Beneficial effects of a novel agonist of the adenosine A2A receptor on monocrotaline-induced pulmonary hypertension in rats.

BACKGROUND AND PURPOSE: Pulmonary arterial hypertension (PAH) is characterized by enhanced pulmonary vascular resistance, right ventricular hypertrophy and increased right ventricular systolic pressure. Here, we investigated the effects of a N-acylhydrazone derivative, 3,4-dimethoxyphenyl-N-methyl-benzoylhydrazide (LASSBio-1359), on monocrotaline (MCT)-induced pulmonary hypertension in rats. EXPERIMENTAL APPROACH: PAH was induced in male Wistar rats by a single i.p. injection of MCT (60 mg·kg(-1)) and 2 weeks later, oral LASSBio-1359 (50 mg·kg(-1)) or vehicle was given once daily for 14 days. Echocardiography was used to measure cardiac function and pulmonary artery dimensions, with histological assay of vascular collagen. Studies of binding to human recombinant adenosine receptors (A1, A2A, A3) and of docking with A2A receptors were also performed. KEY RESULTS: MCT administration induced changes in vascular and ventricular structure and function, characteristic of PAH. These changes were reversed by treatment with LASSBio-1359. MCT also induced endothelial dysfunction in pulmonary artery, as measured by diminished relaxation of pre-contracted arterial rings, and this dysfunction was reversed by LASSBio-1359. In pulmonary artery rings from normal Wistar rats, LASSBio-1359 induced relaxation, which was decreased by the adenosine A2A receptor antagonist, ZM 241385. In adenosine receptor binding studies, LASSBio-1359 showed most affinity for the A2A receptor and in the docking analyses, binding modes of LASSBio-1359 and the A2A receptor agonist, CGS21680, were very similar. CONCLUSION AND IMPLICATIONS: In rats with MCT-induced PAH, structural and functional changes in heart and pulmonary artery were reversed by treatment with oral LASSBio-1359, most probably through the activation of adenosine A2A receptors.

Antihypertensive profile of 2-thienyl-3,4-methylenedioxybenzoylhydrazone is mediated by activation of the A2A adenosine receptor.

Several N-acylhydrazone derivatives synthesized from safrole have been found to promote intense vasodilation and antihypertensive activity. The present work describes the synthesis and antihypertensive profile of 2-thienyl-3,4-methylenedioxybenzoylhydrazone (LASSBio-1027), a new analogue of the lead compound 3,4-methylenedioxybenzoyl-2-thienylhydrazone. Thoracic aortas from Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) were prepared for isometric tension recording. Noninvasive blood pressure measurements were made during 14 days of intraperitoneal (10 mg/kg) or oral (20 mg/kg) administration of LASSBio-1027. LASSBio-1027 exhibited partially endothelium-dependent vasorelaxant activity, which was attenuated in the presence of l-NAME, glibenclamide, or ZM 241385. LASSBio-1027 exhibited an antihypertensive effect in SHR during 14 days of intraperitoneal or oral administration, but did not induce a hypotensive effect in normotensive WKY rats. LASSBio-1027-induced vascular relaxation of aortas from WKY rats was mediated by the activation of A(2A) adenosine receptors. Docking studies and binding assays suggested that LASSBio-1027 has affinity for A(2A) and A(3) adenosine receptors. This new N-acylhydrazone derivative represents a potential strategy for the treatment of arterial hypertension.