Hormonal regulation of fat esterification & oxidation in hepatocytes from fed rats: modulation by 3-mercaptopicolinate.
3-Mercaptopicolinate, an inhibitor of phosphoenolpyruvate carboxykinase (PEPCK), decreased esterification of [1-14C] oleate and [1-14C] myristate in hepatocytes from fed rats. In the absence of 3-mercaptopicolinate, adrenaline, noradrenaline, vasopressin or angiotensin II increased esterification to triacylglycerol of [1-14C] oleate but not [1-14C] myristate. Cyclic AMP decreased esterification of both oleate and myristate. In the presence of 3-mercaptopicolinate, stimulation of oleate esterification by the catecholamines, vasopressin or angiotensin II was increased, and stimulatory effects of these hormones on myristate esterification were observed. Adrenaline, noradrenaline, vasopressin or angiotensin II increased 14CO2 production from both [1-14C] oleate and [1-14C] myristate but the degree of stimulation was similar in the absence or presence of 3-mercaptopicolinate. The results indicate a role for the catecholamines and angiotensin II in the regulation of liver fat metabolism and emphasize the potential importance of changes in activity of PEPCK as determinants of hepatic carbon flux.
Schofield
P S
PS
Kirk
C J
CJ
Sugden
M C
MC
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D004952:Esters / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism; D006728:Hormones / Q000494:pharmacology; D008099:Liver / Q000378:metabolism*; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism*; D019301:Oleic Acid; D009829:Oleic Acids / Q000378:metabolism*; D010084:Oxidation-Reduction; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000037:antagonists & inhibitors; D010848:Picolinic Acids / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity
D004952:Esters; D006728:Hormones; D009227:Myristic Acids; D009829:Oleic Acids; D010848:Picolinic Acids; D019814:Myristic Acid; D019301:Oleic Acid; D003994:Bucladesine; C008363:3-mercaptopicolinic acid; D010729:Phosphoenolpyruvate Carboxykinase (GTP); D005947:Glucose