EFFECT OF TIlE PROSTAGLANDIN SYNTHESIS IN- HIBITORS INDOMETHACIN AND EICOSA-5,8,1l,14- TETRAYNOIC ACID ON ADRENERGIC RESPONSES IN DOG CUTANEOUS VASCULATURE”2

din synthesis inimibitors indomethacin and eicosa-5, 8, 11, 14-tetraynoic acid on adrenergic responses in dog cutaneous vasculature. J. Pharmacol. Exp. Ther. 187: 315-323, 1973. The present study was carried out to determine time effect of the prostaglandin synthesis inhibitors indomethacin and eicosa-5, 8, 1 1, 14-tetraynoic acid on adrenergic responses in the dog paw perfused at constant blood flow. Low-dose intra-arterial infusions of indomethacin, 3 X 10-#{176}M, and eicosa-5, 8, 1 1, 14-tetraynoic acid, 1.5 to 3 X 10 M, into the paw had no significant effect on responses to iiorepinephrine injected intra-arterially or adrenergic nerve stimulation. Highmer dose infusions of indomethacin, 6x 10 M, and eicosa-5,8, 11, 14-tetraynoie acid, 3 to 6 x 10 M, were effective in potentiating time responses to both norepinephmrine and adrenergic nerve stinmulation. There was also a tendency for vasconstriction to occur in the paw after administration of time inhibitors as reflected by a gradual increase in perfusion pressure during the course of these experi-ments. Time adrenergic potentiating effect is not attributable to a blockade of adrenergic uptake by the prostaglandin synthesis inhibitors since in time concentrations enmploye