PubMed Health⌕ Search

Biomedical subjects

H J Fallon

Publications and source records attributed to H J Fallon.

At least 55 records · Page 3Linked to original sources
PubMed1971

Inhibition of hepatic triglyceride formation by clofibrate.

The effect of clofibrate (CPIB) on hepatic glycerolipid formation has been studied in vivo and in vitro in the rat. Feeding 0.25% CPIB in laboratory chow significantly reduced serum triglyceride levels by 6 hr and concomitantly decreased the rate of glycerol-(14)C incorporation into hepatic and serum glycerides, in vivo. These changes persisted for at least 14 days. A similar decrease in serum triglyceride and glycerol incorporation into hepatic glycerides was observed in rats fed high glucose diets containing 0.25% CPIB. Serum glycerol was reduced by feeding CPIB for 14 days. The formation of diglyceride and triglyceride from (14)C-sn-glycerol-3-P by rat liver homogenates was inhibited by addition of 1-40 mM CPIB to the reaction mixture. These results suggest that CPIB reduces hepatic glycerolipid synthesis, possibly by inhibition of one or more reactions in the esterification of sn-glycerol-3-P. This change may account for the early fall in serum triglyceride. At later time periods, serum glycerol levels fall and in some experiments, hepatic triglyceride content increases. Therefore, it is likely that additional metabolic alterations may contribute to the sustained hypotriglyceridemic effects of CPIB.

Animals↗
PubMed1970

Foreign bodies.

Explore the source record for details and available documents.

Animals↗
PubMed1968

Effects of diet on hepatic triglyceride synthesis.

The effects of diet on the rate of triglyceride synthesis by rat liver homogenates was measured. Changes in triglyceride synthesis were correlated with the level of activity of L-alpha-glycerophosphate acyltransferase, the enzyme catalyzing the first specific reaction in hepatic glycerolipid synthesis. Fasting for 48-72 hr depressed the synthesis of triglyceride from L-alpha-glycerophosphate. High carbohydrate diets, fed to rats for 6 days, resulted in increased triglyceride synthesis. Diets high in starch were less effective than high glucose, sucrose, or fructose diets in increasing triglyceride synthesis. Diets high in corn oil did not alter triglyceride synthesis. These studies established the importance of dietary factors in the regulation of hepatic triglyceride synthesis.L-alpha-Glycerophosphate acyltransferase activity was measured after the same dietary changes. Both high carbohydrate and high fat diets resulted in increased enzyme specific activity. Fasting for 72 hr did not decrease activity. Thus, the specific activity of this enzyme did not correlate well with the measured rate of triglyceride synthesis indicating that other factors must participate in the regulation of triglyceride biosynthesis.

Acyltransferases↗
PubMed1968

Acylation of sn-glycerol 3-phosphate by cell fractions of rat liver.

The esterification of sn-glycerol 3-(dihydrogen phosphate) with long-chain fatty acids by rat liver microsomal preparations has been studied. A newly modified spectrophotometric assay for glycerolphosphate acyltransferase (GP-acyltransferase) compared favorably with other assay methods, including measurement of the incorporation of sn-glycerol-(14)C 3-(dihydrogen phosphate) into glycerolipids. Cofactor requirements, preliminary kinetic constants, and optimum pH were determined. The product of the reaction was identified as monoacylglycerophosphate by thin-layer chromatography. Albumin activated GP-acyltransferase at low concentrations of acyl CoA but was inhibitory at higher concentrations. Serum -lipoprotein also caused activation of GP-acyltransferase. The effect of albumin could not be attributed to binding of substrate or fatty acids or the provision of metal ions. Diacylglycerophosphate, cytidine triphosphate, sulfhydryl binding agents, and sodium palmitate were identified as inhibitors of microsomal GP-acyltransferase. The physiological significance of these inhibitors remains to be established.

Acyltransferases↗