title: Effects of celiac superior mesenteric ganglionectomy on glucose homeostasis and hormonal changes during oral glucose tolerance testing in rats.
abstract: The liver plays an important role in maintaining glucose homeostasis in the body. In the prandial state, some of the glucose which is absorbed by the gastrointestinal tract is converted into glycogen and stored in the liver. In contrast, the liver produces glucose by glycogenolysis and gluconeogenesis while fasting. Thus, the liver contributes to maintaining blood glucose level within normoglycemic range. Glycogenesis and glycogenolysis are regulated by various mechanisms including hormones, the sympathetic and parasympathetic nervous systems and the hepatic glucose content. In this study, we examined a rat model in which the celiac superior mesenteric ganglion (CSMG) was resected. We attempted to elucidate how the celiac sympathetic nervous system is involved in regulating glucose homeostasis by assessing the effects of CSMG resection on glucose excursion during an oral glucose tolerance test, and by examining hepatic glycogen content and hepatic glycogen phosphorylase (GP) activity. On the oral glucose tolerance test, CSMG-resected rats demonstrated improved glucose tolerance and significantly increased GP activity compared with sham-operated rats, whereas there were no significant differences in insulin, glucagon or catecholamine levels between the 2 groups. These results suggest that the celiac sympathetic nervous system is involved in regulating the rate of glycogen consumption through GP activity. In conclusion, the examined rat model showed that the celiac sympathetic nervous system regulates hepatic glucose metabolism in conjunction with vagal nerve innervations and is a critical component in the maintenance of blood glucose homeostasis.
authors: Third Department of Internal Medicine, Tokyo Medical University, Tokyo 160-0023, Japan. kurakuma999@gmail.com
authors: Atsushi
authors: A
authors: Kumakura
authors: Junpei
authors: J
authors: Shikuma
authors: Norikazu
authors: N
authors: Ogihara
authors: Jun-ichi
authors: J
authors: Eiki
authors: Masao
authors: M
authors: Kanazawa
authors: Yōko
authors: Y
authors: Notoya
authors: Masatoshi
authors: M
authors: Kikuchi
authors: Masato
authors: M
authors: Odawara
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D002395:Catecholamines / Q000097:blood*; D015536:Down-Regulation; D005728:Ganglia, Sympathetic / Q000601:surgery; D015171:Ganglionectomy; D005934:Glucagon / Q000097:blood*; D005951:Glucose Tolerance Test; D006003:Glycogen / Q000096:biosynthesis; D025001:Glycogen Phosphorylase, Liver Form / Q000378:metabolism; D050261:Glycogenolysis; D006706:Homeostasis; D007328:Insulin / Q000097:blood*; D008099:Liver / Q000098:blood supply / Q000294:innervation / Q000378:metabolism*; D008297:Male; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013152:Splanchnic Circulation; D015430:Weight Gain
chemical_list: D001786:Blood Glucose; D002395:Catecholamines; D007328:Insulin; D006003:Glycogen; D005934:Glucagon; D025001:Glycogen Phosphorylase, Liver Form