The expression and correlation of intermediate conductance calcium-activated potassium channels in cavernous tissue of spontaneously hypertensive rats

Abstract

Objective Intermediate conductance calcium-activated potassium channels (IKCa),one of the key material of the endothelium-derived hyperpolarizing factor (EDHF) passway.To detect the expression of IKCa and explore hypertension impact IKCa expression in cavernous tissue of spontaneously hypertensive rats.Methods Male spontaneously hypertensive rats (SHR) (n =20) and normotensive Wistar Kyoto rats (WKY,n =10) were studied,Systolic blood pressure (SBP) was measured by noninvasive blood pressure instrument and erectile function was tested by injecting with apomorphine (APO),the rats were divided into 3 groups,namely hypertensive with erectile dysfunction (HBP-ED)group (n =13),hypertensive (HBP) group (n =7) and control group (n =10).The expression of IKCa gene mRNA and protein was assessed by Western blotting and reverse transcription-polymerase chain reaction (RT-PCR).Results Versus the WKY group,SHR group showed a higher systolic blood pressure [(202.43 ±9.89)vs.(127.21 ± 3.48) mmHg (1 mmHg =0.133 k Pa),P ＜ 0.01].The expressions of IKCa protein and mRNA were the highest in the control group and the lowest in HBP-ED group.Conclusion The erectile function of penis is impacted seriously by hypertension,which may be related to the decreased expression of IKCa in cavernous tissue of spontaneously hypertensive rats. Key words: Hypertension ; Penis erection ; Corpus cavernosum; Intermediate conductance calcium-activated potassium channels