[Calcitonin gene-related peptide induces phenotypic transformation of corpus cavernosum smooth muscle cells in diabetic rats with erectile dysfunction].

OBJECTIVE: To explore the effect of the calcitonin gene related peptide (CGRP) on the phenotypic transformation of corpus cavernosum smooth muscle cells (CCSM) in diabetic rats with erectile dysfunction (ED).
METHODS: Models of diabetes and diabetic ED were established in male Sprague-Dawley rats by administration of streptozotocin, and CCSMs were primarily cultured and subjected to immunocytochemical assay. The cells were divided into a diabetic ED and a normal control group, and exposed to 0, 10, 60 and 100 nmol/L of CGRP for 24 hours. Then the relative expressions of calponin 1 (Cnn1) and osteopontin (OPN) mRNA were determined by real-time fluorescence quantitative RT-PCR (qRT-PCR).
RESULTS: The rate of SMalpha-actin positive cells in the CCSMs was (95.94 +/- 0.03) %. The expression of Cnn1 mRNA was significantly lower while that of OPN mRNA remarkably higher in the diabetic ED rats (4.41 +/- 0.29 and 5.28 +/- 0.32) than in the normal controls (10.35 +/- 0.62 and 1.32 +/- 0.24) (P < 0.01). Exposure to 100 nmol/L of CGRP significantly upregulated the expression of Cnn1 mRNA and downregulated that of OPN mRNA as compared with the unexposed rats (6.9 +/- 0.22 vs 4.41 +/- 0.29 and 3.26 +/- 0.31 vs 5.28 +/- 0.32, P < 0.01).
CONCLUSION: CGRP can transform the phenotype of CCSMs in diabetic ED rats from contractile to synthetic type.