Microinjection of L-NAME into dorsal raphe nucleus inhibits nociceptive response in sigmoid pain model of rats.
- Author:
Bin YANG
1
;
Li-Cai ZHANG
;
Yin-Ming ZENG
Author Information
1. Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College, Xuzhou 221002. amyangbin@163.com
- Publication Type:Journal Article
- MeSH:
Analgesics;
pharmacology;
Animals;
Genes, fos;
Microinjections;
NG-Nitroarginine Methyl Ester;
pharmacology;
Neurons;
physiology;
Nitric Oxide Synthase;
metabolism;
Nociceptors;
physiology;
Pain;
chemically induced;
physiopathology;
Pain Measurement;
Raphe Nuclei;
physiology;
Rats;
Rats, Sprague-Dawley;
Sigmoid Diseases;
chemically induced;
physiopathology
- From:
Acta Physiologica Sinica
2003;55(5):577-582
- CountryChina
- Language:Chinese
-
Abstract:
By means of Fos immunocytochemistry, nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and microinjection methods, the role of nitric oxide synthase (NOS) of dorsal raphe (DR) neurons in the modulation of rats sigmoid pain was studied. The results showed: (1) Rats exhibited aversive behavioral responses related to visceral pain after injecting formalin into the sigmoid wall. NOS neurons in DR were up-regulated, in addition, about 8% of NOS-labeled neurons were Fos positive. By contrast, there were no Fos/NOS double-labeled neurons in the control group. (2) Formalin-induced sigmoid pain scores and the expression of Fos in the spinal cord at S1 segment were decreased after microinjecting L-NAME into the DR. These findings suggest that NOS neurons are involved in the modulation of formalin-induced sigmoid pain and that NO may play an important role in the transmission of visceral nociceptive message in the midbrain.
