Testicular atrophy, zinc concentration, and angiotensin-converting enzyme activity in the testes of vitamin A-deficient rats

Angiotensin-converting enzyme (ACE) as a part of the renin angiotensin syst em (RES) regulates blood pressure and fluid and electrolyte homeostasis, an d the enzyme is considered to have a function in reproduction. Reduced enzy me activities have been observed in atrophied testes as a results of zinc a nd pituitary deficiencies. Vitamin A deficiency causes atrophy of testes. T he present study was conducted on three groups of male, 3-wk-old, Wistar ra ts. After 54 d of the experimental period, testicular weights of the vitami n A- deficient rats (A- group, allowed free access to vitamin A- deficient diet) was significantly lower than its pair-fed, PF (given restricted amoun t control diet) and A+ (allowed free access to control diet) groups. Zinc c oncentrations and both soluble and particulate ACE activities in the testes of vitamin A- deficient rats (A- group) were significantly lower than the other two groups. No significant differences were observed regarding zinc c oncentration, particulate ACE, and total ACE activities in the testes of PF and A+ groups. Vitamin A deficiency did not significantly affect the enzym e activity in the lung. From the observations of the present study, we spec ulate that testicular atrophy in vitamin A deficiency may have resulted fro m lower zinc concentration and decreased ACE activity in that organ.