The Lipids of Mouse Brown Fat

Abstract

The lipids of the interscapular brown fat of the white mouse have been examined by means of silicic acid column chromatography and quantitative paper chromatography. The fatty acid composition of the glycerides and phosphatides was determined by gas chromatography. Comparative studies of mouse brown and white fat are presented.The fatty acid composition of the glycerides of the two tissues was similar a t all ages examined. In both tissues, the average chain length of the glyceride fatty acids increased with age. The glycerides of brown fat a t all ages contained less palmitoleic acid and more stearic acid than the corresponding white fat.The adult brown fat contained more polyglycerophosphatide and less sphingomyelin than white fat. The fatty acid composition of the lecithins of the two tissues was very similar. The similarity of brown fat and liver phosphatides is discussed.Studies on the brown fat, or "hibernating gland", have been reviewed by Johansson (1). T h e lipids have been examined mainly by histochemical techniques. LaChance (2) measured the total lipid content of the interscapular fat of growing rats. Langer and Langer-Schierer (3, 4) measured the total lipid and lipid phosphorus in the brown fat of European hamsters and growing rats. T o our knowledge, no detailed study of the phosphatides of brown fat has been made.T h e present study is part of an extended project t o study the host-virus relationship in experimental infection of a number of hibernating and nonhibernating species (S), with particular reference t o the susceptibility of brown fat.

Crystal Structure of Human Arylsulfatase A: The Aldehyde Function and the Metal Ion at the Active Site Suggest a Novel Mechanism for Sulfate Ester Hydrolysis,

“…This assumption is based on the high degree of structural similarity of the two enzymes at and around the active site (see below) and the observation that ox liver ASA displays phosphodiesterase activity in that it hydrolyzes adenosine and guanosine 3′,5′-cyclic phosphates to the corresponding nucleoside 5′-monophosphates (Uchida et al, 1981). The analogy is further strengthened by infrared spectroscopy using H 2 18 O (Spencer, 1958(Spencer, , 1962 and by 17 O NMR (Marker & Roy, 1983), indicating that ASA hydrolyzes the RO-SO 3bond comparable to the hydrolysis of RO-PO 3 2by AP (Coleman, 1992).…”

Messenger ribonucleic acid of cerebral nuclei

“…However, use of this procedure assumes that there is uniform labelling of phosphate within the RNA molecules. This assumption seems to be unwarranted (Spencer, 1962).…”

Hormonal Sensitivity of Brown Fat Cells of Fetal Rats in Monolayer Culture

“…The fatty acid of uniocular fat cells in culture was also approximately the same, in ratio, as those above. But the ratios of palmitoleic and stearie acids were somewhat different; the difference probably just reflects the way white fat and brown fat differs in terms of their fatty acid composition (Spencer et al, 1962;Napolitano et al, 1965). Table 3 Analysis of fraction of the main constituent fatty acids of the brown fat (tissue in vivo), the brown fat cells in cu1ture 'and the unilocular fat cells in culture, by gas chromatography Table 1.…”