Effects of Noradrenaline and Felypressin on Cutaneous Local Blood Flow After Sympathetic Denervation: A Study on Rats

The effect of two vasoconstrictors, nor-adrenaline and felypressin (Octapressin®, Sandoz), on the elimination rate of a radioactive indicator 133Xe was studied in rat skin where two areas, the scalp and the back, were compared. After denervation of the scalp skin by means of bilateral excision of the cervical ganglia the sensitivity to noradrenaline was increased, whereas no change in sensitivity to felypressin was shown. The alpha-receptor blocking drug, phentolamine (Regitine®, Ciba), could partly counteract the catecholamine effect, but did not influence the effect of felypressin. This indicates different sites of action for the two vasoconstrictors. It also indicates that felypressin is to prefer as a vasoconstrictor adjunct in denervated tissues.