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Biomedical subjects

F M Sullivan

Publications and source records attributed to F M Sullivan.

At least 91 records · Page 5Linked to original sources
PubMed1975

The relation between maternal restraint and food deprivation, plasma corticosterone, and induction of cleft palate in the offspring of mice.

The blood level of corticosterone was measured in mice following the injection on day 14 of pregnancy of a dose of corticosterone sufficient to cause a low frequency of cleft palate in the fetuses. This was compared with the blood levels present during maternal restraint and food deprivation that produced a similar frequency of cleft palate. The mean blood level over the 24 h following injection of corticosterone was 660 mug/100 ml, and during a similar period of restraint was 485 mug/100 ml. Other mice were subjected either to restraint or food deprivation for 24 h beginning day 14 of pregnancy, the plasma corticosterone levels measured during that time, and the frequency of cleft palate in late fetuses compared with the individual plasma corticosterone levels during treatment. There was a significant (P less than 0.025) correlation between high maternal corticosteroid levels and the frequency of cleft palate in the offspring of the restrained mice but not in the food-deprived animals. It is suggested that in some stressed mice endogenous plasma corticosterone can reach levels sufficient to account for the development of cleft palate.

Animals↗
PubMed1975

Uterine blood flow in the pregnant rabbit.

Two methods are described for the measurement of uterine blood flow in the pregnant rabbit. The first involves the use of a Parks ultrasonic Doppler probe placed over the exposed uterine artery. The second method uses a drop counter system connected between the uterine and jugular veins. The Doppler flowmeter was used to measure uterine arterial blood flow in twenty rabbits on Day 28 or 29 of pregnancy. No significant difference was observed between blood flow on these 2 days and the absolute blood flow to one horn (plus or minus S. E.) was found to be 16.8 plus or minus 1.4 ml/min, equivalent to 27.1 plus or minus 1.8 ml/100 g tissue/min. Using the drop recorder technique, the flow to one uterine horn in eleven rabbits on Day 27 or 28 of pregnancy was 12.5 plus or minus 1.9 ml/min, equivalent to 23.6 plus or minus 3.2 ml/100 g tissue/min. The pressure-flow relationship in the uterine vascular bed was studied using the Doppler flowmeter and graded mechanical occlusion of the arterial supply. Within the range of pressures studied, the flow was found to be linearly related to the arterio-venous pressure difference. This suggests that the uterine vascular bed was fully dilated under the conditions of study.

Animals↗
PubMed1975

Effects of acute and chronic stress on plasma corticosterone levels in the pregnant and non-pregnant mouse.

Plasma corticosterone levels were measured in the pregnant and non-pregnant mouse after acute and chronic stress. Acute surgical stress in the non-pregnant mouse increased plasma corticosterone from a mean resting level of 2-3 to 50-6 mug/100 ml 1 h after operation. By 24 h after operation, levels had fallen back to 7-6 mug/100 ml. In the pregnant mouse an acute surgical stress on day 14 or pregnancy increased plasma corticosterone levels to 525 mug/100 ml 1 h after surgery from a resting value of 80 mug/100 ml, with a return to resting levels by 24 h. During the chronic stress of 24 h restraint, plasma corticosterone levels in the non-pregnant mouse reached a peak (81-0 mug/100ml) 1 h after the start of restrain and were still raised (mean 24-0 mug/100 ml) after 24 h. In the pregnant restrained mouse a peak value of 733 mug/100 ml was seen at 1 h, with levels maintained at around 500-600 mug/100 ml during the next 16 h of restraint. Increased levels of 268 mug/100 ml were still present at 24 h. After the chronic stress of 24 h food deprivation, plasma corticosterone levels in the non-pregnant and pregnant mice were raised after 7 h to levels slightly lower than those observed in the restrained groups, and at 24 h levels in the respective restrained and food-deprived groups were similar, suggesting that food deprivation is a powerful chronic stressor in the mouse. During chronic stress in the pregnant mouse where plasma corticosterone levels of around 600 mug/100 ml were maintained fro some hours, protein binding studies indicated that 10 mug/100 ml was free, unbound corticosterone. The physiological and pathological consequences of such high levels of free corticosterone during stress in pregnancy are discussed.

Animals↗