Influence of Enovid on the Cytopathic Action of Staphylococcal Alpha Toxin

The effect of the widely employed oral contraceptive steroid, Enovid, on the cytolytic action of the staphylococcal alpha toxin was investigated as an extension of previous studies in which it was shown that steroids were capable of suppressing induced staphylococcal infection in experimental animals. The cytotoxic action of alpha toxin for tissue cultures was evaluated by use of such parameters as total and viable cell counts, glucose and protein determination, and cytopathic effects in the presence and absence of Enovid. To 3-day-old primary rabbit baby kidney tissue cultures a mixture of 20 mug of norethynodrel per ml [17alpha-ethynyl-hydroxy-5(10)-estren-3-one] and 5 mug of mestranol per ml (17-ethynelestradiol-3-methyl ether) was added; growth of tissue cultures in Eagle medium was continued till the sixth day, and then one tissue cytopathic dose of alpha toxin per ml was added and the subsequent fate of tissue cultures was assayed. Such cultures yielded higher total and viable cell counts, utilized more glucose, and contained more protein than the control cultures. In control cultures, cytopathogenicity appeared on the third day after the addition of alpha toxin, and it was complete in 24 hr, whereas in tissue cultures treated with Enovid cytopathogenicity was significantly reduced. Thus the mixture of synthetic hormones known as Enovid, in pharmacological concentrations, was found capable of reducing the cytopathic action of alpha toxin, but only to a slightly lesser degree than such natural hormone as progesterone.