The in Vitro and in Vivo Effects of Dimethyl Sulfoxide on the Pituitary Secretion of Growth Hormone and Prolactin in Mice

Anterior pituitaries from primiparous lactating C3H/He mice cultured in the medium containing 0.1% dimethyl sulfoxide (DMSO) for 48 hours and pituitaries from lactating mice given subcutaneous injections of 0.05 ml DMSO twice daily for two days and once on the morning of the third day were used in the studies of the in vitro and the in vivo effects of DMSO, respectively. Phosphate buffer saline was used in the control. Synthesis and release of growth hormone and prolactin were estimated by the incorporation of [14C]leucine into each hormone during three hours' incubation of the pituitaries pre-exposed to DMSO or PBS. The values in the medium represented released hormone and sum of the values in the medium and the pituitary represented the synthesized hormone. DMSO stimulated synthesis of GH and synthesis and release of prolactin in vitro. Meanwhile, in the vivo study, synthesis of GH and prolactin were lower in the DMSO-injected mice than in the control. The results suggest that the effects of DMSO on the pituitary secretion of GH and prolactin are adverse in vitro and in vivo. In vivo exposure of pituitary to DMSO resulted in the suppression of lactation.