Abstract
ATP is released from blood vessels during periods of hypoxia and may be responsible for hepatic arterial vasodilatation during instances of reduced hepatic portal venous flow. The role of adenosine in ATP-induced vasodilator and vasoconstrictor responses of the hepatic arterial and portal venous vascular networks respectively was studied in the isolated dual-perfused rabbit liver in vitro to ascertain whether ATP could be catabolised to adenosine during transit through the hepatic parenchyma. Intra-arterial and intra-portal injections of ATP (−10 to −4 log mol/100 g liver) resulted in dose-dependent vasodilatation in the hepatic artery and vasoconstriction in the portal vein. Addition of 8-phenyltheophylline (10 μM), a non-selective P 1-purinoceptor antagonist, to the hepatic arterial and portal venous perfusate significantly inhibited the hepatic arterial ED 50 for responses to intra-arterial injected ATP from −8.70±0.22 to −7.63±0.28 log mol/100 g liver ( P<0.001); it also inhibited hepatic arterial responses to, mid-range, portal venous injections of ATP. The data suggest that the hepatic arterial vasodilatation to ATP is partly mediated via catabolism to adenosine and may be an important mechanism during periods of relative hepatic hypoxia associated with portal flow reduction.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.