Argmine Vasopressin in Hypertensive Human Pregnancy

Abstract

Plasma concentrations of arginine vasopressin (P_AVP) and its renal tubular effects were determined in 33 normotensive primigravidae, 20 primigravidae with pregnancy-associated hypertension (P-AH) and 20 subjects with chronic, presumably essential hypertension (CH). PAVP' plasma osmolality (Poan), urine osmolality and urine volume were not significantly different amongst groups but the plasma volutie (P_vap) was contracted (p < 0.001) in those with P-AH. There was no apparent relationship between P^vp and diastolic blood pressure, proteinuria or P_VCL, but P_AVP and Posm were significantly correlated in normotensive subjects (r = 0.52, p < 0.01) and in those with P-AH (r = 0.54, p lt; 0.05). In a separate study, there was no difference in P_AVP measured under conditions of normal hydration during the second trimester, between eight primigravidae who developed P-AH in the third trimester and 48 who remained normotensive throughout pregnancy. These results demonstrate that there is no change in the plasma concentration of, or renal tubular sensitivity to, AVP in either P-AH or CH, and it is unlikely that this hormone plays a role in the development or maintenance of the hypertensive disorders of pregnancy.