EFFECT OF COLD-STORAGE IN UNIVERSITY-OF-WISCONSIN SOLUTION ON THE RESPONSES OF PORCINE HEPATIC ARTERIES TO 5-HYDROXYTRYPTAMINE AND BRADYKININ IN-VITRO

1 Responses to 5-hydroxytryptamine (5-HT), bradykinin and sodium nitro prusside (SNP) were examined in hepatic arteries of the pig 1 h after dissection (fresh) and following 24 h storage in either Ca2+-free Kreb s solution or the cryopreservative University of Wisconsin (UW) soluti on. 2 In fresh arteries contracted to approximately 40% of the maximum response to potassium with U46619, a thromboxane A(2)-mimetic, concen tration-response curves to 5-HT (10(-10)-10(-5) M) were biphasic, with relaxation at low concentrations (<10(-8) M) and contraction at high concentrations. Bradykinin (10(-10)-10(-7) M) produced concentration-d ependent relaxation of precontracted fresh arteries with no apparent c onstrictor response. 3 Following 24 h storage in Ca2+-free Krebs solut ion, relaxation responses to 5-HT and the sensitivity of the arteries to bradykinin were significantly reduced. Storage in UW solution did n ot affect relaxation responses to either 5-HT or bradykinin. Relaxatio n responses to SNP (10(-8)-10(-3) M) were unaffected by storage in eit her solution. 4 Treatment of fresh arteries with N-G-nitro-L-arginine (L-NOARG, 10(-4) M) significantly attenuated the relaxation response t o 5-HT and displaced the bradykinin concentration-response curve four fold to the right with no affect on its maximum relaxation. 5 From the se results it is concluded that endothelial cell function is better pr eserved during cold storage in UW solution than in Ca2+-free Krebs sol ution.