Doxazosin blockade of α 1-adrenergic receptors increases rat serum progesterone levels: a putative role of ovarian angiotensin III in steroidogenesis

Abstract

To analyze the role of the local renin-angiotensin system (RAS) in the female reproductive system to modulate ovarian steroidogenesis and its relationship with alpha(1)adrenergic receptors. Observational study. University laboratory. Adult female Wistar rats treated with doxazosin (10 mg/kg) or vehicle for 15 days. Samples from the whole right ovary were dissected after perfusion with saline. The soluble and membrane-bound fractions were obtained from these samples. Also, blood samples were used to obtain the serum. Fluorometric measurement of soluble and membrane-bound RAS-regulating proteolytic regulatory enzyme activities by using arylamide derivatives as substrates. Time-resolved fluoroimmunoassay of serum E(2) and P. alpha(1)Adrenergic receptor blockade increases ovarian soluble and membrane-bound aminopeptidase A and decreases membrane-bound aminopeptidase N and aminopeptidase B. Furthermore, serum P levels increased, whereas serum E(2) did not change. Ovarian P production, at least in the rat, is regulated by noradrenaline through a mechanism of action in which the RAS is involved, with a main role for angiotensin III.