Activation of 5-HT2 receptors induces glycogenolysis in the rat brain.
The effect of 5-HT(2) receptor activation on brain glycogen and the extracellular concentration of glucose was investigated in the present study. An injection of 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) (2 mg/kg, i.p.) or mescaline (10 mg/kg, i.p.) at an ambient temperature of 29 degrees C produced a 35-45% decrease in brain glycogen that persisted for at least 2 h. DOI also increased the extracellular concentration of glucose in the striatum by 60%. Maintenance of rats at 22 degrees C significantly attenuated DOI-induced glycogenolysis, as well as DOI-induced hyperthermia, and the increase in the extracellular concentration of glucose in the striatum. DOI-induced hyperthermia, glycogenolysis and increase in the extracellular concentration of glucose also were attenuated in rats treated with the 5-HT(2) receptor antagonist, 6-methyl-1-(methylethyl)-ergoline-8beta-carboxylic acid 2-hydroxy-1-methylpropyl ester maleate (LY-53,857) (3 mg/kg, ip). These results support the conclusion that 5-HT(2) receptor activation promotes glycogenolysis and that hyperthermia exerts a prominent role in this process.
Darvesh
Altaf S
AS
College of Pharmacy, University of Cincinnati, 3223 Eden Avenue, OH 45267, USA.
Gudelsky
Gary A
GA
D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D004873:Ergolines / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism*; D066298:In Vitro Techniques; D007215:Indophenol / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D017551:Microdialysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors
D004873:Ergolines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C113896:dimethoxy-4-indophenyl-2-aminopropane; D007215:Indophenol; D006003:Glycogen; D005947:Glucose; C032663:LY 53857