Efficient lipid elimination from sertoli cells after apoptotic death of spermatogenic cells

AYUZA ARESTI PL; ORESTI GM; FURLAND NE; FERRARIS M; AVELDAÑO MI

Mar del Plata

Congreso; XLIII Reunión Nacional de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB); 2007

Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB)

Testicular exposure to X-rays and to temperatures higher than 38ºC induces apoptosis of spermatogenic cells, compromising fertility. The former mostly affects mitotically dividing spermatogonia and the latter non-dividing spermatocytes and spermatids, both sparing Sertoli cells. In this study we surveyed the in vivo effects on rat testicular lipids and their fatty acids several weeks after having locally irradiated (6.5 Gy) or heated (15 min, 43ºC) the testis. In both cases Sertoli cells behaved as competent phagocytes, efficiently processing and disposing of materials formerly composing germ cells, including cholesterol and phospholipids. Germ-cell related 22:5n-6-rich glycerophospholipids and species of sphingomyelin and ceramide with 28:4n-6 and 30:5n-6 were cleared from the testis in a few weeks. In the process, neutral glycerides and cholesterol esters (CE) temporarily increased, accumulating more 22:5n-6 than other fatty acids. The buildup of CE reached a maximum and eventually decreased. The described changes including complete clearing of CE occurred earlier after hyperthermia than after irradiation, a slow but significant re-population of the testis with germ cells ensuing. The results suggest that only when Sertoli cells have processed and got rid of all materials derived from germ cell corpses they are ready to resume support of a new round of spermatogenesis.