Stimulation of aldosterone by ACTH in normal and hypertensive pregnancy

Abstract

The observation that plasma renin (PRC) is suppressed to a greater degree than aldosterone (Paldo) concentration in preeclampsia has led us to examine the role of nonangiotensin factors in the control of aldosterone release in pregnancy. The aim of this study was to determine whether the aldosterone response to adrenocorticotrophic hormone (ACTH) was altered in normal or preeclamptic pregnancy. After 4 days of a 100 mmol/day sodium diet, serum cortisol, PRC, and Paldo were measured every 20 min during an incremental low-dose ACTH infusion (over 80 min) in 10 nonpregnant, nine normal pregnant, and nine preeclamptic women. Baseline PRC, Paldo, and cortisol were significantly higher in normal pregnant than in nonpregnant women (P < .05), but serum ACTH concentration was similar. Following ACTH infusion there was significant stimulation of cortisol in both groups (P < .001) and the maximum rise (963[824,1163] nmol/L, median [interquartile range]) was greater in pregnant than in nonpregnant women (507[402,837]), P < .01. Plasma aldosterone also rose significantly following ACTH in both groups (P < .01) and the maximum rise was also greater in normal pregnant (1186[828,2609] fmol/mL) than nonpregnant women (874[598,1065]), P = .05. These changes were not related to basal cortisol or aldosterone concentrations in either group. Baseline PRC was significantly lower in preeclamptic than in normal pregnant women (P < .05) but Paldo, serum ACTH, and cortisol concentrations did not differ significantly. Following ACTH there was significant stimulation of cortisol in both groups (P < .0001) and the maximum increment in preeclamptic women following ACTH infusion (807[708,1007] nmol/L) was similar to that of normal pregnant women.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma renin activity and aldosterone serum concentration are decreased in severe preeclampsia but not in the HELLP‐syndrome

“…Our results confirm that there is a significant decrease in plasma renin activity and aldosterone serum concentrations in patients with severe preeclampsia. This has been reported repeatedly in earlier studies (11)(12)(13). There may be many reasons for a diminished activation of RAAS in hypertensive pregnancy.…”

The Renin-Aldosterone Response to Stimulation and Suppression During Normal Pregnancy

“…During the posture study, the cortisol decrease is likely a consequence of its diurnal fall over the morning; however, the levels were still higher during pregnancy than postpartum at comparable time points. Aldo is stimulated by ACTH (25,37), albeit a secondary influence compared to AngII and potassium regulation. The increased cortisol levels we observed during pregnancy, although in part due to increased level of cortisol binding globulin characteristic of pregnancy, likely also reflect increased unbound cortisol.…”

The Renin-Aldosterone Response to Stimulation and Suppression During Normal Pregnancy

“…The dissociation suggests that either pregnancy confers greater sensitivity of the adrenal aldosterone response to changes in PRA (mediated by angiotensin II) or factors other than the RAAS hormones contribute to aldosterone secretion in pregnancy. Factors that have been implicated in affecting aldosterone release outside of pregnancy include potassium (18,19), catecholamines (20)(21)(22)(23)(24), adrenocorticotrophic hormone [ACTH; (25)], and digitalis-like factor [DLF; (26)(27)(28)]. Dopamine may also play a role in the modulation of aldosterone levels, independently of angiotensin II (AngII) and potassium (29).…”