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981.
982.
983.
Effects of prolonged incubation of isolated fat cells on their response to hormones stimulating lipolysis and glucose metabolism
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1. The metabolism of isolated fat cells from parametrial adipose tissue of starved normal rats was studied during 8hr. incubation. 2. There was a three- to eight-fold increase in conversion of glucose into carbon dioxide, fatty acids and glycerol during the fourth to eighth hours of incubation in 4% albumin buffer over that seen during the first 4hr. of incubation. 3. The addition of growth hormone and dexamethasone to fat cells at the start of the incubation period accelerated lipolysis during the first 4hr. of incubation but no further effect was seen during the fourth to eighth hours of incubation. Addition of growth hormone and dexamethasone to fat cells that had been incubated for 4hr. did not accelerate lipolysis during the next 4hr. whether fat cells were incubated with or without glucose. 4. Fat cells incubated for prolonged periods also displayed a reduced sensitivity to the lipolytic action of adrenocorticotrophic hormone. 5. During prolonged incubation there was no damage to the cells as judged by the retention of two soluble cytoplasmic enzymes, lactate dehydrogenase and malate dehydrogenase, within the cells. 相似文献
984.
Comparative studies of bile salts. Myxinol disulphate, the principal bile salt of hagfish (Myxinidae) 总被引:3,自引:3,他引:0
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G. A. D. Haslewood 《The Biochemical journal》1966,100(1):233-237
1. The principal bile salt, myxinol disulphate, of two hagfish species, Eptatretus stoutii and Myxine glutinosa, has been shown by chemical methods and by optical-rotatory and mass-spectral considerations to be probably the C-3,27-disulphate ester of 3beta,7alpha,16alpha,27-tetrahydroxy-5beta-cholestane. 2. Myxine liver sterols were about half ;free' and half esterified: cholesterol only was identified. 3. The chemical nature of myxinol is what might be expected for the bile alcohol of a very primitive vertebrate. 相似文献
985.
The metabolism of [2-14C]indole in the rat 总被引:3,自引:1,他引:2
1. [2-14C]Indole has been synthesized from [14C]formate and o-toluidine via N[14C]-formyltoluidine. 2. When fed to rats, the 14C of [14C]indole (dose 70–80mg./kg. body wt.) is fairly rapidly excreted, and in 2 days an average of 81% appears in the urine, 11% in the faeces and 2·4% as carbon dioxide in the expired air. 3. Radioactivity is excreted in the urine as indoxyl sulphate (50% of the dose), indoxyl glucuronide (11%), oxindole (1·4%), isatin (5·8%), 5-hydroxyoxindole conjugates (3·1%), N-formylanthranilic acid (0·5%) and unchanged indole (0·07%). The faeces contain indoxyl sulphate (0·4% of the dose) and indole (0·2%), but the major metabolites have not been identified. 4. Fed to rats with biliary cannulae an average of 5·6% of a dose of [14C]indole (20–60mg./kg. body wt.) is excreted in the bile in 2 days. Radioactivity is present as indoxyl sulphate (0·8% dose) and 5-hydroxyoxindole conjugates (0·6%). 5. Rats further metabolize indoxyl into N-formylanthranilic acid and anthranilic acid, and oxindole into 5-hydroxyoxindole. 6. With rat-liver microsomes plus supernatant under aerobic conditions, indole gives indoxyl, oxindole, possibly isatin, N-formylanthranilic acid and anthranilic acid, but under anaerobic conditions gives only oxindole. Similarly, under aerobic conditions, oxindole gives 5-hydroxyoxindole, anthranilic acid and o-aminophenylacetic acid. 7. Indole is metabolized by two pathways, one via indoxyl to isatin, N-formylanthranilic acid and anthranilic acid, and the other via oxindole to 5-hydroxyoxindole and possibly to o-aminophenylacetic and anthranilic acid. 8. The following new compounds are described: 4-hydroxy-2-nitrophenylacetic acid, 3-, 4- and 5-benzyloxy-2-nitrophenylacetic acid, 5- and 7-hydroxyoxindole and 5-aminoacridine indoxyl sulphate. 相似文献
986.
987.
Nutrition of Coryneform Bacteria from Milk and Dairy Sources 总被引:1,自引:1,他引:0
S ummary . Growth requirements were determined for 112 cultures of coryneform bacteria including strains of Corynebacterium bovis, C. ulcerans and C. lacticum ; in general they were quite distinctive. Of 42 C. bovis strains all had an unsaturated fatty acid requirement fulfilled in chemically defined media by Tween 80, and, but for an atypically nonureolytic strain, all utilized ammonia and urea nitrogen. Whereas vitamins were unessential for the majority of C. bovis. 18 strains failed to grow in the absence of nicotinic acid; however, for 11 of these Casamino Acids replaced nicotinic acid in supporting growth. Thirteen C. ulcerans strains from aseptically drawn milk, as well as two Type Culture strains (NCTC 7907 and 7908) from the human throat required amino acid nitrogen sources, nicotinic acid, pantothenate and biotin. Some nutritional heterogeneity was shown by 46 strains collectively described as C. lacticum obtained from market milk, milk products and dairy utensils; nevertheless the nutritional differences between the groups of these strains correlated broadly with other distinguishing properties. A group of 9 markedly caseolytic strains required amino acid nitrogen sources, thiamine and biotin, whereas a second group of 30 strains, some utilizing inorganic nitrogen sources, required thiamine and pantothenate, with or without biotin. The remaining C. lacticum strains together with a number of unidentified strains from similar sources were generally slow growing and had widely differing growth requirements. 相似文献
988.
989.
990.