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Renin substrate in plasma of unanaesthetized pregnant ewes and their foetal lambs.
Author(s) -
Carver J G,
Mott J C
Publication year - 1978
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1978.sp012242
Subject(s) - substrate (aquarium) , plasma renin activity , medicine , endocrinology , gestation , fetus , renin–angiotensin system , chemistry , pregnancy , biology , blood pressure , ecology , genetics
1. In unanaesthetized preparations 6‐14 days after catheterization, the concentration of renin substrate (AI 212 +/‐ 20 ng/ml. S.E. of mean) in the plasma of foetal lambs during the last third of gestation was significantly less than that of paired samples of maternal plasma (AI 350 +/‐ 27 ng/ml.). 2. During the first 5 days following catheterization the concentration of renin substrate in maternal plasma was lower than subsequently but was raised if the uterus contained a nephrectomized foetus. 3. The concentration of renin substrate in the plasma of intact foetal lambs without nephrectomized twins varied little in the post‐catheterization period and later; the concentration of substrate in nephrectomized foetal lambs averaged threefold that of intact lambs and a similar concentration of substrate was found in intact twins of such lambs in the immediate post‐catheterization period. 4. It is suggested that the ratio of foetal/maternal plasma renin activity understates their relative enzyme activity since foetal substrate concentration is so considerably less than maternal.