[Effect of estradiol and a series of other endocrine factors on the angiotensinogen level in rat blood plasma].

The effects of estradiol (E2) and some other endocrine factors on rat plasma angiotensinogen (AG) have been studied. AG was determined by RIA. Both single and multiple injections of E2 to female rats were shown to cause a dose-dependent increase in AG in the blood. The effect of E2 was inhibited by cycloheximide. Multiple injections of E2 to male rats caused the same hepatic AG synthesis induction as those to female rats. Unlike E2, long-term treatment with large doses of testosterone propionate did not affect AG synthesis. AG levels in blood plasma of ovariectomized and immature female rats did not differ from those seen in mature intact rats. However, immature females were insensitive to the stimulant effect of the pharmacological doses of E2. Drastic reduction in hepatocyte sensitivity of the stimulant effect of E2 was seen in hypophysectomized female rats as well. Treatment of hypophysectomized animals with human GH, which did not affect AG levels per se, caused an almost complete recovery of hepatocyte ability to react by increasing AG synthesis in response to E2 injection. The possible role of different hormonal and genetic hepatotrophic factors in hepatocyte reactivity to the stimulant effect of E2 on AG synthesis is discussed.