EFFECTS OF BASIC FIBROBLASTIC GROWTH-FACTOR ON THE FUNCTION AND PROLIFERATION OF HUMAN CLINICALLY NONFUNCTIONAL PITUITARY-ADENOMAS WHICH SECRETED GLYCOPROTEIN HORMONES IN-VITRO

The effects of human recombinant basic fibroblastic growth factor (bFG F) on the secretion, viability, proliferation, attachment and morpholo gy of ten dispersed human clinically non-functional (NF) adenomas were examined in vitro. Four clinically NF adenomas secreting FSH and/or L H in vitro were unaffected by 10 nM bFGF over a 4-h period. Over 4 day s 10 nM bFGF stimulated LH secretion (66% and 72%, P<0.01) from two ou t of seven clinically NF adenomas secreting LH, whilst FSH (three tumo urs) and alpha-subunit secretion (three tumours) were unaffected. One adenoma co-secreting LH and alpha-subunit and one secreting LH alone w ere studied over 21 days; LH secretion fell progressively, but the dec line was significantly less (P<0.05) with bFGF (10 nM) treatment after 14 and 21 days in both adenomas, whilst the fall in a-subunit secreti on was unaffected by bFGF treatment. A 24-h GnRH test performed at the start and end of the 21-day period in one of these tumours showed an increase in both basal and stimulated LH secretion in the bFGF-treated group over control (124%, P<0.001). There was no effect of bFGF (10 n M) on viability, S-phase proliferation, attachment or morphology of ad enoma cells over a 4-day period. These results suggest that bFGF has a role in tumorous LH secretion from these adenomas, but is not mitogen ic (at least over 4 days) and is without effect on other parameters of in vitro differentiated function.