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)

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

Subcellular fractionation studies in resting human neutrophils indicated a bimodal distribution for cytochrome b. A major peak of cytochrome b co-sedimented with gelatinase under different experimental conditions. This localization was partially overlapped with specific granules (using lysozyme and lactoferrin as specific granule markers), but clearly resolved from azurophilic granules, plasma membrane, mitochondria, as well as from a novel alkaline phosphatase-rich intracellular organelle. A minor localization of cytochrome b was found in fractions enriched in both the plasma membrane marker 5'-nucleotidase and alkaline phosphatase. A significant portion of ubiquinone cell content co-fractionated with the gelatinase-containing granules. After phorbol myristate acetate (PMA)-cell stimulation, cytochrome b was mobilized to fractions showing respiratory burst activity and enriched in 5'-nucleotidase activity. This mobilization paralleled secretion of gelatinase and lysozyme to the extracellular medium. Furthermore, neutrophil stimulation with fluoride in the absence of cytochalasin B induced release of gelatinase and generation of superoxide anion with only minimal release of lysozyme. Preincubation of cells with the anion channel blocker 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) prevented lysozyme release, but had only a minor effect on the release of gelatinase and did not inhibit the superoxide anion generation elicited by N-formyl-methionyl-leucyl-phenylalanine or PMA. These results suggest a main location of cytochrome b in mobilizable gelatinase-containing granules, which can constitute a subpopulation of specific granules. Furthermore, these findings show that the gelatinase-containing granule is functionally involved in the respiratory burst in neutrophils and that membrane fusion between plasma membrane and the gelatinase-containing granule occurs during activation of cells.
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PMID:Cytochrome b co-fractionates with gelatinase-containing granules in human neutrophils. 165 2