Effects of alpha 1-adrenoceptor blocker prazosin on microcirculation in terminal rabbit ileum.
The influence of the specific alpha 1-blocker prazosin on the microcirculation of the terminal ileum was examined in 10 rabbits. For this purpose an isotope clearance test was carried out by administering 133-Xenon solution into the intestinal wall before and after the intra-arterial injection of prazosin (1.0 mg) via the superior mesenteric artery. These experiments were supplemented by haemodynamic and thermographic measurements in a further group of 5 rabbits. Due to the systemic circulatory effect of prazosin, i.e. the drug-induced hypotension, the bowel segment exhibited, contrary to expectations, significantly delayed values for isotope elimination indicating a reduced local tissue clearance and blood supply. Thermographic observations also confirmed the impairment of mesenteric blood flow after prazosin. Therapeutic applicability of alpha 1-adrenoceptor blockers to treat intestinal circulatory disturbances in diseases of vascular genesis thus remains dubious.
Lehmann
C
C
Department of Surgery, Humboldt University, Berlin, GDR.
Lewerenz
A
A
Kreyer
I
I
Luther
B
B
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D005260:Female; D007082:Ileum / Q000098:blood supply*; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D011224:Prazosin / Q000494:pharmacology*; D011817:Rabbits; D013152:Splanchnic Circulation / Q000187:drug effects; D013817:Thermography; D014980:Xenon Radioisotopes
D000317:Adrenergic alpha-Antagonists; D014980:Xenon Radioisotopes; D011224:Prazosin