Cadmium effects on rat testicular lipids and fatty acids

ZANETTI, S. R.; AVELDAÑO, M. I.

Mar del Plata

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Investigación en Bioqu-imic ay Biología Molecular; 2007

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

CADMIUM EFFECTS ON RAT TESTICULAR LIPIDS AND FATTY ACIDS Zanetti SR and Aveldaño MI INIBIBB, CONICET-UNS, 8000 Bahía Blanca, Argentina. The molecular mechanisms by which cadmium, a ubiquitous environmental contaminant, damages major organs in mammals are largely unknown. At high doses (≥ 5 mg/kg) CdCl2 induces testicular damage in rodents. Necrosis is evident in 48 hours, followed by interstitial edema, hemorrhage, and changes in the seminiferous tubules affecting spermatogenesis. Here we surveyed the effects on rat testis of repeated s. c. doses (1mg/kg) of CdCl2 (one every 4 days) administered for a month. The effects on lipids were studied at the end of this month and 2 weeks later, most suggesting irreversibility. In treated animals the testicular weight decreased to one-third, and the testicular lipid phosphorus to one-fifth, that of controls. Although all fatty acids decreased, 22:5n-6 was reduced the most. Its percentage diminished 4-fold (20% to 5% of the acyl chains) in the greatly decreased glycerophospholipids (GPL). Neutral glycerides including triacyl and diacylglycerols decreased much less than GPL. Cholesterol esters increased more than 4-fold, probably to temporarily store part of the fatty acids originally composing germ cell membrane GPL. The amounts of testicular sphingomyelin decreased, and a concomitant production of ceramide (Cer) resulted. Unexpectedly, this Cer remained in the testis 2 weeks after having finished Cd administration, suggesting a Cd-induced inhibition of Cer metabolism or transport. This possibility is worth investigating among the factors determining Cd toxicity in the testis and possibly also in other organs.