Effects Of Estrogen On The Expression Of Ryanodine Receptor Type 1 And Cav1.3 L-type Calcium Channel In The Vaginal Smooth Muscle Cells Of Rats

Abstract: Objective: To determine the expression of ryanodine receptor type 1(RyR1) and Cav1.3 L-type calcium channel(Cav1.3) in the vaginal smooth muscle cells of castrated rats and investigate the correlation between RyR1,Cav1.3 and estrogen in female sexual dysfunction. Methods: 40 SD female rats of 8 weeks were randomly devided into sham-operated 2 weeks group(group A), sham-operated 4 weeks group (group B), castrated 2 weeks group(group C), castrated 4 weeks group(group D) respectively. To determine the serum estradiol level in automated immunochemiluminescence system and investigate the expression of RyR1 and Cav1.3 in vaginal smooth muscle of rats by immunohistochemistry staining and RT-PCR 2 and 4 weeks after operation respectively. Gray scale ratio represents expression amount of RyR1 mRNA and Cav1.3 mRNA . Optical density value denotes protein expression amount of RyR1 and Cav1.3. Results: The serum estradiol in group C[(8. 17±0. 72)ng/dl] significantly decreased as compared with group A[ (13.76±1. 43)ng/dl](P＜0.01), group D[( 3. 54±0. 85)ng/dl] significantly decreased as compared with group B[(12. 94±1. 58)ng/dl ](P＜0.01). RyR1 and Cav1.3 express in all groups. RyR1 mRNA in group C(0.68±0.073) significantly decreased as compared with group A(0.95±0.064)(P＜0.01), group D(0.22±0.032) significantly decreased as compared with group B(0.89±0.072)(P±0.01). Cav1.3 mRNA in group C(0.58±0.043) significantly decreased as compared with group A(0.87±0.019)(P＜0.01), group D(0.19±0.020) significantly decreased as compared with group B(0.82±0.021)(P＜0.01). RyR1 protein in group C(96.67±7.75) was significantly decreased as compared with group A(123.69±10.66)(P＜0.01), group D(86.45±8.16) significantly decreased as compared with group B(109.31±9.87)(P＜0.01). Cav1.3 protein in group C(87.97±6.96) was significantly decreased as compared with group A(106.46±8.04)(P＜0.01), group D(69.43±8.30) significantly decreased as compared with group B(97.38±7.56)(P＜0.01). Conclusion: RyR1 and Cav1. 3 express in the vaginal smooth muscle cells of rats. Estrogen might mediate the female sexual reaction through RyR1 and Cav1.3 in the vaginal smooth muscle of rats.