Impact of aging on the secretion of insulin-like growth factor-1 in the corpus cavernosum smooth muscle cells of rats in vitro

Objective: To observe the secretion of insulin-like growth factor-1(IGF-1) in corpus cavernosum smooth muscle cells(CCSMCs) in rats of different ages and explore the possible relationship of IGF-1 with aging-related erectile dysfunction(ED).Methods: We primarily cultured CCSMCs of rats aged 4,12 and 24 months,and identified them by immunohistochemistry.We quantitatively cultured the CCSMCs in 6-well culture plates,determined the levels of IGF-1 secreted from the CCSMCs by enzyme immunoassay(EIA) and analyzed the effect of age on the IGF-1 level.Results: CCSMCs were successfully cultured in vitro.The level of IGF-1 secreted from the CCSMCs was decreased with the increase of age,with 7.1 ng/105 cells in the 4-month-old group,2.2 ng/105 cells in the 12-month group,and 1.9 ng/105 cells in the 24-month group,with statistically significant differences among the three groups(P0.01).Conclusion: The secretion of IGF-1 is reduced with the increase of age,and the decreased expression of IGF-1 might be associated with aging-related ED.