Effects of repeated exposure of cadmium on testicular lipids with long- and very long-chain polyunsaturated fatty acids¡±

ZANETTI SR; AVELDAÑO MI

Mar del Plata

Congreso; XLIII Reunión Anual de SAIB; 2007

The molecular mechanisms by which cadmium, a ubiquitous environmental contaminant, damages major organs in mammals are largely unknown. At high doses (¡Ý 5 mg/kg) CdCl2 induces testicular damage in rodents. Necrosis is evident in 2 days, followed by interstitial edema, hemorrhage, and germ cell degeneration. Here we surveyed the effects on rat testis of repeated sc 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. All fatty acids decreased, but 22:5n-6 was the most affected, its percentage falling 4-fold in the decreased glycerophospholipids (GPL) (20% to 5% of the acyl chains). Neutral glycerides including triacyl and diacylglycerols decreased, but less than GPL. Cholesterol esters accumulated, in part storing temporarily fatty acids originally composing germ cell GPL. Sphingomyelin decreased, and a concomitant accumulation of ceramide (Cer) resulted. Unexpectedly, this Cer remained unchanged 2 weeks after finishing treatment, 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.