Search Results
You are looking at 1 - 2 of 2 items for
- Author: DENISE MADILL x
- Refine by access: All content x
Search for other papers by J. M. BASSETT in
Google Scholar
PubMed
Search for other papers by DENISE MADILL in
Google Scholar
PubMed
SUMMARY
Merino ewes whose foetuses had surgically-implanted, indwelling vascular cannulae were used to determine the influence of maternal nutritional status on foetal plasma hormone levels during the last month of gestation. Observations were made during feeding of the ewes on a lucerne chaff diet ad libitum, during restricted feeding on the same diet and during fasting. Foetuses survived for an average of 31 days after the operation and seven out of the ten ewes lambed normally. In both ewes and foetuses, plasma concentrations of insulin were significantly higher 3–12 h after feeding than in prefeeding samples. Similar changes were seen with restricted and ad-libitum feeding. Fasting for 48 h caused significant decreases in insulin levels of both ewes and foetuses, but the decrease in foetal plasma insulin concentration was less than that in ewes. In agreement with earlier studies, foetal and maternal glucose concentrations were closely correlated and foetal fructose concentrations were closely related to foetal glucose concentrations. Foetal plasma insulin concentrations were closely correlated with glucose and fructose concentrations. Plasma growth hormone (GH) levels increased significantly in both ewes and foetuses during fasting. There were also significant increases during fasting in the plasma corticosteroid levels of the ewes, but not in those of their foetuses. Feeding did not cause significant changes in foetal plasma GH or corticosteroid concentrations although maternal GH concentrations were significantly increased and corticosteroid concentrations decreased 3–12 h after feeding on the restricted diet.
The results suggest that alterations in foetal plasma hormone concentrations could play an important role in foetal adaptation to fluctuations in maternal nutrient supply during the last month of gestation.
Search for other papers by J. M. BASSETT in
Google Scholar
PubMed
Search for other papers by DENISE MADILL in
Google Scholar
PubMed
SUMMARY
Chronically cannulated foetal lambs close to term were infused intravenously with glucose at rates of 40 or 70 mg/min for up to 5 days. Infusion at these rates increased the foetal plasma glucose concentration to values in the ranges 35–45 and 60–80 mg/100 ml respectively. There were related increases in plasma fructose and lactate concentrations.
Foetal plasma insulin concentrations increased within the first hour and remained raised throughout infusion. Plasma insulin concentrations were significantly correlated with plasma glucose concentrations. The secretory response of insulin to subsequent glucose infusions at a rate of 140 mg/min was not increased by the previous prolonged glucose infusions.
Glucose infusion resulted in decreased plasma growth hormone concentrations in three of the lambs infused, but over the total number of observations plasma glucose and growth hormone concentrations were not significantly correlated.
