ABSTRACT
Exposure of sated rats to 45% N2 in air for 5h increased serum triglyceride levels by 212% over the levels in normoxic rats. This increase in triglyceride levels was accompanied by a decrease in plasma triglyceride hydrolase activity after intravenous injection of heparin. Further fractionation of the activity by inhibition of lipoprotein lipase indicated that the low triglyceride hydrolase activity is mainly due to a reduction in hepatic triglyceride lipase, which is inversely correlated with the serum triglyceride level. The hypoxic exposure decreased the arterial blood [acetoacetate]/[beta-hydroxybutyrate] ratio in the sated rats, which is believed to reflect the oxidation-reduction state in hepatic mitochondria, but did not affect the level of serum enzymes indicative of tissue damage. On the other hand, triglyceride levels did not change during hypoxic exposure in fasted rats. Thus, hypertriglyceridemia in sated rats following exposure to hypoxia may result from impaired removal of circulating triglycerides by hepatic triglyceride lipase located in the sinusoidal surface of the liver.
Subject(s)
Hypertriglyceridemia/blood , Hypoxia , Lipase/blood , Lipoprotein Lipase/blood , Triglycerides/blood , Animals , Fasting , Hypertriglyceridemia/physiopathology , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/therapeutic use , Liver/enzymology , Male , Mitochondria/metabolism , Oxidation-Reduction , Rats , Rats, Sprague-Dawley , Time FactorsABSTRACT
Cold induces increased intake of salt in mice. To examine involvement of renin and catecholamines, male ICR mice were exposed to cold (7-9 degrees C; 6 h/day; 4 days), and half of them were allowed to choose between water and 0.9% NaCl. Plasma renin activity (PRA) and catecholamine concentrations in plasma, adrenal gland, kidney, brown adipose tissue (BAT) and brain were examined in three phases: for 9 h before exposure to cold, during 6 h of cold exposure and for 9 h after the exposure. The amount of salt intake from NaCl solution and from food, PRA and noradrenaline (NE) concentrations in kidney and medulla oblongata were higher during cold and the 9 h after exposure to cold than during the 9 h before the exposure. These results are consistent with the suggestion that cold induced catecholamine metabolism enhanced activity in the renin-angiotensin system, which played an important role in the arousal of salt appetite. During cold exposure, concentrations of NE and dopamine in BAT were higher in mice with access to NaCl solution than those without NaCl to drink. These results suggest that cold-induced salt intake enhanced non-shivering thermogenesis, and are consistent with our previous report that high salt intake helped to maintain colonic temperature under cold exposure.
Subject(s)
Body Temperature Regulation/physiology , Catecholamines/metabolism , Cold Temperature , Renin/blood , Sodium Chloride, Dietary/administration & dosage , Adipose Tissue, Brown/metabolism , Adrenal Glands/metabolism , Animals , Catecholamines/blood , Dopamine/blood , Dopamine/metabolism , Drinking , Eating , Epinephrine/blood , Epinephrine/metabolism , Hypothalamus/metabolism , Kidney/metabolism , Male , Medulla Oblongata/metabolism , Mice , Mice, Inbred ICR , Norepinephrine/blood , Norepinephrine/metabolism , Sodium, Dietary/administration & dosageABSTRACT
The rapid and effective purification of soluble fumarate reductase from baker's yeast achieved by Blue Sepharose CL-6B chromatography. Cibacron Blue F3GA, the chromophore of Blue Sepharose, inhibited the activity of fumarate reductase. The enzyme bound to the column was selectively eluted by flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN) or riboflavin. The purified enzyme was essentially homogeneous as indicated by polyacrylamide gel electrophoresis under nondenaturing conditions and under denaturing conditions in sodium dodecylsulfate. By this procedure, the enzyme could be rapidly purified with high yield from yeast cells.
Subject(s)
Chromatography, Affinity/methods , Saccharomyces cerevisiae/enzymology , Sepharose/analogs & derivatives , Succinate Dehydrogenase/isolation & purification , Cytoplasm/enzymology , Electrophoresis, Polyacrylamide GelABSTRACT
Hepatocyte growth factor (HGF) is a polypeptide involved in liver regeneration. Its amino acid sequence and gene structure are similar to those of coagulation-related serine proteases. We have used a cDNA clone of HGF and flow-sorted human chromosomes to assign this gene to chromosome 7. Fluorescence in situ hybridization of the HGF genomic clones to human metaphase chromosome spreads showed the localization of this gene to 7q21. Estimation of fluorescent signals relative to arbitrary reference points (ARPs) allowed further localization to 7q21.1.