J Clin Endocrinol Metab. 1977 Jan;44(1):69-77. doi: 10.1210/jcem-44-1-69.

The effect of posture and saline loading on plasma renin activity and aldosterone concentration in pregnant, non-pregnant and estrogen-treated women.

The Journal of clinical endocrinology and metabolism

M H Weinberger, N J Kramer, C E Grim, L P Petersen

PMID: 833263 DOI: 10.1210/jcem-44-1-69

Abstract

The effect of contraceptive ingestion and pregnancy on components of the renin-angiotensin-aldosterone system was compared in 17 non-pregnant women, 8 non-pregnant women taking oral contraceptives, and 11 pregnant women. Plasma renin substrate concentrations and the dynamic responses of plasma renin activity and aldosterone concentrations to upright posture and iv saline infusion were evaluated. Renin substrate was significantly higher in those women taking oral contraceptives and among the pregnant subjects than the other non-pregnant group. No significant differences in plasma renin activity or aldosterone concentrations were seen before or after postural stimulation among the 2 non-pregnant groups. After saline loading renin was higher and aldosterone lower in the contraceptive-treated group. In contrast, the pregnant group had significantly higher values at every point. The response to posture and saline among the pregnant subjects was similar in direction and magnitude to those of the non-pregnant groups. The urinary excretion of sodium before and after saline infusion was significantly lower in the pregnant group than in the non-pregnant groups. These observations suggest that estrogen-induced increases in renin substrate do not alone account for the increases in the renin-angiotensin-aldosterone system observed during pregnancy, but rather such increases appear to represent a physiological response to increased sodium need during pregnancy.

Keywords: Biology; Cardiovascular Effects; Clinical Research; Contraception; Contraceptive Methods--side effects; Family Planning; Homeostasis; Oral Contraceptives, Combined; Oral Contraceptives--side effects; Physiology; Pregnancy--side effects; Renin-angiotensin-aldosterone Effects; Reproduction; Research Methodology

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Substances

• Contraceptives, Oral
• Contraceptives, Oral, Synthetic
• Angiotensin II
• Sodium Chloride
• Aldosterone
• Sodium
• Renin
• Potassium

MeSH terms

• Adolescent
• Adult
• Aldosterone / blood
• Angiotensin II
• Contraceptives, Oral / pharmacology
• Contraceptives, Oral, Synthetic / pharmacology
• Female
• Humans
• Natriuresis / drug effects
• Posture*
• Potassium / urine
• Pregnancy
• Renin / blood
• Sodium / urine
• Sodium Chloride / pharmacology

Publication Types

• Journal Article
• Research Support, U.S. Gov't, P.H.S.

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