Effects of hyperthermia on rat seminiferous tubule cell lipids and polyunsaturated fatty acids

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

Rosario, Argentina

Congreso; XLII Reunión Nacional de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB); 2006

Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB)

Previous work showed that cryptorchidism selectively damages testicular germ cells at specific stages and rapidly results in an important depletion of testicular germ cells. The aim of this study was to examine the long-term effects of short (15 min) periods of relative hyperthermia (43ºC) applied once a day on seminiferous tubule lipid composition and labeling with [3H]arachidonic acid. After 5 days of this treatment, a progressive decrease in testicular weight and germ cell depletion started, most of the tubules showing a selective decrease of spermatocytes and spermatids. Three weeks later, practically no germ cells remained in the tubules, which consisted mainly of Sertoli cells and spermatogonia. This involution was accompanied by a loss of 22:5n-6-rich glycerophospholipids (GPL), those remaining being instead relatively richer in 20:4n-6. When [3H]20:4n-6 was used as a marker, control seminiferous tubules incorporated similar amounts in the major GPL as in the relatively minor triglycerides (TG). The esterification of [3H]20:4 into GPL per unit weight was as active in control as in germ cell depleted seminiferous tubules, but the latter showed a marked reduction in TG labeling.  This difference points to an important role of TG in the metabolism and distribution of PUFA among lipids of cell populations within the seminiferous tubule.