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

---

Query: EC:1.9.3.1 (cytochrome oxidase)
8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Regional variations in capillary density, glucose utilization rate, and activities of the glycolytic enzyme lactate dehydrogenase and the mitochondrial enzyme cytochrome oxidase were compared in the rat brain. The distributions of capillaries and enzymes were studied by means of histochemical staining techniques, and glucose metabolism was measured by means of [14C]2-deoxyglucose autoradiography. Analysis of 18 gray and five white matter regions revealed a positive correlation between capillary density and glucose utilization rate. A negative correlation was found between capillary density and lactate dehydrogenase among gray matter structures. Analysis of capillaries and enzymes was also performed within laminated histological fields: hippocampus, olfactory bulb, and olfactory cortex. In general, this revealed reciprocal patterns of staining for lactate dehydrogenase and cytochrome oxidase. Capillary density paralleled cytochrome oxidase activity. The zones of intense staining for lactate dehydrogenase and cytochrome oxidase corresponded to the synaptic terminal fields of different input pathways. These findings demonstrate distinct distributions of a glycolytic and an oxidative enzyme within the brain which are at least partly associated with pathway specificity.
...
PMID:Metabolic anatomy of brain: a comparison of regional capillary density, glucose metabolism, and enzyme activities. 255 35

Littermate rat pups underwent either unilateral surgical occlusion of the right external naris or sham surgery on postnatal Day 1. At 4-, 8-, 12-, 20- or 30-days postpartum, olfactory bulb sections were histochemically reacted to reveal either succinate dehydrogenase (SDH) or cytochrome oxidase (CO) activity. Microdensitometry was used to determine levels of staining in glomeruli and the external plexiform layer at standardized locations within the bulb. In experimental subjects asymmetries in left/right bulb SDH staining patterns were detected as early as Day 4, suggesting that the deprivation procedure resulted in quite rapid changes in the metabolic function of olfactory bulb cells. Control animals did not exhibit left/right differences in bulb staining, but inter-glomerular and regional variations in staining were observed throughout the early developmental period. Understanding these early variations in metabolic activity may be important for a complete understanding of olfactory bulb maturation.
...
PMID:Unilateral odor deprivation: effects on the development of staining for olfactory bulb succinate dehydrogenase. 282 May 49

Cytochrome oxidase staining of the rat olfactory bulb external plexiform layer (EPL) produces a darkly stained intermediate zone bordered by lightly stained superficial and deep zones. Similar zonal staining was seen in cats, rabbits, and hamsters. These zones vary in relative thickness around the circumference of the olfactory bulb; the deep zone is proportionally thicker in the most dorsal and ventral parts of the bulb. Tufted cell somata are unevenly distributed within the EPL; the outer part of the EPL has more somata. The distribution of the cytochrome oxidase reaction product shows that the darkly stained intermediate zone is not produced by staining of tufted cell somata. Zones of cytochrome oxidase staining correspond to the sublaminar distribution of mitral and tufted cell basal dendrites. This was demonstrated by labeling mitral and tufted cells with small extracellular horseradish peroxidase injections and processing alternate sections for horseradish peroxidase and for cytochrome oxidase. Because there was cross-reaction of the cytochrome oxidase procedure with horseradish peroxidase, it was possible to trace many neurons through both series of sections. Middle tufted cells of the superficial EPL have basal dendrites confined to the superficial zone of light cytochrome oxidase staining. Internal tufted cells and middle tufted cells of the intermediate zone send their basal dendrites into the intermediate zone. One group of mitral cells (type I) has basal dendrites confined to the deep zone of lighter cytochrome oxidase staining. A second group of mitral cells (type II) and tufted cells of the intermediate EPL has basal dendrites primarily confined to the intermediate zone of dark cytochrome oxidase staining. The correlation of the enzyme staining with the dendritic laminar patterns supports the existence of three relatively distinct sublaminae in the EPL and supports the designation of two types of mitral cells. The staining pattern also provides an independent method for evaluating the sublaminae of the EPL without the necessity of labeling individual groups of cells. Finally, the staining pattern suggests that the intermediate zone of the EPL may be subjected to more tonic synaptic input, causing it to have an increased level of metabolic activity.
...
PMID:Cytochrome oxidase staining marks dendritic zones of the rat olfactory bulb external plexiform layer. 283 32

Young rats exposed to an odor while receiving reinforcing stimulation come to approach that odor upon subsequent presentation. In addition, such pups have increased 14C-2-deoxyglucose (2DG) uptake within focal areas of the glomerular layer in response to that odor, compared to control animals experiencing the odor for the first time. In this study, the morphology of the glomerular areas underlying these 2DG foci was examined to determine whether early olfactory learning imposed local structural changes that could produce the enhanced 2DG uptake. Alternate sections either were processed with a silver and a Nissl stain to label both cell bodies and their processes or were histochemically treated for the mitochondrial enzymes cytochrome oxidase (CO) or succinic dehydrogenase (SDH) to define the glomerular core of the bulb; 2DG autoradiographs were aligned with adjacent stained sections, and regions underlying the high 2DG uptake foci were examined. In odor-familiar animals, large glomerular clusters that protruded into the external plexiform layer or the olfactory nerve layer were associated with the focal areas of increased 2DG uptake. Morphometric analysis of these regions revealed that the glomerular layer underlying the foci of high 2DG uptake was 30% wider in odor-familiar animals than comparable areas in odor-unfamiliar animals; the cross-sectional areas of individual glomeruli were 21% larger in odor-familiar animals. The foci of enhanced 2DG uptake therefore appear to be associated with groups of enlarged glomeruli. These data demonstrate that early olfactory learning influences the morphology of the olfactory bulb.
...
PMID:Localized changes in olfactory bulb morphology associated with early olfactory learning. 366 67

The effects of unilateral olfactory bulbectomy on cytochrome oxidase (CO) activity in the olfactory cortex were studied in adult rabbits. In intact rabbits, layer Ia of the olfactory cortex stained symmetrically for CO activity as a continuous brown band. In animals with unilateral lesion of the olfactory bulb (OB), a great decrease in the level of CO activity was found in layer Ia ipsilaterally. The change became prominent about 12 hr after OB lesion. Thereafter no further decrease in CO activity was observed up to 6 months. A decrease in the level of CO activity was observed in only the denervated lamina to which the OB neurons project directly, but not along the synaptic chain in the olfactory cortex.
...
PMID:Changes in cytochrome oxidase activity of the rabbit olfactory cortex following unilateral olfactory bulbectomy. 608 55

Developmental studies examining the changes in oxidative metabolic activity are useful for understanding how and if the vomeronasal and olfactory systems respond to stimulation during embryogenesis. Garter snakes are good candidates for examining the potential functionality of the vomeronasal system in utero. In adult garter snakes, the vomeronasal system mediates many behaviors. Neonatal garter snakes exhibit these same behaviors, and the vomeronasal system has been shown to mediate feeding behavior in neonates. Using cytochrome oxidase histochemistry, we examined changes in the oxidative metabolic activity of main and accessory olfactory bulbs of embryonic and neonatal garter snakes (Thamnophis sirtalis sirtalis and T. s. parietalis). Cytochrome oxidase staining is greater in the accessory olfactory bulb than in the main olfactory bulb of embryonic garter snakes. However, neonates show no differences in the staining of the accessory and main olfactory bulbs, suggesting a change in the stimulation of the main olfactory bulb after birth. This is the first report of cytochrome oxidase histochemistry in reptiles and in the vomeronasal system of embryonic vertebrates.
...
PMID:Developmental changes in cytochrome oxidase histochemistry in the main and accessory olfactory bulbs of embryonic and neonatal garter snakes (Thamnophis sirtalis spp.). 750 13

Cytochrome oxidase staining selectively highlights the synapse-rich neuropil of olfactory bulb glomeruli. Detailed morphometric enumeration of glomeruli in cytochrome oxidase-stained sections from postnatally developing rats reveals that the entire adult population of glomeruli (2400/bulb) forms early in life, the process being complete by days 3-5 postnatal. Newborn's glomeruli range in diameter from a mean of about 50 microns to a maximum of about 70 microns and undergo a 3-fold increase in diameter and a 20-fold increase in volume during days 1-50 postnatal. The presence of the entire adult's glomeruli in the neonate calls for a serious revision of some current views on glomerular development and, given the critical roles of glomeruli as modules, the findings bear important implications for the organization of olfactory system and early development of olfactory functions.
...
PMID:Morphometry of rat olfactory bulbs stained for cytochrome oxidase reveals that the entire population of glomeruli forms early in the neonatal period. 768 81

The development of the nasal chemical senses of reptiles is of particular interest since evidence suggests that neonatal reptiles use both their olfactory and vomeronasal systems. This review focuses on the embryonic development of these nasal chemosensory systems in garter snakes (Thamnophis spp.). Three approaches have been used to examine development: (1) Normal morphological studies, (2) 3H-thymidine autoradiographic studies, and (3) metabolic mapping of the accessory and main olfactory bulbs with cytochrome oxidase histochemistry. In addition, garter snake embryos have been grown in vitro to facilitate experimental procedures. The results of these studies show that reptiles are a rich and diverse group for investigating the developmental processes that form the neurobiological basis for naturally occurring chemosensory-mediated behaviors.
...
PMID:The ontogeny of nasal chemical senses in garter snakes. 838 85

The activation of nitric oxide synthase (NOS) has been linked to excitatory input via NMDA receptors. We hypothesized that NOS-positive neurons that have NMDA receptors on their surface would have high levels of cytochrome oxidase (C.O.) as energy generator for membrane repolarization. In order to compare the distribution of these markers on the same section, we reacted rat brain sections for C.O. histochemistry followed by NOS immunogold silver staining (IGSS). Adjacent sections were reacted for NOS IGSS followed by indirect immunoperoxidase for NMDA receptor subunit R1 (NMDAR1). We found that the staining pattern varied among regions but were consistent within each region examined. There are three types of NOS immunoreactive (NOS-ir) cells: (1) NOS-ir neurons that had moderate to high levels of both NMDAR1 and C.O. staining, such as the pontine reticular nuclei, motor and mesencephalic nuclei of the trigeminal nerve, and some motor neurons in the spinal cord. (2) NOS-ir neurons that were immunoreactive for NMDAR1 (NMDAR1-ir) but had low levels of C.O. activity in thei- somata. Their dendrites, however, were both NMDAR1-ir and rich in C.O. Examples of this type include neurons in the caudate and putamen, and periglomerular cells in the olfactory bulb. (3) We also found that some NOS-ir neurons were not NMDAR1-ir and had low C.O. activity. In addition to postsynaptic neurons, C.O. and NOS levels were both high in the inner segments of retinal photoreceptor cells where energy-demanding active ion transport maintains the dark current and where NO presumably activates guanylate cyclase for the production of cGMP, which keeps the Na+ channels open in the dark. Our findings suggest that NMDA receptors are available for the majority of NOS-ir neurons, which comprise a heterogenous population with varying energy demands.
...
PMID:Do nitric oxide synthase, NMDA receptor subunit R1 and cytochrome oxidase co-localize in the rat central nervous system? 887 89

Hydrogen sulphide (H2S) is the primary chemical hazard in natural gas production in 'sour' gas fields. It is also a hazard in sewage treatment and manure-containment operations, construction in wetlands, pelt processing, certain types of pulp and paper production, and any situation in which organic material decays or inorganic sulphides exist under reducing conditions. H2S dissociates into free sulphide in the circulation. Sulphide binds to many macromolecules, among them cytochrome oxidase. Although this is undoubtedly an important mechanism of toxicity due to H2S, there may be others H2S provides little opportunity for escape at high concentrations because of the olfactory paralysis it causes, the steep exposure-response relationships, and the characteristically sudden loss of consciousness it can cause which is colloquially termed 'knockdown.' Other effects may include mucosal irritation, which is associated at lower concentrations with a keratoconjunctivitis called 'gas eye' and at higher concentrations with risk of pulmonary oedema. Chronic central nervous system sequelae may possibly follow repeated knockdowns: this is controversial and the primary effects of H2S may be confounded by anoxia or head trauma. Treatment is currently empirical, with a combination of nitrite and hyperbaric oxygen preferred. The treatment regimen is not ideal and carries some risk.
...
PMID:Hydrogen sulphide. 891 53


1 2 3 Next >>

---