title: Influence of the heme-oxygenase pathway on cerebrocortical blood flow.
abstract: Heme-oxygenase (HO)-derived carbon monoxide (CO) is generated in the cardiovascular and in the central nervous systems. Endogenous CO exerts direct vascular effects and has also been shown to inhibit nitric oxide synthase (NOS). In the current study, the heme-oxygenase blockade [zinc deuteroporphyrin 2,4-bis glycol (ZnDPBG), 45 micromol/kg intraperitoneally] decreased cerebral CO production and increased cerebrocortical blood flow (CBF) in anesthetized rats. This latter effect was abrogated by the NOS blockade (50 mg/kg L-NAME intravenously). Furthermore, inhibition of CO production had no effect on stepwise hypoxia/hypercapnia-stimulated increases in CBF. Our results indicate that endogenous CO reduces the resting CBF via inhibition of NOS but fails to influence the CBF response to hypoxia and hypercapnia in adult rats.
authors.affiliation: Institute of Human Physiology and Clinical Experimental Research, Semmelweis University, Budapest, Hungary.
authors.forename: Miriam
authors.initials: M
authors.lastname: Leszl-Ishiguro
authors.forename: Béla
authors.initials: B
authors.lastname: Horváth
authors.forename: Robert A
authors.initials: RA
authors.lastname: Johnson
authors.forename: Fruzsina K
authors.initials: FK
authors.lastname: Johnson
authors.forename: Gábor
authors.initials: G
authors.lastname: Lenzsér
authors.forename: Péter
authors.initials: P
authors.lastname: Hermán
authors.forename: Eszter M
authors.initials: EM
authors.lastname: Horváth
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Benyó
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000098:blood supply* / Q000187:drug effects; D003905:Deuteroporphyrins / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006419:Heme Oxygenase (Decyclizing) / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000502:physiology; D006935:Hypercapnia / Q000503:physiopathology; D000860:Hypoxia / Q000503:physiopathology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D003905:Deuteroporphyrins; D004791:Enzyme Inhibitors; C060750:zinc deuteroporphyrin IX 2,4-bis(glycol); D006419:Heme Oxygenase (Decyclizing); D019331:NG-Nitroarginine Methyl Ester