Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The extranuclear mitochondrial oligomycin-resistant mutation of Aspergillus nidulans, (oliA1), was transferred asexually into four nuclear oligomycin-resistant strains of different phenotypes. In all four cases, the possession of the nuclear plus extranuclear mutation led to an increase in the in vivo level of oligomycin resistance. In two cases, the altered cytochrome spectrum and impaired growth ability determined by (oliA1) were suppressed by the nuclear mutations. In the third case, the in vitro oligomycin resistance of the double mutant ATPase was dramatically increased above that of either of the component single mutant strains, indicating a synergystic interaction between the nuclear and extranuclear gene products. In the fourth case, the double mutant became cold-sensitive. A new extranuclear mitochondrial oligomycin-resistant mutation (oliB332) is described. This mutant is phenotypically similar to, though not identical with, (oliA1) but is separable by recombination. A range of nuclear oligomycin-resistant mutants have been mapped. Despite presenting five distinctly different phenotypes, they all map at the same locus.
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PMID:Nuclear-extranuclear interactions affecting oligomycin resistance in Aspergillus nidulans. 14 64

Triiodothyronine (T3) treatment induced marked hypertrophy of the brown adipose tissue (BAT), similar to that observed in cold-acclimated animals, although partly due to fat deposition. Similar to cold acclimation, T3 treatment also increased the oxidation of succinate by tissue slices without concomitant increase in isolated mitochondria. It is therefore suggested that thyroid hormones, like cold acclimation, effect conformational changes in the mitochondria, leading to greater expression of the succinic oxidase in the tissue. T3 treatment was not followed by any change in the respiratory activity of tissue slices in the presence of alpha-GP. Likewise, no change was found either in other oxidative activities tested in isolated mitochondria (e.g., NADH and cytochrome oxidases) or in the concentration of the components of the electron transport chain in the mitochondria.
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PMID:Metabolic activity of brown adipose tissue in T3-treated hamsters. 18 8

Cold acclimation caused the following changes in the brown adipose tissue (BAT) of the hamster: the relative weight of the tissue increased, it color darkened, the multilocular structure predominated, and tissue protein content increased while fat content decreased. There was also an increase in the mitochondrial protein content. Heat acclimation had the opposite effects, i.e., the color became lighter, total and mitochondrial protein decreased, fat content increased, and tissue structure was mostly unilocular. Accordingly, cold acclimation was accompanied by increased tissue respiration in the presence of chi-glycerophosphate (chi-GP) and succinate, whereas heat acclimation reduced the respiratory activity of the tissue with these substrates. Isolated BAT mitochondria from cold-acclimated animals increased activities of chi-GP and NADH oxidase, whereas the activities of succinic and cytochrome oxidases and the amount of mitochondrial cytochromes were unchanged. The effects of heat acclimation were more pronounced: there was a decrease in the activities of chi-GP, succinic, NADH, and cytochrome oxidases, as well as in the cytochrome a and a3 content. When respiration of tissue slices on succinate was compared to the maximal potential respiration, as measured with mitochondria disrupted by freezing and thawing, it was found that the relative activity (slices vs. disrupted mitochondria) was highest in cold-acclimated animals and decreased progressively with increasing acclimation temperatures. It is suggested that the differences in the apparent activity of the mitochondria were due to changes in the conformation of the mitochondria as a result of acclimation.
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PMID:Metabolic adaptations in brown adipose tissue of the hamster in extreme ambient temperatures. 96 55

The cytochrome spectra of two extranuclear mutants of Aspergillus nidulans and the double-mutant recombinant formed from them have been examined both at room temperature and at the temperature of liquid N2 and compared with those of the wild-type strain. The oligomycin-resistant, slow growing mutant contained an increased amount of cytochrome c without any loss of cytochromes b and a,a3. The cold-sensitive mutant, apparently normal when grown at 37 C, showed an increased amount of cytochrome c and a partial loss of cytochromes b and a,a3 when grown at 20 C. A combination of these effects was observed in the double-mutant recombinant. Cyanide-resistant respiration was present in both mutant strains and in the recombinant at much higher levels than in the wild-type strain. In the oligomycin-resistant mutant, this was usually present together with cyanide-sensitive respiration, whereas in the cold-sensitive mutant and recombinant grown at 20 C cyanide-resistant approached 100%. Inhibitor and growth yield studies indicated that the cyanide-resistant pathway was not used by the cold-sensitive mutant during growth at 20 C.
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PMID:Cytochrome abnormalities and cyanide-resistant respiration in extranuclear mutants of Aspergillus nidulans. 110 21

Cardiac storage for transplantation is currently limited to 6 hours. To better understand the metabolic changes that occur during hypothermic (4 degrees C) storage, we monitored the morphologic and metabolic changes in the canine myocardium at 0, 12, and 24 hours of storage in University of Wisconsin solution. Attempts to isolate cardiac mitochondria resulted in a progressive decline in the yield (milligrams of mitochondria per gram of heart tissue), which decreased (p less than 0.05) from 9.2 +/- 0.4 at 0 hours (control) to 4.0 +/- 0.3 after 12 hours and further decreased (p less than 0.05) to 1.9 +/- 0.2 after 24 hours of cold storage. Mitochondrial state 3 respiration fell to 64% of control after 12 hours and 28% of control after 24 hours of cold storage (p less than 0.05). Citrate synthetase activity, but not cytochrome C oxidase activity, was significantly depressed after 12 and 24 hours of cold storage. Adenosine triphosphate content decreased to 67% of control after 12 hours and 50% of control after 24 hours. After 12 hours of storage, sufficient adenosine diphosphate and monophosphate were present to permit some restoration of adenosine triphosphate, provided mitochondrial function was normal after transplantation. However, restoration of mitochondrial function and adenosine triphosphate levels sufficient to support myocardial contractility was unlikely after 24 hours of storage. This study suggests that a return of adequate cardiac function after transplantation may be possible after 12 hours of cold storage in University of Wisconsin solution but not after 24 hours of cold storage.
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PMID:Prolonged hypothermic cardiac storage for transplantation. The effects on myocardial metabolism and mitochondrial function. 132 14

Previous studies showed that hydrocarbon induction of hepatic microsomal monooxygenase activity is attenuated in the teleost fish Fundulus heteroclitus acclimated to low temperature. The basis of that attenuation, and the effects of temperature on monooxygenase activity, were examined by analyzing liver cytochrome P4501A (CYP1A) mRNA, protein, and catalytic activity in control and beta-naphthoflavone (BNF)-treated F. heteroclitus acclimated to 6 or 16 degrees C. There were no temperature-related differences in total P450 content, NADPH-cytochrome c (P450) reductase activity, ethoxyresorufin O-deethylase (EROD) activity, or immunoquantified CYP1A content in hepatic microsomes of untreated fish. Fish acclimated to 16 degrees C and given a single intraperitoneal injection of BNF exhibited a rapid rise and fall in CYP1A mRNA content and an induction of EROD activity and CYP1A protein that was undiminished over 7 days. Similarly treated fish acclimated at 6 degrees C showed an increase in CYP1A mRNA content greater than that in 16 degrees C fish, but with no significant increase in EROD activity or CYP1A content over 7 days. Examined over a longer term, microsomal EROD activity was significantly induced by BNF in fish at both temperatures; activity peaked at 5-7 days in 16 degrees C fish, while in 6 degrees C fish the activity continued to rise slowly over 25 days. However, the greatest activity reached in 6 degrees C fish (0.68 nmol/min/mg) was less than half that seen in the warmer animals (1.46 nmol/min/mg). Immunodetectable CYP1A content showed the same trend as EROD activity, and the turnover number (nmol product formed/min/nmol CYP1A) for EROD activity was about the same in all groups, indicating that concentration of the catalyst alone could account for the different patterns of microsomal activity. CYP1A mRNA content was again induced to a similar degree by BNF in both the 6 and the 16 degrees C fish; the apparent half-life of the mRNA was substantially longer in cold-acclimated than in warm-acclimated BNF-treated fish. Comparing the levels of CYP1A mRNA and protein at the two acclimation temperatures following BNF treatment indicates that translational activity, rather than transcriptional activity, is the sensitive point in the effect of temperature on CYP1A induction in these fish.
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PMID:Effects of temperature acclimation on the expression of hepatic cytochrome P4501A mRNA and protein in the fish Fundulus heteroclitus. 144 51

Radiolabeled Nerve Growth Factor (NGF) was injected into either the mandibular process of the first visceral arch or the limb bud of chick embryos at Days 3.5-14 or Days 4-13 of incubation, respectively. Control embryos received injections of labeled cytochrome-C or labeled NGF plus an excess of unlabeled NGF. The tissues were then processed for autoradiography. The 125I-NGF was retrogradely transported by motoneurons of the trigeminal (V) motor nucleus on Days 3.5-8 of incubation, but not at later stages. Similar transport was seen in motoneurons of the spinal cord lateral motor column from Days 4-10 of incubation, but not at later stages. Sensory neurons of the V ganglion and of the dorsal root ganglia transported NGF at all injection ages. In no instance was the 125I-cytochrome-C transported by sensory or motor neurons. The injection of an excess of cold NGF along with labeled NGF resulted in no evidence of retrograde transport of the labeled NGF indicating that the transport was saturable. The time of transport by these brainstem and spinal cord motoneurons corresponds closely to the points during development at which they have been found to exhibit specific NGF binding. The present results, then, provide further evidence for a possible biological role for NGF during early developmental stages of these motoneuron populations.
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PMID:The ontogeny of specific retrograde transport of nerve growth factor by motoneurons of the brainstem and spinal cord. 169 Jun 77

Ubiquinol-cytochrome c reductase of beef heart mitochondria was crystallized in the presence of decanoyl-N-methylglucamide, heptanetriol, and sodium chloride with poly(ethylene glycol) as precipitant. The largest crystal has dimensions of 4 x 2 x 1 mm. The crystalline enzyme is composed of 10 subunits. It contains 2.5 nmol of ubiquinone, 8.4 nmol of cytochrome b, 4.2 nmol of cytochrome c1, 4.2 nmol of iron-sulfur cluster, and 140 nmol of phospholipid per milligram of protein. Of the last, 36% is with diphosphatidylglycerol. The crystals are very stable in the cold and show full enzymatic activity when redissolved in aqueous solution. Absorption spectra of the redissolved crystals show a Soret to UV ratio of 0.88 and 1.01 in the oxidized and the reduced forms, respectively.
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PMID:Crystallization of mitochondrial ubiquinol-cytochrome c reductase. 184 94

A chronological study was performed to investigate the postnatal development of the thermogenic capacity of the brown adipose tissue (BAT) comparing rats born and reared at 16 degrees C (cold) or 28 degrees C (control). Mitochondrial mass, cytochrome-c-oxidase activity (index of oxidative capacity) and GDP binding to mitochondria (uncoupling test) were investigated in rats from 1 to 33 days of age. Specific cytochrome-c-oxidase activity was the same in both groups during the first week, then increased in the cold group and decreased in controls; from the 9th day it was always twice as high in the former as in the latter. Specific binding of GDP to mitochondrial proteins remained almost constant in control rats during the first week contrasting with a rapid increase in that for cold rats. Afterwards it decreased in both groups until weaning but remained five times as high in cold rats as in control rats. As growth of BAT is faster and mitochondrial content greater in cold reared rats, the capacity of the tissue for thermogenesis appeared to be greatly temperature dependent soon after birth and during the entire suckling period. However the mechanisms of this stimulation remain to be elucidated.
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PMID:Thermogenic capacity of the brown adipose tissue of developing rats; effects of rearing temperature. 196 47

Staggerer mutant mice are lean despite their hyperphagia. Brown adipose tissue activity may be implicated in this phenomenon. The aim of this work is to determine the energetic metabolism and to detail some characteristics of the brown adipose tissue of Staggerer mutant mice born and reared either at 28 degrees C (within the thermoneutral zone) or 22 degrees C (cold temperature) compared to nonmutant control mice. In mutant mice reared at thermoneutrality the resting metabolism was found to be higher than that of controls, and further the activity of the brown adipose tissue increased as indicated in relative mass, composition and cytochrome oxydase activity. A stimulatory effect of cold exposure was observed in both mutant and nonmutant mice. It is suggested that Staggerer mice may provide a good model for the study of the cold-induced or diet-induced mechanisms of brown fat stimulation.
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PMID:Effects of cold acclimation on the energetic metabolism of the staggerer mutant mouse. 233 49


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