[Role of VIP-neurons in the hypothalamic suprachiasmatic nucleus in the control of blood glucose].
The hypothalamic suprachiasmatic nucleus (SCN), a master circadian oscillator in mammals, contains VIP-neurons. In our study on the mechanism of the central regulation of glucose metabolism in rats, we obtained following results: 1) intracranial injection of either 2-deoxy-D-glucose (2DG) or VIP elicited hyperglycemia by enhancing neural activities of the sympathetic nerves and by the suppression of the insulin secretion and enhances of secretions of adrenaline and glucagon; 2) bilateral lesions of the SCN eliminated the hyperglycemia and sympathetic excitation induced by intracranial injection of 2DG, and intracranial administration of VIP restored the 2DG-hyperglycemia; 3) infusion of VIP-antisense oligo in the SCN reduced the VIP content in the SCN and abolished the 2DG-hyperglycemia, and intracranial injection of VIP restored the 2DG-hyperglycemia in rats infused the VIP-antisense oligo; 4) intrapancreatic injection of pseudorabies virus (PRV, Bartha), which is retrogradedly transported, caused the transfer of PRV to VIP-neurons in the SCN, and denervations of both the sympathetic and parasympathetic nerves innervating the pancreas eliminated the retrograde transport of PRV to VIP-neurons in the SCN. These findings suggest that VIP-neurons in the SCN regulate the blood glucose level through the enhancement of the sympathetic activity.
Nagai
Katsuya
K
Division of Protein Metabolism, Institute for Protein Research, Osaka University, Japan. k_nagai@protein.osaka-u.ac.jp
D000818:Animals; D000963:Antimetabolites / Q000494:pharmacology; D017776:Autonomic Pathways / Q000502:physiology; D001786:Blood Glucose; D003847:Deoxyglucose / Q000494:pharmacology; D003864:Depression, Chemical; D004837:Epinephrine / Q000378:metabolism; D005934:Glucagon / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D009474:Neurons / Q000502:physiology*; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology; D051381:Rats; D013268:Stimulation, Chemical; D013493:Suprachiasmatic Nucleus / Q000166:cytology / Q000502:physiology*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism / Q000494:pharmacology
D000963:Antimetabolites; D001786:Blood Glucose; D007328:Insulin; D020319:Oligodeoxyribonucleotides, Antisense; D014660:Vasoactive Intestinal Peptide; D005934:Glucagon; D003847:Deoxyglucose; D004837:Epinephrine