Jpn. J. Pharmacol. 85 (2), 183-188 (2001)

Hemodynamic Effects of Synephrine Treatment in Portal Hypertensive Rats

Yi-Tsau Huang1, Han-Chieh Lin2,*, Yuan-Yi Chang1, Ying-Ying Yang2, Shou-Dong Lee2 and Chuang-Ye Hong1

1Institute of Traditional Medicine, National Yang-Ming University, Taipei, Taiwan
2Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, and School of Medicine, National Yang-Ming University; 201, Section 2, Shih-Pai Road, Taipei 11217, Taiwan
*Corresponding author. FAX: +886-2-2873 9318

Abstract: Synephrine, a sympathomimetic a1-adrenoceptor agonist, has been shown to induce dose-dependent portal hypotensive effects after acute intravenous infusion. The present study was undertaken to investigate the hemodynamic effects of 8-day administration of synephrine in portal hypertensive rats. Portal hypertension was induced by either partial portal vein ligation (PVL) or bile duct ligation (BDL). Portal hypertensive rats were allocated into one of two groups: vehicle group (0.1 N HCl, 0.5 ml/12 h) or synephrine group (1 mg/kg per 12 h), with 7 rats in each group. Synephrine or vehicle was administered by gavage into PVL and BDL rats for 8 consecutive days. Systemic as well as splanchnic hemodynamic parameters were measured thereafter. Synephrine significantly ameliorated the hyperdynamic state in both PVL and BDL rats. The portal venous pressure in PVL and BDL rats (-13.5% and -10.1%, respectively), portal tributary blood flow (-19.5% and -20.4%) and cardiac SUP (-12.1% and -18.8%) were significantly reduced, while mean arterial pressure (10.4% and 23.4%) and systemic (26.3% and 51.0%) as well as portal territory (47.1% and 67.7%) vascular resistance were enhanced by treatment of synephrine as compared with vehicle treatment. Our results showed that eight-day administration of synephrine exerted beneficial hemodynamic effects in two models of portal hypertensive rats.

Keywords: Portal hypertension, Hemodynamics, Synephrine, Radioactive microsphere method

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