Potentiating effect of methysergide on norepinephrine-induced constriction of the isolated internal carotid artery of the dog.

Abstract

Abstract-The stainless steel cannula inserting method was used to examine the effects of methysergide on 5-hydroxytryptamine (5-HT) and norepinephrine induced vasoconstriction in the isolated internal carotid artery of the dog. 5-HT, at a dose of 0.3 /cg, induced a marked increase in perfusion pressure, usually over 100 mm Hg. On the other hand, norepinephrine produced a relatively small increase in perfusion pressure (20-40 mm Hg) at a large dose of 10 /cg. Methysergide inhibited 5-HT-induced vasconstriction.

Vascular Responses of Isolated, Perfused Canine Femoral Arteries and Veins to Vasoactive Substances

“…The femoral arteries and veins selected for study were 1.0-3.5 cm in length and 1.0-2.7 mm in outer diameter. A stainless steel cannula (1.0 2.65 mm in outer diameter for arteries or 1.8 3.5 mm in outer diameter for veins and each of 3 cm length) with small holes at a 2-5 mm distance from the distal sealed end was carefully inserted into each vessel segment to avoid injury of the intraluminal surface of the isolated vessel as reported before (1,2). They were perfused with Krebs' solution at 37'C, which was gassed with 95%02 and 5% CO2.…”

Blocking Effects of OPC-21268 and OPC-31260 (Vasopressin V1- and V2-Receptor Antagonists) on Vasopressin-Induced Constrictions in Isolated, Perfused Dog Femoral Arteries

“…The perfusion pressure was continuously measured with an electric manometer. The details of the cannula inserting method were de scribed in previous papers (7,8) When NE was administered into the cannulated fem oral artery of the dog, the vasoconstrictor response was readily induced in a dose-related manner as reported previously (8). VP also induced a dose-related vasocon striction.…”

Pharmacological features of vascular responses of isolated rat common carotid arteries to vasroactive substances revealed by the cannula insering method.

“…A stainless steel cannula with small holes 2 mm from the distal sealed end (0.6 to 0.8 mm in outer diameter and 3 cm in length) was carefully inserted into each vessel segment to avoid injury of the intraluminal surface of the isolated vessel. Segments were set up in the bath for preparation as described by Tsuji and Chiba (1984). The perfusion solution contained (mmole/ liter) : NaCI 118, KCl 4.7, CaC12 2.5, NaHCO3 25, MgSO4 1.2, KH2PO4 1.2 and glucose 11; and bubbled with 95% 02 and 5% CO2 which maintained the pH of the solution 7.2-7.4.…”

“…In 1983, Hongo and Chiba developed a new perfusion technique for isolated vessels, and Tsuji and Chiba (1984) modified it as a steel cannula inserting method. Using this method, vascular responsiveness to a number of vasoactive substances has been investigated, because vessel preparations perfused by use of the cannula inserting method readily give an adequate perfusion pressure, and maintain a stable perfusion pressure during the experiment for a long time at a constant temperature of 3TC.…”