Biomedical subjects

B C Woodside

Publications and source records attributed to B C Woodside.

3 recordsLinked to original sources

PubMed1995

Suppression of LH secretion in food-restricted lactating females: effects of ovariectomy and bromocryptine treatment.

It has been shown that restricting food in lactating rats for the first 2 weeks postpartum at a level of 60% of the ad-libitum daily ration increases the length of lactational dioestrus by about 7 days but little is known about correlated changes in hormone levels. In the first experiment we report changes in LH, prolactin (PRL) and ACTH secretion in food-restricted and ad-libitum fed lactating rats at various stages of lactation. Our results demonstrate that food restriction during the first 2 weeks of lactation did not affect PRL or ACTH secretion, but decreased plasma LH levels despite comparable GnRH receptor density between food-restricted and ad-libitum fed females. In the second experiments we investigated a possible causal relationship between the increased secretion of progesterone seen in food-restricted females and the suppression of plasma LH levels, by determining the effects of bromocryptine treatment and ovariectomy on LH secretion in both ad-libitum fed and food-restricted lactating females. LH suppression in food-restricted lactating females was not affected by ovariectomy or bromocryptine treatment, although the latter treatment significantly increased GnRH receptor number. These data suggest that factors other than ovarian steroids, PRL or increased adrenocortical activity modulate LH secretion and the length of lactational dioestrus in food-restricted lactating females.

Adrenocorticotropic Hormone↗

PubMed1990

Nest temperature: effects on maternal behavior, pup development, and interactions with handling.

These studies compared the patterns of mother-young contact under different thermal environments and assessed the implications of the differing patterns of contact for pup development and the dam's behavior. In the first experiment, the warm surface dramatically reduced the total amount of contact time between dams and litters and the dam's food intake, but the effects on the pups were limited to smaller adrenal glands. A replication of the first experiment in which daily weighing and handling of the pups was eliminated produced no differences in development. In a third experiment, during which dams had access to a warm surface outside of the next area and the daily weighing and handling was resumed, the pups showed smaller adrenal glands, lower body temperatures and less thermoregulatory ability. A comparison of results suggests that handling increased the weight of adrenal glands of pups reared under the unmanipulated condition, but not the warm-rearing condition.

Adipose Tissue, Brown↗

PubMed1989

Self-selection of protein during pregnancy and lactation in rats.

Protein self-selection was investigated in female rats throughout pregnancy and lactation. In the first experiment, impregnated rats were presented with either a choice between low and high protein (casein) diets, or standard lab chow and their protein intake was compared to that of non-impregnated controls. Impregnated females showed an increase in both absolute and relative protein intake at the end of pregnancy and during the second week of lactation when compared to both their own baseline intake and that of non-impregnated rats. In the second experiment, lactating rats and non-lactating controls were presented with a choice between low and high protein (casein) diets, a high protein (soybean meal) and a high carbohydrate diet, or lab chow. Lactating rats consumed more protein than non-lactating rats regardless of diet condition, but percentage protein intake was found to differ across diet choice conditions. Differences in diet fraction choice are discussed in terms of protein: carbohydrate ratios, and how different sources of protein might be utilized differently within the body.

Animals↗