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Updated: Jul 23, 2026

Detection of Microregional Hypoxia in Mouse Cerebral Cortex by Two-photon Imaging of Endogenous NADH Fluorescence
Published on: February 21, 2012
Targeted gene deletion of heme oxygenase 2 reveals neural role for carbon monoxide
R Zakhary1, K D Poss, S R Jaffrey
1Department of Neuroscience, Johns Hopkins University School of Medicine, 725 North Wolfe Street Baltimore, MD 21205, USA.
Abstract:
Neuronal nitric oxide synthase (nNOS) generates NO in neurons, and heme-oxygenase-2 (HO-2) synthesizes carbon monoxide (CO). We have evaluated the roles of NO and CO in intestinal neurotransmission using mice with targeted deletions of nNOS or HO-2. Immunohistochemical analysis demonstrated colocalization of nNOS and HO-2 in myenteric ganglia. Nonadrenergic noncholinergic relaxation and cyclic guanosine 3',5' monophosphate elevations evoked by electrical field stimulation were diminished markedly in both nNOSDelta/Delta and HO-2(Delta)/Delta mice. In wild-type mice, NOS inhibitors and HO inhibitors partially inhibited nonadrenergic noncholinergic relaxation. In nNOSDelta/Delta animals, NOS inhibitors selectively lost their efficacy, and HO inhibitors were inactive in HO-2(Delta)/Delta animals.

