Relaxant effect of a metal-based drug in human corpora cavernosa and its mechanism of action

• Published in: International journal of impotence research Vol. 28; no. 1; pp. 20 - 24
• Main Authors: Leitão Junior, A S, Campos, R M, Cerqueira, J B G, Fonteles, M C, Santos, C F, de Nucci, G, Sousa, E H S, Lopes, L G F, Gonzaga-Silva, L F, Nascimento, N R F
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.01.2016; Nature Publishing Group
• Subjects: 13/95; 631/154/436; 692/699/2732/515; Cyclic GMP - physiology; Drug therapy; Endothelium; Ethics; Experiments; Guanylate Cyclase - physiology; Health aspects; Humans; Impotence; Male; Medicine; Medicine & Public Health; Muscle relaxants; Muscle Relaxation - drug effects; Muscle Relaxation - physiology; Muscle, Smooth - drug effects; Muscle, Smooth - physiology; Nitric oxide; Nitric Oxide - metabolism; Nitric Oxide Donors - pharmacology; Nitroprusside - pharmacology; original-article; Penile Erection - drug effects; Penile Erection - physiology; Penis - pathology; Penis - physiology; Penis - physiopathology; Pharmacology, Experimental; Physiological aspects; Potassium; Receptors, Cytoplasmic and Nuclear - physiology; Reproductive Medicine; Research Design; rology; Ruthenium; Ruthenium Compounds - pharmacology; Smooth muscle; Soluble Guanylyl Cyclase; Urology; Brazil
• ISSN: 0955-9930; 1476-5489
• DOI: 10.1038/ijir.2015.27

We studied the mechanisms involved in the human corpora cavernosa (HCC) relaxation induced by a new metal-based nitric oxide (NO) donor, the ruthenium complex cis-[Ru(bpy) 2 Imn(NO)] +3 (FOR0811). FOR0811 produced relaxation in phenylephrine (PE)-precontracted HCC with a maximal response that achieved 112.9±10.6%. There was no difference between the maximal relaxation induced by FOR0811 when compared with sodium nitroprusside (SNP) (106.8±7.3%), BAY41-2272 (107.6±4.1%) or vardenafil (103.4±3.8%), however, FOR0811 was less potent than SNP and vardenafil. L-N G -nitroarginine methyl ester (L-NAME), a NO synthase inhibitor, had no effect in the concentration–response curve elicited by FOR0811. 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a heme-site inhibitor of soluble guanylyl cyclase (sGC) was able to either block or reverse the relaxation induced by FOR0811. On the other hand, the relaxation induced by FOR0811 was not affected by glibenclamide, a blocker of ATP-sensitive potassium channels. FOR0811 (10 μM) was able to increase cyclic guanosine monophosphate (cGMP) levels in corpora cavernosa strips. FOR0811 completely relaxes HCC by a sGC-cGMP-dependent mechanism and can be a lead compound in the development of new stable NO donors.