Action of (1-des(aspartic acid), 8-isoleucine) angiotensin II upon the pressor and steroidogenic activity of angiotensin II.
The vascular and steroidogenic responses to (1-Sarcosine, 8-Isoleucine)-, and to (1-Des (Aspartic acid), 8-Isoleucine) angiotensin II were compared in bilaterally nephrectomized, ACTH-suppressed dogs receiving constant infusions of angiotensin II. Aldosterone secretion rate was significantly inhibited by pretreatment with 200 ng/Kg/min of the heptapeptide, (1-Des(Aspartic acid), 8-Isoleucine) ang II, but not by similar doses of the octapeptide, (1-Sarcosine, 8-Isoleucine) ang II. In contrast, the pressor action of ang II was unaffected by (1-Des (Aspartic acid), 8-Isoleucine) ang II though significant inhibition occurred with relatively small doses of (1-Sarcosine, 8-Isoleucine) ang II. This study suggests that: (a) angiotensin receptors in adrenal cortex and vascular smooth muscle are functionally different, and (b) (1-Des(Aspartic acid),8-Isoleucine) angiotensin II is a specific antagonist of steroidogenic effect of ang II.
D000302:Adrenal Cortex / Q000378:metabolism; D000450:Aldosterone / Q000378:metabolism*; D000804:Angiotensin II / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D000818:Animals; D001224:Aspartic Acid; D001665:Binding Sites; D001794:Blood Pressure; D004285:Dogs; D007532:Isoleucine; D008297:Male
D007532:Isoleucine; D000804:Angiotensin II; D001224:Aspartic Acid; D000450:Aldosterone