THE MECHANISM OF THE FALL OF BLOOD PRESSURE AT LATE PREGNANCY IN EXPERIMENTALLY HYPERTENSIVE RATS : Experimental Study on the Blood Pressure of Pregnant Hypertensive Rats

Abstract

The mechanism of the fall of blood pressure during pregnancy in experimentally hypertensive rats was studied in this report. 1. Fetal ablation carried out on the 16th day of pregnancy without damage to the placenta interfered with the fall of blood pressure in hypertensive rats with renal infarction. 2. Intraperitoneal transplantation of new born kidney, liver, spleen or placenta as cell suspension or parenteral injection of placental homogenate to renal hypertensive rats was per-formed and the changes of blood pressure by these procedures were studied. In these studies, only new born kidney transplantation led to a definite fall of blood pressure. Histologically the viable epithelial cells of new born kidney assumed a tubular structure or irregular cluster in the peritoneal granule or lymphnode. 3. Judging from these data, the fetus kidneys may play an important role in the fall of blood pressure at late pregnancy in experimentally and spontaneously hypertensive rats, that is, the fetus kidney may secrete some antihypertensive substances which can lower the blood pressure of pregnant hypertensive rat.