Is brain a gluconeogenic organ?
Glucagon increased the activities of alanine amino transferase (AAT), fructose-1:6-bisphosphatase (fru-P2ase) and glucose-6-phosphatase (G-6-Pase) in goat brain tissue by about 100%, 150% and 50% respectively. These increase in activities were reversed by beta-antagonists propranolol. Well known alpha-agonist and antagonist like phenylephrine and phenoxybenzamine also increased AAT and G-6-Pase activities and these increased activities were reversed by propranolol. Phenylephrine and phenoxybenzamine however did not increase brain Fru-P2ase activity. However the most interesting finding is that cerebral cortical slices could produce glucose from alanine and this glucose production was enhanced by glucagon, phenylephrine and phenoxybenzamine. Propranolol reversed the effects of these agonists and antagonist to a great extent. From all these experiments we suggest brain to be a gluconeogenic organ although much less efficient than liver.
Bhattacharya
S B
SB
Indian Institute of Chemical Biology, Calcutta.
Datta
A G
AG
D000409:Alanine / Q000378:metabolism*; D000410:Alanine Transaminase / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D006597:Fructose-Bisphosphatase / Q000187:drug effects / Q000378:metabolism; D005943:Gluconeogenesis / Q000187:drug effects / Q000502:physiology*; D005952:Glucose-6-Phosphatase / Q000187:drug effects / Q000378:metabolism; D006041:Goats; D066298:In Vitro Techniques; D010643:Phenoxybenzamine / Q000378:metabolism; D010656:Phenylephrine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology
D010643:Phenoxybenzamine; D010656:Phenylephrine; D011433:Propranolol; D000410:Alanine Transaminase; D006597:Fructose-Bisphosphatase; D005952:Glucose-6-Phosphatase; D000409:Alanine