Effect of i.v. prostaglandin E2 on the secretion of pituitary hormones in healthy men.

The intravenous administration of prostaglandin E2 (PGE2) has been proposed as a diagnostic tool in the differentiation of hypothalamic and pituitary forms of growth hormone deficiency. We have therefore studied the effect of PGE2 (200 micrograms i.v.) on serum concentrations of GH, LH, FSH, PRL, TSH, and cortisol in six healthy, male subjects. Side-effects, reported as highly unpleasant, occurred within two minutes after i.v. PGE2 in each individual. The individual response in serum concentrations of GH and LH following PGE2 was variable. Thus, a stimulatory effect was seen in some, but not in all individuals. Concentrations of FSH, PRL, and TSH did not change after PGE2-challenge, but a transient rise in serum cortisol was observed (p less than 0.01). The release of GH and LH upon i.v. PGE2 may be part of a systemic reaction or be due to a direct action of PGE2 on the anterior pituitary. The inhomogeneity of the obtained results and the unpleasant side-effects of i.v. PGE2 disqualify its use for the evaluation of pituitary GH-releasing capacity.