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
E-mail: hclin@vghtpe.gov.tw
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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