Dietary Fat Influences Testosterone, Cholesterol, Aminopeptidase A, and Blood Pressure in Male Rats

Abstract

A high intake of monounsaturated fat (MUFA) has been proposed to be a dietary factor able to decrease the incidence of cardiovascular disease and hypertension [1]. It has been shown that an increase in the saturation of dietary fat results in increased concentrations of total plasma cholesterol [2] and higher blood pressure [3]. It was previously shown that serum total cholesterol levels were higher in mice fed diets containing saturated oils than in those consuming unsaturated fat. In addition, angiotensin II-degrading (aminopeptidase A) activity increased progressively with the degree of saturation of dietary fatty acids [4]. A subsequent study found that dietary fatty acid composition affected aminopeptidase A activity in the testes of mice, suggesting a role for fatty acids in male reproductive functions, including androgen synthesis [5]. It was recently observed that a diet enriched with Iberian pig lard remarkably increased serum testosterone levels in comparison to diets containing other types of fatty acids with different degrees of saturation [6]. This and other studies suggested an influence of gonadal steroids and cholesterol on angiotensin-degrading activities [7]. Other actions of gonadal steroids by nongenomic-dependent mechanisms have been reported, such as stimulation of insulin secretion and Ca2+ uptake as well as vasodilatory effects [8] [9]. In the present report we analyze the effect of various diets enriched in fatty acids with different degrees of saturation on systolic blood pressure, plasma levels of testosterone, total cholesterol, HDL cholesterol, LDL cholesterol, and angiotensin II-degrading activity.