Obesity in obese-hyperglycaemic mouse is associated with an increase in number and size of adipocytes. Adipocytes from the obese mouse showed increased incorporation of [14C]acetate and[14C]glucose into triacylglycerol. This increased capacity of triacylglycerol formation was correlated with increased activities of various triacylglycerol-forming enzymes measured in the microsomal fraction of a...

Microsomal membrane preparations from Mortierella alpina catalysed the conversion of sn-glycerol 3-phosphate and [(14)C]oleoyl-CoA to radioactive phosphatidic acid, diacylglycerol and triacylglycerol. Experiments with lysophosphatidic acid and [(14)C]oleoyl-CoA gave a similar pattern of radioactivity in the complex lipids. The specific activity of lysophosphatidate acyltransferase was almost ei...

Introduction In several experimental animal systems, lack of vitamin A is associated with enhanced susceptibility to chemical carcinogenesis [1-3] and there are reports also of alterations in the activity of certain microsomal oxidation-reduction enzymes [4-:-6]. It seemed possible that both effects are related to loss of vitamin A protection against free radical-induced membrane-lipid peroxida...

Protein synthesis was studied in slices from rat cerebral cortex and localized in various purified subcellular membrane fractions isolated after incubation with L-leucine. A synaptosomal fraction isolated from a several times washed crude mitochondrial pellet showed very little contamination by free membranes, and the synaptic membrane fraction isolated from it was estimated to c +ain about 50%...

Fractions of plasma membranes, Golgi apparatus, endoplasmic reticulum (ER), and nuclear envelope were isolated from rat liver and were characterized by electron microsocpe and biochemical methods. The purity of the fractions was controlled by morphometry and by marker enzyme activities. Amounts of cytochromes b5, P-450, and P-420 were measured, as well as the NADPH- and NADPH-cytochrome c reduc...

The separation of rat epididymal adipocytes into plasma-membrane, mitochondrial, microsomal and cytosol fractions is described. The fractions, which were characterized by marker-enzyme analysis and electron-micrographic observation, from the cells of fed and 24 h-starved animals were used to prepare acetone/diethyl ether-dried powders for the measurement of lipoprotein lipase activities. The hi...

High affinity Ca2+-stimulated Mga+-dependent ATPase activity of nerve ending particles (!vnaphmm) from rat brain tissue appears to be associated primarily with isolated synaptic plasma membranes. The synaptic membrane (Ca2+ + Mga+)-ATPase activity was found to exhibit strict dependence on Mg+ for the presence of the activity, a high affinity for Ca2+ (&.a = 0.23 NM), and relatively high affini...

These findings could be interpreted as implying that the enhancement by carcinogens in vitro of hamster hepatic microsomal biphenyl 2-hydroxylase (McPherson ‘et al., 19746) is mediated through an effect on the microsomal membrane rather than via direct specific conformational modification of the biphenyl 2-hydroxylase enzyme itself. In an attempt to differentiate between the soluble and microso...

1. On incubating cerebral-cortex slices at 37 degrees in an oxygenated medium marked changes resulted in the subcellular distribution of proteins and phosphoproteins in the tissue. The protein content of the nuclear fraction more than doubled, whereas the yields of microsomal and supernatant proteins were both markedly decreased. The amount of phosphoprotein/mg. of protein decreased in the micr...

The distribution of adenylate cyclase (AC) in Golgi and other cell fractions from rat liver was studied using the Golgi isolation procedure of Ehrenreich et al. In liver homogenate the AC activity was found to decay with time, but addition of 1 mM EGTA reduced the rate of enzyme loss. The incorporation of 1 mM EGTA into the sucrose medium used in the initial two centrifugal steps of the Golgi i...