INVOLVEMENT OF POLYAMINES IN THE CONTRAGESTATIONAL EFFECT OF HYPERTHERMIA

Although hyperthermia produces teratogenic effects in a great variety of animal species, the molecular mechanisms by which hyperthermia exer ts its action remain unknown. We have studied the implications of poly amines in contragestational hyperthermia in rats. Our results show tha t the contragestational action of hyperthermia when applied in consecu tive periods during days 8, 9 and 10 of rat pregnancy could be complet ely prevented by the previous administration of polyamines (putrescine and spermidine, 0.6 mmoles/kg and 0.03 mmoles/kg respectively) in com bination with the diamine oxidase inhibitor aminoguanidine or by this inhibitor alone (0.12 mmoles/kg). The administration of polyamines alo ne partially prevented the fetotoxic effect of hyperthermia but produc ed a marked mortality (50%) in the pregnant rats. These findings suppo rt a major and complex role of polyamines in the mechanisms of hyperth ermia-mediated teratogenesis, and suggest that the oxidative catabolis m of polyamines could be in part responsible of the deleterious effect produced by hyperthermia in rat pregnancy.