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Ovarian hormones in man: their effects on resting vascular tone, angiotensin converting enzyme activity and angiotensin II‐induced vasoconstriction
Author(s) -
Lee Alison F. C.,
McFarlane Lesley C.,
Struthers Allan D.
Publication year - 2000
Publication title -
british journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.216
H-Index - 146
eISSN - 1365-2125
pISSN - 0306-5251
DOI - 10.1046/j.1365-2125.2000.00227.x
Subject(s) - angiotensin ii , vasoconstriction , medicine , endocrinology , vasodilation , angiotensin converting enzyme , renin–angiotensin system , medroxyprogesterone , hormone , blood pressure , medroxyprogesterone acetate
AimsOestrogens in women have been shown to cause vasodilation which may reflect alterations in the activity of vascular angiotensin converting enzyme (ACE) and/or sensitivity to angiotensin II. The aim of this study was to assess the effect of ovarian hormones on vascular tone, vascular ACE activity and vasoconstriction to angiotensin II in males.MethodsEight volunteers were randomised in a crossover design to oestradiol, medroxy‐progesterone, and placebo. Vasoconstriction to angiotensin I and angiotensin II was assessed by forearm plethysmography.ResultsAlthough baseline forearm flow was increased with oestradiol, suggesting generalized vasodilation, there were no changes in the vasoconstrictor responses to angiotensin I or angiotensin II. Medroxy‐progesterone affected neither baseline flow nor vasoconstrictor responses. The results expressed as percentage reduction in flow (mean ± s.d.) were: angiotensin I 48 pmol ml −1 : placebo −48 ± 14%; oestradiol −42 ± 16%; medroxyprogesterone −43 ± 8% and for angiotensin II 16 pmol ml −1 : placebo −42 ± 10%; oestradiol −39 ± 11%; medroxyprogesterone −46 ± 13%.ConclusionsAcute administration of oestradiol caused vasodilation in males, the effect was not due to alterations in vascular ACE activity or to altered sensitivity to angiotensin II.