EurekaMag.com logo
+ Site Statistics
References:
53,214,146
Abstracts:
29,074,682
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Triacylglycerol lipase activity in the rabbit renal medulla



Triacylglycerol lipase activity in the rabbit renal medulla



Biochimica et Biophysica Acta 921(3): 449-456



Although the renal medulla is rich in triacylglycerols, the lipolysis of these intracellular triacylglycerols by a renomedullary triacylglycerol lipase has not been directly demonstrated. The present study demonstrates triacylglcyerol lipase activity localized in the particulate subcellular fractions of rabbit renal medullae. Renomedullary triacylglycerol lipase activity, as determined by the hydrolysis of [14C]triolein to [14C]oleic acid, was observed to have a pH optimum of 5.8. Addition of cAMP/ATP'magnesium acetate resulted in an 80% activation of crude homogenate triacylglycerol lipase activity; addition of exogenous cAMP-dependent protein kinase resulted in a further activation of lipolysis. 3 mM CaCl2 had no effect on basal triacylglycerol lipase activity. 1 M NaCl did not inhibit lipolysis, suggesting that the lipase activity measured was not due to lipoprotein lipase. Endogenous renomedullary triacylglycerols were hydrolysed by a lipase in the 100,000 7x g pellet of renomedullary homogenates, resulting in the release of free fatty acids including arachidonic and adrenic acids. Dispersed renomedullary cells were prepared to monitor hormone-sensitive triacylglycerol lipase activity in intact cells. Addition of 10 .mu.M forskolin and 10 .mu.M epinephrine resulted in 8-fold and 50-fold increases in triacylglycerol lipase activity, respectively, as defined by release of free glycerol from the cells. These studies demonstrate that a cAMP-dependent hormone-sensitive triacylglycerol lipase is present in the renal medulla, and is responsible for the hydrolysis of renomedullary triacylglycerols.

Accession: 006840440

Download citation: RISBibTeXText

PMID: 2822129

DOI: 10.1016/0005-2760(87)90071-3

Download PDF Full Text: Triacylglycerol lipase activity in the rabbit renal medulla



Related references

Triacylglycerol lipase mediated release of arachidonic acid for prostaglandin synthesis in rabbit kidney medulla microsomes. European Journal of Pharmacology 183(6): 2078, 1990

Comparison of the effects of homologous and heterologous albumins on the activity of blood plasma lipoprotein lipase and hepatic triacylglycerol lipase in rabbit brain. Voprosy Meditsinskoi Khimii 31(3): 93-99, 1985

Comparison of the triacylglycerol hydrolase activity of human post-heparin plasma lipoprotein lipase and hepatic triacylglycerol lipase. A monolayer study. Biochemistry 25(5): 1166-1170, 1986

Effect of cholera toxin on triacylglycerol lipase activity and triacylglycerol content of rat heart. Canadian Journal of Physiology & Pharmacology 65(1): 60-63, 1987

Lipolysis and neutral triacylglycerol lipase activity in triacylglycerol enriched cardiac myocytes. Journal of Molecular and Cellular Cardiology 16(supp-S2): 21-21, 1984

Enzymatic coupling of phospho lipase a 2 and prostaglandin synthase activities in sub cellular fractions from renal rabbit medulla. Israel Journal of Medical Sciences 17(6): 498-499, 1981

Relationship of lipoprotein lipase and hepatic triacylglycerol lipase activity to serum adiponectin levels in Japanese hyperlipidemic men. Hormone and Metabolic Research 37(8): 505-509, 2005

Stimulation of prostaglandin e 2 synthesis by exogenous phospho lipase a 2 and phospho lipase c in rabbit kidney medulla slices. Biochemical Journal 218(1): 69-74, 1984

Ureteral obstruction decreases ATP dependent H(+)-pump activity of rabbit renal outer medulla. Tohoku Journal of Experimental Medicine 160(3): 223-229, 1990

Determination of triacylglycerol lipase activity using carbon 13 labeled triacylglycerols and nuclear magnetic resonance spectroscopy evidence that hepatic lipase hydrolyzes medium chain triacylglycerols. Magnetic Resonance in Medicine 9(2): 273-277, 1989

Triacylglycerol lipase, monoacylglycerol lipase and phospholipase activities of highly purified rat hepatic lipase. Biochimica et Biophysica Acta 710(3): 464-470, 1982

Ureteral obstruction decreases atp dependent proton pump activity of rabbit renal outer medulla. Tohoku Journal of Experimental Medicine 160(3): 223-230, 1990

The complete digestion of human milk triacylglycerol in vitro requires gastric lipase, pancreatic colipase-dependent lipase, and bile salt-stimulated lipase. Journal of Clinical Investigation 85(4): 1221-1226, 1990