Xiao-Ping Yang and Shigetoshi Chiba*
Department of Pharmacology, Shinshu University School of Medicine, Matsumoto 390 - 8621, Japan
* To whom correspondence should be addressed.
Abstract: The present study demonstrated the progressive inhibition by prolonged cold storage (4, 7 and 14 days at 4) on prejunctional and postjunctional functions of purinergic and adrenergic components of double-peaked vasoconstrictor responses to periarterial electrical nerve stimulation in the isolated canine splenic artery. After the cold storage for 4 days, the first phase constriction was markedly decreased, whereas the second response was not significantly modified. Furthermore, after the 7 days of cold storage, the first phase was substantially depressed at low frequencies, but at high frequencies, a low level of contractile responses was still observed. On the other hand, the second phase in the cold stored artery for 7 days largely remained at any used frequencies. Moreover, the 14 days of cold storage almost completely inhibited the vasoconstrictor responses to nerve stimulation. Tyramine-induced constrictions were progressively decreased in the stored-days dependent manner, although the ATP and the noradrenaline-induced one was not modified for 4 and 7 days of the cold storage. In conclusion, 1) the 4 cold stored artery for 4 days may show preferential injury of its tyramine-dependent noradrenaline releasing mechanisms, whereas nerve excited ones might well remain; and 2) the prejunctional contractile response of purinergic transmission might be damaged more preferentially than that of adrenergic transmission within 7 days storage.
Keywords: Cold storage, Tyramine, Sympathetic nerve stimulation, Purinergic transmission, Splenic artery