Participation of adrenal medulla in 6-amino-nicotinamide-induced hyperglycaemia in the rat.
In fasted rats 6-aminonicotinamide (6-AN) produced delayed hyperglycaemia, the peak effect being seen by 7 h. Fasting plasma insulin concentrations were not significantly altered but liver glycogen concentrations were decreased following treatment with 6-AN. Adrenalectomy, demedullation and pretreatment with reserpine, phentolamine, nicotinamide and nicotinic acid completely blocked the hyperglycaemic response whereas guanethidine and propranolol or oxprenolol were ineffective. Catecholamine concentrations in the adrenal venous plasma were markedly increased by treatment with 6-AN, the peak effect being seen by 5 h. It is concluded that adrenal medullary release, which is slow in onset, is mainly responsible for the development of sustained hyperglycaemia in the rat.
D015120:6-Aminonicotinamide / Q000494:pharmacology*; D000313:Adrenal Medulla / Q000502:physiology*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D006145:Guanethidine / Q000494:pharmacology; D006943:Hyperglycemia / Q000139:chemically induced*; D007330:Insulin Antibodies / Q000378:metabolism; D008112:Liver Glycogen / Q000378:metabolism; D009536:Niacinamide / Q000031:analogs & derivatives*; D009539:Nicotinic Acids / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D051381:Rats; D012110:Reserpine / Q000494:pharmacology
D001786:Blood Glucose; D007330:Insulin Antibodies; D008112:Liver Glycogen; D009539:Nicotinic Acids; D009536:Niacinamide; D015120:6-Aminonicotinamide; D012110:Reserpine; D010646:Phentolamine; D006145:Guanethidine