RESUMO
Modulation of specific binding of prolactin to murine mammary gland as a response to treatment with various doses of estradiol benzoate (EB) was studied. Measurements of serum and pituitary levels of prolactin were also carried out simultaneously. Estradiol benzoate at a dose of 5 microgram significantly increased the binding of 125I-labelled rat prolactin (rPRL) to mammary gland concomitant with increased serum prolactin levels in ovariectomized mice. Administration of bromoergocryptine along with EB resulted in decreased serum prolactin levels as well as binding of prolactin to breast tissue. It thus appears that the influence of estradiol on binding of prolactin to mammary gland is mediated primarily via its property of enhancing serum prolactin concentration apart from its possible direct effect at the target tissue level.
Assuntos
Bromocriptina/farmacologia , Estradiol/farmacologia , Glândulas Mamárias Animais/metabolismo , Prolactina/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Castração , Relação Dose-Resposta a Droga , Feminino , Glândulas Mamárias Animais/efeitos dos fármacos , Camundongos , Hipófise/metabolismo , Receptores de Superfície Celular/efeitos dos fármacosRESUMO
Toxicological study was carried out in rats with chloroform-soluble fraction of the nuts of Semecarpus anacardium to determine its safe non-toxic dose. The fraction produced toxicity at all levels tested (50-400 mg/kg) but the extent of toxicity was found dose-dependent. At lower doses this fraction induced partial growth inhibition over 36 days and higher doses proved fatal within 6 days. It was observed that 230 mg/kg caused 50% mortality in rats and this value is 1380 mg/m2 when expressed for body surface area. This work will be of some use in the cancer chemotherapy study of the fraction.