Biomaterial Database

Studies on sphingomyelinase activity in cultured cells and leucocytes. 1978

G T Besley

Using both [3H]ceramide-sphingomyelin and [14C]methyl choline-sphingomyelin as substrate, enzyme activity was determined in skin fibroblasts, cultured amniotic fluid cells and leucocytes. Sphingomyelinase activities of fibroblasts from two patients with Niemann-Pick disease were about 1% of the mean control values (22.9 nmol/h/mg protein and 65.6 nmol/h/mg protein, with [3H]sphingomyelin and [14C]sphingomyelin respectively). Leucocyte sphingomyelinase activity is much lower than that of cultured cells. Optimum sphingomyelinase activity of cultured cells is at pH 5.0 and the apparent Km values are 58 mumol/1 and about 200 mumol/1 for [3H]sphingomyelin and [14C]sphingomyelin respectively. These properties are similar to those for residual sphingomyelinase activity in Niemann-Pick fibroblasts.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007962	Leukocytes	White blood cells. These include granular leukocytes (BASOPHILS; EOSINOPHILS; and NEUTROPHILS) as well as non-granular leukocytes (LYMPHOCYTES and MONOCYTES).	Blood Cells, White,Blood Corpuscles, White,White Blood Cells,White Blood Corpuscles,Blood Cell, White,Blood Corpuscle, White,Corpuscle, White Blood,Corpuscles, White Blood,Leukocyte,White Blood Cell,White Blood Corpuscle
D009542	Niemann-Pick Diseases	A group of autosomal recessive disorders in which harmful quantities of lipids accumulate in the viscera and the central nervous system. They can be caused by deficiencies of enzyme activities (SPHINGOMYELIN PHOSPHODIESTERASE) or defects in intracellular transport, resulting in the accumulation of SPHINGOMYELINS and CHOLESTEROL. There are various subtypes based on their clinical and genetic differences.	ASM Deficiency,ASM-Deficient Niemann-Pick Disease,Acid Sphingomyelinase Deficiency,Acid Sphingomyelinase-deficient Niemann-Pick Disease,Niemann-Pick Disease,ASM Deficiencies,ASM Deficient Niemann Pick Disease,ASM-Deficient Niemann-Pick Diseases,Acid Sphingomyelinase deficient Niemann Pick Disease,Deficiencies, ASM,Deficiencies, Acid Sphingomyelinase,Deficiency, ASM,Deficiency, Acid Sphingomyelinase,Disease, ASM-Deficient Niemann-Pick,Diseases, ASM-Deficient Niemann-Pick,Niemann Pick Disease,Niemann Pick Diseases,Niemann-Pick Disease, ASM-Deficient,Niemann-Pick Diseases, ASM-Deficient,Sphingomyelinase Deficiencies, Acid,Sphingomyelinase Deficiency, Acid
D010727	Phosphoric Diester Hydrolases	A class of enzymes that catalyze the hydrolysis of one of the two ester bonds in a phosphodiester compound. EC 3.1.4.	Phosphodiesterase,Phosphodiesterases,Hydrolases, Phosphoric Diester
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D005260	Female		Females
D005347	Fibroblasts	Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.	Fibroblast
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000653	Amniotic Fluid	A clear, yellowish liquid that envelopes the FETUS inside the sac of AMNION. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (AMNIOCENTESIS).	Amniotic Fluid Index,Amniotic Fluid Indices,Amniotic Fluids,Fluid Index, Amniotic,Fluid Indices, Amniotic,Fluid, Amniotic,Fluids, Amniotic,Index, Amniotic Fluid,Indices, Amniotic Fluid