Abstract
Sixty women were given intravenous injection of 200 μg TRH to assess its diagnostic potential as a stimulus to PRL release. Following the administration of TRH, there was a prompt increase in serum PRL to 614.6%, to 296%, to 282.1 %, and 34% in normal women, amenorrheic patients, non tumoral galactorrhea cases, and patients with pituitary tumors respectively. The TRH response above baseline of PRL levels was statistically significant in all groups, but the women with pituitary tumors which showed a blunted response. The per cent of increment of PRL levels after TRH was similar in amenorrheic women regardless the presence or not of galactorrhea; this increase was significantly greater than in patients with pituitary tumors (p < 0.01). The per cent of increment above baseline of PRL was significantly greater in menstruating women than in amenorrheic patients (p < 0.001). In basis of present data: 1) there is a diminished PRL secretion after TRH in amenorrheic women regardless the presence of galactorrhea or hyperprolactinemia; 2) a blunted response to TRH in hyperprolactinemic women may be indicative of a pituitary tumor.