Abstract: Objective To observe the effects of p38 mitogen-activated protein kinase inhibitor SB203580 on proliferation and growth hormone secretion of rat pituitary GH3 cells and explore the p38 MAPK pathway as a potential therapy target for growth homone adenoma. Methods After treated with different concentrations of SB203580 for 24, 48, 72 h, the proliferation of rat pituitary GH3 cells was determined by MTT. The apoptosis levels were measured by Annexin V/PI. And the expression of growth hormone levels in the supernatant of GH3 cells treated with increasing concentrations of SB203580 for 72 h were measured by ELISA. Results SB203580 caused significant cytotoxicity in GH3 cells with a concentration- and time-dependent manner. Treatment with SB203580 induced GH3 cells apoptosis in a concentration-dependent manner (P <0.05). In addition, the level of growth hormone was significantly decreased in the supernatant of GH3 cells after exposure to SB203580 (P <0.05). Conclusion p38 mitogen-activated protein kinase inhibitor SB203580 may inhibit the proliferation and growth hormone secretion of rat pituitary GH3 cells.

Key words: MAPK cell signal, SB203580, inhibitor, growth homone adenoma, GH3 cell line