over an 18-month period at 8 general hospitals or clinics located at 2,700-4,700 m in the Tibet Autonomous Region, China. Birth weight, gestational age, and other information were recorded for each delivery. Prenatal and postnatal mortality were calculated using information obtained from all pregnancies or babies born to study participants. Tibetan babies weighed more than the Han, averaging 310 g heavier at altitudes 2,700-3,000 m (95% CI = 126, 494 g; P < 0.01) and 530 g heavier at 3,000-3,800 m (210, 750 g; P < 0.01). More Han than Tibetan babies were born prematurely. Prenatal and postnatal mortality rose with increasing elevation and were 3-fold higher across all altitudes in the Han than the Tibetans (P < 0.05). Tibetans experience less altitude-associated IUGR than Han and have lower levels of prenatal and postnatal mortality. When the relationships between birth weight and altitude are compared among these and other high-altitude populations, those living at high altitude the longest have the least altitude-associated IUGR. This may suggest the occurrence of an evolutionary adaptation.
Collapse
Affiliation(s)
- L G Moore
- University of Colorado at Denver and Health Sciences Center, Colorado 80262, USA.
| | | | | | | | | |
Collapse
|
17
|
Braun B, Rock PB, Zamudio S, Wolfel GE, Mazzeo RS, Muza SR, Fulco CS, Moore LG, Butterfield GE. Women at altitude: short-term exposure to hypoxia and/or alpha(1)-adrenergic blockade reduces insulin sensitivity. J Appl Physiol (1985) 2001; 91:623-31. [PMID: 11457773 DOI: 10.1152/jappl.2001.91.2.623] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
After short-term exposure to high altitude (HA), men appear to be less sensitive to insulin than at sea level (SL). We hypothesized that the same would be true in women, that reduced insulin sensitivity would be directly related to the rise in plasma epinephrine concentrations at altitude, and that the addition of alpha-adrenergic blockade would potentiate the reduction. To test the hypotheses, 12 women consumed a high-carbohydrate meal at SL and after 16 h at simulated 4,300-m elevation (HA). Subjects were studied twice at each elevation: once with prazosin (Prz), an alpha(1)-adrenergic antagonist, and once with placebo (Pla). Mathematical models were used to assess insulin resistance based on fasting [homeostasis model assessment of insulin resistance (HOMA-IR)] and postprandial [composite model insulin sensitivity index (C-ISI)] glucose and insulin concentrations. Relative to SL-Pla (HOMA-IR: 1.86 +/- 0.35), insulin resistance was greater in HA-Pla (3.00 +/- 0.45; P < 0.05), SL-Prz (3.46 +/- 0.51; P < 0.01), and HA-Prz (2.82 +/- 0.43; P < 0.05). Insulin sensitivity was reduced in HA-Pla (C-ISI: 4.41 +/- 1.03; P < 0.01), SL-Prz (5.73 +/- 1.01; P < 0.05), and HA-Prz (4.18 +/- 0.99; P < 0.01) relative to SL-Pla (8.02 +/- 0.92). Plasma epinephrine was significantly elevated in HA-Pla (0.57 +/- 0.08 ng/ml; P < 0.01), SL-Prz (0.42 +/- 0.07; P < 0.05), and HA-Prz (0.82 +/- 0.07; P < 0.01) relative to SL-Pla (0.28 +/- 0.04), but correlations with HOMA-IR, HOMA-beta-cell function, and C-ISI were weak. In women, short-term exposure to simulated HA reduced insulin sensitivity compared with SL. The change does not appear to be directly mediated by a concurrent rise in plasma epinephrine concentrations.
Collapse
Affiliation(s)
- B Braun
- Geriatric Research, Education and Clinical Center, Veterans Affairs Health Care System, Stanford University School of Medicine, Palo Alto, California 94304, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Mazzeo RS, Carroll JD, Butterfield GE, Braun B, Rock PB, Wolfel EE, Zamudio S, Moore LG. Catecholamine responses to alpha-adrenergic blockade during exercise in women acutely exposed to altitude. J Appl Physiol (1985) 2001; 90:121-6. [PMID: 11133901 DOI: 10.1152/jappl.2001.90.1.121] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have previously documented the importance of the sympathetic nervous system in acclimatizing to high altitude in men. The purpose of this investigation was to determine the extent to which alpha-adrenergic blockade affects the sympathoadrenal responses to exercise during acute high-altitude exposure in women. Twelve eumenorrheic women (24.7 +/- 1.3 yr, 70.6 +/- 2.6 kg) were studied at sea level and on day 2 of high-altitude exposure (4,300-m hypobaric chamber) in either their follicular or luteal phase. Subjects performed two graded-exercise tests at sea level (on separate days) on a bicycle ergometer after 3 days of taking either a placebo or an alpha-blocker (3 mg/day prazosin). Subjects also performed two similar exercise tests while at altitude. Effectiveness of blockade was determined by phenylephrine challenge. At sea level, plasma norepinephrine levels during exercise were 48% greater when subjects were alpha-blocked compared with their placebo trial. This difference was only 25% when subjects were studied at altitude. Plasma norepinephrine values were significantly elevated at altitude compared with sea level but to a greater extent for the placebo ( upward arrow 59%) vs. blocked ( upward arrow 35%) trial. A more dramatic effect of both altitude ( upward arrow 104% placebo vs. 95% blocked) and blockade ( upward arrow 50% sea level vs. 44% altitude) was observed for plasma epinephrine levels during exercise. No phase differences were observed across any condition studied. It was concluded that alpha-adrenergic blockade 1) resulted in a compensatory sympathoadrenal response during exercise at sea level and altitude, and 2) this effect was more pronounced for plasma epinephrine.
Collapse
Affiliation(s)
- R S Mazzeo
- Department of Kinesiology and Applied Physiology, University of Colorado, Boulder, Colorado 80309, USA
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Abstract
High-altitude reduces infant birth weight as a result of intrauterine growth restriction (IUGR) and is associated with increased neonatal mortality. We hypothesized that babies born to Tibetan compared to Han (Chinese) high-altitude residents were protected from IUGR as the result of increased maternal O(2) transport due, in turn, to increased uterine artery (UA) blood flow. We studied 68 nonpregnant or pregnant Tibetan or Han residents of Lhasa, Tibet Autonomous Region, China (3,658 m). The pregnant women had higher hypoxic ventilatory responses (HVR A) and resting ventilations (V(E)) than their nonpregnant counterparts (Tib HVR = 134 +/- 16 (SEM) vs. 30 +/- 8, Han HVR = 134 +/- 16 vs. 66 +/- 18 A units; Tib V(E) = 11.8 +/- 0.3 vs. 10.1 +/- 0.5, Han V(E) = 10.7 +/- 0.5 vs. 9.4 +/- 0.5 l BTPS/min; all P < 0.05). Pregnancy did not change hemoglobin concentration in the Han but lowered values more than 2 g/dl in the Tibetans, serving to reduce arterial O(2) content below Han values (15.4 +/- 0.3 vs. 17.4 +/- 0.5 ml O(2)/100 ml whole blood, P < 0.05). Compared with the Han, the pregnant Tibetans had higher UA blood flow velocity (58.5 +/- 2.9 vs. 49.1 +/- 3.2, P < 0. 05) and distributed a higher portion of common iliac (CI) blood flow to the UA (4.8 +/- 0.4 vs. 3.3 +/- 0.3, P < 0.05). Birth weights averaged 635 g greater in the Tibetan than Han high-altitude residents (3,280 +/- 78 vs. 2,645 +/- 96 g, P < 0.01), or 694 g more when adjusted for maternal age, parity, height, and near-term body weight. Heavier birth weight babies were born to women with higher V(E) (r = 0.62, P < 0.01) and greater distribution of CI blood flow to the UA (r = 0.42, P < 0.05). We conclude that increased UA blood flow, and not higher arterial O(2) content, permits Tibetan women to increase uteroplacental O(2) delivery and protect their infants from altitude-associated IUGR.
Collapse
Affiliation(s)
- L G Moore
- Department of Anthropology, University of Colorado at Denver, Denver, Colorado 80262, USA.
| | | | | | | | | |
Collapse
|
20
|
Mazzeo RS, Child A, Butterfield GE, Braun B, Rock PB, Wolfel EE, Zamudio S, Moore LG. Sympathoadrenal responses to submaximal exercise in women after acclimatization to 4,300 meters. Metabolism 2000; 49:1036-42. [PMID: 10954023 DOI: 10.1053/meta.2000.7706] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The purpose of this investigation was to determine the sympathoadrenal response to exercise in women after acclimatization to high altitude. Sixteen eumenorrheic women (age, 23.6 +/- 1.2 years; weight, 56.2 +/- 4.3 kg) were studied at sea level and after 10 days of high-altitude exposure (4,300 m) in either the follicular (n = 11) or luteal (n = 5) phase. Subjects performed two 45-minute submaximal steady-state exercise tests (50% and 65% peak O2 consumption [VO2 peak]) at sea level on a bicycle ergometer. Exercise tests were also performed on day 10 of altitude exposure (50% VO2 peak at sea level). As compared with rest, plasma epinephrine levels increased 36% in response to exercise at 50% VO2 peak at sea level, with no differences found between cycle phases. This increase was significantly greater (increase 44%) during exercise at 65% VO2 peak. At altitude, the epinephrine response was identical to that found for 65% VO2 peak exercise at sea level (increase 44%), with no differences found between phase assignments. The plasma norepinephrine response differed from that for epinephrine such that the increase with exercise at altitude (increase 61%) was significantly greater compared with 65% Vo2 peak exercise at sea level (increase 49%). Again, no phase differences were observed. It is concluded that the sympathoadrenal response to exercise (1) did not differ between cycle phases across any condition and (2) was similar to that found previously in men, and (3) the relative exercise intensity is the primary factor responsible for the epinephrine response to exercise, whereas altitude had an additive effect on the norepinephrine response to exercise.
Collapse
Affiliation(s)
- R S Mazzeo
- Department of Kinesiology and Applied Physiology, University of Colorado, Boulder 80309, USA
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Affiliation(s)
- S Zamudio
- Department of Anesthesiology, University of Colorado Health Sciences Center, Denver 80260, USA
| | | |
Collapse
|
22
|
Norred CL, Zamudio S, Palmer SK. Use of complementary and alternative medicines by surgical patients. AANA J 2000; 68:13-8. [PMID: 10876447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
This study examined the frequency of surgical patient use of complementary and alternative medicines prior to surgery. After conducting a literature review on the known effects of alternative medicines, we evaluated their potential interactions with anesthetics. At the University of Colorado Health Sciences Center, Denver, Colo, we surveyed 500 elective surgical outpatients about alternative medicines taken during the 2 weeks prior to surgery. Of the 500 patients surveyed, 51% preoperatively took herbs, vitamins, dietary supplements, or homeopathic medicines (range, 1-22 per patient). Substances from 2 or more categories of alternative medicines (herbs, vitamins, dietary supplements, or homeopathic medicines) were consumed by 24% of patients. Twenty-four percent of surveyed patients consumed 50 different herbs, 41% took 9 types of vitamins, 44% took 31 types of dietary supplements, and 1% of patients took the homeopathic arnica. Classification by potential adverse effects revealed that 27% of surgical patients consumed alternative medicines that may inhibit coagulation, affect blood pressure (12%), cause sedation (9%), have cardiac effects (5%), or alter electrolytes (4%). Greater communication, knowledge, and scientific research are needed to safely integrate complementary and alternative medicines in the future management of the surgical patient.
Collapse
Affiliation(s)
- C L Norred
- School of Nursing, University of Colorado Health Sciences Center, Denver, USA
| | | | | |
Collapse
|
23
|
Palmer SK, Moore LG, Young D, Cregger B, Berman JC, Zamudio S. Altered blood pressure course during normal pregnancy and increased preeclampsia at high altitude (3100 meters) in Colorado. Am J Obstet Gynecol 1999; 180:1161-8. [PMID: 10329872 DOI: 10.1016/s0002-9378(99)70611-3] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Our purpose was to determine the case incidences of preeclampsia at low and high altitudes and whether maternal blood pressure course during pregnancy differs between low and high altitudes. STUDY DESIGN This was a retrospective cohort study of pregnancies in sociodemographically matched communities at low and high altitudes in Colorado; each community had a small hospital served by family practitioners and was located >100 miles from major urban areas. Included were consecutive singleton pregnancies of women without chronic disease that resulted in live-born infants at >28 weeks' gestation during an 18-month period (n = 116 at 1260 m, n = 93 at 3100 m). Clinic and hospital medical records were searched and data pertaining to hypertensive complications of pregnancy and serial blood pressure measurements were abstracted. RESULTS Despite similar maternal risk factors, the case incidences of preeclampsia were 16% at 3100 m and 3% at 1260 m. As in sea-level pregnancies, mean blood pressure fell until week 20 in normotensive pregnancy at 1260 m. Mean pressure rose linearly, however, in normotensive women at 3100 m and in women with preeclampsia at both 1260 m and 3100 m. High altitude acted independently of known risk factors and yielded an odds ratio for preeclampsia of 3.6 (95% confidence interval 1. 1-11.9). Birth weight was 285 g lower at 3100 m despite similar gestational ages. CONCLUSION The normal pregnancy-associated fall in blood pressure was absent at 3100 m, even in women who remained normotensive. The incidence of preeclampsia was increased at high altitude. Residence at high altitude interferes with the normal vascular adjustments to pregnancy, increasing the incidence of preeclampsia, and is perhaps analogous to other conditions that decrease uteroplacental oxygen delivery.
Collapse
Affiliation(s)
- S K Palmer
- Department of Anesthesiology, Women's Health Research Center, University of Colorado Health Sciences Center, Denver, USA
| | | | | | | | | | | |
Collapse
|
24
|
Abstract
Studies of the ways in which persons respond to the adaptive challenges of life at high altitude have occupied an important place in anthropology. There are three major regions of the world where high-altitude studies have recently been performed: the Himalayas of Asia, the Andes of South America, and the Rocky Mountains of North America. Of these, the Himalayan region is larger, more geographically remote, and likely to have been occupied by humans for a longer period of time and to have been subject to less admixture or constriction of its gene pool. Recent studies of the physiological responses to hypoxia across the life cycle in these groups reveal several differences in adaptive success. Compared with acclimatized newcomers, lifelong residents of the Andes and/or Himalayas have less intrauterine growth retardation, better neonatal oxygenation, and more complete neonatal cardiopulmonary transition, enlarged lung volumes, decreased alveolar-arterial oxygen diffusion gradients, and higher maximal exercise capacity. In addition, Tibetans demonstrate a more sustained increase in cerebral blood flow during exercise, lower hemoglobin concentration, and less susceptibility to chronic mountain sickness (CMS) than acclimatized newcomers. Compared to Andean or Rocky Mountain high-altitude residents, Tibetans demonstrate less intrauterine growth retardation, greater reliance on redistribution of blood flow than elevated arterial oxygen content to increase uteroplacental oxygen delivery during pregnancy, higher levels of resting ventilation and hypoxic ventilatory responsiveness, less hypoxic pulmonary vasoconstriction, lower hemoglobin concentration, and less susceptibility to CMS. Several of the distinctions demonstrated by Tibetans parallel the differences between natives and newcomers, suggesting that the degree of protection or adaptive benefit relative to newcomers is enhanced for the Tibetans. We thus conclude that Tibetans have several physiological distinctions that confer adaptive benefit consistent with their probable greater generational length of high-altitude residence. Future progress is anticipated in achieving a more integrated view of high-altitude adaptation, incorporating a sophisticated understanding of the ways in which levels of biological organization are articulated and a recognition of the specific genetic variants contributing to differences among high-altitude groups.
Collapse
Affiliation(s)
- L G Moore
- Department of Anthropology, University of Colorado at Denver, 80217-3364, USA
| | | | | |
Collapse
|
25
|
Chapman AB, Abraham WT, Zamudio S, Coffin C, Merouani A, Young D, Johnson A, Osorio F, Goldberg C, Moore LG, Dahms T, Schrier RW. Temporal relationships between hormonal and hemodynamic changes in early human pregnancy. Kidney Int 1998; 54:2056-63. [PMID: 9853271 DOI: 10.1046/j.1523-1755.1998.00217.x] [Citation(s) in RCA: 317] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The systemic hemodynamic profile of human pregnancy is characterized by a decrease in mean arterial pressure, a rise in cardiac output and plasma volume in association with an increase in renal plasma flow and glomerular filtration rate. The factors and the time course responsible for the initial hemodynamic changes seen in human pregnancy have not been completely documented. We hypothesize that systemic and renal hemodynamic changes occur early, prior to the presence of the fetal-placental unit. METHODS Thirteen women were studied prior to and immediately following conception in identical fashion at gestational weeks 6, 8, 10, 12, 24 and 36. Individuals underwent mean arterial pressure, cardiac output, inulin and PAH clearance determinations. RESULTS Mean arterial pressure decreased by six weeks gestation (mid follicular 81.5 +/- 2.6 vs. six weeks 68.7 +/- 2.0 mm tig, P < 0.001) in association with a significant increase in cardiac output, a decrease in systemic vascular resistance and an increase in plasma volume. Renal plasma flow and glomerular filtration rate increased by six weeks gestation. Plasma renin activity and aldosterone concentration increased significantly by six weeks, whereas norepinephrine levels did not change throughout pregnancy. Atrial natriuretic peptide levels increased later, at 12 weeks gestation. Plasma cGMP levels decreased and cGMP clearance increased by six and eight weeks, respectively. CONCLUSIONS Peripheral vasodilation occurs early in pregnancy prior to full placentation in association with renal vasodilation and activation of the renin-angiotensin-aldosterone system. Plasma volume expansion occurs early, followed later by increases in ANP concentration, suggesting that ANP increases in response to changes in intravasular volume.
Collapse
Affiliation(s)
- A B Chapman
- Department of Medicine, University of Colorado Health Sciences Center, St. Louis, Missouri, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Braun B, Butterfield GE, Dominick SB, Zamudio S, McCullough RG, Rock PB, Moore LG. Women at altitude: changes in carbohydrate metabolism at 4,300-m elevation and across the menstrual cycle. J Appl Physiol (1985) 1998; 85:1966-73. [PMID: 9804605 DOI: 10.1152/jappl.1998.85.5.1966] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We hypothesized that, in women, the blood glucose response to a meal (BGR) would be lower after exposure to 4,300 m compared with sea level (SL) and that BGR would be reduced in the presence of estrogen plus progesterone (E+P) relative to estrogen alone (E). Sixteen women were studied in both the E and E+P conditions at SL and in either the E or E+P condition at 4,300 m. On day 9 in each condition, blood was sampled before, and every 30 min for 2 h after, the subjects ate a high-carbohydrate meal. At 4,300 m, BGR peaked at a lower value (5.73 +/- 0.94 mM) than at SL (6.44 +/- 1.45 mM) and returned to baseline more slowly (P < 0.05). Plasma insulin values were the same but C peptide was slightly higher at 4,300 m (P < 0. 05). At SL, BGR returned to baseline more slowly in E+P condition (5. 13 +/- 0.89 and 5.21 +/- 0.91 mM at 60 and 90 min, respectively) relative to E condition (4.51 +/- 0.52 and 4.69 +/- 0.88 mM, respectively) (P < 0.05). Insulin and C peptide were not different between E and E+P conditions. The data indicate that BGR is lower in women at high altitude compared with the SL, possibly due to greater suppression of hepatic glucose production or stimulation of peripheral glucose uptake by insulin. BGR was lower in E condition relative to E+P condition at SL and possibly at 4,300 m, but the relative concentrations of ovarian hormones do not appear to alter the magnitude of the change in BGR when women are exposed to high altitude.
Collapse
Affiliation(s)
- B Braun
- Aging Study Unit, General Research and Education Clinical Center, Veterans Affairs Health Care System, Palo Alto, California 94304, USA.
| | | | | | | | | | | | | |
Collapse
|
27
|
Katz JJ, Mandell MS, House RM, Bilir BM, Barton B, Zamudio S. Cerebral blood flow velocity in patients with subclinical portal-systemic encephalopathy. Anesth Analg 1998; 86:1005-9. [PMID: 9585286 DOI: 10.1097/00000539-199805000-00018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
UNLABELLED Alterations in cerebral blood flow (CBF) are implicated in the etiology of portal-systemic encephalopathy. We hypothesized that CO2 reactivity of the cerebral circulation may be impaired in subjects with chronic liver disease (CLD) who also had subclinical portal-systemic encephalopathy (SPSE). We compared the relationship between PETCO2 and cerebral blood flow velocity in 10 patients with CLD with those of 10 healthy control subjects. Middle cerebral artery mean blood flow velocity (MCAMFV) was measured using transcranial Doppler during rest, hyperventilation, and hypoventilation. The degree of SPSE was quantified by using psychometric testing. Patients with CLD had poorer psychometric test scores compared with control subjects. Patients with CLD had lower PETCO2, MCAMFV, and blood pressure values and higher heart rates, differing from control subjects in all ventilation states. However, CO2 reactivity, the rate of change in MCAMFV to changes in ventilation (expressed as percent change in CBF velocity per mm Hg change in PETCO2) was similar for both groups (4.6% +/- 0.6% vs 4.2% +/- 0.5% for patients with CLD versus control subjects, P = 0.15). IMPLICATIONS Psychometric test scores in patients with chronic liver disease revealed subclinical impairment compared with control subjects. Transcranial Doppler measurements of middle cerebral artery blood flow with varying PETCO2 were conducted, but the CO2 response of patients with liver disease was within the range of control subjects.
Collapse
Affiliation(s)
- J J Katz
- Department of Anesthesiology, University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | | | | | | | |
Collapse
|
28
|
Mazzeo RS, Child A, Butterfield GE, Mawson JT, Zamudio S, Moore LG. Catecholamine response during 12 days of high-altitude exposure (4, 300 m) in women. J Appl Physiol (1985) 1998; 84:1151-7. [PMID: 9516178 DOI: 10.1152/jappl.1998.84.4.1151] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We have previously demonstrated that acclimatization to high altitude elicits increased sympathetic nerve activity in men. The purpose of this investigation was to determine 1) whether women respond in a similar manner as found previously in men and 2) the extent to which menstrual cycle phase influences this response. Sixteen eumenorrheic women (age, 23.6 +/- 1.2 yr; weight, 56.2 +/- 4. 3 kg) were studied at sea level and during 12 days of high-altitude exposure (4,300 m) in either their follicular (F; n = 11) or luteal (L; n = 5) phase. Twenty-four-hour urine samples were collected at sea level and during each day at altitude. Catecholamines were determined by high-performance liquid chromatography with electrochemical detection. Compared with sea-level values, urinary norepinephrine excretion increased significantly during altitude exposure, peaking on days 4-6. Thereafter, levels remained constant throughout the duration of altitude exposure. The magnitude of this increase was similar between the F (138%) and L (93%) phase. Urinary epinephrine levels were elevated on day 2 of altitude exposure compared with sea-level values for both F and L subjects (93%). Thereafter, urinary epinephrine excretion returned to sea-level values, and no differences were found between F and L subjects. Plasma catecholamine content was consistent with urinary values and supports the concept of an elevation in sympathetic activity over time at altitude. Mean and diastolic blood pressure as well as heart rate adjustments to high altitude correlated significantly with urinary norepinephrine excretion rates. It was concluded that 1) urinary and plasma catecholamine responses to 12 days of high-altitude exposure in women are similar to those previously documented to occur for men; 2) whereas no differences in catecholamine levels were observed between F- and L-phase assignments, for a given urinary norepinephrine excretion rate, blood pressure and heart rates were lower for F vs. L subjects; and 3) several cardiovascular adaptations associated with high-altitude exposure correlated with 24-h urinary norepinephrine excretion rates and thus sympathetic nerve activity.
Collapse
Affiliation(s)
- R S Mazzeo
- Department of Kinesiology, University of Colorado, Boulder, Colorado 80309, USA
| | | | | | | | | | | |
Collapse
|
29
|
Abstract
Studies of the ways in which persons respond to the adaptive challenges of life at high altitude have occupied an important place in anthropology. There are three major regions of the world where high-altitude studies have recently been performed: the Himalayas of Asia, the Andes of South America, and the Rocky Mountains of North America. Of these, the Himalayan region is larger, more geographically remote, and likely to have been occupied by humans for a longer period of time and to have been subject to less admixture or constriction of its gene pool. Recent studies of the physiological responses to hypoxia across the life cycle in these groups reveal several differences in adaptive success. Compared with acclimatized newcomers, lifelong residents of the Andes and/or Himalayas have less intrauterine growth retardation, better neonatal oxygenation, and more complete neonatal cardiopulmonary transition, enlarged lung volumes, decreased alveolar-arterial oxygen diffusion gradients, and higher maximal exercise capacity. In addition, Tibetans demonstrate a more sustained increase in cerebral blood flow during exercise, lower hemoglobin concentration, and less susceptibility to chronic mountain sickness (CMS) than acclimatized newcomers. Compared to Andean or Rocky Mountain high-altitude residents, Tibetans demonstrate less intrauterine growth retardation, greater reliance on redistribution of blood flow than elevated arterial oxygen content to increase uteroplacental oxygen delivery during pregnancy, higher levels of resting ventilation and hypoxic ventilatory responsiveness, less hypoxic pulmonary vasoconstriction, lower hemoglobin concentration, and less susceptibility to CMS. Several of the distinctions demonstrated by Tibetans parallel the differences between natives and newcomers, suggesting that the degree of protection or adaptive benefit relative to newcomers is enhanced for the Tibetans. We thus conclude that Tibetans have several physiological distinctions that confer adaptive benefit consistent with their probable greater generational length of high-altitude residence. Future progress is anticipated in achieving a more integrated view of high-altitude adaptation, incorporating a sophisticated understanding of the ways in which levels of biological organization are articulated and a recognition of the specific genetic variants contributing to differences among high-altitude groups.
Collapse
Affiliation(s)
- L G Moore
- Department of Anthropology, University of Colorado at Denver, 80217-3364, USA
| | | | | |
Collapse
|
30
|
Chapman AB, Zamudio S, Woodmansee W, Merouani A, Osorio F, Johnson A, Moore LG, Dahms T, Coffin C, Abraham WT, Schrier RW. Systemic and renal hemodynamic changes in the luteal phase of the menstrual cycle mimic early pregnancy. Am J Physiol 1997; 273:F777-82. [PMID: 9374841 DOI: 10.1152/ajprenal.1997.273.5.f777] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Blood pressure decreases during early pregnancy in association with a decrease in peripheral vascular resistance and increases in renal plasma flow and glomerular filtration rate. These early changes suggest a potential association with corpora lutea function. To determine whether peripheral vasodilation occurs following ovulation, we studied 16 healthy women in the midfollicular and midluteal phases of the menstrual cycle. A significant decrease in mean arterial pressure in the midluteal phase of the cycle (midfollicular of 81.7 +/- 2.0 vs. midluteal of 75.4 +/- 2.3 mmHg, P < 0.005) was found in association with a decrease in systemic vascular resistance and an increase in cardiac output. Renal plasma flow and glomerular filtration rate increased. Plasma renin activity and aldosterone concentration increased significantly in the luteal phase accompanied by a decrease in atrial natriuretic peptide concentration. Serum sodium, chloride, and bicarbonate concentrations and osmolarity also declined significantly in the midluteal phase of the menstrual cycle. Urinary adenosine 3',5'-cyclic monophosphate (cAMP) excretion increased in the luteal compared with the follicular phase, whereas no changes in urinary cGMP or NO2/NO3 excretion were found. Thus peripheral vasodilation occurs in the luteal phase of the normal menstrual cycle in association with an increase in renal plasma flow and filtration. Activation of the renin-angiotensin-aldosterone axis is found in the luteal phase of the menstrual cycle. These changes are accompanied by an increase in urinary cAMP excretion indicating potential vasodilating mediators responsible for the observed hemodynamic changes.
Collapse
Affiliation(s)
- A B Chapman
- University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Sun S, Oliver-Pickett C, Ping Y, Micco AJ, Droma T, Zamudio S, Zhuang J, Huang SY, McCullough RG, Cymerman A, Moore LG. Breathing and brain blood flow during sleep in patients with chronic mountain sickness. J Appl Physiol (1985) 1996; 81:611-8. [PMID: 8872625 DOI: 10.1152/jappl.1996.81.2.611] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Chronic mountain sickness (CMS) patients have lower arterial O2 saturation (SaO2) during sleep compared with healthy high-altitude residents, but whether nocturnal arterial O2 content (CaO2) and brain O2 delivery are reduced is unknown. We measured SaO2, CaO2, sleep-disordered breathing (SDB), and internal carotid artery flow velocity in 8 CMS patients, 8 age-matched healthy CMS controls, 11 healthy younger-aged Han, and 11 healthy younger-aged Tibetan male residents of Lhasa, Tibet (3,658 m). CMS patients spent a greater portion of the night in SDB (total no. of episodes of apnea, hypopnea, and hypoventilation) than did the CMS controls, young Han, or young Tibetans (15% vs. 5, 1, and 1%, respectively; P < 0.05) because of more frequent apnea and hypoventilation episodes and longer duration of all types of episodes. SDB and unexplained arterial O2 desaturation caused nocturnal SaO2 to be lower and more variable in CMS patients than in CMS controls or in younger-aged Han or Tibetan men. Average CaO2 was similar, but the CMS patients spent 29%, whereas the other groups spent < 4%, of the night at values < 18 ml O2/100 ml whole blood. Internal carotid artery flow velocity during wakefulness was similar in CMS patients and CMS controls despite higher end-tidal PcO2 values in the CMS patients. When contiguous sleep stages are compared, flow velocity rose from stage 2 to rapid-eye-movement sleep in both groups. Whereas flow velocity remained elevated from awake to rapid-eye-movement sleep in the CMS controls, it fell in the CMS patients. During episodes of SDB, internal carotid flow velocity increased in CMS controls but did not change in the CMS patients such that values were lower in the CMS patients than in CMS controls at the end and after SDB episodes. We concluded that SDB and episodes of unexplained desaturation lowered nocturnal SaO2 and CaO2, which, together with a lack of compensatory increase in internal carotid artery flow velocity, likely decreased brain O2 delivery in CMS patients during a considerable portion of the night.
Collapse
Affiliation(s)
- S Sun
- Tibet Institute of Medical Sciences, Lhasa, Tibet Autonomous Region, People's Republic of China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Affiliation(s)
- M M White
- Department of Obstetrics and Gynecology, University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | | | | | | | | | |
Collapse
|
33
|
de la Cruz F, Uriostégui T, Zamudio S, Pacheco J, Garcia M, Quevedo L, Chuc E. Potentiation of the immobility response elicited by bandaging and clamping in mesencephalic rats. Physiol Behav 1995; 58:737-42. [PMID: 8559784 DOI: 10.1016/0031-9384(95)00123-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In earlier work, we showed that adult rats exhibit immobility response (IR) if a clamp is fastened to the skin of the nape of the neck, but not at other areas of the body, and not by bandaging. The present study characterizes IR in adult rats with complete mesencephalic transections. In the mesencephalic rats, the duration of the IR not only increased, but the stimuli capable of eliciting it were more diverse. All head and body areas clamped or bandaged were capable of inducing a profound IR. In contrast, the IR in intact rats was of shorter duration, and was only induced by clamping the neck, or by bandaging the upper or the lower torso. Furthermore, unlike the mesencephalic rats the ability of the bandaging to induce IR is reduced after the first trial and finally disappears. Only clamping the neck was able to persistently induce IR in intact rats. These data support the hypothesis that the IR control system is in the midbrain, hindbrain or spinal cord, and that systems above the mesencephalon modulate the IR. Such modulation appears to involve the ability to discriminate amongst tactile stimuli, and to integrate previous experience.
Collapse
Affiliation(s)
- F de la Cruz
- Department of Physiology, National School of Biological Sciences, National Polytechnic Institute, México, D.F. México
| | | | | | | | | | | | | |
Collapse
|
34
|
Abstract
To determine whether uterine blood flow was reduced and indexes of pelvic blood flow distribution altered in normotensive pregnancy at high (3,100 m) compared with low altitude (1,600 m), we measured uterine, common iliac, and external iliac artery blood flow velocities and diameters in women during pregnancy and again postpartum. Pregnancy increased uterine artery diameter, blood flow velocity, and volumetric flow at both altitudes. Uterine artery blood flow velocity was greater (69.0 +/- 2.2 vs. 59.4 +/- 3.0 cm/s; P < 0.005) but diameter was smaller at 3,100 m than at 1,600 m (2.5 +/- 0.3 mm vs. 3.4 +/- 0.2 mm; P < 0.005), resulting in volumetric flow that was one-third lower at week 36 of pregnancy (203 +/- 48 vs. 312 +/- 22 ml/min, respectively; P < 0.01). Pregnancy increased common iliac blood flow velocity and decreased external iliac artery blood flow velocity at both altitudes. The uterine artery received a smaller percent of common iliac flow at 3,100 than at 1,600 m (46 +/- 7 vs. 74 +/- 6%; P < 0.005). Gestational age was similar but birth weight was lower at 3,100 m than at 1,600 m. Among subjects at 1,600 m, variation in uterine blood flow velocity correlated positively with infant birth weight. We concluded that reduced uterine blood flow and altered pelvic blood flow distribution during pregnancy at high altitude likely contributed to the altitude-associated reduction in infant birth weight.
Collapse
Affiliation(s)
- S Zamudio
- Department of Anesthesiology, University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | | | | | | | |
Collapse
|
35
|
Zamudio S, Palmer SK, Dahms TE, Berman JC, Young DA, Moore LG. Alterations in uteroplacental blood flow precede hypertension in preeclampsia at high altitude. J Appl Physiol (1985) 1995; 79:15-22. [PMID: 7559213 DOI: 10.1152/jappl.1995.79.1.15] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
High-altitude residence during pregnancy is associated with an increased incidence of preeclampsia. To determine whether uteroplacental blood flow was reduced and pelvic blood flow distribution altered before the onset of hypertension, we measured common iliac (CI), uterine (UA), and external iliac (EI) artery flow velocities (FV), indexes of flow distribution, and blood volume (BV) at week 12, 24, and 36 of pregnancy and 6 mo postpartum in 23 normotensive, 7 preeclamptic, 5 transiently hypertensive, and 3 chronically hypertensive residents of 3,100 m. Normotensive women had a progressive increase in CIFV and UAFV, decrease in EIFV, redistribution of CIFV from the EI to the UA, and increase in BV with advancing pregnancy. Preeclamptic women attained maximal UAFV and redistribution of CIFV from the EI to the UA well before the onset of hypertension and, unlike normotensive women, showed no further increases near term. Plasma volume increment with pregnancy related to the fall in the EIFV/CIFV ratio. Transiently hypertensive women resembled normotensive subjects in the parameters measured, whereas chronically hypertensive subjects resembled preeclamptic subjects. We concluded that preeclamptic vs. normotensive pregnant residents of high altitude had less redistribution of CI flow to the UA and no increase in UA blood flow near term. That these differences were present before the onset of hypertension supports the concept that preeclampsia is characterized by an incomplete vascular adjustment to pregnancy.
Collapse
Affiliation(s)
- S Zamudio
- Department of Anesthesiology, University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | | | | | | | |
Collapse
|
36
|
Alderman BW, Zamudio S, Barón AE, Joshua SC, Fernbach SK, Greene C, Mangione EJ. Increased risk of craniosynostosis with higher antenatal maternal altitude. Int J Epidemiol 1995; 24:420-6. [PMID: 7635605 DOI: 10.1093/ije/24.2.420] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND During the 1980s, the Colorado Department of Health received reports from several high-altitude communities of clusters of the malformation craniosynostosis. In a population-based, case-control study, we examined the association between overall and trimester-specific maternal antenatal altitude exposure and the occurrence of infant craniosynostosis. METHODS We identified case children through a statewide registry and randomly sampled control children from birth records. By telephone interview, each mother provided data on the locations of all antenatal residences and places of employment as well as other factors. Staff mapped all locations and abstracted the corresponding altitudes. RESULTS The odds ratio (OR) of any synostosis for a time-weighted mean antenatal altitude of > or = 2000 metres (high altitude) versus < 2000 metres (low altitude) was 1.4 (lower bound of the one-sided 95% test-based confidence interval (CI): 0.9). The OR was elevated in smokers but not in non-smokers. As compared to non-smokers, the OR of any synostosis for high-altitude smokers was 4.6 (lower bound of the 95% one-sided exact CI: 1.7). Particularly elevated were the corresponding OR of coronal (18.1, 4.4) and metopic synostosis (16.3, 2.8), and OR for high-altitude exposure during the second trimester (any synostosis: 6.4, 1.99; coronal: 28.6, 6.1; metopic: 26.7, 4.1). CONCLUSIONS Antenatal maternal high-altitude exposure and smoking are associated with increased risk of infant craniosynostosis, perhaps through generation of intermittent hypoxaemia.
Collapse
Affiliation(s)
- B W Alderman
- Department of Epidemiology, University of Washington, Seattle, USA
| | | | | | | | | | | | | |
Collapse
|
37
|
Zamudio S, Leslie KK, White M, Hagerman DD, Moore LG. Low serum estradiol and high serum progesterone concentrations characterize hypertensive pregnancies at high altitude. J Soc Gynecol Investig 1994; 1:197-205. [PMID: 9419771 DOI: 10.1177/107155769400100304] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE Intrauterine growth retardation and preeclampsia are more common at high than at low altitude. Because altered hormonal profiles have been linked with these disorders, we asked whether placental steroid hormone concentrations were altered during pregnancy at high altitude. METHODS We measured progesterone, unconjugated estradiol, and estriol (by radioimmunoassay) at weeks 20, 30, and 36 of pregnancy in 18 women at low altitude (1600 m) and 40 women at high altitude (3100 m). RESULTS Women at 3100 m compared with 1600 m had lower serum estradiol concentrations at week 36 of pregnancy, and lower estriol and higher progesterone concentrations throughout pregnancy. As a result, the progesterone/estradiol ratio was greater in the high- versus the low-altitude women. Estradiol fell between weeks 30 and 36 in women who developed transient hypertension or preeclampsia. The fall in estradiol was accompanied by a marked increase in progesterone concentrations among the preeclamptic women. At 3100 m, estradiol correlated negatively (r = -0.37, P < .05) and progesterone positively (r = 0.46, P < .05) with mean arterial pressure at week 36 of pregnancy. CONCLUSIONS We speculate that reduced placental oxygen pressure (PO2) at high altitude may decrease placental aromatase activity and thereby lower estradiol and estriol concentrations. The factor(s) responsible for the rise in progesterone is unknown. Possibly, high progesterone relative to estradiol concentrations contributes to the development of preeclampsia at high altitude.
Collapse
Affiliation(s)
- S Zamudio
- Department of Anesthesiology, University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | | | | | |
Collapse
|
38
|
Torroni A, Miller JA, Moore LG, Zamudio S, Zhuang J, Droma T, Wallace DC. Mitochondrial DNA analysis in Tibet: implications for the origin of the Tibetan population and its adaptation to high altitude. Am J Phys Anthropol 1994; 93:189-99. [PMID: 8147435 DOI: 10.1002/ajpa.1330930204] [Citation(s) in RCA: 117] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Mitochondrial DNAs (mtDNAs) of 54 Tibetans residing at altitudes ranging from 3,000-4,500 m were amplified by polymerase chain reaction (PCR), examined by high-resolution restriction endonuclease analysis, and compared with those previously described in 10 other Asian and Siberian populations. This comparison revealed that more than 50% of Asian mtDNAs belong to a unique mtDNA lineage which is found only among Mongoloids, suggesting that this lineage most likely originated in Asia at an early stage of the human colonization of that continent. Within the Tibetan mtDNAs, sets of additional linked polymorphic sites defined seven minor lineages of related mtDNA haplotypes (haplogroups). The frequency and distribution of these haplogroups in modern Asian populations are supportive of previous genetic evidence that Tibetans, although located in southern Asia, share common ancestral origins with northern Mongoloid populations. This analysis of Tibetan mtDNAs also suggests that mtDNA mutations are unlikely to play a major role in the adaptation of Tibetans to high altitudes.
Collapse
Affiliation(s)
- A Torroni
- Department of Genetics and Molecular Medicine, Emory University School of Medicine, Atlanta, Georgia 30322
| | | | | | | | | | | | | |
Collapse
|
39
|
Zamudio S, Palmer SK, Dahms TE, Berman JC, McCullough RG, McCullough RE, Moore LG. Blood volume expansion, preeclampsia, and infant birth weight at high altitude. J Appl Physiol (1985) 1993; 75:1566-73. [PMID: 8282605 DOI: 10.1152/jappl.1993.75.4.1566] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Low blood volume (BV) during pregnancy is associated with intrauterine growth retardation and preeclampsia, which are more common at high altitude (HA) than at low altitude. We hypothesized that reduced BV expansion during pregnancy predisposed some women to develop preeclampsia and/or have lower-birth-weight infants at HA. BV was lower in 34 HA residents (3,100 m) than in 22 moderate-altitude residents (1,600 m) while nonpregnant (58.3 +/- 1.2 vs. 72.3 +/- 1.3 ml/kg; P < 0.001) and 36 wk pregnant (69.9 +/- 1.9 vs. 83.3 +/- 3.6 ml/kg; P < 0.01). BV fell between weeks 24 and 36 of pregnancy, and total BV increment with pregnancy was less in women who developed preeclampsia or transient hypertension at HA (n = 12). At HA, total blood and plasma volume expansion and arterial O2 saturation correlated negatively with the highest mean arterial pressure recorded during pregnancy (r = -0.73, P < 0.01 and r = -0.58, P < 0.01, respectively). Total BV and late pregnancy change in BV correlated positively with infant birth weight. We concluded that BV expansion in normotensive pregnancy at HA vs. moderate altitude was similar but that nonpregnant BV was less among HA women, accounting for the low BV in pregnancy. HA women who developed preeclampsia or transient hypertension had less BV expansion, particularly during the third trimester, which was associated with smaller infants.
Collapse
Affiliation(s)
- S Zamudio
- Cardiovascular Pulmonary Research Laboratory, University of Colorado Health Sciences Center, Denver 80262
| | | | | | | | | | | | | |
Collapse
|
40
|
Zamudio S, Droma T, Norkyel KY, Acharya G, Zamudio JA, Niermeyer SN, Moore LG. Protection from intrauterine growth retardation in Tibetans at high altitude. Am J Phys Anthropol 1993; 91:215-24. [PMID: 8317562 DOI: 10.1002/ajpa.1330910207] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Intrauterine growth retardation has long been recognized at high altitude. Since growth-retarded babies have a decreased chance of survival, intrauterine growth retardation would be expected to have been selected against in populations long resident at high altitude. We have previously reported that Tibetan babies born at 3,658 m weighed more than their North or South American altitude counterparts. This study sought to determine whether Tibetans were protected from altitude-associated intrauterine growth retardation. We compared birth weights in Tibetans living at low altitude in Kathmandu, Nepal (elevation 1,200 m), or at high altitude in Lhasa, Tibet Autonomous Region, China (elevation 3,658 m). Birth weights were similar in 45 low-altitude and 34 high-altitude Tibetan births regardless of whether all infants or only full-term births were considered, or whether birth weight was adjusted for variation in maternal parity, gestational age, and infant sex. In comparison with literature observations, the altitude-associated difference in birth weight was smallest in Tibetans, intermediate in South America, and greatest in North America. These data support the hypothesis that Tibetans are protected from altitude-associated intrauterine growth retardation and suggest that selection for optimization of birth weight at high altitude has occurred in Tibetans.
Collapse
Affiliation(s)
- S Zamudio
- Cardiovascular Pulmonary Research Laboratory, University of Colorado Health Sciences Center, Denver 80262
| | | | | | | | | | | | | |
Collapse
|
41
|
Palmer SK, Zamudio S, Coffin C, Parker S, Stamm E, Moore LG. Quantitative estimation of human uterine artery blood flow and pelvic blood flow redistribution in pregnancy. Obstet Gynecol 1992; 80:1000-6. [PMID: 1448242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE To determine the contributions of uterine artery diameter and mean flow velocity to the increase in volumetric flow during human pregnancy. METHODS Volunteers (18 pregnant and six not pregnant) were studied using both a commercially available Doppler instrument with imaging ultrasound and an improved Doppler instrument with software that can determine instantaneous true mean blood flow velocity. Diameter and mean flow velocity measurements were combined to yield volumetric flows in the common iliac, external iliac, and uterine arteries during and after pregnancy. RESULTS Compared with the nonpregnant state, uterine artery diameter doubled by week 21 (from 1.4 +/- 0.1 to 2.8 +/- 0.2 mm; P < .05), did not change between weeks 21 and 30 (2.9 +/- 0.1 mm), and increased between weeks 30 and 36 (to 3.4 +/- 0.2 mm). Uterine artery mean flow velocity rose progressively from nonpregnant values to attain at week 36 a velocity nearly eight times faster (8.4 +/- 2.2 versus 61.4 +/- 3.0 cm/second; P < .05). Unilateral uterine artery blood flow at week 36 was 312 +/- 22 mL/minute. CONCLUSIONS Compared with nonpregnant values, common iliac artery flow increased and external iliac artery flow decreased during pregnancy, suggesting that redistribution of pelvic flow to favor the uterus contributed to the pregnancy-associated rise in uterus artery flow. Early in pregnancy, the increase in uterine artery blood flow was due in equal parts to changes in uterine artery diameter and mean flow velocity, whereas late in pregnancy, the rise was due mainly to faster mean flow velocity.
Collapse
Affiliation(s)
- S K Palmer
- Department of Anesthesiology, University of Colorado Health Sciences Center, Denver
| | | | | | | | | | | |
Collapse
|
42
|
Moore LG, Curran-Everett L, Droma TS, Groves BM, McCullough RE, McCullough RG, Sun SF, Sutton JR, Zamudio S, Zhuang JG. Are Tibetans better adapted? Int J Sports Med 1992; 13 Suppl 1:S86-8. [PMID: 1483804 DOI: 10.1055/s-2007-1024605] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Evidence is reviewed from our recent (1987-1991) investigations which demonstrate better high-altitude adaptation among Tibetans than in acclimatized newcomers or other lifelong high-altitude residents. Characteristics of oxygen transport contributing to the Tibetans' remarkable exercise performance are described.
Collapse
|
43
|
Abstract
Cystic fibrosis (CF) is the most common fatal genetic disorder of caucasians. While it has been hypothesized that there is a CF heterozygote advantage which allowed the gene to achieve such high prevalence, the nature of that advantage remains a mystery. The recent identification and sequencing of the CF gene has increased the probability that the CF heterozygote advantage will be discovered. In this hypothesis we review the information which is known about the selection of the CF mutation and its cellular consequences, and present evidence which suggests that resistance to cholera may have been the environmental factor which selected CF heterozygotes over their 'normal' homozygote cohort. Future lines of experimentation and possible clinical applicability to therapy of secretory diarrhea are presented.
Collapse
Affiliation(s)
- D M Rodman
- Division of Pulmonary Sciences, University of Colorado Health Sciences Center, Denver 80262
| | | |
Collapse
|
44
|
Velázquez A, Zamudio S, Báez A, Murguía-Corral R, Rangel-Peniche B, Carrasco A. Indicators of biotin status: a study of patients on prolonged total parenteral nutrition. Eur J Clin Nutr 1990; 44:11-6. [PMID: 2112997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Plasma biotin concentration and lymphocyte propionyl CoA carboxylase (PCC) and its activation index (the ratio of enzyme activity in cells incubated with biotin to activity in cells incubated without the vitamin) were compared as markers of biotin status in patients on biotin-free prolonged total parenteral nutrition (TPN). Five patients had been on biotin-free TPN for over 1 month when the study was started, and had already developed clinical signs that may be caused by this vitamin deficiency. They had markedly reduced levels of both biotin and carboxylase levels, which increased to near normal levels 4 months after biotin was added to the TPN. They initially presented subnormal plasma zinc concentrations which were normal at the end of the study. Another 4 patients also received biotin-free TPN. After 1 month propionyl CoA carboxylase, which was already below normal in 3 of them at admission, further decreased and became undetectable in 1 of them, who presented clinical deficiency manifestations. The enzyme activation index increased more than twice, although plasma biotin remained normal. When the vitamin was added to the TPN solution, PCC activity increased and its activation index decreased to normal. Plasma zinc concentrations remained normal throughout in this other group of patients indicating that changes of biotin markers are not likely to be related to zinc status variation. Plasma biotinidase, a key enzyme in biotin endogenous recycling, was already subnormal at admission and had become normal at the end of the study, but was not associated with the biotin status.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- A Velázquez
- Unidad de Genética de la Nutrición, Instituto de Investigaciones Biomédicas UNAM, México, DF
| | | | | | | | | | | |
Collapse
|
45
|
Velázquez A, Martín-del-Campo C, Báez A, Zamudio S, Quiterio M, Aguilar JL, Pérez-Ortiz B, Sánchez-Ardines M, Guzmán-Hernández J, Casanueva E. Biotin deficiency in protein-energy malnutrition. Eur J Clin Nutr 1989; 43:169-73. [PMID: 2499449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Several of the clinical and biochemical manifestations of biotin deficiency also occur in severe protein-energy malnutrition (PEM). Average plasma biotin concentrations were lower in 16 malnourished children (10 with marasmus, 3 with kwashiorkor and 3 with marasmic kwashiorkor) than in 31 controls. Lymphocyte mitochondrial carboxylase activities were studied in 11 controls and in 10 patients with PEM; on the average, they were lower in the patients. Their activation indices (the ratio of enzyme activity in cells incubated with biotin to activity in cells incubated without the vitamin) were higher in PEM. All these differences were statistically significant. None of these parameters were age-dependent in a range between 3 and 72 months. Carboxylase activities and plasma biotin levels increased to normal during nutritional recovery in two malnourished patients who were further studied. These results suggest that there is biotin deficiency in severe PEM. Urinary biotin concentrations, expressed per g of creatinine, were higher in the patients than in the controls; this may have been caused by increased renal clearance or by the reduced creatinine excretion which occurs in malnourished individuals. It will be important in future studies to determine the relative contribution of biotin deficiency to the malnourished phenotype.
Collapse
Affiliation(s)
- A Velázquez
- Unidad de Genética de la Nutrición, Universidad Nacional Autónoma de México
| | | | | | | | | | | | | | | | | | | |
Collapse
|