OXIDATION OF GLUCOSE-U-C14 AND PALMITATE-1-C14 BY LIVER, KIDNEY, AND DIAPHRAGM FROM HAMSTERS IN COLD EXPOSURE AND HIBERNATION

Joan Baumber; Arliss Denyes

doi:10.1139/o65-085

OXIDATION OF GLUCOSE-U-C14 AND PALMITATE-1-C14 BY LIVER, KIDNEY, AND DIAPHRAGM FROM HAMSTERS IN COLD EXPOSURE AND HIBERNATION

Canadian Journal of Biochemistry ◽

10.1139/o65-085 ◽

1965 ◽

Vol 43 (6) ◽

pp. 747-753 ◽

Cited By ~ 2

Author(s):

Joan Baumber ◽

Arliss Denyes

Keyword(s):

Cold Acclimation ◽

Cold Exposure ◽

Tissue Slices ◽

Golden Hamsters ◽

Liver Slices ◽

Oxidation Of Glucose

The percentage of glucose-U-C14 and palmitate-1-C14 converted to C14O2 by tissue slices from golden hamsters exposed to cold, hibernating, and arousing from hibernation was studied. Liver, kidney, and diaphragm were the tissues selected. It was found that liver slices had an increased capacity to oxidize palmitate and a decreased capacity to oxidize glucose to CO2 throughout cold exposure, hibernation, and arousal. Kidney also had an increased oxidation of palmitate at 48 hours of cold exposure, but this declined on cold acclimation. During hibernation, in vitro conversion of both palmitate and glucose to CO2 was reduced. Conversion of palmitate and glucose to CO2 by diaphragm was depressed during hibernation. During arousal, oxidation of glucose by diaphragm was greater than that during hibernation, while oxidation of palmitate did not change. It was concluded that the results did not support a view that there is a preferential catabolization of lipid by all tissues in the cold-acclimated and hibernating hamster.

Download Full-text

Acetate-1-C14 metabolism of white fat from hamsters in cold exposure and hibernation

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1963.205.5.905 ◽

1963 ◽

Vol 205 (5) ◽

pp. 905-908 ◽

Cited By ~ 80

Author(s):

Joan Baumber ◽

Arliss Denyes

Keyword(s):

Cold Exposure ◽

Room Temperature ◽

Fat Pad ◽

Golden Hamsters ◽

Epididymal Fat ◽

Cold Room ◽

White Fat

Incorporation of C14 from acetate-1-C14 into lipid and CO2 by epididymal fat from golden hamsters kept at room temperature, acclimated to 5 ± 1 C, in hibernation and arousing from hibernation, was measured in vitro at 37 C. Summer and winter series were compared. The C14O2 production by tissue from control and acclimated animals was similar but the C14O2 production of tissue from hibernating and arousing hamsters was significantly greater than that from acclimated animals. There was a large increase in the lipid-C14 of tissue from cold-acclimated animals and this increase persisted into hibernation but was slightly depressed in tissue from arousing animals. Many acclimated and all hibernating hamsters had involuted testes and a greater incorporation of C14 into lipid than those with noninvoluted testes. A greater percentage of hamsters hibernated in the cold room during the winter and at this time the incorporation of C14 into lipid by the fat pad was greater than in the summer.

Download Full-text

Adaptive changes in insulin and glucagon secretion during cold acclimation in the rat

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1986.250.6.e669 ◽

1986 ◽

Vol 250 (6) ◽

pp. E669-E676 ◽

Cited By ~ 2

Author(s):

C. I. Edwards ◽

R. J. Howland

Keyword(s):

Cold Acclimation ◽

Cold Exposure ◽

Hormone Secretion ◽

Glucagon Secretion ◽

Molar Ratio ◽

Adaptive Process ◽

Insulin And Glucagon Secretion ◽

Pancreatic Hormone

Arginine-stimulated insulin and glucagon outputs from isolated perfused pancreata of warm-acclimated and 2-, 4-, and 6-wk cold-acclimated rats (4 degrees C) were determined to assess whether observed changes in these parameters were a result of cold exposure per se or a part of the adaptive process of cold acclimation. Progressive and sequential changes were seen in both insulin and glucagon outputs. At 2 wk cold acclimation, glucagon rose and insulin output tended to fall, at 4 wk, glucagon output remained elevated and insulin output was further reduced, and at 6 wk, glucagon output had returned to control levels, whereas insulin output was substantially further reduced. These changes resulted in reduction of the insulin-to-glucagon molar ratio of the total arginine-induced output from 7.27 +/- 1.76 (SE) in the warm acclimate to 2.31 +/- 0.79 (SE) at 2 wk, 1.42 +/- 0.29 (SE) at 4 wk, and 1.26 +/- 0.21 (SE) at 6 wk cold acclimation. The data do not provide in vitro support for the hypothesis that changes in pancreatic hormone secretion in vivo are a consequence of cold exposure and not cold acclimation.

Download Full-text

Effect of Prolonged Cold Exposure on in Vitro Respiration and Anaerobic Glycolysis of Rat Liver

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1958.192.2.253 ◽

1958 ◽

Vol 192 (2) ◽

pp. 253-257 ◽

Cited By ~ 9

Author(s):

John P. Hannon

Keyword(s):

Respiratory Rate ◽

Rat Liver ◽

Cold Exposure ◽

Tissue Slice ◽

Exact Nature ◽

Anaerobic Glycolysis ◽

Control Value ◽

Liver Slices

Liver slices were prepared from rats that had been exposed to cold (5 ± 1°C) for intervals of 2, 4, 6 or 9 weeks, and assays were made for respiratory rate and the rate of anaerobic glycolysis. The results of the respiration experiments indicated the first 4 weeks' cold exposure was associated with increasing qo2 values, whereas exposure longer than 4 weeks was associated with qo2 that returned toward the control value. The results indicated further that the exact nature of the substances being metabolized in the conventional tissue slice experiment was unknown. The results of the anaerobic experiments indicated the rate of anaerobic glycolysis decreased progressively as the duration of cold exposure was increased.

Download Full-text

The utilization of glucose by tissue slices of liver and other organs of the domestic fowl

Canadian Journal of Biochemistry ◽

10.1139/o68-198 ◽

1968 ◽

Vol 46 (10) ◽

pp. 1321-1326 ◽

Cited By ~ 10

Author(s):

H. J. Duncan

Keyword(s):

Fatty Acids ◽

Total Lipid ◽

Rat Heart ◽

Domestic Fowl ◽

Sexual Maturity ◽

Egg Production ◽

Tissue Slices ◽

Liver Slices ◽

Mammalian Tissues ◽

Oxidation Of Glucose

The utilizations of glucose-1-14C, glucose-6-14C, and glucose-U-14C by liver slices from the immature and the laying domestic fowl have been evaluated. The relative degrees of incorporation of C-1 and C-6 into CO2, total lipid, fatty acids, and glyceride-glycerol resulted in C-1/C-6 quotients that approximated unity for both groups of fowl. The amounts of incorporation of the two specifically labelled carbon atoms into glycogen were significantly different for liver from the immature bird, but not for that from the laying fowl. These results indicate that the commencement of egg production is not accompanied by activation of the phosphogluconate oxidative pathway.When compared on a DNA basis, the amounts of isotope from glucose-U-14C incorporated into CO2, total lipid, fatty acids, glyceride-glycerol, and glycogen by liver slices from the immature fowl were almost equal to the degrees of incorporation observed following incubation of liver obtained from laying birds. The results with glucose-U-14C suggest that little or no modification of carbohydrate metabolism occurred when sexual maturity was reached.Yields of 14CO2 from the oxidation of glucose-1-14C and glucose-6-14C by various fowl tissues other than the liver are also reported. The observed C-1/C-6 ratios were in general lower than values reported in the literature for corresponding mammalian tissues, except that the quotients for fowl heart and ovary were higher than those reported for rat heart and ovary.

Download Full-text

THE METABOLISM OF ALDOSTERONE

Acta Endocrinologica ◽

10.1530/acta.0.0390087 ◽

1962 ◽

Vol 39 (1) ◽

pp. 87-102 ◽

Cited By ~ 17

Author(s):

Thomas Sandor ◽

André Lanthier

Keyword(s):

Human Kidney ◽

Water Soluble ◽

Tissue Slices ◽

Kidney Slices ◽

Liver Slices ◽

Glucuronide Conjugation ◽

The Media ◽

Human Liver Slices ◽

Acid Labile

ABSTRACT A study was made of the metabolism of synthetic dl- and d-aldosterone and biosynthetic d-aldosterone-4-14C by surviving human liver slices, and of the metabolism of d-aldosterone by human kidney slices. After incubation of aldosterone with the tissue slices in a Krebs-Ringer-phosphate glucose medium at 37° C, the media were subjected to fractional hydrolysis and extracted with chloroform. In this way, it was possible to study not only the metabolites of the substrate but also the formation of water soluble conjugates of these metabolites and of aldosterone. It was found that the major in vitro metabolite of aldosterone, using liver slices as a source of enzymes, was the glucuronide of a Ring A reduced α-ketolic steroid (A2). It was possible to show that this metabolite was identical to the tetrahydroaldosterone found in glucuronide conjugation in human urine. In addition, several other metabolites were isolated but in smaller quantities. These include metabolite A1, a possible stereoisomer of A2, two Δ4-3-ketonic, non reducing metabolites and a number of 14C substances characterized only by chromatographic mobilities. Chemically unchanged aldosterone was present in free, glucuronide and acid labile conjugation. Human kidney slices, in addition to producing small amounts of A2, did conjugate aldosterone in both the glucuronide and acid labile form. The intravenous infusion of d-aldosterone to an adrenalectomized patient resulted in the urinary excretion of A2-glucuronide, aldosterone-glucuronide and the mild acid labile aldosterone conjugate.

Download Full-text

CORTICOSTEROID-UMSATZ UND CORTICOSTEROID-PRODUKTION BEI RATTEN UNTER DER BEHANDLUNG MIT ANABOLEN STEROIDEN

Acta Endocrinologica ◽

10.1530/acta.0.0480263 ◽

1965 ◽

Vol 48 (2) ◽

pp. 263-271 ◽

Cited By ~ 8

Author(s):

Herbert Schriefers ◽

Gerlinde Scharlau ◽

Franzis Pohl

Keyword(s):

Production Rate ◽

Adult Female ◽

Anabolic Steroids ◽

Reduction Rate ◽

Female Rats ◽

Adrenal Weight ◽

Hydrogenase Activity ◽

Anabolic Effect ◽

Liver Slices

ABSTRACT After the administration of anabolic steroids to adult female rats in daily doses of 1 mg per animal for 14 days, the following parameters were investigated: the rate of the Δ4-5α-hydrogenase-catalyzed cortisone reduction in liver slices and microsomal fractions, the adrenal weight and the in vitro corticosterone production rate. Among the steroids tested, only 17α-methyl-testosterone and 17α-ethyl-19-nor-testosterone were effective in lowering significantly cortisone reduction rate by liver slices with concomitant decreases in microsomal Δ4-5α-hydrogenase-activity. Testosterone, 19-nor-testosterone, 17α-ethinyl-19-nor-testosterone, 17α-methyl-17β-hydroxy-androsta-1,4-dien-3-one and 1-methyl-17β-hydroxy-androst-1-en-3-one were ineffective or only slightly effective. Adrenal weight and absolute corticosterone production rate (μg/60 min per animal) were decreased after treatment with 17α-methyl-testosterone, 17α-ethyl-19-nor-testosterone and 1-methyl-17β-hydroxy-androst-1-en-3-one. Corticosterone production was decreased with 17α-ethinyl-19-nor-testosterone in spite of an unchanged adrenal weight. The relative corticosterone production rate (μg/60 min · 100 mg adrenal) was in any cases unaffected. According to these results there exists – with the exception of 17α-ethinyl-19-nor-testosterone – a strict parallelism between corticosteroid turnover and corticosterone production rate: unchanged turnover is correlated with unchanged corticosterone production rate, while a decreased turnover is correlated with decreased adrenal activity. The protein-anabolic effect of certain anabolic steroids may be partly due to an anti-catabolic action of these compounds resulting from a decreased corticosteroid inactivation and production rate. Possible mechanisms by which anabolic steroids may affect corticosteroid-balance are discussed.

Download Full-text

Precision-cut Guinea-pig Liver Slices as a Tool for Studying the Toxicity of Volatile Anaesthetics

Alternatives to Laboratory Animals ◽

10.1177/026119299001800120.1 ◽

1990 ◽

Vol 18 (1_part_1) ◽

pp. 191-199

Author(s):

Hanan N. Ghantous ◽

Jeanne Fernando ◽

Scott E. Morgan ◽

A. Jay Gandolfi ◽

Klaus Brandel

Keyword(s):

Guinea Pig ◽

Rank Order ◽

Normal Liver ◽

Liver Slice ◽

Volatile Anaesthetics ◽

Pig Liver ◽

Liver Slices ◽

Guinea Pig Liver ◽

Krebs Henseleit Buffer

Cultured precision-cut liver slices retain normal liver architecture and physiological biochemical functions. Hartley male guinea-pig liver slices have proven to be a good model for studying the biotransformation and toxicity of halothane. This system was used to evaluate the biotransformation and toxicity of different volatile anaesthetics (halothane, enflurane, isoflurane and sevoflurane), and compare their effects to those of new anaesthetics (desflurane). Liver slices (250–300μm thick) were incubated in sealed roller vials, containing Krebs Henseleit buffer at 37°C under 95% O2:5% CO2 atmosphere. Volatile anaesthetics were delivered by volatilisation after pre-incubation for 1 hour to produce a constant concentration in the medium. Production of the metabolites, trifluroacetic acid and fluoride ion, was measured. Intracellular potassium ion content, protein synthesis and secretion were determined as indicators of viability of the slices. The rank order of biotransformation of anaesthetics by the liver slices was halothane >sevoflurane>isoflurane and enflurane>desflurane. The rank order of hepatotoxicity of these anaesthetics was halothane>isoflurane and enflurane>sevoflurane and desflurane. Halothane is the anaesthetic which is metabolised furthest and has the most toxic effect, while desflurane is the least metabolised anaesthetic and has the least toxicity. This in vitro cultured precision-cut liver slice system appears to be suitable for studying the biotransformation of volatile anaesthetics and correlating its role in the resulting toxicity.

Download Full-text