TY - JOUR
T1 - The pressor response to angiotensin II
T2 - The roles of peripheral and cardiac responses in pregnant and nonpregnant sheep
AU - Naden, Raymond P.
AU - Grant, Norman F.
AU - Rosenfeld, Charles R.
N1 - Funding Information:
From the Departments ofObstetrics and Gynecology and Pediatrics, Southwestern Medical School. Supported in part by National Institutes of Health Grant No. HD08783. Presented in part at the Thirtieth Annual Meeting of the Societyfor Gynecologic Investigation, Washington, D. C., March 17-20, 1983. Reprint requests: Charles R. Rosenfeld, M.D., Department of Pediatrics, 5323 Harry Hines Boulevard, Dallas, Texas 75235. *Fellow in Maternal-Fetal Medicine.
PY - 1984/2/15
Y1 - 1984/2/15
N2 - A reduced pressor response to infused angiotensin II has been observed in pregnancy. Although this has been considered to reflect reduced sensitivity of the peripheral vasculature to angiotensin II, it has also been suggested that the reduced pressor response is due to a fall in cardiac output during infusion of angiotensin II in pregnancy. In the present study we investigated the hemodynamic responses to infused angiotensin II in chronically instrumented, pregnant and nonpregnant sheep. We measured changes in cardiac output and systemic vascular resistance and related these changes to the increase in mean arterial pressure. The response in systemic vascular resistance to angiotensin II was substantially reduced in pregnant sheep. During angiotensin II infusion cardiac output fell in both groups, but the effect of the fall in cardiac output in reducing the pressor response was greater in nonpregnant animals. Thus, it appears that the reduced pressor response to angiotensin II in pregnant sheep is due to reduced systemic vascular responsiveness and not to differences in cardiac output responses.
AB - A reduced pressor response to infused angiotensin II has been observed in pregnancy. Although this has been considered to reflect reduced sensitivity of the peripheral vasculature to angiotensin II, it has also been suggested that the reduced pressor response is due to a fall in cardiac output during infusion of angiotensin II in pregnancy. In the present study we investigated the hemodynamic responses to infused angiotensin II in chronically instrumented, pregnant and nonpregnant sheep. We measured changes in cardiac output and systemic vascular resistance and related these changes to the increase in mean arterial pressure. The response in systemic vascular resistance to angiotensin II was substantially reduced in pregnant sheep. During angiotensin II infusion cardiac output fell in both groups, but the effect of the fall in cardiac output in reducing the pressor response was greater in nonpregnant animals. Thus, it appears that the reduced pressor response to angiotensin II in pregnant sheep is due to reduced systemic vascular responsiveness and not to differences in cardiac output responses.
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U2 - 10.1016/0002-9378(84)90725-7
DO - 10.1016/0002-9378(84)90725-7
M3 - Article
C2 - 6696002
AN - SCOPUS:0021362919
SN - 0002-9378
VL - 148
SP - 450
EP - 457
JO - American journal of obstetrics and gynecology
JF - American journal of obstetrics and gynecology
IS - 4
ER -