Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of both exogenous and endogenous changes in thyroid status on in vitro tissue respiration and thermogenic enzymes (sodium-potassium-adenosine triphosphatase and alpha-glycerophosphate dehydrogenase) was studied in fetal and newborn sheep. Oxygen consumption of liver and brain increased from 25 +/- 4.1 and 58.5 +/- 2.8 microliters O2 X 100 mg-1 X h-1, respectively, in tissues from unthyroidectomized fetal animals at 136-140 days gestation to 60 +/- 4.2 and 72 +/- 1.5 microliters O2 X 100 mg-1 X h-1 in tissues from unthyroidectomized newborn lambs between birth and 7 days of age. The physiological changes in thyroid function that normally occur at birth resulted in a mean (+/- SE) plasma triiodothyronine (T3) concentration of 563 +/- 39 ng/dl in the newborn lambs compared with 39 +/- 8 ng/dl in the fetal animals. Kidney respiration and thermogenic enzyme activities in the several tissues studied did not change. Liver, kidney, and brain respiration and thermogenic enzymes from T3-treated thyroidectomized fetal and newborn lambs were not increased (compared with untreated thyroidectomized animals) despite a marked increase in plasma T3 concentrations. Conclusions are that 1) liver, kidney cortex, and frontal brain cortex in the fetal and newborn lamb are relatively insensitive to the calorigenic effect of thyroid hormones, and 2) a perinatal increase in hepatic and cerebral respiration occurs in newborn animals (compared with fetal animals) but is probably not due solely to perinatal increases in thyroid hormones.
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PMID:Effect of changes in thyroid status on tissue respiration in fetal and newborn sheep. 630 3

The effects of exogenous changes in thyroid status on in vitro brown adipose tissue (BAT) cellular respiration and thermogenic enzymes (sodium-potassium ATP' ase and alpha-glycerophosphate dehydrogenase) were studied in fetal sheep. Thyroidectomy and insertion of a constant infusion pump followed by 8 days of infusion of either T3 (n = 7) or vehicle (n = 4) were performed in fetal lambs at 119-121 days gestation. The animals were then killed, and perirenal BAT was removed for study. T3 infusion resulted in a mean plasma T3 concentration of 322 +/- 52 ng/dl compared to levels at the limits of detection (9 ng/dl) in the vehicle-infused animals. Basal respiration values with or without ouabain were similar in the two groups. Maximum mean norepinephrine (NE; 10(-6) M)-stimulated respiration (110.2 +/- 11.6 microliter O2/10(6) cells X h) in the T3-treated group was greater than stimulated mean respiration (55.3 +/- 15.6 microliter O2/10(6) cells X h) in the untreated animals (P less than 0.02). NE-stimulated respiration in the presence of ouabain (i.e. nonsodium transport-dependent respiration) was increased in the T3-treated animals (P less than 0.01), while sodium transport-dependent respiration was not different. (Bu)2cAMP-stimulated respiration was greater in the T3-treated group (P less than 0.001), while alpha-glycerophosphate substrate respiration was not different. Mitochondrial alpha-glycerophosphate dehydrogenase and Na-K-ATPase activities were similar. These studies demonstrate that BAT catecholamine-stimulated respiration is influenced by thyroid status in the ovine fetus. The increase in both NE- and (Bu)2cAMP-stimulated respiration suggests a postreceptor effect on intracellular metabolism, though an effect on beta-adrenergic receptors also might have occurred. Neither sodium transport (NA-K-ATPase)-dependent respiration nor mitochondrial alpha-glycerophosphate dehydrogenase appear to be involved. These data suggest that the relative hyperthyroid state that occurs in the newborn of both man and sheep may be important through its effects on BAT metabolism to insure adequate temperature regulation during neonatal adaptation.
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PMID:Thyroid hormones augment catecholamine-stimulated brown adipose tissue thermogenesis in the ovine fetus. 632 28

A method for demonstration of activity for ATPase and various oxidative enzymes (succinic dehydrogenase, alpha-glycerophosphate dehydrogenase, and lactic dehydrogenase) in muscle/bone sections of fixed and demineralized tissue has been developed. It was found that it is possible to preserve considerable amounts of the above mentioned enzymes in the muscle fibres at the muscle/bone interfaces. The best results were obtained after 20 min fixation, and 2-3 weeks of storage in MgNa2EDTA containing media. As the same technique previously has been used to describe patterns of resorption and deposition with the aid of a mapping of presence of phosphomonoesterases on bone surfaces, the method may be used to study possible biochemical interactions between bone and muscle tissue at the muscle/bone interface.
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PMID:Methods for demonstration of enzyme activity in muscle fibres at the muscle/bone interface in demineralized tissue. 645 30

The profiles of fiber types in hindlimb muscles from the tree shrew (Tupaia glis), lesser bushbaby (Galago senegalensis), and the slow loris (Nycticebus coucang) were determined using histochemical techniques. Fibers were classified as fast-twitch oxidative-glycolytic (FOG), fast-twitch glycolytic (FG), slow-twitch oxidative (SO), or fast-twitch oxidative (FO), according to reactions for alkaline-stable ATPase, acid-stable ATPase, alpha-glucan phosphorylase, reduced nicotinamide adenine dinucleotide diaphorase, succinate dehydrogenase, mitochondrial alpha-glycerophosphate dehydrogenase (MaGPDH), and beta-hydroxybutyric dehydrogenase, as well as glycogen staining by the periodic acid-Schiff technique. Prolonged dissection of numerous muscles was carried out on hindlimbs submersed in cold Tyrode's solution; such treatment had no qualitative effect on enzyme staining reactions, but it is not a suitable procedure if one wishes to stain for glycogen. Fast-twitch oxidative (FO) fibers are alkaline-stable ATPase-positive and possess low MalphaGPDH enzyme activity. These fibers have not been reported previously in any hindlimb muscles. No muscles of any species studies were homogeneous with respect to fiber type. Slow loris muscles lacked FG fibers. The majority of the muscles of the slow loris contained numerous SO fibers. The relationship between enzyme activities and locomotor pattern is discussed.
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PMID:Comparative histochemical study of prosimian primate hindlimb muscles. I. Muscle fiber types. 645 15

A histochemical characterization of the masseter muscle was performed on biopsy samples of dentate subjects with normal occlusion. There was a continuum of ranges of oxidative and glycolytic capacities of the masseter muscle fibres. Besides the lightly-stained type I and the darkly-stained type II fibres, fibres with intermediate staining reactions for standard ATPase at pH 9.4, IM fibres, were seen in all biopsy samples. IM fibres had some staining characteristics in common with type I, i.e. the reaction for NADH-TR and for ATPase after preincubation at pH 4.6 and 4.2. Like type II fibres they showed strong reaction for menadione-linked alpha-glycerophosphate dehydrogenase and for phosphorylase. The ATPase reaction after preincubation at pH 4.6 did not generally reveal subtypes of type II. It is concluded that the masseter muscle in normal human subjects has a very special fibre composition, with ATPase-IM fibres being a part of the normal fibre population.
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PMID:Histochemical fibre-type profile in the human masseter muscle. 646 93

Serial 10-micron cryostat cross-sections of the tensor tympani muscle and of the medial gastrocnemius muscle from adult domestic cats were incubated for myofibrillar ATPase, NADH tetrazolium reductase (NADH-TR), succinic dehydrogenase (SDH), malate dehydrogenase (MDH) and menadione-linked alpha-glycerophosphate dehydrogenase (alpha GPDH). The optical density of individual tensor tympani and gastrocnemius muscle fibres after different incubation procedures was measured photometrically. The absorbance values of the tensor tympani fibres were related to the values of the type I, type IIA and type IIB fibres of the gastrocnemius muscle. Only two different types of fibre could be demonstrated in the tensor tympani, one type resembling the type I and another resembling the type IIA of the gastrocnemius muscle. The findings are discussed in relation to other, recent immunohistochemical studies on cat tensor tympani muscle fibres.
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PMID:Histochemical characteristics of the tensor tympani muscle in relation to the medial gastrocnemius muscle of the cat. 649 59

The populations of fiber types in hindlimb muscles of the tree shrew (Tupaia glis), lesser bushbaby (Galago senegalensis), and the slow loris (Nycticebus coucang) were described and an attempt was made to correlate populations of fiber types and locomotor patterns. Muscle fibers were assigned to one of the following groups: fast-twitch glycolytic (FG), fast-twitch oxidative-glycolytic (FOG), and slow-twitch oxidase (SO). Histochemical techniques for the demonstration of alkaline- and acid-stable ATPase, succinic dehydrogenase, and mitochondrial alpha-glycerophosphate dehydrogenase were used in the classification of muscle fibers. Results indicated that the FG fiber type is the predominant fiber type in muscles used for jumping, the FOG fiber type is predominant in muscles used for running, and the SO fiber type occurs in high percentages in postural muscles. The SO fiber was also the most common fiber in muscles of the slow loris-a species that exhibits a slow, deliberate, sustained locomotor pattern. Intramuscular regional variations in populations were seen in some larger muscles of the tree shrew, but not in the lesser bushbaby and slow loris. Our results did not support the contentions of others that analogous muscles in different species have similar populations of fiber types.
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PMID:Comparative histochemical study of prosimian primate hindlimb muscles. II. Populations of fiber types. 679 89

Procyclic culture forms of Trypanosoma brucei stock 427 have been screened for the presence of enzymes involved in glycolysis, mitochondrial energy metabolism and threonine degradation. The enzyme activities in the procyclics were compared with those of the blood stream forms. The specific activities of glycolytic enzymes represented 30-70% of the respective levels in the blood stream form, except for hexokinase which was 25-fold reduced. Cell fractionation showed that the enzymes involved in the early sequence of the glycolytic pathway, i.e. from hexokinase to phosphoglycerate kinase, and the enzymes NAD+-linked glycerol-3-phosphate dehydrogenase and glycerol kinase were all present in glycosomes equilibrating at a density of 1.23 g/cm3 in sucrose gradients. Malate dehydrogenase was 8-fold more active in procyclics than in bloodstream forms. This increase in activity was the result of the appearance of malate dehydrogenase in the glycosomes of the procyclics, in addition to mitochondrial and cell-sap activities which were present in both stages of the life cycle. Glycosomes contained part of the adenylate kinase activity, which was also associated with the mitochondrion. Succinate dehydrogenase and sn-glycerol-3-phosphate dehydrogenase, together with oligomycin-sensitive ATPase, were located in the mitochondrion which had a density in sucrose ranging from 1.16 to 1.18 g/cm3. This organelle also contained L-threonine 3-dehydrogenase and carnitine acetyltransferase, two enzymes involved in threonine catabolism. The latter two enzymes had activities which were, respectively, 15-and 13-fold higher in the procyclics than in the bloodstream form. Mitochondrial sn-glycerol-3-phosphate dehydrogenase was decreased 4-fold.
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PMID:Localization of malate dehydrogenase, adenylate kinase and glycolytic enzymes in glycosomes and the threonine pathway in the mitochondrion of cultured procyclic trypomastigotes of Trypanosoma brucei. 680 9

1. This report describes selected histochemical and physiological properties of the motor units of adult cat soleus muscle approximately one year after self- and cross-reinnervation with the nerve of the heterogenous flexor hallucis longus (f.h.l.). Self-reinnervated f.h.l. motor units are also considered. Whole muscles were tested for fibre reaction to alkaline pre-incubated ATPase, alpha-glycerophosphate dehydrogenase (alpha-GPD) and reduced nicotinamide adenine dinucleotide diaphorase (NADH-D). Motor units were isolated and studied by splitting the ventral root in acute preparations.2. The histochemical fibre type profile in the self-reinnervated muscle was comparable to normal muscle as was mean twitch contraction time, twitch-tetanus ratio and fatigue index. The mean tetanic tension of the soleus self- and cross-reinnervated motor units appeared close to a normal soleus whereas the mean tetanic tension of the f.h.l. self-reinnervated units was significantly less than a normal f.h.l.3. An average of 14% of the fibres of the soleus cross-reinnervated muscles had high ATPase and a alpha-GPD staining intensity in contrast to normal and self-reinnervated soleus in which such fibres are absent. Thus alkaline lability of myofibrillar ATPase increased in some fibres of what was originally a homogeneous population. The small increase in the number of densely staining fibres for ATPase at an alkaline pH (14%) was associated with a 73% decrease in (mean) contraction time (41 +/- 11 ms) of the thirty-three cross-reinnervated muscle units studied, with no unit's contraction time greater than 60 ms. Mean contraction times for the self-reinnervated soleus and f.h.l. muscles were 78 +/- 31 ms and 27 +/- 8 ms respectively.4. All fibres of the soleus cross-reinnervated muscles showed intense reaction to NADH-D, as was true of self-reinnervated soleus. This staining pattern is typical of normal soleus. In concordance, these motor units consistently demonstrated a high resistance to fatigue when stimulated for a four-minute period.5. These results suggest that in the adult self-and cross-reinnervated soleus muscle, there is some active mechanism which regulates the eventual size of motor units as reflected by tetanic tension.6. Change in contraction time from that typical for a soleus unit to that similar to an f.h.l. unit remains incomplete one year after cross-reinnervation. Within this time this partial change in single motor units reflects incomplete neural control of this property rather than a mixture of self- and foreign-innervation.7. A greater degree of independence from neural control to conversion of the histochemically demonstrated myofibrillar ATPase activity exists than is the case for contraction time.
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PMID:Histochemical and physiological properties of cat motor units after self-and cross-reinnervation. 715 31

Yeast cells can respond and adapt to osmotic stress. In our attempt to clarify the molecular mechanisms of cellular responses to osmotic stress, we cloned seven cDNAs for hyperosmolarity-responsive (HOR) genes from Saccharomyces cerevisiae by a differential screening method. Structural analysis of the clones revealed that those designated HOR1, HOR3, HOR4, HOR5 and HOR6 encoded glycerol-3-phosphate dehydrogenase (Gpd1p), glucokinase (Glk1p), hexose transporter (Hxt1p), heat-shock protein 12 (Hsp12p) and Na+, K+, Li(+)-ATPase (Ena1p), respectively. HOR2 and HOR7 corresponded to novel genes. Gpd1p is a key enzyme in the synthesis of glycerol, which is a major osmoprotectant in S. cerevisiae. Cloning of HOR1/GPD1 as a HOR gene indicates that the accumulation of glycerol in yeast cells under hyperosmotic stress is, at least in part, caused by an increase in the level of GPDH protein. We performed a series of Northern blot analyses using HOR cDNAs as probes and RNAs prepared from cells grown under various conditions and from various mutant cells. The results suggested that all the HOR genes are regulated by common signal transduction pathways. However, the fact that they exhibited certain distinct responses indicated that they might also be regulated by specific pathways in addition to the common pathways. Ca2+ seemed to be involved in the signaling systems. In addition, Hog1p, one of the MAP kinases in yeast, appeared to be involved in the regulation of expression of HOR genes, although its function seemed to be insufficient for the overall regulation of expression of these genes.
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PMID:Cloning and characterization of seven cDNAs for hyperosmolarity-responsive (HOR) genes of Saccharomyces cerevisiae. 750 Sep 33


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