Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Macrophages (m phi s), important cells in host resistance, undergo a series of biochemical changes during their progression from the resident to the fully activated stage. Both resident and inflammatory m phi s are characterized by some unique properties. In the present study, female BALB/c mice were prenatally treated with 8 mg/kg body weight of chlordane, a cyclodiene poly-chlorinated hydrocarbon that appears to reduce immunocompetence by selectively impairing m phi function. Therefore, we examined functions in m phi s from chlordane-treated mice that had been stimulated with thioglycollate. The 5'-nucleotidase activity, present in high levels in resident m phi s but low levels in inflammatory m phi s was elevated in resident m phi s from vehicle-exposed animals. Conversely, inflammatory m phi s from these animals showed significantly diminished levels of this function. Moreover, chlordane-exposed m phi s, regardless of whether they were resident or inflammatory, exhibited decreased 5'-nucleotidase responses. When a second function, transferrin receptor binding, was analyzed, vehicle-treated inflammatory m phi s displayed high levels of activity whereas the resident m phi s showed very little transferrin binding. However, both resident and inflammatory m phi s from the chlordane-exposed group demonstrated transferrin binding activity similar in magnitude to that of the vehicle-treated inflammatory m phi s. Finally, two-dimensional polyacrylamide gel electrophoresis analysis of m phi s from chlordane-exposed mice have characteristics of normal m phi s that have advanced to the inflammatory stage.
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PMID:In vivo prenatal chlordane exposure induces development of endogenous inflammatory macrophages. 156

The seminal vesicles originate in embryos of about 58 mm crown-rump-length from the Wolffian duct under the influence of testosterone. Along with the ampulla of the vas deferens and the ejaculatory duct, they form a functional unit that develops slowly until the onset of puberty. Developmental malformations occur as uni- or bilateral agenesis, aplasia, cysts, or ureterovesicular fistules. After puberty, the glands form sac-like structures which have a capacity of about 3.4-4.5 ccm and contribute about 70% of the seminal fluid. In addition to secretion, they are capable of reabsorption of fluids or dissolved substances, and of spermatophagy (ingestion and degradation of damaged spermatozoa by epithelial cells). Secretory activity of the glands is a measure of testosterone supplementation to the epithelium. Nervous regulation of secretion is realized by cholinergic post-ganglionic, sympathetic (and perhaps parasympathetic) fibres, derived from pelvic plexus. Contraction of the muscular wall occurs under the influence of excitatory adrenergic and modulatory NPY-encephalin-peptidergic nerve fibres. The secretory products of the seminal vesicles encompass (1) ions (K+: 1.1 mM ml-1) (2) low molecular weight substances (fructose: above 1.2 mg ml-1; prostaglandins above 250 microliters ml-1, (3) peptides (endorphin: 330 pg ml-1), and (4) proteins. In addition to plasma protein related forms such as transferrin, lactoferrin, and fibronectin, specific proteins such as semenogelin (52 kDa) are synthesized, the scaffold protein of semen coagulate forming the substrate for PSA (prostate specific antigen), sperm motility inhibitor (ca. 18 kDa), and others (placental protein 5, protein kinase inhibitor, carboanhydrase, 5'-nucleotidase), some of which are immunosuppressive. Therefore, functions of the seminal vesicles concern (a) formation of seminal coagulum, (b) modification of sperm functions (motility, capacitation), and (c) immunosuppression. Additional functions within the female genital system, perhaps during pre-implantation period, are likely, but remain to be proven experimentally.
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PMID:Morphology and functions of the human seminal vesicle. 164 33

The cleavage of a high-mannose form of Ii to p25 was demonstrated in an intracellular compartment of B cells. Subcellular fractions of 72 hr-activated B cells, separated by Percoll density gradient centrifugation, were immunoprecipitated with anti-class II or anti-Ii serum and characterized for 5'-nucleotidase, acid phosphatase, and radiolabeled transferrin. The cleavage of p25 from Ii as a C-terminal fragment occurred from 20 to 60 min after synthesis in an intracellular compartment which was intermediate in density between lysosomal and plasma membrane fractions and coincided with the lighter to two internalized transferrin compartments. Chloroquine or monensin treatments, at maximal nontoxic doses, which block Golgi and lysosomal functions, did not seem to alter the cleavage of Ii to p25. p25 molecules were reduced to about 10,500 daltons by treatment with endoglycosidases F or H. We conclude that p25 was generated from a high mannose form of Ii in the endoplasmic reticulum or cis-Golgi. This finding could either implicate that site for class II MHC desetope charging with foreign peptides or reflect a mechanism for degradation of "excess" Ii molecules.
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PMID:Time-dependent cleavage of a high-mannose form of Ii to p25 in an intracellular compartment. 281 9

Sperm maturation and storage occur in a unique milieu created in large part by the epididymal epithelium. To learn more about the interaction of the epididymal epithelial cell with both luminal and systemic environments, we now report on the preparation and characterization of epididymal epithelial cell plasma membranes. A preparation enriched for epididymal epithelial cell plasma membranes was isolated from collagenase-digested epididymal tubule fragments by hand-Dounce homogenization, differential centrifugation, and sucrose gradient centrifugation. The final membrane fraction was enriched 11-fold for the plasma membrane marker 5'-nucleotidase; 2.6-fold for the lysosomal marker acid phosphatase, and 3-fold for the Golgi marker thiamine pyrophosphatase. No enrichment was observed for mitochondrial or endoplasmic reticulum enzyme markers. Specific and saturable transferrin-binding activity was also detected in the final preparation. Electron microscopy revealed the presence of vesicles and sheets of membranes as well as an occasional Golgi apparatus. The plasma membrane fraction was used to generate monoclonal antibodies. Of 102 wells exhibiting growth, 12 were positive by immunofluorescent staining of frozen sections. Ten of these recognized determinants in epithelial cells, and 2 stained peritubular smooth muscle cells. Most of the epithelial cell-specific antibodies stained brush border alone or in combination with the basolateral plasma membrane. Three antibodies stained the Golgi apparatus. Most antibodies were specific for particular epididymal regions, 3 also recognized determinants in the kidney, and 1 stained residual bodies in the testis.
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PMID:Isolation and characterization of epididymal epithelial cell plasma membranes. 336 69

The ubiquitous trace metal zinc has been discovered since a long time as an intrinsic element in all biological systems. However, its role other than structural or catalytic in enzymes is poorly defined. Zinc plays a determinative role both in primary and secondary T lymphocyte production. Experimental data support the notion that during intrathymic maturation, non-autoreactive, immunocompetent T cell clones are selected from the excess of immature thymocytes as a result of expansion of bone marrow derived prothymocytes in response to pleiotropically acting alarmon (s) and a subsequent escape via the thymic stroma cells from nucleotide-mediated "biochemical suicide". The activity of alarmon (Ap4A), nucleotide metabolizing enzymes (TdT, DNA polymerase, thymidine kinase, 5'-nucleotidase) and some of the soluble stromal cell products (FTS) require constitutive zinc. In the peripheral lymphoid organs the magnitude and duration of antigen induced, T cell mediated immunoreactions are regulated by T-cell growth factor (IL-2). Using receptor specific monoclonal antibody probes, it has been established recently that the intracellular role of IL-2 is probably to induce the phenotypic expression of high affinity transferrin receptors, known to be the main zinc transporter system in T-lymphocytes. The coordinative role of zinc in T lymphocyte development via the inducible metallothionein system is emphasized. Some clinical aspects of zinc metabolism are discussed.
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PMID:Zinc and immunity. 623 34

Plasma membrane was prepared from human placental tissue by two standard methods. The preparations, termed PVM and PPM, examined by electron microscopy and polyacrylamide gel electrophoresis, were characterized with respect to their binding properties for insulin, transferrin, alpha 2-macroglobulin and the immunoglobulins, IgM and IgG1. By means of sucrose density-gradient centrifugation, it was possible to fractionate the PVM into two distinct fractions. The first fraction, under the conditions used, was heavier (density greater than 1.080 g . cm-3) and was obtained as a pellet. It bound transferrin and IgM and had low specific activities for 5'-nucleotidase and for the binding of IgG1. The lighter fraction (density range 1.048-1.050 g . cm-3) had a high specific activity for 5'-nucleotidase and for IgG1 binding. Transferrin and IgM did not bind to this fraction. Insulin bound to both the fractions with comparable levels of specific binding activity, while alpha 2-macroglobulin binding was undetectable. The PPM preparation was found to have binding properties similar to those of the light fraction of PVM.
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PMID:Examination of different preparations of human placental plasma membrane for the binding of insulin, transferrin and immunoglobulins. 702 85

Some indices that reflect the damaging processes in the cells and tissue structures have been found in 152 patients with pulmonary tuberculosis and in those with inactive lung tissue changes. There is evidence for that increases in the activity of plasma 5'-nucleotidase, ceruloplasmin/transferrin ratio and the appearance of free radical compounds in the plasma are accompaniments of active pulmonary tuberculosis. It is found that the greatest changes in these parameters are, the more acutely the disease runs, the more pronounced an exudative component in the general picture of inflammation is. If there are positive changes in these indices during combined therapy, the activity of 5'-nucleotidase becomes normal just after 5-6 months, and the values of other indices tends to normalize after treatment termination. A combined determination of the ceruloplasmin/transferrin ratio and the plasma levels of free radical compounds allows the activity of a tuberculous process to be established in 70% of cases.
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PMID:[Markers of alteration of tissue structures as indicators of pulmonary tuberculosis activity]. 1256 42