Effects of dopamine on pial arteriolar diameter and CSF prostanoid levels in piglets.
We examined effects of topically applied dopamine on pial arteriolar diameter and CSF prostanoid levels in newborn pigs. Vascular responses were determined using the closed cranial window technique and intravital microscopy, and prostanoids were determined by radioimmunoassay. Topical application of dopamine did not change arteriolar diameter at 10(-7)-10(-5) M, but constricted arterioles at 10(-4) (16%) and 10(-3) M (30%). Intravenous administration of indomethacin (5 mg/kg) did not alter this constriction. In addition, CSF prostanoid levels did not increase in response to application of dopamine except for a modest increase of prostaglandin E2 at 10(-3) M. We conclude that dopamine is a constrictor at high doses of piglet pial arterioles and that this response is not modified by endogenous prostanoids.
Busija
D W
DW
Department of Physiology and Biophysics, University of Tennessee, Memphis 38163.
Leffler
C W
CW
D015121:6-Ketoprostaglandin F1 alpha / Q000134:cerebrospinal fluid*; D000818:Animals; D001160:Arterioles / Q000033:anatomy & histology / Q000187:drug effects; D015237:Dinoprost / Q000134:cerebrospinal fluid*; D015232:Dinoprostone / Q000134:cerebrospinal fluid*; D004298:Dopamine / Q000494:pharmacology*; D005260:Female; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D010841:Pia Mater / Q000098:blood supply*; D013552:Swine
D015121:6-Ketoprostaglandin F1 alpha; D015237:Dinoprost; D015232:Dinoprostone; D004298:Dopamine; D007213:Indomethacin