| Theme |
The Beginning of Neurogastroenterology |
| Title |
Integrative Regulation of Feeding Behavior, Gastric Emptying, and Thermogenesis by Galaninand Enterostatin Involve Brain-gut Relationship |
| Author |
Hajime Nagase |
Department of Gastroenterology, Yokohama Rosai Hospital |
| Author |
Masahiro Sugisawa |
The Third Department of Internal Medicine, Yokohama City University |
| Author |
Masahiko Inamori |
The Third Department of Internal Medicine, Yokohama City University |
| Author |
Hisahiko Sekihara |
The Third Department of Internal Medicine, Yokohama City University |
| [ Summary ] |
Galanin and enterostatin, which are distributed both in the central nervous system and the gastrointestinal tract, play a number of physiological roles. Centrally injected galanin dose-dependently increased the intake of high-fat diet. In contrast, enterostatin suppressed the intake of high-fat diet. Galanin significantly suppressed gastric emptying rate, in a dose-dependent manner. On the other hand, gastric emptying showed no response to enterostatin. Galanin produced a dose-dependent suppression of the firing rate of the sympathetic nerves, which innervate interscapular brownadipose tissue. In rats fed a high-fat diet, injection of enterostatin showed a dose-dependent increase in firing rate. Immunohistochemical identification indicated that the Fos protein was observed in the nucleus tractus solitarius, parabrachial, paraventricular and supraoptic nuclei after ip enterostatin administration. These responses to ip enterostatin were blocked by hepatic vagotomy. Peripheral gastric galanin inhibited the response in nucleus tractus solitarius neurons receiving gastric vagal inputs. These results suggested that galanin and enterostatin, in coordination regulate feeding behavior, gastric emptying, and sympathetic activity in relation to interscapular brown adipose tissue, via central and peripheral sites of action, of which interaction was observed to exist through the vagal system. Disturbed responses to galanin and enterostatin are supposed to result in functional disorders of the gastrointestinal tract and metabolic disorders, such as obesity. |