Biomaterial Database

Fatty acid desaturation in experimental diabetes mellitus. 1979

M G Eck, and J O Wynn, and W J Carter, and F H Faas

Microsomal fatty acid desaturation is defective in streptozotocin-induced experimental diabetes. This defect is correctable by insulin treatment. The electron transport chain needed for microsomal fatty acid desaturation was studied in liver microsomes of streptozotocin diabetic rats, and the defect was localized to the terminal desaturase enzyme. Cytochrome b5 levels were elevated in the face of decreased fatty acid desaturation and returned to normal after 48 h of insulin treatment; 2 U of regular insulin every 6 h for 24 h repaired the fatty acid desaturation defect, while 0.5 U failed to correct the defect. Both the delta 6 and delta 9 desaturase defects (linoleic acid and stearoyl-CoA desaturation) required similar amounts of insulin and periods of time for correction, although these are different enzymes. This is consistent with the desaturation defect being due to a protein synthetic effect. Diabetic rats treated twice daily with injections of 4 U of NPH insulin showed a "super" repair of their desaturase defect by 48 h: delta 9 desaturase activity increased eight times over control activity, while delta 6 desaturase activity increased two and one-half times over control activity. This, together with the fact that delta 6 desaturase activity in diabetes (64% of control) is altered less than is delta 9 desaturase activity (22% of control), indicates that delta 6 desaturase enzyme activity is less responsive to insulin than is delta 9 desaturase enzyme activity. The physiologic significance of altered fatty acid desaturation in diabetes mellitus is unknown.

UI	MeSH Term	Description	Entries
D007328	Insulin	A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).	Iletin,Insulin A Chain,Insulin B Chain,Insulin, Regular,Novolin,Sodium Insulin,Soluble Insulin,Chain, Insulin B,Insulin, Sodium,Insulin, Soluble,Regular Insulin
D007770	L-Lactate Dehydrogenase	A tetrameric enzyme that, along with the coenzyme NAD+, catalyzes the interconversion of LACTATE and PYRUVATE. In vertebrates, genes for three different subunits (LDH-A, LDH-B and LDH-C) exist.	Lactate Dehydrogenase,Dehydrogenase, L-Lactate,Dehydrogenase, Lactate,L Lactate Dehydrogenase
D008297	Male		Males
D008862	Microsomes, Liver	Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.	Liver Microsomes,Liver Microsome,Microsome, Liver
D001786	Blood Glucose	Glucose in blood.	Blood Sugar,Glucose, Blood,Sugar, Blood
D003580	Cytochromes	Hemeproteins whose characteristic mode of action involves transfer of reducing equivalents which are associated with a reversible change in oxidation state of the prosthetic group. Formally, this redox change involves a single-electron, reversible equilibrium between the Fe(II) and Fe(III) states of the central iron atom (From Enzyme Nomenclature, 1992, p539). The various cytochrome subclasses are organized by the type of HEME and by the wavelength range of their reduced alpha-absorption bands.	Cytochrome
D003921	Diabetes Mellitus, Experimental	Diabetes mellitus induced experimentally by administration of various diabetogenic agents or by PANCREATECTOMY.	Alloxan Diabetes,Streptozocin Diabetes,Streptozotocin Diabetes,Experimental Diabetes Mellitus,Diabete, Streptozocin,Diabetes, Alloxan,Diabetes, Streptozocin,Diabetes, Streptozotocin,Streptozocin Diabete
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004579	Electron Transport	The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)	Respiratory Chain,Chain, Respiratory,Chains, Respiratory,Respiratory Chains,Transport, Electron
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia