Cytocidal effects of bromocriptine, somatostatin analog, and heat on growth hormone-secreting pituitary adenoma in vitro.

The effects of bromocriptine (BC), a somatostatin analog (SMS), and heat on the secretion of growth hormone (GH) and prolactin (PRL), and on the morphologic features of human GH-secreting pituitary adenoma were studied in vitro. The treatment with BC, SMS, or heat (41.5 degrees C and 42.5 degrees C) markedly suppressed the secretion of GH and PRL from the adenoma cells and reduced the number of cells immunoreactive with GH or PRL. The combined treatment with BC and heat induced a marked reduction in the number of GH and PRL cells consistent with the effect on the secretion of GH and PRL. These results suggest that BC, SMS, and heat treatments produced the cytotoxic effects on pituitary adenoma cells, and that the simultaneous treatment of BC and heat enhanced this effect.