Expression and function of ryanodine receptors in rabbit penile corpus cavernosum smooth muscle cells

This study aimed to investigate the expression and function of ryanodine receptors (RyRs) in rabbit penile corpus cavernosum smooth muscle (CCSM) cells. New Zealand white rabbit CCSM cells were cultured by primary tissue culture and identified by immunofluorescence technique. mRNA of three RyRs subunits in cultured CCSM cells was detected by reverse transcription polymerase chain reaction (RT-PCR). After excitation by noradrenaline, the concentration of Ca(2+) in CCSM cells was detected by laser scanning confocal microscopy. It was found that only the RyRs1 subunit is expressed in CCSM by RT-PCR. The CCSM cells were divided into two groups: Group A, CCSM cells + 10 micromol l(-1) noradrenaline and Group B, CCSM cells + 50 micromol l(-1) procaine 10 micromol l(-1) noradrenaline. Compared with the base level and the level after noradrenaline excitation, fluorescence intensity improved 44.10 +/- 6.01% in the test group A (n = 8) and 32.92 +/- 4.92% (n = 8) in the procaine control group B, respectively. There were statistically significant differences between group A and group B (P < 0.01). It is concluded that RyRs1 subunit is expressed in CCSM cells and may contribute to regulating the cytoplasmic Ca(2+) level.