Role of autonomic nervous system in the time-dependent hyperglycemia induced by intracranial injection of D-mannitol and D-glucose.
Intracranial injection of D-mannitol (MA) or D-glucose (GL) caused photoperiodic hyperglycemia in rats; MA injection elicited hyperglycemia only in the light period, while GL injection induced it only in the dark period. To elucidate the mechanisms of these hyperglycemias, we examined the effect of the autonomic nervous system on them in rats under the L:D (12:12) condition. Propranolol, a beta-adrenergic blocker, and hexamethonium, a ganglion blocker, effectively inhibited hyperglycemia induced in either the light (MA) or dark (GL) period. In contrast, phenoxybenzamine, an alpha-adrenergic blocker, and atropine, a cholinergic blocker, inhibited hyperglycemia induced in the light period (MA), but not that induced in the dark period (GL). These findings suggest that alpha and beta-adrenergic and cholinergic mechanisms are involved in the hyperglycemia induced by MA in the light period, while only the beta-adrenergic mechanism is involved in the hyperglycemia induced by GL in the dark period.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001341:Autonomic Nervous System / Q000187:drug effects / Q000503:physiopathology*; D002940:Circadian Rhythm; D003624:Darkness; D005947:Glucose / Q000008:administration & dosage / Q000633:toxicity*; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology; D006943:Hyperglycemia / Q000139:chemically induced / Q000503:physiopathology* / Q000517:prevention & control; D007276:Injections, Intraventricular; D008027:Light; D008297:Male; D008353:Mannitol / Q000008:administration & dosage / Q000633:toxicity*; D010643:Phenoxybenzamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D006584:Hexamethonium Compounds; D010643:Phenoxybenzamine; D018738:Hexamethonium; D008353:Mannitol; D001285:Atropine; D011433:Propranolol; D005947:Glucose