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Piccolo B, Chen A, Louey S, Thornburg K, Jonker S. Physiological response to fetal intravenous lipid emulsion. Clin Sci (Lond) 2024; 138:117-134. [PMID: 38261523 PMCID: PMC10876438 DOI: 10.1042/cs20231419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/08/2024] [Accepted: 01/23/2024] [Indexed: 01/25/2024]
Abstract
In preterm neonates unable to obtain sufficient oral nutrition, intravenous lipid emulsion is life-saving. The contribution of post-conceptional level of maturation to pathology that some neonates experience is difficult to untangle from the global pathophysiology of premature birth. In the present study, we determined fetal physiological responses to intravenous lipid emulsion. Fetal sheep were given intravenous Intralipid 20® (n = 4 females, 7 males) or Lactated Ringer's Solution (n = 7 females, 4 males) between 125 ± 1 and 133 ± 1 d of gestation (term = 147 d). Manufacturer's recommendation for premature human infants was followed: 0.5-1 g/kg/d initial rate, increased by 0.5-1 to 3 g/kg/d. Hemodynamic parameters and arterial blood chemistry were measured, and organs were studied postmortem. Red blood cell lipidomics were analyzed by LC-MS. Intravenous Intralipid did not alter hemodynamic or most blood parameters. Compared with controls, Intralipid infusion increased final day plasma protein (P=0.004; 3.5 ± 0.3 vs. 3.9 ± 0.2 g/dL), albumin (P = 0.031; 2.2 ± 0.1 vs. 2.4 ± 0.2 g/dL), and bilirubin (P<0.001; conjugated: 0.2 ± 0.1 vs. 0.6 ± 0.2 mg/dL; unconjugated: 0.2 ± 0.1 vs. 1.1 ± 0.4 mg/dL). Circulating IGF-1 decreased following Intralipid infusion (P<0.001; 66 ± 24 vs. 46 ± 24 ng/mL). Compared with control Oil Red O liver stains (median score 0), Intralipid-infused fetuses scored 108 (P=0.0009). Lipidomic analysis revealed uptake and processing of infused lipids into red blood cells, increasing abundance of saturated fatty acids. The near-term fetal sheep tolerates intravenous lipid emulsion well, although lipid accumulates in the liver. Increased levels of unconjugated bilirubin may reflect increased red blood cell turnover or impaired placental clearance. Whether Intralipid is less well tolerated earlier in gestation remains to be determined.
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Affiliation(s)
- Brian D. Piccolo
- USDA/ARS-Arkansas Children’s Nutrition Center, Little Rock, AR, U.S.A
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, U.S.A
| | - Athena Chen
- Department of Pathology, Oregon Health and Science University, Portland, OR, U.S.A
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, U.S.A
| | - Samantha Louey
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, U.S.A
| | - Kent L.R. Thornburg
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, U.S.A
| | - Sonnet S. Jonker
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, U.S.A
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Onohara D, Hagen M, Louey S, Giraud G, Jonker S, Padala M. Chronic in utero mitral inflow obstruction unloads left ventricular volume in a novel late gestation fetal lamb model. JTCVS OPEN 2023; 16:698-707. [PMID: 38204723 PMCID: PMC10775114 DOI: 10.1016/j.xjon.2023.09.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 09/26/2023] [Accepted: 09/28/2023] [Indexed: 01/12/2024]
Abstract
Objective The in utero no flow/no grow hypothesis postulates that reduced inflow of blood into the left ventricle due to a stenotic mitral valve could lead to ventricular hypoplasia and hypoplastic left heart syndrome. This has been demonstrated in chick embryos, but less so in large animals. We investigated the impact of mitral obstruction on left and right ventricular growth in fetal lambs. Methods Twelve pregnant ewes, most bearing twins, were instrumented at 119 ± 1 days gestational age. Carotid artery and jugular vein catheters, an ascending aorta flow probe, and a left atrial deflated balloon catheter were implanted into 1 fetus (left atrial balloon group), and the twin remained an uninstrumented control. The balloon was inflated gradually over 8 days until net antegrade aortic flow was eliminated. Fetal transesophageal echocardiography was performed at the time of surgery and just before termination in both groups. Results Terminal fetal body weights were comparable between groups. Terminal heart/body weight ratio was higher in left atrial balloon group fetuses (6.9 ± 0.8 g/kg) compared with controls (5.9 ± 0.6 g, P = .0126). The left ventricular/right ventricular weight ratio was 24% (P = .0077) lower in left atrial balloon group fetuses than in controls. Left ventricular/heart weight (0.24 ± 0.04 g/g vs 0.30 ± 0.04 g/g, P = .0009), left ventricular end-diastolic volume (2.3 ± 0.7 mL vs 7.1 ± 0.8 mL; P = .0012), and left ventricular end-systolic volume (1.01 mL [0.95-1.95 mL] vs 3.38 mL [3.28-3.57 mL], P = .0042) were lower in left atrial balloon group fetuses compared with controls. Right ventricular weight (g/kg), right ventricular end-diastolic volume, and right ventricular end-systolic volume were similar between groups. Conclusions In this late-gestation fetal lamb model, in utero obstruction of mitral inflow slowed left ventricular growth and caused right ventricular remodeling.
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Affiliation(s)
- Daisuke Onohara
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, Atlanta, Ga
- Division of Cardiothoracic Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, Ga
| | - Matthew Hagen
- Center for Development Health, Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Ore
| | - Samantha Louey
- Center for Development Health, Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Ore
| | - George Giraud
- Center for Development Health, Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Ore
- Department of Cardiology, Portland Veterans Affairs Medical Center, Portland, Ore
| | - Sonnet Jonker
- Center for Development Health, Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Ore
| | - Muralidhar Padala
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, Atlanta, Ga
- Division of Cardiothoracic Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, Ga
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Manfra O, Louey S, Jonker SS, Perdreau-Dahl H, Frisk M, Giraud GD, Thornburg KL, Louch WE. Augmenting workload drives T-tubule assembly in developing cardiomyocytes. J Physiol 2023:10.1113/JP284538. [PMID: 37128962 PMCID: PMC10854476 DOI: 10.1113/jp284538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 04/11/2023] [Indexed: 05/03/2023] Open
Abstract
Contraction of cardiomyocytes is initiated at subcellular elements called dyads, where L-type Ca2+ channels in t-tubules are located within close proximity to ryanodine receptors in the sarcoplasmic reticulum. While evidence from small rodents indicates that dyads are assembled gradually in the developing heart, it is unclear how this process occurs in large mammals. We presently examined dyadic formation in fetal and newborn sheep (Ovis aries), and the regulation of this process by fetal cardiac workload. By employing advanced imaging methods, we demonstrated that t-tubule growth and dyadic assembly proceed gradually during fetal sheep development, from 93 days of gestational age until birth (147 days). This process parallels progressive increases in fetal systolic blood pressure, and includes step-wise colocalization of L-type Ca2+ channels and the Na+ /Ca2+ exchanger with ryanodine receptors. These proteins are upregulated together with the dyadic anchor junctophilin-2 during development, alongside changes in the expression of amphiphysin-2 (BIN1) and its partner proteins myotubularin and dynamin-2. Increasing fetal systolic load by infusing plasma or occluding the post-ductal aorta accelerated t-tubule growth. Conversely, reducing fetal systolic load with infusion of enalaprilat, an angiotensin converting enzyme inhibitor, blunted t-tubule formation. Interestingly, altered t-tubule densities did not relate to changes in dyadic junctions, or marked changes in the expression of dyadic regulatory proteins, indicating that distinct signals are responsible for maturation of the sarcoplasmic reticulum. In conclusion, augmenting blood pressure and workload during normal fetal development critically promotes t-tubule growth, while additional signals contribute to dyadic assembly. KEY POINTS: T-tubule growth and dyadic assembly proceed gradually in cardiomyocytes during fetal sheep development, from 93 days of gestational age until the post-natal stage. Increasing fetal systolic load by infusing plasma or occluding the post-ductal aorta accelerated t-tubule growth and hypertrophy. In contrast, reducing fetal systolic load by enalaprilat infusion slowed t-tubule development and decreased cardiomyocyte size. Load-dependent modulation of t-tubule maturation was linked to altered expression patterns of the t-tubule regulatory proteins junctophilin-2 and amphiphysin-2 (BIN1) and its protein partners. Altered t-tubule densities did not influence dyadic formation, indicating that distinct signals are responsible for maturation of the sarcoplasmic reticulum.
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Affiliation(s)
- Ornella Manfra
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
| | - Samantha Louey
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, OR, USA
| | - Sonnet S Jonker
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, OR, USA
| | - Harmonie Perdreau-Dahl
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Michael Frisk
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - George D Giraud
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, OR, USA
- VA Portland Health Care System Portland, OR, USA
| | - Kent L Thornburg
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, OR, USA
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
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Wang W, Yu K, Zhao SY, Mo DG, Liu JH, Han LJ, Li T, Yao HC. The impact of circulating IGF-1 and IGFBP-2 on cardiovascular prognosis in patients with acute coronary syndrome. Front Cardiovasc Med 2023; 10:1126093. [PMID: 36970368 PMCID: PMC10036580 DOI: 10.3389/fcvm.2023.1126093] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 02/22/2023] [Indexed: 03/12/2023] Open
Abstract
BackgroundWhile insulin-like growth factor 1 (IGF-1) exerts a cardioprotective effect in the setting of atherosclerosis, insulin-like growth factor binding protein 2 (IGFBP-2) is involved in metabolic syndrome. Although IGF-1 and IGFBP-2 are known to be predictors for mortality in patients with heart failure, their use in clinic as prognostic biomarkers for acute coronary syndrome (ACS) requires investigation. We evaluated the relationship between IGF-1 and IGFBP-2 levels at admission and the risk of major adverse cardiovascular events (MACEs) in patients with ACS.MethodsA total of 277 ACS patients and 42 healthy controls were included in this prospective cohort study. Plasma samples were obtained and analyzed at admission. Patients were followed for MACEs after hospitalization.ResultsAmong patients who suffered acute myocardial infarction, plasma levels of IGF-1 and IGFBP-2 were lower and higher, respectively, as compared to healthy controls (both p < 0.05). The mean follow-up period was 5.22 (1.0–6.0) months and MACEs incidence was 22.4% (62 of 277 patients). Kaplan–Meier survival analysis revealed that patients with low IGFBP-2 levels had a greater event-free survival rate than patients with high IGFBP-2 levels (p < 0.001). Multivariate Cox proportional hazards analysis revealed IGFBP-2, but not IGF-1, to be a positive predictor of MACEs (hazard ratio 2.412, 95% CI 1.360–4.277; p = 0.003).ConclusionOur findings suggest that high IGFBP-2 levels are associated with the development of MACEs following ACS. Moreover, IGFBP-2 is likely an independent predictive marker of clinical outcomes in ACS.
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Affiliation(s)
- Wei Wang
- Department of Cardiology, Liaocheng People's Hospital, Shandong University, Jinan, China
- Department of Cardiology, Liaocheng People's Hospital Affiliated to Shandong First Medical University, Liaocheng, China
| | - Kang Yu
- Department of Laboratory Medicine, Liaocheng People's Hospital Affiliated to Shandong First Medical University, Liaocheng, China
| | - Shou-Yong Zhao
- Department of Laboratory Medicine, Liaocheng People's Hospital Affiliated to Shandong First Medical University, Liaocheng, China
| | - De-Gang Mo
- Department of Cardiology, Liaocheng People's Hospital Affiliated to Shandong First Medical University, Liaocheng, China
| | - Jia-Hui Liu
- Department of Cardiology, Liaocheng People's Hospital Affiliated to Shandong First Medical University, Liaocheng, China
| | - Li-Jinn Han
- Department of Cardiology, Liaocheng People's Hospital Affiliated to Shandong First Medical University, Liaocheng, China
| | - Tai Li
- Department of Nursing, Liaocheng Vocational & Technical College, Liaocheng, China
| | - Heng-Chen Yao
- Department of Cardiology, Liaocheng People's Hospital, Shandong University, Jinan, China
- Department of Cardiology, Liaocheng People's Hospital Affiliated to Shandong First Medical University, Liaocheng, China
- Correspondence: Heng-Chen Yao
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Hagen MW, Louey S, Alaniz SM, Belcik T, Muller MM, Brown L, Lindner JR, Jonker SS. Changes in microvascular perfusion of heart and skeletal muscle in sheep around the time of birth. Exp Physiol 2023; 108:135-145. [PMID: 36420621 PMCID: PMC9805518 DOI: 10.1113/ep090809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 11/04/2022] [Indexed: 11/25/2022]
Abstract
NEW FINDINGS What is the central question of this study? How does the microvascular perfusion of striated muscle change during the dynamic developmental period between the late gestation fetus and early neonate? What is the main finding and its importance? In both myocardium and skeletal muscle, perfusion of striated muscle is significantly reduced in the neonate compared to the late term fetus, but flow reserve is unchanged. The results suggest striated muscle capillary networks grow more slowly relative to the myofibres they nourish during the perinatal period. ABSTRACT Microvascular perfusion of striated muscle is an important determinant of health throughout life. Birth is a transition with profound effects on the growth and function of striated muscle, but the regulation of microvascular perfusion around this transition is poorly understood. We used contrast-enhanced ultrasound perfusion imaging (CEUS) to study the perfusion of left ventricular myocardium and hindlimb biceps femoris, which are populations of muscle with different degrees of change in pre- to postnatal workloads and different capacities for postnatal proliferative growth. We studied separate groups of lambs in late gestation (135 days' gestational age; 92% of term) and shortly after birth (5 days' postnatal age). We used CEUS to quantify baseline perfusion, perfusion during hyperaemia induced by adenosine infusion (myocardium) or electrically stimulated unloaded exercise (skeletal muscle), flow reserve and oxygen delivery. We found heart-to-body weight ratio was greater in neonates than fetuses. Microvascular volume and overall perfusion were lower in neonates than fetuses in both muscle groups at baseline and with hyperaemia. Flux rate differed with muscle group, with myocardial flux being faster in neonates than fetuses, but skeletal muscle flux being slower. Oxygen delivery to skeletal muscle at baseline was lower in neonates than fetuses, but was not significantly different in myocardium. Flow reserve was not different between ages. Given the significant somatic growth, and the transition from hyperplastic to hypertrophic myocyte growth occurring in the perinatal period, we postulate that the primary driver of lower neonatal striated muscle perfusion is faster growth of myofibres than their associated capillary networks.
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Affiliation(s)
- Matthew W. Hagen
- Center for Developmental HealthOregon Health & Science UniversityPortlandORUSA
- Knight Cardiovascular InstituteOregon Health & Science UniversityPortlandORUSA
| | - Samantha Louey
- Center for Developmental HealthOregon Health & Science UniversityPortlandORUSA
- Knight Cardiovascular InstituteOregon Health & Science UniversityPortlandORUSA
| | - Sarah M. Alaniz
- Center for Developmental HealthOregon Health & Science UniversityPortlandORUSA
| | - Todd Belcik
- Knight Cardiovascular InstituteOregon Health & Science UniversityPortlandORUSA
| | - Matthew M. Muller
- Knight Cardiovascular InstituteOregon Health & Science UniversityPortlandORUSA
| | - Laura Brown
- Department of PediatricsUniversity of Colorado Anschutz Medical CampusAuroraCOUSA
| | - Jonathan R. Lindner
- Knight Cardiovascular InstituteOregon Health & Science UniversityPortlandORUSA
- Division of Cardiovascular MedicineUniversity of Virginia Medical CenterCharlottesvilleVAUSA
| | - Sonnet S. Jonker
- Center for Developmental HealthOregon Health & Science UniversityPortlandORUSA
- Knight Cardiovascular InstituteOregon Health & Science UniversityPortlandORUSA
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Hagen MW, Louey S, Alaniz SM, Brown L, Lindner JR, Jonker SS. Coronary conductance in the normal development of sheep during the perinatal period. PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS 2022; 10:e15523. [PMID: 36461657 PMCID: PMC9718948 DOI: 10.14814/phy2.15523] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 11/03/2022] [Accepted: 11/05/2022] [Indexed: 12/04/2022]
Abstract
Birth is associated with substantial shifts in cardiovascular physiology. Little is known about coronary vascular adaptations during this period. We used fetal and neonatal lambs to measure coronary function at late gestation (92% of term) and shortly after birth (5-6 days postnatal age). In each animal we measured unanesthetized myocardial perfusion and oxygen delivery using a circumflex artery flow probe. We used inflatable occluders and adenosine to determine coronary conductance and flow reserve. In a subset of animals, we used myocardial contrast echocardiography (MCE, anesthetized) to assess its utility as a tool for studying changes in regional myocardial perfusion in normal development. Separate age-matched animals were instrumented with aortic and coronary sinus sampling catheters to determine myocardial oxygen extraction (unanesthetized). With an average of 17 days of developmental time separating our neonatal and fetal cohorts we found that heart-to-body weight ratio was significantly greater in neonates than fetuses. In resting animals, we found significant decreases in weight-normalized perfusion of, and oxygen delivery to, neonatal relative to fetal myocardium. Similar results were seen when measuring baseline MCE-derived perfusion. Pressure-flow relationship studies revealed lower baseline and maximal coronary conductance in neonates than fetuses, with similar coronary flow reserve between groups. There was greater oxygen extraction in neonates than fetuses. Combined analysis of oxygen extraction with coronary flow suggested greater oxygen consumption by the fetal than neonatal myocardium. We conclude that, during the immediate perinatal period, cardiac growth outpaces coronary microvascular growth resulting in lower capacity for microvascular perfusion in the early neonate.
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Affiliation(s)
- Matthew W. Hagen
- Center for Developmental HealthOregon Health & Science UniversityPortlandOregonUSA,Knight Cardiovascular Institute, Oregon Health & Science UniversityPortlandOregonUSA
| | - Samantha Louey
- Center for Developmental HealthOregon Health & Science UniversityPortlandOregonUSA,Knight Cardiovascular Institute, Oregon Health & Science UniversityPortlandOregonUSA
| | - Sarah M. Alaniz
- Center for Developmental HealthOregon Health & Science UniversityPortlandOregonUSA
| | - Laura Brown
- Department of PediatricsPerinatal Research CenterUniversity of Colorado Anschutz Medical CampusAuroraColoradoUSA
| | - Jonathan R. Lindner
- Knight Cardiovascular Institute, Oregon Health & Science UniversityPortlandOregonUSA
| | - Sonnet S. Jonker
- Center for Developmental HealthOregon Health & Science UniversityPortlandOregonUSA,Knight Cardiovascular Institute, Oregon Health & Science UniversityPortlandOregonUSA
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Stremming J, Heard S, White A, Chang EI, Shaw SC, Wesolowski SR, Jonker SS, Rozance PJ, Brown LD. IGF-1 infusion to fetal sheep increases organ growth but not by stimulating nutrient transfer to the fetus. Am J Physiol Endocrinol Metab 2021; 320:E527-E538. [PMID: 33427051 PMCID: PMC7988781 DOI: 10.1152/ajpendo.00453.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) is an important fetal growth factor. However, the role of fetal IGF-1 in increasing placental blood flow, nutrient transfer, and nutrient availability to support fetal growth and protein accretion is not well understood. Catheterized fetuses from late gestation pregnant sheep received an intravenous infusion of LR3 IGF-1 (LR3 IGF-1; n = 8) or saline (SAL; n = 8) for 1 wk. Sheep then underwent a metabolic study to measure uterine and umbilical blood flow, nutrient uptake rates, and fetal protein kinetic rates. By the end of the infusion, fetal weights were not statistically different between groups (SAL: 3.260 ± 0.211 kg, LR3 IGF-1: 3.682 ± 0.183; P = 0.15). Fetal heart, adrenal gland, and spleen weights were higher (P < 0.05), and insulin was lower in LR3 IGF-1 (P < 0.05). Uterine and umbilical blood flow and umbilical uptake rates of glucose, lactate, and oxygen were similar between groups. Umbilical amino acid uptake rates were lower in LR3 IGF-1 (P < 0.05) as were fetal concentrations of multiple amino acids. Fetal protein kinetic rates were similar. LR3 IGF-1 skeletal muscle had higher myoblast proliferation (P < 0.05). In summary, LR3 IGF-1 infusion for 1 wk into late gestation fetal sheep increased the weight of some fetal organs. However, because umbilical amino acid uptake rates and fetal plasma amino acid concentrations were lower in the LR3 IGF-1 group, we speculate that animals treated with LR3 IGF-1 can efficiently utilize available nutrients to support organ-specific growth in the fetus rather than by stimulating placental blood flow or nutrient transfer to the fetus.NEW & NOTEWORTHY After a 1-wk infusion of LR3 IGF-1, late gestation fetal sheep had lower umbilical uptake rates of amino acids, lower fetal arterial amino acid and insulin concentrations, and lower fetal oxygen content; however, LR-3 IGF-1-treated fetuses were still able to effectively utilize the available nutrients and oxygen to support organ growth and myoblast proliferation.
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Affiliation(s)
- Jane Stremming
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Sara Heard
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Alicia White
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Eileen I Chang
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Steven C Shaw
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Stephanie R Wesolowski
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Sonnet S Jonker
- Knight Cardiovascular Institute, Center for Developmental Health, Oregon Health & Science University, Portland, Oregon
| | - Paul J Rozance
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Laura D Brown
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
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