Isolation of canine prolactin by polyacrylamide gel electrophoresis.

The electrophoretic mobility of prolactin obtained from canine pituitary extract was studied with the aid of polyacrylamide disc electrophoresis. Using a preparative gel electrophoretic system the immunoreactive material was purified on a quantitative scale which was then used to develop a homologous radioimmunoassay for canine prolactin. The radioimmunoassay system was able to detect prolactin in the plasma of dogs after the administration of agents which would be expected to affect prolactin secretion.

Oestradiol stimulation of prolactin release from canine pituitary in culture.

Anterior canine pituitaries were maintained in tissue culture for 8 days, and the immunoreactive prolactin released, was measured by a heterologous radioimmunoassay for canine prolactin. Luteinizing hormone-releasing hormone (LH-RH) and thyrotrophic hormone-releasing hormone (TRH) did not affect prolactin release, while theophylline and oestradiol-17 beta stimulated the release of canine prolactin.

Effect of luteinizing hormone releasing hormone on plasma levels of luteinizing hormone, oestradiol and testosterone in the male dog.

An injection of luteinizing hormone releasing hormone (LH-RH) increased plasma LH and testosterone concentrations in the male dog, but no significant increase in plasma oestradiol-17beta levels was observed. Repeated injections of LH-RH produced an increase in plasma LH levels but there was a progressive decline in the response with each injection. The concentration of plasma testosterone reached a maximum within 40 min of the first injection of LH-RH and remained constant thereafter while plasma oestradiol concentration gradually increased with successive injections of LH-RH.

Inhibition by oestradiol of the pituitary response to luteinizing hormone releasing hormone in the dog.

Intravenous injections of synthetic LH-RH stimulated LH secretion in male dogs. Pretreatment with 50 mug oestradiol-17beta, 60 or 165 min but not 15 min before LH-RH, inhibited LH secretion. Injection of 0.

The effect of chlorpromazine on the secretion of immunoreactive beta-MSH and prolactin in man.

The effect of chlorpromazine (50 mg. im) on the plasma concentration of immunoreactive beta-melanocyte-stimulating hormone (beta-MSH) and prolactin was studied in 8 hospitalized subjects with non-endocrine skin disorders. Plasma beta-MSH concentrations remained unchanged over a period of 7 h in 6 subjects.