AJP - Cell Physiology, Vol 254, Issue 4 C564-C570, Copyright © 1988 by American Physiological Society
A bioenergetic model of gossypol action: effects of gossypol on adult rat spermatogenic cells
J. Reyes, L. Borriero and D. J. Benos
Departamento de Fisiologia y Biofisica, Facultad de Medicina, Universidad de Chile, Santiago.
Rat spermatogenic cells have glycolytic rates of 124 +/- 36 nmol lactate.mg
protein-1.h-1. Maximum glycolytic rates in the absence of oxidative
phosphorylation do not exceed the basal rates by greater than 40%. From the
rates of oxygen consumption and lactate production it can be calculated
that less than 8% of the total ATP produced by spermatogenic cells is
provided by glycolysis. These properties of spermatogenic cells would
render them highly susceptible to cytotoxicity due to the action of agents
like gossypol that impair mitochondrial oxidative phosphorylation or to
conditions that produce testicular hypoxia. The main effect of gossypol on
spermatogenic cell energy metabolism is to uncouple mitochondrial oxidative
phosphorylation. In the absence of glucose, this uncoupling action of
gossypol would change the NAD+/NADH redox coupling and, consequently, could
modify metabolic fluxes through the lactic dehydrogenase catalyzed
reaction.
