Amino acid metabolism in the ovine fetus

1983 ◽  
Vol 244 (5) ◽  
pp. E459-E466 ◽  
Author(s):  
J. A. Lemons ◽  
R. L. Schreiner
Keyword(s):  
Amino Acids ◽  
Blood Flow ◽  
Umbilical Vein ◽  
Fetal Tissue ◽  
Maternal Circulation ◽  
Fed State ◽  
Arterial Circulation ◽  
Umbilical Blood ◽  
Ovine Fetus ◽  
Branched Chain

Quantitative measurements of the umbilical uptake of a variety of substrates were made in the ovine fetus in both the fed state and after 5 days of maternal fasting. Blood flow was measured in both study periods using the antipyrine method, with the simultaneous measurement of umbilical vein and arterial concentrations of glucose, oxygen, and 25 amino acids in whole blood. Umbilical blood flow and fetal oxygen consumption remained unchanged between the fed and fasted states. Umbilical glucose uptake decreased from a mean of 6.85 to 2.79 mg X kg-1 X min-1 with a concomitant fall in the glucose:oxygen quotient from a mean of 0.70 to 0.31. Whereas the majority of gluconeogenic amino acids decreased in concentration in the maternal circulation during fasting, the branched-chain amino acids, as well as 3-methylhistidine, increased. In contrast the majority of amino acids in the fetal arterial circulation either increased significantly or remained unchanged in concentration. Although the fetal excretion of urea increased by 70% during the period of maternal fasting, the total fetal uptake of nitrogen in the form of free amino acids via the umbilical circulation did not change (1,337 vs. 1,027 mg X kg-1 X day-1). These data suggest that the supply of amino acids from the mother to the fetus does not change dramatically during maternal fasting. Therefore, the fetus must either catabolize amino acids previously destined for fetal tissue synthesis and/or begin catabolizing its own protein stores.

scholarly journals UMBILICAL VEIN BLOOD FLOW IN THE OVINE FETUS: COMPARISON OF DOPPLER AND STEADY STATE TECHNIQUES 246

1997 ◽  
Vol 41 ◽  
pp. 43-43
Author(s):  
Henry L. Galan ◽  
Michael Hussey ◽  
Misu Chung ◽  
Enrico Ferrazzi ◽  
John C. Hobbins ◽  
...  
Keyword(s):  
Blood Flow ◽  
Steady State ◽  
Umbilical Vein ◽  
Ovine Fetus

scholarly journals Which of the branched-chain amino acids increases cerebral blood flow in hepatic encephalopathy? A double-blind randomized trial

2018 ◽  
Vol 19 ◽  
pp. 302-310 ◽  
Author(s):  
Fernando Gomes Romeiro ◽  
Marjorie do Val Ietsugu ◽  
Letícia de Campos Franzoni ◽  
Laís Augusti ◽  
Matheus Alvarez ◽  
...  
Keyword(s):  
Amino Acids ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Hepatic Encephalopathy ◽  
Randomized Trial ◽  
Branched Chain Amino Acids ◽  
Double Blind ◽  
Branched Chain

Fetal neuromuscular blockade: effect on oxygen demand and placental transport

1989 ◽  
Vol 257 (3) ◽  
pp. H734-H738
Author(s):  
R. B. Wilkening ◽  
D. W. Boyle ◽  
G. Meschia
Keyword(s):  
Blood Flow ◽  
Oxygen Saturation ◽  
Neuromuscular Blockade ◽  
Umbilical Vein ◽  
Oxygen Demand ◽  
Arterial Oxygen ◽  
Uterine Blood Flow ◽  
Umbilical Blood ◽  
Steady State Method ◽  
Umbilical Blood Flow

To study mechanisms by which variations in fetal oxygen demand alter fetal oxygen saturation and PO2, we measured uterine and umbilical blood flow and transplacental oxygen diffusion rate in eight chronically prepared pregnant ewes before and during fetal neuromuscular blockade with pancuronium bromide (0.2 mg/kg). Uterine and umbilical blood flows were measured by applying the steady-state method using ethanol as the test substance. Fetal oxygen uptake decreased 7.5% (P less than 0.05). Umbilical blood flow increased 6% (P less than 0.05), whereas uterine blood flow did not change significantly. Fetal arterial oxygen saturation increased markedly (54.8–60.9%; P less than 0.001). There were also significant increases in umbilical vein oxygen saturation (83.6–86.9%; P less than 0.01), uterine vein oxygen saturation (70.7–72.2%; P less than 0.01), umbilical vein PO2 (29.4–32.1 Torr; P less than 0.001), and uterine vein PO2 (49.4–50.7 Torr; P less than 0.01). The uterine-umbilical venous PO2 difference decreased significantly (20.0–18.6 Torr; P less than 0.001), whereas there was no significant change in the uterine-umbilical venous PCO2 difference or in the umbilical ethanol shunt. The data indicate that follows a small decrease in fetal oxygen demand is caused by two aspects of placental oxygen transport: 1) umbilical and uterine blood flow do not react homeostatically to prevent the rise of PO2 in the placental circulation, and 2) the decrease in oxygen flux from placenta to fetus is associated with a decrease in the transplacental PO2 gradient.

Effects of gastric nutritional supplementation on fetal umbilical uptake of nutrients

1981 ◽  
Vol 241 (3) ◽  
pp. E178-E185 ◽  
Author(s):  
V. E. Charlton ◽  
B. L. Reis
Keyword(s):  
Amino Acids ◽  
Blood Flow ◽  
Average Rate ◽  
Nitrogen Concentration ◽  
Amino Nitrogen ◽  
Therapeutic Benefit ◽  
Nutritional Supplementation ◽  
Concentration Gradients ◽  
Nitrogen Levels ◽  
Umbilical Blood

Intrauterine nutritional supplementation may be of therapeutic benefit to the malnourished, growth-retarded fetus. Using 14 chronically catheterized, third trimester fetal lambs, we evaluated the effects of gastric infusions of amino acids and glucose on umbilical uptake of alpha-amino nitrogen, glucose, lactate, and oxygen. When amino acids were infused, amino nitrogen was gained through the intestine at an average rate equal to 45% of fetal umbilical uptake of amino nitrogen. There were no consistent changes in umbilical uptake of the measured nutrients, except for a small decrease in umbilical uptake of oxygen (P less than 0.05). No relationship were found between changes in fetal amino nitrogen levels or changes in fetal-maternal amino nitrogen concentration gradients and umbilical uptake of amino nitrogen. When glucose was infused, glucose was absorbed through the intestine at an average rate equal to 42% of fetal umbilical uptake of glucose. There were no changes in umbilical uptake of amino nitrogen, lactate, or oxygen. Umbilical uptake of glucose decreased, however, in inverse proportion to both the glucose infusion rate (P less than 0.005) and the rise in fetal glucose concentration (P less than 0.025). This limited the quantity of glucose that could be gained by the fetus, via gastrointestinal supplementation. During the infusions, we also observed a change in the pattern of fetal lower body blood flow. There was a 12% decrease in the mean umbilical blood flow (P less than 0.005) and a 22% increase in mean intestinal flow (P less than 0.05).

Branched-chain amino acids alleviate nonalcoholic steatohepatitis in rats

2013 ◽  
Vol 38 (8) ◽  
pp. 836-843 ◽  
Author(s):  
Tianrun Li ◽  
Leiluo Geng ◽  
Xin Chen ◽  
Miranda Miskowiec ◽  
Xuan Li ◽  
...  
Keyword(s):  
Amino Acids ◽  
Blood Flow ◽  
High Fat Diet ◽  
Plasma Lipid ◽  
Branched Chain Amino Acids ◽  
Fat Deposition ◽  
The Body ◽  
High Fat ◽  
Branched Chain ◽  
Rat Livers

Nonalcoholic steatohepatitis (NASH) is a prevalent disease in countries around the world. The branched-chain amino acids (BCAAs) leucine, isoleucine, and valine cannot be synthesized by the body and have been shown to promote muscle buildup; thus, it is logical to suggest that BCAAs can reduce fat deposition in the body. We used gonadectomized rats fed a high-fat diet to investigate the effects of BCAAs on lipid metabolism over an 8-week experimental period. Body composition, tissue histology, plasma lipid indices, and hormone levels were examined. We demonstrated that the body weights of rats were not significantly decreased but the mesenteric fat was significantly decreased (p < 0.05) in BCAA-treated rats. In addition, BCAAs decreased plasma lipid levels and fat deposition in the liver. At week 4, when the untreated rats displayed macrovesicular steatosis, BCAA-treated rats had only macrovesicular droplets in their hepatocytes. At week 8, when the untreated rat livers displayed profound inflammation and cirrhosis, BCAA-treated rat livers remained in the macrovesicular stage of steatosis. BCAAs induced higher blood glucose and plasma insulin levels (p < 0.05). BCAAs also improved liver blood flow by increasing mean arterial blood pressure and decreasing portal pressure, which helped delay the change in blood flow pattern to that of cirrhosis. BCAAs also induced the skeletal muscle to express higher levels of branched-chain α-keto acid dehydrogenase E1α, which indicates an enhanced metabolic capacity of BCAAs in muscle tissue. This study clearly demonstrates the effects of BCAAs on the amelioration of fat deposition in rats fed a high-fat diet.

Effects of branched-chain amino acids on placental amino acid transfer and insulin and glucagon release in the ovine fetus

2001 ◽  
Vol 185 (2) ◽  
pp. 487-495 ◽  
Author(s):  
Maciej Józwik ◽  
Cecilia Teng ◽  
Randall B. Wilkening ◽  
Giacomo Meschia ◽  
Janet Tooze ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Branched Chain Amino Acids ◽  
Glucagon Release ◽  
Ovine Fetus ◽  
Branched Chain

Fetal O2 consumption in sheep during controlled long-term reductions in umbilical blood flow

1986 ◽  
Vol 250 (6) ◽  
pp. H1037-H1042 ◽  
Author(s):  
D. F. Anderson ◽  
C. M. Parks ◽  
J. J. Faber
Keyword(s):  
Blood Flow ◽  
Polynomial Regression ◽  
Umbilical Vein ◽  
Control Period ◽  
Control Flow ◽  
Aortic Flow ◽  
O2 Consumption ◽  
Umbilical Blood ◽  
Umbilical Blood Flow

Electromagnetic flow sensors and inflatable occluders were placed on the distal aortas of nine fetal lambs of 111-124 days gestation; indwelling vascular catheters were placed in a lower body artery and vein and the common umbilical vein. After a control period of 7.6 +/- 2.1 (SD) days, distal aortic flow was reduced to about 60% of control flow; placental flow fractions of distal aortic flow were 77 +/- 5%, control; 69 +/- 11% during flow reduction. Duration of the flow reductions was 9.6 +/- 6.5 days. Fetal O2 consumption fell from 6.4 +/- 1.5 to 5.3 +/- 1.1 ml X min-1 X kg-1 (P less than 0.02) as umbilical blood flow was reduced from 202 +/- 47 to 116 +/- 36 ml X min-1 X kg-1 (P less than 0.001). Least-squares polynomial regression analysis showed that O2 consumption was a linear function of umbilical blood flow (P less than 0.01). With regard to long-term fetal O2 consumption, there was no evidence for a margin of safety in fetal umbilical blood flow.

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