• The Korean Journal of Pharmacology
• /
• v.23 no.1
• /
• pp.15-23
• /
• 1987

To elucidate the mechanism of splanchnic hyperemia associated with chronic portal hypertension, we have investigated the alteration in visceral reflexes in conjuction with circulatory hemodynamics in portal ligated portal hypertension in cats. When capsaicin, bradykinin and vasopressin were injected via splenic artery of sham cat, respectively, they caused not only reflex excitation of systemic arterial pressure, but also elevation of splenic venous pressure with unchanged heart rates. Simultaneously, they evoked the sympathetic efferent excitation of liver (spleno-hepatic reflex) as well as of spleen (spleno-splenic reflex). Similarly, capsaicin upon pledging on the liver surface evoked a significant increase in the pressor reflex with hepatic nerve excitation (hepato-hepatic reflex). After portal ligation, the splenic venous pressure was gradually elevated in association with decrease in systemic arterial pressure. However, the excitation of pressor reflex was enhanced on the and day, thereafter, being returned to the control, and the reflexly induced spleno-splenic, spleno-hepatic and hepato-hepatic sympathetic excitations were significantly diminished on the 8th day following portal vein ligation. In conclusion, it is suggested that sympathetic reflexes to spleen and liver are specifically intervened by the same central pathways and furthermore, the diminution of these viscero-visceral reflex excitations after portal ligation may be related to the intestinal hyperemia.