DIFFERENTIAL REGULATION OF CYCLIC-GMP LEVELS IN THE FRONTAL-CORTEX AND THE CEREBELLUM OF ANESTHETIZED RATS BY NITRIC-OXIDE - AN IN-VIVO MICRODIALYSIS STUDY

Citation
Jt. Laitinen et al., DIFFERENTIAL REGULATION OF CYCLIC-GMP LEVELS IN THE FRONTAL-CORTEX AND THE CEREBELLUM OF ANESTHETIZED RATS BY NITRIC-OXIDE - AN IN-VIVO MICRODIALYSIS STUDY, Brain research, 668(1-2), 1994, pp. 117-121
Citations number
27
Categorie Soggetti
Neurosciences
Journal title
ISSN journal
00068993
Volume
668
Issue
1-2
Year of publication
1994
Pages
117 - 121
Database
ISI
SICI code
0006-8993(1994)668:1-2<117:DROCLI>2.0.ZU;2-Q
Abstract
A microdialysis method combined with a sensitive radioimmunoassay was used to monitor extracellular cyclic GMP (cGMP) levels in the frontal cortex and the cerebellum of anesthetized rats in vivo. Basal cGMP rel ease remained constant throughout the perfusion period and was approxi mate to 2 fmol/30 min in the frontal cortex and approximate to 4 fmol/ 30 min in the cerebellum. The nitric oxide (NO) donor sodium nitroprus side (SNP) stimulated cGMP release transiently in both regions. Howeve r, the maximal response was 3-fold in the frontal cortex (obtained wit h 5 mu M SNP) but 90-fold in the cerebellum (obtained with 1 mM SNP). Perfusion with the NO synthase (NOS) inhibitor N-G-nitro-L-arginine me thyl ester (L-NAME) suppressed cerebellar cGMP release by 74% indicati ng that NO is the major regulator of basal cGMP levels in the cerebell um. Quite opposite, L-NAME exhibited no potency in the frontal cortex suggesting that other activators of guanylyl cyclase may regulate basa l cortical cGMP levels in vivo.