Lethal effects of the combination of hyperthermia and bromocriptine or a somatostatin analogue on normal pituitary cells and pituitary tumour cells

Effects of hyperthermia alone and combined with bromocriptine (BC) or a somatostatin analogue (SMS 201-995) were studied in vitro on normal pituitary and pituitary tumour cells (GH3 cells). GH3 cells were more sensitive to heat than normal pituitary cells and a maximal difference in survival was obtained with hyperthermia at 42.5 degrees C for 6 h. BC had cytotoxic and antiproliferative effects on GH3 cells, whereas SMS 201-995 was not effective. Hyperthermia at 42.5 degrees C for 3 h in combination with BC enhanced selective cytotoxicity for GH3 cells. In contrast, combined treatment with hyperthermia and SMS 201-995 failed to enhance cytotoxicity for GH3 cells. The combination of hyperthermia and BC could provide improved therapeutic efficacy in patients with pituitary adenomas.