The effects of maternal deprivation and of refeeding on the blood pressure of infant rats.

Blood pressure regulation was explored in infant rats 12-14 days of age during the 30-40% changes in cardiac rate that accompany nutrient (maternal) deprivation and refeeding at this age. Using specially modified tail cuff and intraarterial cannulation techniques, blood pressure was found to be maintained at stable levels (65-75 mm Hg) throughout these marked changes in pumping rate. The results suggest that adrenergic vasoconstrictor tone is controlled reciprocally with heart rate during a complex cardiovascular response to changes in nutrient levels at this early age. The possible role of such a mechanism in the development of "spontaneous" hypertension is discussed.