Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neurons of the tuberomammillary nucleus (TM) in the rat have previously been shown to contain the enzymes adenosine deaminase (ADA), histidine decarboxylase (HDC) and glutamate decarboxylase (GAD). Some neurons coextensive with this cell group also exhibit immunoreactivity for the neuropeptide galanin, express monoamine oxidase activity (MAO), or display the ability to accumulate and decarboxylate 5-hydroxytryptophan (5-HTP). Histochemical and immunohistochemical techniques were used to determine the extent to which these neurochemical properties are colocalized in neurons immunoreactive for adenosine deaminase. Galanin was found to coexist with ADA in about 45% of the neurons in the TM. In addition, a large number of cells immunoreactive for galanin alone were observed in the posterior hypothalamus outside the confines of TM. Neurons displaying MAO activity formed a subpopulation of those immunoreactive for ADA; all neurons containing MAO also contained ADA whereas only 60% of the ADA-immunoreactive cells were reactive for MAO. Approximately 20% of ADA-immunoreactive neurons represented nearly all cells having 5-HTP uptake capability. However, a very few cells in TM showing 5-HTP uptake capability appeared to be devoid of ADA immunoreactivity. These results demonstrate that although neurons of TM are homogeneous with respect to a number of possible neurotransmitters markers and associated enzymes, these neurons are heterogeneous with respect to their expression of galanin, MAO and 5-HTP uptake. In certain respects the segregation of histochemical properties within TM correlates with previous histochemical work by others, and suggests the possibility of functional diversity of TM.
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PMID:Neuronal colocalization of adenosine deaminase, monoamine oxidase, galanin and 5-hydroxytryptophan uptake in the tuberomammillary nucleus of the rat. 242 41

Adenosine deaminase in the hypothalamic tuberomammillary nucleus and median eminence of rat and mouse brains was investigated with two different antibodies generated against the enzyme derived from either calf or mouse. Both antibodies labelled neurons in the tuberomammillary nucleus and, as determined in rat, they immunolabelled the same neurons. In the median eminence, immunopositive fibres and terminals were detected with anti-mouse adenosine deaminase in both rat and mouse, while no such staining was seen in either species with antibody against the calf enzyme. These fibres were most concentrated in the external median eminence, had a more restricted distribution than those containing either galanin or tyrosine hydroxylase and only partially overlapped with oxytocin-positive fibres. By electron microscopy, adenosine deaminase was found in terminals containing both small, clear vesicles with diameters of 35 to 45 nm and large dense-core vesicles with diameters of 100 to 140 nm. Preadsorption of antibodies with purified enzyme derived from the species against which they were directed eliminated all staining in rat, while antibody adsorptions across species were less effective. Preadsorption of anti-mouse adenosine deaminase antibody with the mouse deaminase led to increased labelling in mouse median eminence, suggesting an interaction between tissue components and antibody-linked enzyme. Tests for the presence of adenosine deaminase-complexing protein (CD26) with an antibody against this protein gave positive labelling in the median eminence of both species and this labelling was co-distributed with that seen for adenosine deaminase. These results confirm the expression of adenosine deaminase in restricted populations of neurons in rodent brain as revealed with a novel antibody, suggest the presence of a distinct form or localization of the enzyme in the median eminence, and raise the possibility that it contributes, perhaps along with CD26, to purinergic regulation of hormone secretion in this structure.
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PMID:Adenosine deaminase in rodent median eminence: detection by antibody to the mouse enzyme and co-localization with adenosine deaminase-complexing protein (CD26). 878 62