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Biomedical subjects

R L Pike

Publications and source records attributed to R L Pike.

At least 19 recordsLinked to original sources
PubMed1978

Progressive gross changes in renal medullary composition in pregnant rats.

The biochemical composition of the renal medulla and the blood pressures of pregnant rats and nonpregnant controls were compared on days 15, 18, 20, and 22 of pregnancy. Deoxyribonucleic acid and protein content of the renal medulla changed together with the tissue weight (wet weight) during gestation except on day 20 when a slight increase in protein was observed. However, the glycerophospholipids (phosphatidyl ethanolamine, phosphatidyl choline, and phosphatidyl serine) and sphingomyelin showed significant increases throughout the latter stages of pregnancy with the maxima in most cases occurring on day 20 of the gestation period. Medullary hypertrophy and increased lipid content per cell coexist with the decrease in blood pressure and may indicate peak activity in production of antihypertensive renal lipids.

Animals↗
PubMed1976

Soidum requirement of the rat during pregnancy.

The sodium requirement for the pregnant rat was established on the basis of a series of studies in which the following parameters were investigated on varying levels of soidum intake: sodium retention, plasma and tissue sodium concentrations, hematocrit, juxtaglomerular index (JGI), zona glomerulosa (ZG) width, ultrastructure of the ZG cell, and aldosterone-producing capacity of the ZG cell. The recommended level of 26 mEq sodium/100 g diet was identified as the level of intake that permitted the pregnant rat to achieve the homeostatic adjustment to sodium need with as little apparent stress on the JGI and ZG as in nonpregnant rats; as a criterion, we used thepoint in the continuum of physiological adjustment where the first recognizable changes in cellular morphology could be identified. These data, along with addtional data on blood pressure and renal medullary lipid concentration, indicate that during pregnancy a chronology of events occurs which suggests a working model for the maintenance of sodium homeostasis and blood pressure regulation.

Adrenal Cortex↗