Department of Pharmacology, Pharmacy Faculty, Cukurova University, Adana, Turkey.
Department of Pharmacology, Medical Faculty, Cukurova University, Adana, Turkey.
Nitric Oxide. 2019 Apr 1;85:54-60. doi: 10.1016/j.niox.2019.02.001. Epub 2019 Feb 13.
Rho-kinase activity is a key regulator in the maintenance of corporal vasoconstriction and penile detumescense. Also, importance of l-cysteine/HS pathway in erectile tissue has been shown; however it is currently unknown the role RhoA/Rho-kinase pathway in HS-induced inhibition in cavernosal tissue. We investigated the role of RhoA/Rho-kinase pathway in the inhibitory effect of l-cysteine and NaHS, as endogenous and exogenous HS, respectively, on phenylephrine-induced contractions of mouse cavernosal strips. Phenylephrine, α receptor agonist, (10 nM-100 μM) induced a concentration-dependent contraction in CC. l-cysteine (endogenous HS substrate; 10 mM) and exogenous HS (NaHS; 1 mM) significantly inhibited the contractile response to phenylephrine (P < 0.05). Inhibition of CSE and CBS enzymes by PAG (10 mM) and AOAA (1 mM), respectively, significantly reversed the inhibitory effects of l-cysteine on phenylephrine-induced contraction (P < 0.05). Y-27632 (1 μM), a specific Rho-kinase inhibitor, significantly augmented the inhibitory effect of l-cysteine and NaHS on phenylephrine-induced contraction, and this inhibition was reversed by PAG and AOAA (P < 0.05). In addition, the formation of HS was increased by approximately 1.8 fold over basal values after incubation of tissue homogenates with l-cysteine. Y-27632 significantly increased both basal and l-cysteine-induced HS formation and this augmentation diminished by PAG and AOAA (P < 0.05). Furthermore, the pMYPT-1 expression was significantly decreased by l-cysteine, NaHS or Y-27632 alone. Also, pMYPT-1 expression was completely abolished by the l-cysteine/NaHS plus Y-27632 combination, and this inhibition was reversed by PAG and AOAA (P < 0.05). These results suggest that there is an interaction between Rho-kinase and HS pathways. Rho-kinase may be, at least in part, inhibits CSE/CBS enzymes in mouse corpus cavernosal tissue; however, it is not excluded the other kinases such as PKC and Zip-kinase.
Rho-kinase 活性是维持 corporal vasoconstriction 和 penile detumescense 的关键调节剂。此外，已经证明 l-cysteine/HS 途径在勃起组织中的重要性；然而，目前尚不清楚 RhoA/Rho-kinase 途径在 HS 诱导的 cavernosal 组织抑制中的作用。我们研究了 RhoA/Rho-kinase 途径在 l-cysteine 和 NaHS（分别为内源性和外源性 HS）对小鼠 cavernosal 条带中苯肾上腺素诱导收缩的抑制作用中的作用。苯肾上腺素，α 受体激动剂（10 nM-100 μM）引起 CC 浓度依赖性收缩。l-cysteine（内源性 HS 底物；10 mM）和外源性 HS（NaHS；1 mM）显著抑制了对苯肾上腺素的收缩反应（P<0.05）。分别用 PAG（10 mM）和 AOAA（1 mM）抑制 CSE 和 CBS 酶，显著逆转了 l-cysteine 对苯肾上腺素诱导收缩的抑制作用（P<0.05）。特异性 Rho-kinase 抑制剂 Y-27632（1 μM）显著增强了 l-cysteine 和 NaHS 对苯肾上腺素诱导收缩的抑制作用，并且这种抑制作用被 PAG 和 AOAA 逆转（P<0.05）。此外，组织匀浆孵育后，HS 的形成增加了约 1.8 倍基础值。Y-27632 显著增加了基础值和 l-cysteine 诱导的 HS 形成，并且这种增加被 PAG 和 AOAA 减少（P<0.05）。此外，l-cysteine、NaHS 或 Y-27632 单独作用可显著降低 pMYPT-1 表达。此外，l-cysteine/NaHS 与 Y-27632 的组合完全消除了 pMYPT-1 的表达，并且这种抑制作用被 PAG 和 AOAA 逆转（P<0.05）。这些结果表明 Rho-kinase 和 HS 途径之间存在相互作用。Rho-kinase 可能至少部分抑制了小鼠 cavernosal 组织中的 CSE/CBS 酶；然而，不能排除其他激酶，如 PKC 和 Zip-kinase。
