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Massmann GA, Zhang J, Seong WJ, Kim M, Figueroa JP. Sex-dependent effects of antenatal glucocorticoids on insulin sensitivity in adult sheep: role of the adipose tissue renin angiotensin system. Am J Physiol Regul Integr Comp Physiol 2017; 312:R1029-R1038. [PMID: 28356296 DOI: 10.1152/ajpregu.00181.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 03/23/2017] [Accepted: 03/24/2017] [Indexed: 01/09/2023]
Abstract
Exposure to glucocorticoids in utero is associated with changes in organ function and structure in the adult. The aims of this study were to characterize the effects of antenatal exposure to glucocorticoids on glucose handling and the role of adipose tissue. Pregnant sheep received betamethasone (Beta, 0.17 mg/kg) or vehicle 24 h apart at 80 days of gestation and allowed to deliver at term. At 9 mo, male and female offspring were fed at either 100% of nutritional allowance (lean) or ad libitum for 3 mo (obese). At 1 yr, they were chronically instrumented under general anesthesia. Glucose tolerance was evaluated using a bolus of glucose (0.25 g/kg). Adipose tissue was harvested after death to determine mRNA expression levels of angiotensinogen (AGT), angiotensin-converting enzyme (ACE) 1, ACE2, and peroxisome proliferator-activated receptor γ (PPAR-γ). Data are expressed as means ± SE and analyzed by ANOVA. Sex, obesity, and Beta exposure had significant effects on glucose tolerance and mRNA expression. Beta impaired glucose tolerance in lean females but not males. Superimposed obesity worsened the impairment in females and unmasked the defect in males. Beta increased ACE1 mRNA in females and males and AGT in females only (P < 0.05 by three-way ANOVA). Obesity increased AGT in females but had no effect on ACE1 in either males or females. PPAR-γ mRNA exhibited a significant sex (F = 42.8; P < 0.01) and obesity (F = 6.9; P < 0.05) effect and was significantly higher in males (P < 0.01 by three-way ANOVA). We conclude that adipose tissue may play an important role in the sexually dimorphic response to antenatal glucocorticoids.
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Affiliation(s)
- G Angela Massmann
- Perinatal Research Laboratory, Department of Obstetrics and Gynecology, Center for Research in Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Jie Zhang
- Perinatal Research Laboratory, Department of Obstetrics and Gynecology, Center for Research in Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Won Joon Seong
- Perinatal Research Laboratory, Department of Obstetrics and Gynecology, Center for Research in Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, North Carolina.,Department of Obstetrics and Gynecology, Kyungpook National University, Daegu, South Korea; and
| | - Minhyoung Kim
- Perinatal Research Laboratory, Department of Obstetrics and Gynecology, Center for Research in Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, North Carolina.,Department of Obstetrics and Gynecology, Cheil General Hospital and Women's Healthcare Center, Dankook University College of Medicine, Yongin, South Korea
| | - Jorge P Figueroa
- Perinatal Research Laboratory, Department of Obstetrics and Gynecology, Center for Research in Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, North Carolina;
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Abstract
Since their introduction more than forty years ago, antenatal glucocorticoids have become a cornerstone in the management of preterm birth and have been responsible for substantial reductions in neonatal mortality and morbidity. Clinical trials conducted over the past decade have shown that these benefits may be increased further through administration of repeat doses of antenatal glucocorticoids in women at ongoing risk of preterm and in those undergoing elective cesarean at term. At the same time, a growing body of experimental animal evidence and observational data in humans has linked fetal overexposure to maternal glucocorticoids with increased risk of cardiovascular, metabolic and other disorders in later life. Despite these concerns, and somewhat surprisingly, there has been little evidence to date from randomized trials of longer-term harm from clinical doses of synthetic glucocorticoids. However, with wider clinical application of antenatal glucocorticoid therapy there has been greater need to consider the potential for later adverse effects. This paper reviews current evidence for the short- and long-term health effects of antenatal glucocorticoids and discusses the apparent discrepancy between data from randomized clinical trials and other studies.
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Bi J, Contag SA, Chen K, Su Y, Figueroa JP, Chappell MC, Rose JC. Sex-specific effect of antenatal betamethasone exposure on renal oxidative stress induced by angiotensins in adult sheep. Am J Physiol Renal Physiol 2014; 307:F1013-22. [PMID: 25209867 PMCID: PMC4216986 DOI: 10.1152/ajprenal.00354.2014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Accepted: 09/09/2014] [Indexed: 12/24/2022] Open
Abstract
Prenatal glucocorticoid administration in clinically relevant doses reduces nephron number and renal function in adulthood and is associated with hypertension. Nephron loss in early life may predispose the kidney to other insults later but whether sex influences increases in renal susceptibility is unclear. Therefore, we determined, in male and female adult sheep, whether antenatal glucocorticoid (betamethasone) exposure increased 8-isoprostane (marker of oxidative stress) and protein excretion after acute nephron reduction and intrarenal infusions of angiotensin peptides. We also examined whether renal proximal tubule cells (PTCs) could contribute to alterations in 8-isoprostane excretion in a sex-specific fashion. In vivo, ANG II significantly increased 8-isoprostane excretion by 49% and protein excretion by 44% in male betamethasone- but not in female betamethasone- or vehicle-treated sheep. ANG-(1-7) decreased 8-isoprostane excretion but did not affect protein excretion in either group. In vitro, ANG II stimulated 8-isoprostane release from PTCs of male but not female betamethasone-treated sheep. Male betamethasone-exposed sheep had increased p47 phox abundance in the renal cortex while superoxide dismutase (SOD) activity was increased only in females. We conclude that antenatal glucocorticoid exposure enhances the susceptibility of the kidney to oxidative stress induced by ANG II in a sex-specific fashion and the renal proximal tubule is one target of the sex-specific effects of antenatal steroids. ANG-(1-7) may mitigate the impact of prenatal glucocorticoids on the kidney. P47 phox activation may be responsible for the increased oxidative stress and proteinuria in males. The protection from renal oxidative stress in females is associated with increased SOD activity.
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Affiliation(s)
- Jianli Bi
- Department of Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina; The Center of Research for Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina;
| | - Stephen A Contag
- Department of Obstetrics and Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland
| | - Kai Chen
- Department of Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina; The Center of Research for Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | - Yixin Su
- Department of Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina; The Center of Research for Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | - Jorge P Figueroa
- Department of Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina; The Center of Research for Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | - Mark C Chappell
- Hypertension and Vascular Disease Center, Wake Forest University School of Medicine, Winston-Salem, North Carolina; and
| | - James C Rose
- Department of Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina; The Center of Research for Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina
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Siddique K, Guzman GL, Gattineni J, Baum M. Effect of postnatal maternal protein intake on prenatal programming of hypertension. Reprod Sci 2014; 21:1499-507. [PMID: 24740990 DOI: 10.1177/1933719114530186] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
This study examined whether postnatal maternal dietary protein deprivation during the time of nursing can program hypertension when the offspring are studied as adults. Rats were fed either a 6% or 20% protein diet during the second half of pregnancy and continued on the same diet while rats were nursing their pups. The neonates of all of the rats were cross-fostered to a different mother and studied as adults. Adult rats that had a normal prenatal environment but were reared by mothers fed a low-protein diet until weaning (20%-6%) were hypertensive, had a higher renal Na(+)-K(+)-2Cl(-) cotransporter (NKCC2) and Na(+)-Cl(-) cotransporter (NCC) protein abundance yet a comparable number of glomeruli, and had higher plasma renin and angiotensin II levels compared to control (20%-20%). Rats whose mothers were fed a 6% protein diet and cross-fostered to a different rat fed a 6% protein diet until weaning (6%-6%) were hypertensive, had elevated plasma renin and angiotensin II levels, and had a reduction in nephron number but had NKCC2 and NCC levels comparable to 20% to 20% offspring. The 6% to 20% had blood pressure and glomerular numbers comparable to 20% to 20% rats. The hypertension resulting from prenatal dietary protein deprivation can be normalized by improving the postnatal environment. Combined prenatal and postnatal maternal dietary protein deprivation and maternal dietary protein deprivation while nursing alone (20%-6%) results in hypertension, but the mechanism for the hypertension in these groups is different.
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Affiliation(s)
- Khurrum Siddique
- Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - German Lozano Guzman
- Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Jyothsna Gattineni
- Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Michel Baum
- Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
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Gao S, Park BM, Cha SA, Park WH, Park BH, Kim SH. Angiotensin AT2 receptor agonist stimulates high stretch induced- ANP secretion via PI3K/NO/sGC/PKG/pathway. Peptides 2013; 47:36-44. [PMID: 23791669 DOI: 10.1016/j.peptides.2013.06.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 06/08/2013] [Accepted: 06/10/2013] [Indexed: 11/16/2022]
Abstract
Angiotensin II (Ang II) type 1 receptor (AT1R) mediates the major cardiovascular effects of Ang II. However, the effects mediated via AT2R are still controversial. The aim of the present study is to define the effect of AT2R agonist CGP42112A (CGP) on high stretch-induced ANP secretion and its mechanism using in vitro and in vivo experiments. CGP (0.01, 0.1 and 1μM) stimulated high stretch-induced ANP secretion and concentration from isolated perfused rat atria. However, atrial contractility and the translocation of extracellular fluid did not change. The augmented effect of CGP (0.1μM) on high stretch-induced ANP secretion was attenuated by the pretreatment with AT2R antagonist or inhibitor for phosphoinositol 3-kinase (PI3K), nitric oxide (NO), soluble guanylyl cyclase (sGC), or protein kinase G (PKG). However, antagonist for AT1R or Mas receptor did not influence CGP-induced ANP secretion. In vivo study, acute infusion of CGP for 10min increased plasma ANP level without blood pressure change. In renal hypertensive rat atria, AT2R mRNA and protein levels were up-regulated and the response of plasma ANP level to CGP infusion in renal hypertensive rats augmented. The pretreatment with AT2R antagonist for 10min followed by CGP infusion attenuated an increased plasma ANP level induced by CGP. However, pretreatment with AT1R or Mas receptor antagonist unaffected CGP-induced increase in plasma ANP level. Therefore, we suggest that AT2R agonist CGP stimulates high stretch-induced ANP secretion through PI3K/NO/sGC/PKG pathway and these effects are augmented in renal hypertensive rats.
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MESH Headings
- Angiotensin II/analogs & derivatives
- Angiotensin II/pharmacology
- Animals
- Atrial Natriuretic Factor/metabolism
- Atrial Pressure/drug effects
- Cyclic GMP-Dependent Protein Kinases/genetics
- Cyclic GMP-Dependent Protein Kinases/metabolism
- Gene Expression Regulation
- Guanylate Cyclase/genetics
- Guanylate Cyclase/metabolism
- Heart Atria/drug effects
- Heart Atria/metabolism
- Hypertension, Renal/genetics
- Hypertension, Renal/metabolism
- Hypertension, Renal/physiopathology
- Imidazoles/pharmacology
- Losartan/pharmacology
- Male
- Nitric Oxide/metabolism
- Oligopeptides/pharmacology
- Peptide Fragments/pharmacology
- Phosphatidylinositol 3-Kinases/genetics
- Phosphatidylinositol 3-Kinases/metabolism
- Pyridines/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptor, Angiotensin, Type 2/agonists
- Receptor, Angiotensin, Type 2/genetics
- Receptor, Angiotensin, Type 2/metabolism
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Signal Transduction/drug effects
- Soluble Guanylyl Cyclase
- Tissue Culture Techniques
- Vasodilator Agents/pharmacology
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Affiliation(s)
- Shan Gao
- Department of Pharmacology, Taishan Medical University, Shandong, China
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Cheng CJ, Lozano G, Baum M. Prenatal programming of rat cortical collecting tubule sodium transport. Am J Physiol Renal Physiol 2011; 302:F674-8. [PMID: 22189946 DOI: 10.1152/ajprenal.00633.2011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Prenatal insults have been shown to lead to elevated blood pressure in offspring when they are studied as adults. Prenatal administration of dexamethasone and dietary protein deprivation have demonstrated that there is an increase in transporter abundance for a number of nephron segments but not the subunits of the epithelial sodium channel (ENaC) in the cortical collecting duct. Recent studies have shown that aldosterone is elevated in offspring of protein-deprived mothers when studied as adults, but the physiological importance of the increase in serum aldosterone is unknown. As an indirect measure of ENaC activity, we compared the natriuretic response to benzamil in offspring of mothers who ate a low-protein diet (6%) with those who ate a normal diet (20%) for the last half of pregnancy. The natriuretic response to benzamil was greater in the 6% group (821.1 ± 161.0 μmol/24 h) compared with the 20% group (279.1 ± 137.0 μmol/24 h), consistent with greater ENaC activity in vivo (P < 0.05). In this study, we also directly studied cortical collecting tubule function from adult rats using in vitro microperfusion. There was no difference in basal or vasopressin-stimulated osmotic water permeability. However, while cortical collecting ducts of adult offspring whose mothers ate a 20% protein diet had no sodium transport (-1.9 ± 3.1 pmol·mm(-1)·min(-1)), the offspring of rats that ate a 6% protein diet during the last half of pregnancy had a net sodium flux of 10.7 ± 2.6 pmol·mm(-1)·min(-1) (P = 0.01) in tubules perfused in vitro. Sodium transport was measured using ion-selective electrodes, a novel technique allowing measurement of sodium in nanoliter quantities of fluid. Thus we directly demonstrate that there is prenatal programming of cortical collecting duct sodium transport.
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Affiliation(s)
- Chih-Jen Cheng
- Dept. of Pediatrics, U.T. Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9063, USA
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Habib S, Zhang Q, Baum M. Prenatal programming of hypertension in the rat: effect of postnatal rearing. NEPHRON EXTRA 2011; 1:157-65. [PMID: 22470389 PMCID: PMC3290837 DOI: 10.1159/000333477] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Background/Aims Dietary protein deprivation during pregnancy causes hypertension in offspring when they become adults. This study examined if postnatal rearing had an effect on blood pressure and glomerular number in male rats whose mothers were fed either a control diet or a low protein diet. Methods Neonates were cross fostered at 1 day of age to a different mother. After birth, all nursing and weaned rats were fed a control diet. Blood pressure and glomerular number were measured in adult offspring. Results Control rats cross fostered to another control mother had a lower blood pressure than low protein rats cross fostered to another low protein mother (133 ± 4 vs. 151 ± 4 mm Hg, p < 0.05) and a greater number of glomeruli (28,388 ± 989 vs. 25,045 ± 851, p < 0.05). Fostering pups from the 20% group to mothers that were fed a 6% diet during pregnancy did not cause hypertension or a reduction in the number of glomeruli. However, fostering the 6% group on to mothers that were fed a 20% protein diet during pregnancy resulted in normalization of the blood pressure and number of glomeruli. Conclusion The hypertension and reduced glomerular number resulting from prenatal dietary protein deprivation can be normalized by improving the postnatal environment.
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Affiliation(s)
- Sabeen Habib
- Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, Dallas, Tex., USA
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Rotte A, Pasham V, Eichenmüller M, Yang W, Bhandaru M, Lang F. Influence of Dexamethasone on Na +/H + Exchanger Activity in Dendritic Cells. Cell Physiol Biochem 2011; 28:305-14. [DOI: 10.1159/000331746] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2011] [Indexed: 11/19/2022] Open
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Wu L, Mao C, Liu Y, Shi A, Xu F, Zhang L, Xu Z. Altered dipsogenic responses and expression of angiotensin receptors in the offspring exposed to prenatal high sucrose. Peptides 2011; 32:104-11. [PMID: 20965221 PMCID: PMC3010528 DOI: 10.1016/j.peptides.2010.10.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Revised: 10/11/2010] [Accepted: 10/11/2010] [Indexed: 01/13/2023]
Abstract
The present study determined water and salt intake as well as expression of AT(1) and AT(2) receptors in the brain and kidney in the adult offspring rats prenatally exposed to high sucrose. Following the exposure during pregnancy, water intake and salt intake at baseline levels were not changed in the adult offspring. However, after 24h water deprivation, consumption of water and salt was significantly increased compared to that of the control. Plasma sodium and osmolality levels remained the same between the offspring in the control and the exposed groups, while hematocrit was higher in the offspring exposed to prenatal high sucrose immediately following water deprivation. Density of renal AT(1) receptor protein was the same between the control and the exposed group, while AT(2) receptor protein in the kidney was significantly increased in the offspring exposed to prenatal high sucrose in association of thicker basal membrane of glomerular. In the forebrain, both AT(1) and AT(2) receptor levels were significantly increased in the offspring with history of prenatal high sucrose. In addition, water deprivation induced more c-fos expression in the central dipsogenic areas, including the paraventricular and supraoptic nuclei in the offspring exposed to prenatal high sucrose. The results suggested that prenatal high intake of sucrose may affect development of pathways in regulation of dipsogenic behavior in face of dehydration, which was associated with altered expression of AT(1) or/and AT(2) receptors in the kidney and brain.
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Affiliation(s)
- Lei Wu
- Institute for Fetal Origin Diseases, First Hospital of Soochow University & Prenatal Biology Center of Soochow University, Suzhou 215006, China
| | - Caiping Mao
- Institute for Fetal Origin Diseases, First Hospital of Soochow University & Prenatal Biology Center of Soochow University, Suzhou 215006, China
| | - Yujuan Liu
- Department of Pharmacy, Jinshan Hospital, Fudan University, Shanghai, 200540, China
| | - Aiping Shi
- Institute for Fetal Origin Diseases, First Hospital of Soochow University & Prenatal Biology Center of Soochow University, Suzhou 215006, China
| | - Feichao Xu
- Institute for Fetal Origin Diseases, First Hospital of Soochow University & Prenatal Biology Center of Soochow University, Suzhou 215006, China
| | - Lubo Zhang
- Center for Prenatal Biology, Loma Linda University, CA 92350, USA
| | - Zhice Xu
- Institute for Fetal Origin Diseases, First Hospital of Soochow University & Prenatal Biology Center of Soochow University, Suzhou 215006, China
- Center for Prenatal Biology, Loma Linda University, CA 92350, USA
- Correspondence: Zhice Xu, Director, Institute for Fetal Origin Diseases, First Hospital of Soochow University, Telephone: 86-512-61859998, Fax: 86-512-61850103,
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Eckman DM, Kerr BA, Fuloria M, Simandle SA, Watt SE, Rose JC, Figueroa JP. Antenatal betamethasone alters vascular reactivity in adult female ovine cerebral arteries. Pediatr Res 2010; 68:344-8. [PMID: 20581740 PMCID: PMC3197251 DOI: 10.1203/pdr.0b013e3181edb9fa] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Although the use of antenatal glucocorticoids has resulted in decreased neonatal morbidity/mortality, recent animal studies have raised concerns regarding adverse effects of these medications on postnatal cardiovascular function. We hypothesized that antenatal betamethasone (Beta) exposure alters cerebral vascular reactivity in adult female sheep. We observed that K-induced constriction was comparable in middle cerebral artery (MCA) from Beta-exposed animals and age-matched controls. Pressure-induced constriction was significantly attenuated in MCA from Beta-exposed compared with control sheep. Inhibition of NOS significantly augmented pressure-induced constriction in MCA from both Beta-exposed and control sheep, whereas cyclooxygenase (COX) inhibition augmented pressure-induced constriction only in MCA from Beta-exposed sheep. Furthermore, NOS and COX inhibition significantly attenuated bradykinin (BK)-induced dilation in MCA from both Beta-exposed and control sheep. However, there seemed to be a greater contribution of both NOS and COX to BK-induced dilation in Beta-exposed compared with control MCA. Our findings demonstrate that fetal exposure to a clinically relevant course of Beta alters cerebral vascular tone and reactivity in adult female sheep.
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Affiliation(s)
- Delrae M Eckman
- Department of Pediatrics, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
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Contag SA, Bi J, Chappell MC, Rose JC. Developmental effect of antenatal exposure to betamethasone on renal angiotensin II activity in the young adult sheep. Am J Physiol Renal Physiol 2010; 298:F847-56. [PMID: 20071463 DOI: 10.1152/ajprenal.00497.2009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Antenatal corticosteroids may have long-term effects on renal development which have not been clearly defined. Our objective was to compare the responses to intrarenal infusions of ANG II in two groups of year-old, male sheep: one group exposed to a clinically relevant dose of betamethasone before birth and one not exposed. We wished to test the hypothesis that antenatal steroid exposure would enhance renal responses to ANG II in adult life. Six pairs of male sheep underwent unilateral nephrectomy and renal artery catheter placement. The sheep were infused for 24 h with ANG II or with ANG II accompanied by blockade of the angiotensin type 1 (AT(1)) or type 2 (AT(2)) receptor. Baseline mean arterial blood pressure among betamethasone-exposed sheep was higher than in control animals (85.8 +/- 2.2 and 78.3 +/- 1.0 mmHg, respectively, P = 0.003). Intrarenal infusion of ANG II did not increase systemic blood pressure (P >/= 0.05) but significantly decreased effective renal plasma flow and increased renal artery resistance (P < 0.05). The decrease in flow and increase in resistance were significantly greater in betamethasone- compared with vehicle-exposed sheep (betamethasone P < 0.05, vehicle P >/= 0.05). This effect appeared to be mediated by a heightened sensitivity to the AT(1) receptor among betamethasone-exposed sheep. Sodium excretion initially decreased in both groups during ANG II infusion; however, a rebound was observed after 24 h. AT(1) blockade was followed by a significant rebound after 24 h in both groups. AT(2) blockade blunted the 24-h rebound effect among the vehicle-exposed sheep compared with the betamethasone-exposed sheep. In conclusion, antenatal corticosteroid exposure appears to modify renal responsiveness to ANG II by increasing AT(1)- and decreasing AT(2) receptor-mediated actions particularly as related to renal blood flow and sodium excretion.
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Affiliation(s)
- Stephen A Contag
- Department of Obstetrics and Gynecology, and Center of Research for Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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Zhang J, Massmann GA, Rose JC, Figueroa JP. Differential effects of clinical doses of antenatal betamethasone on nephron endowment and glomerular filtration rate in adult sheep. Reprod Sci 2009; 17:186-95. [PMID: 19897787 DOI: 10.1177/1933719109351098] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Antenatal steroid administration is associated with alterations in fetal kidney development and hypertension. However, a causal relationship between nephron deficit and hypertension has not been established. In this study, we measured nephron number, renal function, and blood pressure in sheep exposed antenataly to betamethasone. Pregnant sheep were given 2 betamethasone doses (0.17 mg/kg) or vehicle at 80 and 81 days gestational age and allowed to deliver at term. Data were obtained from a fetal cohort and 2 adult cohorts and were analyzed by analysis of variance (ANOVA) and/or 2 sample t test. Antenatal betamethasone induced a 26% reduction in the number of nephrons in both males and females in the absence of intrauterine growth restriction and/or prematurity. Adult males presented a reduction in glomerular filtration rate (GFR; 132 +/- 12.7 vs 114 +/- 7.0 mL/min, P < .05). Betamethasone administration was also associated with an increase in arterial blood pressure of similar magnitude in male (mean arterial pressure [MAP] in mm Hg; 98 +/- 2.7 vs 105 +/- 2.4) and female (96 +/- 1.9 vs 105 +/- 2.4) adult sheep and the increase in blood pressure preceded the decrease in GFR in the males. Furthermore, we found no significant association between the magnitude of the decrease in nephron number and the magnitude of the increase in arterial blood pressure. Our data thus support the conclusion that exposure to glucocorticoids at a time of rapid kidney growth is associated with an elevation in blood pressure that does not appear related solely to the reduction in nephron number.
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Affiliation(s)
- Jie Zhang
- Perinatal Research Laboratory, Department of Obstetrics and Gynecology, Center for Research in Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
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Guilherme R, Renaud C, Dommergues M, Mitanchez D. [Repeat doses of prenatal corticosteroids for women at risk of preterm birth: a difficult consensus]. ACTA ACUST UNITED AC 2009; 38:459-68. [PMID: 19473782 DOI: 10.1016/j.jgyn.2008.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 12/19/2008] [Accepted: 12/22/2008] [Indexed: 10/20/2022]
Abstract
A single course of antenatal corticosteroids in women at risk of preterm delivery reduces the risk of neonatal mortality and morbidity. Recent experimental and clinical studies have stated early, medium and long term consequences of single or repeated courses of antenatal corticosteroids. Betamethasone and dexamethasone are the two molecules usually used. Benefits are observed until the first 24 hours after the first injection. Single-course corticosteroids are not effective in babies born more than 7 days after initial treatment. Benefits of corticosteroids were evaluated between 22 and 35 weeks of gestation. Antenatal exposure to single-course betamethasone might result in disruption on glucose metabolism in adult offspring. Weekly courses of prenatal corticosteroids therapy are not recommended. Repeat prenatal corticosteroids given to women at continuing risk of preterm birth 7 or more days after an initial course reduced the inherent respiratory complications of prematurity and improved health outcomes of preterm infants. However, adverse outcomes have been reported concerning cognitive development. Although repeat course may have short term benefits, whether there are effects on health into childhood and beyond must await later assessment. Long term data are needed to recommend repeated courses.
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Affiliation(s)
- R Guilherme
- Service de biologie du développement, hôpital Robert-Debré, université Pierre-et-Marie-Curie, 48, boulevard Sérurier, 75019 Paris, France.
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Tang L, Carey LC, Bi J, Valego N, Sun X, Deibel P, Perrott J, Figueroa JP, Chappell MC, Rose JC. Gender differences in the effects of antenatal betamethasone exposure on renal function in adult sheep. Am J Physiol Regul Integr Comp Physiol 2009; 296:R309-17. [PMID: 19036827 PMCID: PMC2643986 DOI: 10.1152/ajpregu.90645.2008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Accepted: 11/20/2008] [Indexed: 11/22/2022]
Abstract
Exposure to clinically relevant doses of glucocorticoids during fetal life increases blood pressure in adult male and female sheep. The purpose of this study was to evaluate the effects of prenatal exposure to betamethasone at 80-81 days of gestation on renal function in ewes and rams at 1.5 yr of age. In prenatal betamethasone-exposed males, compared with the vehicle-exposed animals, basal glomerular filtration rate (GFR) (1.93 +/- 0.08 vs. 2.27 +/- 0.10 ml.min(-1).kg body wt(-1)) and the ability to excrete an acute Na+ load (37.1 +/- 4.4 vs. 53.7 +/- 9.7%) were reduced. (P < 0.03 and P = 0.03, respectively). In contrast, prenatal betamethasone exposure had no effect on basal GFR, Na+ excretion, or the percentage of the Na+ load excreted during the experiment in females. Systemic infusions of ANG-(1-7) at 9 ng.min(-1).kg(-1) for 2 h had minimal effects on basal GFR, renal plasma flow, and Na+ excretion in males but increased Na+ excretion in females. However, the percentage of Na+ load excreted during ANG-(1-7) infusion did not change in prenatal betamethasone-exposed females (113.1 +/- 14.2 vs. 98.1 +/- 12.2%) compared with the significant increase in vehicle females (139.2 +/- 22.3 vs. 92.2 +/- 7.5%) (P = 0.01). The data indicate that antenatal betamethasone exposure produces gender-specific alternations in renal function and thus suggest that different mechanisms underlie the antenatal steroid-induced elevations in blood pressure in male and female offspring.
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Affiliation(s)
- Lijun Tang
- Department of Obstetrics and Gynecology and Center of Research for Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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Wang X, Villar VAM, Armando I, Eisner GM, Felder RA, Jose PA. Dopamine, kidney, and hypertension: studies in dopamine receptor knockout mice. Pediatr Nephrol 2008; 23:2131-46. [PMID: 18615257 PMCID: PMC3724362 DOI: 10.1007/s00467-008-0901-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Revised: 04/18/2008] [Accepted: 05/07/2008] [Indexed: 02/06/2023]
Abstract
Dopamine is important in the pathogenesis of hypertension because of abnormalities in receptor-mediated regulation of renal sodium transport. Dopamine receptors are classified into D(1)-like (D(1), D(5)) and D(2)-like (D(2), D(3), D(4)) subtypes, all of which are expressed in the kidney. Mice deficient in specific dopamine receptors have been generated to provide holistic assessment on the varying physiological roles of each receptor subtype. This review examines recent studies on these mutant mouse models and evaluates the impact of individual dopamine receptor subtypes on blood pressure regulation.
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Affiliation(s)
- Xiaoyan Wang
- Department of Pediatrics, Georgetown University Medical Center, Washington, DC, USA
| | | | - Ines Armando
- Department of Pediatrics, Georgetown University Medical Center, Washington, DC, USA
| | - Gilbert M. Eisner
- Department of Medicine, Georgetown University Medical Center, Washington, DC, USA
| | - Robin A. Felder
- Department of Pathology, University of Virginia Health Sciences Center, Charlottesville, VA, USA
| | - Pedro A. Jose
- Department of Pediatrics, Georgetown University Medical Center, Washington, DC, USA
- Department of Physiology and Biophysics, Georgetown University Medical Center, Washington, DC, USA
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Di Renzo GC, Al Saleh E, Mattei A, Koutras I, Clerici G. Use of tocolytics: what is the benefit of gaining 48 hours for the fetus? BJOG 2007; 113 Suppl 3:72-7. [PMID: 17206969 DOI: 10.1111/j.1471-0528.2006.01127.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Preterm birth remains one of the serious problems in perinatal medicine and is associated with an increased risk of neonatal complications and long-term morbidity. Although each day that delivery is delayed between 22 and 28 weeks of gestation increases survival by 3%, since most spontaneous preterm labour occurs between 28 and 34 weeks of gestation, this is of secondary concern; the primary goal of delay is to improve the function of certain systems in the fetus and to balance the risks of a hostile intrauterine environment with the complications of extrauterine preterm life. Although there is a lack of definitive evidence that tocolytic drugs improve outcome following spontaneous preterm labour and preterm birth, there is ample evidence that tocolysis delays delivery for long enough to permit administration of a complete course of antepartum glucocorticoids and to facilitate in utero transfer to a tertiary care unit where neonatal care will be optimal. Both these measures have been associated with improved outcomes; antepartum glucocorticoids reduce the incidence of respiratory distress syndrome, intraventricular haemorrhage, periventricular leucomalacia and necrotising enterocolitis, and in utero transfer is associated with decreased morbidity and mortality and less hospital-based intervention compared with postnatal transportation. Consequently, women who are more likely to benefit from tocolysis are those at early gestational ages, those needing transfer to a hospital that can provide neonatal intensive care and those who have not yet received a full course of antepartum glucocorticosteroids. In these cases, delaying labour for at least 48 hours with drugs such as atosiban should be considered, since it offers clear advantages for the fetus.
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Affiliation(s)
- G C Di Renzo
- Department of Gynaecology and Obstetrics, Centre of Reproductive and Perinatal Medicine, University of Perugia, Policlinico Monteluce, Perugia, Italy.
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