A 350619 hydrochloride

Km: 50 μM

Nitric oxide (NO) is a key mediator in many physiological processes and one of the key receptors through which NO exerts its effects is soluble guanylyl cyclase (GC). Guanylyl cyclase converts GTP to cyclic GMP that results in physiological processes such as smooth muscle relaxation, neurotransmission, platelet aggregation inhibition and immune response. A 350619 is a novel soluble guanylyl cyclase activator.

In vitro: A 350619 increased Vmax from 0.1 to 14.5 μmol/min/mg, and lowered Km from 300 to 50 μM. When A 350619 and YC-1 (another GC activator) were combined, a 156 fold increase in Vmax and a 5 fold decrease in Km were observed, indicating the modulation of the enzyme brought about by YC-1 and A 350619 are not additive, indicating a common binding site. Activation of soluble guanylyl cyclase by A 350619 was partially inhibited by ODQ, a specific inhibitor of soluble guanylyl cyclase by oxidation of the enzyme heme [1].

In vivo: Consistent with its biochemical activity, in a conscious rat model, A 350619 (1 μmol/kg) alone induced penile erection. Activation of soluble guanylyl cyclase in cavernosum tissue as an alternate method of enhancing the effect of NO may provide a novel treatment of sexual dysfunction [2].

Clinical trial: Up to now, A 350619 is still in the preclinical development stage.

Reference:
[1] Miller LN, Nakane M, Hsieh GC, Chang R, Kolasa T, Moreland RB, Brioni JD.  A 350619: a novel activator of soluble guanylyl cyclase. Life Sci. 2003 Jan 17;72(9):1015-25.

Anodal iontophoresis of a soluble guanylate cyclase stimulator induces a sustained increase in skin blood flow in rats.[Pubmed:23838678]

J Pharmacol Exp Ther. 2013 Sep;346(3):424-31.

The treatment of systemic sclerosis-related digital ulcers is challenging. Although the only effective drugs are prostacyclin analogs, their use is limited by vasodilation-related adverse reactions. In this study, we assessed the local iontophoresis administration of three soluble guanylate cyclase (A-350619 [3-[2-[(4-chlorophenyl)thiophenyl]-N-[4-(dimethylamino)butyl]-2-propenamide hydrochloride], SIN-1 [amino-3-morpholinyl-1,2,3-oxadiazolium chloride], and CFM 1571 [3-[3-(dimethylamino)propoxy]-N-(4-methoxyphenyl)-1-(phenylmethyl)-1H-pyrazole-5- carboxamide hydrochloride]) and two nonprostanoid prostaglandin I2 (prostacyclin) receptor agonists (MRE-269 [[4-[(5,6-diphenylpyrazinyl)(1-methylethyl)amino]butoxy]-acetic acid] and BMY 45778 [[3-(4,5-diphenyl[2,4'-bioxazol]-5'-yl)phenoxy]acetic acid]) to induce vasodilation onto the hindquarters of anesthetized rats. Skin blood flow was quantified using laser Doppler imaging during the whole experience, and safety was assessed by continuous recording of blood pressure and histopathological examination. Anodal iontophoresis of A-350619 (7.54 mM) induced a sustained increase in cutaneous blood flow (P = 0.008 vs. control). All other drugs exhibited poor or no effect on skin blood flow. Vasodilation with A-350619 iontophoresis was concentration-dependent (7.5, 0.75, and 0.075 mM; P < 0.001, Jonckheere-Terpstra trend test), and repeated administrations do not suggest any risk of tolerance. This study also compared continuous versus intermittent iontophoresis protocols. Continuous anodal iontophoresis of A-350619 at 7.5 mM increases cutaneous blood flow with good local tolerance. Iontophoresis of soluble guanylate cyclase stimulators should be investigated as potential local therapy for digital ulceration in patients with scleroderma.

NO-independent stimulators and activators of soluble guanylate cyclase: discovery and therapeutic potential.[Pubmed:16955067]

Nat Rev Drug Discov. 2006 Sep;5(9):755-68.

Soluble guanylate cyclase (sGC) is a key signal-transduction enzyme activated by nitric oxide (NO). Impaired bioavailability and/or responsiveness to endogenous NO has been implicated in the pathogenesis of cardiovascular and other diseases. Current therapies that involve the use of organic nitrates and other NO donors have limitations, including non-specific interactions of NO with various biomolecules, lack of response and the development of tolerance following prolonged administration. Compounds that activate sGC in an NO-independent manner might therefore provide considerable therapeutic advantages. Here we review the discovery, biochemistry, pharmacology and clinical potential of haem-dependent sGC stimulators (including YC-1, BAY 41-2272, BAY 41-8543, CFM-1571 and A-350619) and haem-independent sGC activators (including BAY 58-2667 and HMR-1766).

A-350619: a novel activator of soluble guanylyl cyclase.[Pubmed:12495780]

Life Sci. 2003 Jan 17;72(9):1015-25.

Nitric oxide (NO) is a key mediator in many physiological processes and one of the major receptors through which NO exerts its effects is soluble guanylyl cyclase. Guanylyl cyclase converts GTP to cyclic GMP as part of the cascade that results in physiological processes such as smooth muscle relaxation, neurotransmission, inhibition of platelet aggregation and immune response. The properties of A-350619, a novel soluble guanylyl cyclase activator, were examined to determine the modulatory effect on the catalytic properties of soluble guanylyl cyclase. A-350619 increased V(max) from 0.1 to 14.5 micromol/min/mg (145 fold increase), and lowered K(m) from 300 to 50 microM (6 fold decrease). When YC-1 (another sGC activator) and A-350619 were combined, a 156 fold increase in V(max) and a 5 fold decrease in Km were observed, indicating that the modulation of the enzyme brought about by YC-1 and A-350619 are not additive, suggesting a common binding site. Activation of soluble guanylyl cyclase by A-350619 was partially inhibited by ODQ, a specific inhibitor of soluble guanylyl cyclase by oxidation of the enzyme heme. YC-1 and A-350619 after pre-treatment with N-omega-nitro-L-arginine, an NO-synthase inhibitor, relaxed cavernosum tissue strips in a dose-dependent manner with EC(50) of 50 microM and 80 microM, respectively. Addition of SNP potentiated the relaxation effect of YC-1 and A-350619, shifting the dose-response curve to the left to 3 microM and 10 microM, respectively. Consistent with its biochemical activity, A-350619 (1 micromol/kg) alone induced penile erection in a conscious rat model. Activation of soluble guanylyl cyclase in cavernosum tissue as an alternate method of enhancing the effect of NO may provide a novel treatment of sexual dysfunction.