NO-ergic neurons of the cervical nucleus of the rat brain in normal conditions and after administration of opiates.
Histochemical reactions for NADPH-diaphorase (NADPH-d) were used to study the dynamics of NO synthesis activity in the cervical nuclei of the rat brain after i.v. administration of morphine hydrochloride. In normal conditions, NADPH-d activity was found in neurons in all the cervical nuclei. Acute and chronic administration of morphine at different doses (0.5 and 5 mg/kg) suppressed the NO-ergic activity of most cervical neurons. Decreases in the level of NADPH-d activity were different in different nuclei. NO-ergic changes were due to activation of opiate receptors, as they were dependent on the dose of morphine used, and treatment with the opiate antagonist naloxone restored the NO-ergic function of cervical neurons. Formation of tolerance to the analgesic effect of opiates was accompanied by significant but short-lived increases in NO synthesis activity. It is suggested that changes in the NO-ergic functions of cervical neurons may affect the balance of serotonin in the brain during opiate treatment.
Dyuizen
I V
IV
Department of Histology, Vladivostok State Medical University.
Deridovich
I I
II
Kurbatskii
R A
RA
Shorin
V V
VV
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D002574:Cervical Vertebrae; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009252:NADPH Dehydrogenase / Q000187:drug effects / Q000378:metabolism*; D009474:Neurons / Q000201:enzymology*; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000187:drug effects* / Q000378:metabolism; D020671:Posterior Horn Cells / Q000201:enzymology* / Q000378:metabolism; D011903:Raphe Nuclei / Q000166:cytology / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar
D000701:Analgesics, Opioid; D009569:Nitric Oxide; D009020:Morphine; D019001:Nitric Oxide Synthase; D009252:NADPH Dehydrogenase