Seven cases with uremia (6 men, 1 woman, mean age = 55.6 +/- 2.2 years) were studied with four combined hypothalamic releasing hormones (corticotropin-releasing hormone, CRH; luteinizing hormone-releasing hormone, LHRH; thyrotropin-releasing hormone, TRH; and growth hormone-releasing hormone, GHRH) for assessment of anterior pituitary functions. The mean basal levels of corticotropin (ACTH, 22.4 +/- 5.2 pg/ml), thyrotropin (TSH, 2.4 +/- 0.6 microU/ml), and follicle stimulating hormone (FSH, 26.0 +/- 3.4 mIU/ml) in uremic patients were not significantly different from those (34.0 +/- 3.5 pg/ml, 2.0 +/- 0.4 microU/ml, and 23.2 +/- 6.4 mIU/ml) of controls (5 men, 1 woman, mean age = 54 +/- 2.5 years), but the ACTH and TSH responses to the releasing hormones were significantly lower than those of the controls. The mean basal levels of luteinizing hormone (LH, 70.7 +/- 16.3 mIU/ml), cortisol (9.8 +/- 1.2 micrograms/dl) and prolactin (109.3 +/- 23.2 ng/ml) in uremic patients were significantly higher than those of normals (27.3 +/- 6.6 mIU/ml, 6.5 +/- 0.7 micrograms/dl and 15.7 +/- 3.4 ng/ml), while suppressed LH, cortisol and prolactin responses to the releasing hormones were observed in the uremic group. The mean basal growth hormone (GH) level in uremic patients (3.1 +/- 0.4 ng/ml) was not significantly different from that (2.8 +/- 0.7 ng/ml) of normals, but the GH response to the releasing hormones was significantly higher than that of controls. These results show pituitary dysfunction, such as blunted ACTH, TSH, LH and prolactin response, exists in uremic patients.(ABSTRACT TRUNCATED AT 250 WORDS)