Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Purified epithelial basolateral membrane vesicles were prepared from lobster hepatopancreas by sorbitol gradient centrifugation. Na+-K+-adenosinetriphosphatase, alkaline phosphatase, and cytochrome-c oxidase enzyme activities in the final membrane preparation were enriched 9.6-, 1.4-, and 0.4-fold, respectively, compared with their activities in the original tissue homogenate. Vesicle osmotic reactivity was demonstrated using 60-min equilibrium 36Cl uptake experiments at a variety of transmembrane osmotic gradients. 36Cl uptake into vesicles preloaded with HCO3 was significantly greater than into vesicles lacking HCO3. This exchange process was stimulated by a transmembrane proton gradient (internal pH greater than external pH). Proton-gradient-dependent Cl-HCO3 exchange was potential sensitive and stimulated by an electrically negative vesicle interior. 36Cl influx (4-s exposures) into HCO3-loaded vesicles occurred by the combination of 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid sensitive, carrier-mediated transfer and "apparent diffusion." 36Cl influx was a hyperbolic function of both internal [HCO3] and internal [Cl]. The two internal anions displayed a 100-fold difference in apparent affinity constants with HCO3 being strongly preferred. 36Cl influx was stimulated more by preloaded monovalent than by divalent anions. Na was an inhibitor of proton-dependent anion antiport, whereas K had no effect. A model for HCl-HCO3 antiport is suggested that employs combined transmembrane concentration gradients of Cl and HCO3 to power anion exchange and transfer protons against a concentration gradient.
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PMID:Proton-stimulated Cl-HCO3 antiport by basolateral membrane vesicles of lobster hepatopancreas. 303 81

Rats were fed a semipurified diet providing 10% casein supplemented with methionine for 2 wk, at which time some animals received the same diet without the methionine for 4 d. Animals that received linamarin were given a single oral dose containing 500 or 250 mg per kilogram of body weight. At the higher linamarin dose all animals died within 5 h after dosing. Biochemical and physiological changes observed in these rats included severe metabolic acidosis, decreased cytochrome oxidase activities, atrial fibrillation, and decreased respiratory rates. In general, the cardiac adenosinetriphosphatase enzymes were inhibited by linamarin. None of these changes were moderated by dietary methionine supplementation. At the lower linamarin dose dietary supplementation with methionine appeared to reduce incidences of clinical toxicity signs and fatalities. No methionine effect was observed in the other biochemical and physiological measurements in rats given this amount of linamarin. The results suggest that dietary supplementation with methionine provided some protection against the toxicity of the lower level of linamarin administered.
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PMID:Influence of dose level and methionine intake on the effects of linamarin administration to rats. 627 76

Sodium azide (AZ) is a nitrovasodilator with diverse biochemical properties. We found that low doses of AZ led to a profound protective effect against postischemic, acute renal failure (ARF) in rats. AZ, given at 250 micrograms/kg iv, before 25 min of renal artery occlusion (RAO) and again before reperfusion, conferred almost complete protection against loss of kidney function determined 18 h after RAO. The effect of AZ was evidenced by a higher creatinine clearance (+348%) and lower levels of blood urea nitrogen (-69%) and histological renal damage (-50%) compared with ischemic control animals. Indexes of kidney function in AZ-treated animals subjected to RAO were not significantly different from those of nonischemic control animals. Two other nitrovasodilators, sodium nitroprusside and hydralazine, at doses which produced decreases in blood pressure similar to that of AZ, were ineffective at preventing ARF. The beneficial effect of AZ may be due to its known ability to inhibit one or more enzymes including adenosinetriphosphatase, cytochrome-c oxidase, and myeloperoxidase.
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PMID:Sodium azide protects against ischemia-induced acute renal failure in rats. 834 10

To investigate the pathogenesis of retina lesions caused by intraocular pressure elevation, activities and distribution of enzymes in retina including lactic dehydrogenase (LDH), succinate dehydrogenase (SDH), adenosinetriphosphatase (AT-Pase), acid phosphatase (ACP), cholinesterase (ChE), cytochrome oxidase (CCO), nucleotidase (5'-Nase) and glucose-6-phosphatase (G6Pase) were determined histochemically in 30 rabbits. It was found that 1) in the early stage of intraocular pressure elevation, the activities of LDH, SDH, ATPase, ACP, and ChE in retina were increased, while the activities of CCO, 5'-Nase decreased; 2) in the late stage of intraocular pressure elevation, the activities of all these enzymes but ACP, which showed a reduced activity, were close to the normal level; 3) in superoxide dismutase.(SOD-CCE) treated group, except the slight increase of LDH and G6Pase activities, the activities of the remaining enzymes were near to normal. Our results suggest that the various histochemical changes in retina induced by intraocular pressure elevation were compensatory in the early stage and were beneficial to the supply of energy needed in retinal tissue and cellular metabolism; while in the late stage, the lesion of retina cells developed due to decompensation. SOD-CCE could alleviate the retinal lesions caused by intraocular pressure elevation, and can be used as auxiliary drug for the treatment of intraocular pressure elevation.
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PMID:Enzymatic histochemistry of retina with experimental intraocular pressure elevation in rabbits. 873 48

Aging of rats results in slower activities of calcium transport by cardiac calcium adenosinetriphosphatase (ATPase) of the sarcoplasmic reticulum (SR) and mitochondrial cytochrome oxidase (COX). These enzyme activities are faster after exercise training of previously sedentary old rats. Our purpose was to determine whether the expression of the genes encoding SR calcium ATPase (SERCA2a) or COX is altered by exercise training. Old (24-mo-old) male Fischer 344 rats were assigned to SO (sedentary old) or EO (exercised old) groups and compared with younger (12-mo-old) sedentary rats (SM). EO rats were trained on a treadmill for 8-10 wk. SERCA2a and COX mRNAs were lower (P < 0.05) in SO compared with SM and EO, whereas glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and cardiac alpha-actin mRNAs were similar across groups. The immunoreactive protein contents of cardiac calcium ATPase, cytochrome c, sarcomeric actin, and GAPDH followed the changes, when observed, in mRNA contents. Thus pretranslational mechanisms may be modified in some genes during aging and exercise training of previously sedentary old rats.
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PMID:SERCA2a and mitochondrial cytochrome oxidase expression are increased in hearts of exercise-trained old rats. 876 Jan 59