EVIDENCE OF INDEPENDENT SECRETION OF PROLACTIN AND GROWTH HORMONE IN VITRO BY ADENOHYPOPHYSES OF RHESUS MONKEYS

Abstract

ABSTRACT The question of whether primate adenohypophyses can secrete prolactin and GH as separate entities was investigated. Explants of pituitaries of male and female rhesus monkeys were incubated in a metabolic shaker bath for up to 11 hr or in organ culture for 13 days. The medium was changed at different times during incubation and prolactin and GH levels therein were estimated by pigeon crop-sac assay and immunoassay, respectively. Male and female pituitaries secreted comparable amounts of GH in the short-term incubation experiments. In contrast, the female glands secreted much more prolactin than did the male adenohypophyses, particularly in the early incubation intervals. Addition of extract of female rat hypothalamic tissue to the medium caused significant stimulation of GH secretion in an incubation experiment and a culture study. The extract did not have a consistent effect on prolactin secretion. At some incubation times it inhibited prolactin secretion and at others it had no effect, while it ...