Effect of i.v. Prostaglandin E₂ on the Secretion of Pituitary Hormones in Healthy Men

Summary

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 μg 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 < 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.