Impromidine-induced changes in the permeability of the blood-brain barrier of normotensive and spontaneously hypertensive rats.
Previous studies suggested histamine receptors mediate changes in the cerebrovascular permeability of rats. To test this, we investigated the effects of impromidine, a specific agonist at the histamine H2-receptor, on blood pressure and permeability of the blood-brain barrier (BBB). Impromidine produced dose-dependent hypotension in Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Two higher doses of impromidine increased BBB permeability to 99mTc-sodium pertechnetate in WKY rats; however, two lower doses decreased permeability in SHR rats. All doses of impromidine increased cerebrovascular permeability to 131I-labeled serum albumin in both species. Doses of the drug were 100 times greater than those required to produce similar alterations using histamine.
Boertje
S B
SB
Department of Biology, Southern University at New Orleans, Louisiana 70126.
Le Beau
D
D
Ward
S
S
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001812:Blood-Brain Barrier / Q000187:drug effects*; D005260:Female; D006146:Guanidines / Q000494:pharmacology*; D006635:Histamine H2 Antagonists / Q000494:pharmacology*; D007093:Imidazoles / Q000494:pharmacology*; D017446:Impromidine; D008297:Male; D010539:Permeability; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012711:Serum Albumin, Radio-Iodinated; D013670:Sodium Pertechnetate Tc 99m
D006146:Guanidines; D006635:Histamine H2 Antagonists; D007093:Imidazoles; D012711:Serum Albumin, Radio-Iodinated; D017446:Impromidine; D013670:Sodium Pertechnetate Tc 99m