Secretagogue-induced diacylglycerol accumulation in isolated pancreatic islets. Mass spectrometric characterization of the fatty acyl content indicates multiple mechanisms of generation

Journal Article · Tue May 16 00:00:00 EDT 1989 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00436a026· OSTI ID:5300949

Wolf, B A; Easom, R A; Hughes, J H; McDaniel, M L; Turk, J ^[1]

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1. Washington Univ. School of Medicine, St. Louis, MO (USA)

Diacylglycerol accumulation has been examined in secretagogue-stimulated pancreatic islets with a newly developed negative ion chemical ionization mass spectrometric method. The muscarinic agonist carbachol induces islet accumulation of diacylglycerol rich in arachidonate and stearate, and a parallel accumulation of {sup 3}H-labeled diacylglycerol occurs in carbachol-stimulated islets that had been prelabeled with ({sup 3}H)glycerol. Islets so labeled do not accumulate {sup 3}H-labeled diacylglycerol in response to D-glucose, but D-glucose does induce islet accumulation of diacylglycerol by mass. This material is rich in palmitate and oleate and contains much smaller amounts of arachidonate. Neither secretagogue influences triacylglycerol labeling, and neither induces release of ({sup 3}H)choline or ({sup 3}H)phosphocholine from islets prelabeled with ({sup 3}H)choline. These observations indicate that the diacylglycerol that accumulates in islets in response to carbachol arises from hydrolysis of glycerolipids, probably including phosphoinositides. The bulk of the diacylglycerol which accumulates in response to glucose does not arise from glycerolipid hydrolysis and must therefore reflect de novo synthesis. The endogenous diacylglycerol which accumulates in secretagogue-stimulated islets may participate in insulin secretion because exogenous diacylglycerol induces insulin secretion from islets, and an inhibitor of diacylglycerol metabolism to phosphatidic acid augments glucose-induced insulin secretion.

• OSTI ID: 5300949
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 28:10; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALCOHOLS
AMINES
AMMONIUM COMPOUNDS
ANIMALS
ARACHIDONIC ACID
BODY
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL MEMBRANES
CHOLINE
DIABETES MELLITUS
DIGESTIVE SYSTEM
DISEASES
DRUGS
ENDOCRINE DISEASES
ENDOCRINE GLANDS
GLANDS
GLYCEROL
HORMONES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INSULIN
LABELLED COMPOUNDS
LIPOTROPIC FACTORS
MAMMALS
MASS SPECTROSCOPY
MEMBRANE PROTEINS
MEMBRANES
METABOLIC DISEASES
METABOLISM
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PANCREAS
PEPTIDE HORMONES
PROTEINS
QUATERNARY COMPOUNDS
RATS
RECEPTORS
RODENTS
SECRETION
SPECTROSCOPY
TRITIUM COMPOUNDS
VERTEBRATES