Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

After separation of three epididymal acid phosphatases their biochemical properties were differently studied. With appropriate substrate and inhibitor selection the distribution of the enzymes in different segments as well as the subcellular fractions of the rat epididymis was also demonstrated. The same biochemical differences were also utilized in the histochemical localization of the enzymes. It was found that Enzyme I had a pH-optimum at 5.0, a molecular weight of 97 000 and Km-constant of 0.901 mM. It was highly sensitive to tartrate and fluoride and it was localized in lysosomes as well as in the epididymal spermatozoa. Enzyme II had an optimum at pH 5.7, a molecular weight of 67 000 and Km-constant of 0.806 mM. It was also inhibited by fluoride but more resistant to tartrate. Its subcellular site was also particulate, but it was also found in the epididymal fluid. Enzyme III had an optimum at pH 5.2, a molecular weight of 135 000 and Km-constant of 0.685 m. It was resistant to low concentrations of fluoride and tartrate but sensitive to heavy metal ions. The enzyme was soluble and it behaved incoherently in thermal inactivation. All enzymes revealed the highest activity in the thin middle segments of the epididymis. Histochemical naphthol substrates gave a diffuse reaction in the epididymal epithelial cells. With the lead salt methods glycerophosphates and p-nitrophenylphosphate gave somewhat different results depending on their specificity as substrates for the epididymal enzymes. Both substrates gave a strong reaction supranuclearly in the Golgi area of the chief cells. This activity was inhibited by tartrate and was most probably due to Enzyme I. The epididymal corpus and cauda showed additionally a very strong apical activity in the chief cells with p-nitrophenylphosphate. This activity was resitant to tartrate but sensitive to fluoride. It was concluded that this enzyme represents Enzyme II activity. Similar activity was also found in the dissolving "holocrine" cells of the corpus and the cauda. The activity of the soluble Enzyme III could not be revealed with the present methods and the spermatozoa in the tubular lumina remained unstained.
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PMID:Acid phosphatases of the rat epididymis. II. Biochemical characteristics, subcellular distribution and histochemical localization. 7 Jan 77

There appear to be two classes of protein kinases in rat heart and adipose tissue, types I and II. Type I elutes from DEAE-cellulose at smaller than 0.1 M NaCl and type II at greater than 0.1 M NaCl. The type I enzyme is more readily dissociated by salt or histone than is the type II enzyme. If the type I kinase is first dissociated by cAMP, the subunits reassociate very slowly at 0 degrees C on removal of the cAMP by Sephadex G-25 chromatography, whereas those of type II reassociate very rapidly. Rat heart contains mostly type I and a small amount of type II enzyme, whereas adipose tissue contains almost exclusively the type II enzyme. The adipose tissue enzyme resembles the heart type II kinase in all of the above properties, although the two enzymes are not identical as indicated by slight differences in elution patterns from DEAE-cellulose columns. Incubation of rat epididymal adipose tissue with low concentrations of epinephrine (0.11 muM) increases glycerol production and the fraction of the protein kinase in the active form (activity ratio). The change in cAMP under these conditions is not statistically significant. The presence of insulin inhibits the epinephrine effect on glycerol production and protein kinase but has no measurable effect on cAMP levels. Incubation of adipose tissue with high epinephrine concentrations (11 muM) increases the cAMP level, the protein kinase activity ratio, and glycerol production. Under these conditions insulin decreases the cAMP level and kinase activity ratio but does not reduce glycerol production. The data suggest that very small changes in the tissue cAMP level, undetectable by the assay method, are magnified during the stepwise activation of glycerol output aided possibly by cooperative effects between cAMP and protein kinase. The procedure developed for determining the state of activation of the cAMP-dependent protein kinase in adipose tissue must be modified by reducing the salt concentration of the buffers in order to carry out similar studies in the heart. This reflects the different types of protein kinase in the two tissues. The addition of charcoal to crude extracts of heart prevents protein kinase activation by added cyclic AMP. Charcoal should therefore prevent any activation that could occur if any sequestered cAMP were released during homogenization. Charcoal addition thereby provides a means to distinguish intracellular cAMP activation of the kinase from that which might occur following cell rupture. If epinephrine-perfused hearts are homogenized in the presence of charcoal, epinephrine stimulation of the protein kinase is only slightly decreased. This indicates that the protein kinase is activated intracellularly by cAMP and suggests that all of the cAMP in the cell is available to the protein kinase; i.e., cAMP is not released during homogenization.
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PMID:Hormonal regulation of adenosine 3',5'-monophosphate-dependent protein kinase. 16 70

The effect of cyclic adenosine 3':5'-monophosphate (cAMP) and caffeine on the motility of spermatozoa obtained in vivo by micropuncture from the rat rete testis, caput epidiymidis, and cauda epididymidis was studied. Spermatozoa from all sites were immobile in their native fluid. Rete testis spermatozoa were not motile under any experimental conditions. After dilution in salt solution, some caput sperm exhibited circular motion, whereas most cauda sperm swam progressively. Dextrose enhanced the motility of sperm from both epidiymal sites. Caffeine further increased the motility of epididymal sperm. Dibutyryl cAMP and cAMP stimulated caput spermatozoa but had no effect on cauda spermatozoa.
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PMID:Micropuncture studies of the motility of rete testis and epididymal spermatozoa. 18 86

Measurements of tissue cyclic AMP (cAMP) concentration, the activity of cAMP-dependent protein kinase and the level of the enzyme's thermostable, macromolecular inhibitor were made on preparations of rat epididymal fat pad from animals fed high fat or high carbohydrate diets. The cAMP concentration from rats adapted to a high lard diet for 14-15 days was 153 +/- 17.8 pmoles/mg protein as opposed to 76 +/- 6.0 found with high glucose diet. No significant difference in total cAMP-dependent protein kinase activity was observed among rats fed high glucose, high lard or laboratory chow, although the enzyme's activity ratio (-cAMP)(+cAMP) was significantly elevated with lard feeding (0.49 +/- 0.02) as opposed to glucose feeding (0.43 +/- 0.01). Crude preparations from lard and glucose fed animals were equivalent in inhibitory activity when tested with enzyme from chow fed animals. Agarose column chromatography separated holoenzyme and C subunit forms of the protein kinase when 500 mM NaCl was present in the elution buffer. Absence of the salt allowed subunit reassociation to occur. Direct addition of NaCl greater than or equal to 75 mM significantly inhibited protein kinase activity. The results indicate that the adipose tissue of rats fed a high lard diet has a higher concentration of cAMP and an increased protein kinase activity ratio than tissue from rats fed a fat free, high glucose diet. Total cAMP-dependent protein kinase activity and the level of a thermostable macromolecular inhibitor remained unchanged.
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PMID:The concentration of cyclic AMP and the activity of cyclic AMP dependent protein kinase and an inhibitor in the adipose tissue of rats fed lard or glucose diets. 21 69

Cytosol prepared from epididymides of castrated adult rabbits contains an estrogen-specific binding component that sediments in the 4--5S region on 0.01 M KCl sucrose gradients. The estrogen-specific binding component is not detectable on sucrose gradients unless the cytosol-[3H]estradiol mixture is first extracted with charcoal to remove uncomplexed and rapidly exchangeable ligand from the sample. The macromolecular bound [3H]estradiol that remains after charcoal extraction dissociates from the receptor with a dissociation half-time of greater than 24 h and is of high affinity (Kd = 6.5 +/- 0.9 X 10(-9) M). The estrogen receptor in the adult rabbit epididymis can also be demonstrated when charcoal-extracted samples are chromatographed on Sephadex G-200. Using this system, the major estrogen-specific binder has an apparent molecular weight of less than 200,000. In contrast, the epididymal estrogen receptor in sexually immature rabbits sediments as an 8S species on low salt gradients and has an apparent molecular weight of 200,000 or greater when assessed by chromatography on Sephadex G-200. The estrogen receptor in both age groups is distributed along the length of the epididymal duct. The highest concentration of the cytoplasmic receptor in both mature and immature rabbits is in the cauda epididymidis. The age-dependent changes in the amount of the receptor suggest that it may be involved in maturational changes in the epididymis. The alterations in the physicochemical properties may reflect physiological changes in the epididymis or in the endocrine status of the animal.
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PMID:The presence of a cytoplasmic estrogen receptor in sexually mature rabbit epididymides: comparison with the estrogen receptor in immature rabbit epididymal cytosol. 48 1

Prostaglandins E2 and F2alpha tromethamine salt caused an increase in amplitude and frequency of rat epididymal contractions. Moreover, they caused a significant potentiation of contractile responses of epididymal smooth muscle to stimulation by norepinephrine or acetylcholine. Indomethacin treatment caused no changes in the spontaneous motility, and this inhibitor of prostaglandins synthesis decreased the responses of epididymis to norepinephrine or acetylcholine. Spontaneous motility of epididymis is possible in the presence of smaller amounts of endogenous prostaglandins, and sudden contraction occurring during ejaculation, induced by sympathetic and parasympathetic nerves stimulation, could be influenced or modulated by prostaglandins.
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PMID:Effects of prostaglandins and indomethacin on rat epididymal responses to norepinephrine and acetylcholine. 74 41

The secretion of epididymal proteins and their binding to spermatozoa in rats were examined after retrograde perfusion of the superior and inferior epididymal arteries with [35S]methionine. PAGE revealed that the pattern of radioactive proteins in the luminal fluid was markedly different from the well-characterized pattern of secretory proteins obtained by in vitro incubation of epididymal minces with labeled methionine. Of the proteins secreted into the lumen, about 1% were associated with Percoll-purified spermatozoa. More proteins were associated with the spermatozoa in the corpus epididymidis than in the caput. Sequential extraction of spermatozoa with an isotonic buffer, a high-salt buffer, Triton X-100, and SDS revealed that almost half of the radiolabeled proteins could be extracted with the isotonic buffer. The firmly bound radioactive proteins remaining, which were extracted with Triton X-100 or SDS, consisted of one major band of 25 kDa and two minor bands of 30 kDa and 32 kDa. Analysis of the sperm-associated proteins at various times after the isotope was administered indicated that tight binding of proteins to spermatozoa occurs within 3 h after isotope injection.
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PMID:Binding of epididymal proteins to rat spermatozoa in vivo. 139 46

Three murine epididymal secretory proteins have been characterized by their site of synthesis, sperm association, and tissue localization by use of polyclonal antisera and immunochemistry. Mouse epididymal protein 7 (MEP 7) was localized initially within the supranuclear regions of some principal epithelial cells in the proximal corpus while other cells remained unstained. In the mid-proximal corpus, all principal cells and stereocilia were stained, and luminal staining increased from corpus to cauda. Some clear cells in the distal corpus and cauda also showed immunoperoxidase staining. Sequential extraction of caudal spermatozoa indicated that MEP 7 was predominantly loosely associated with spermatozoa and that only a small amount of MEP 7 required detergent to extract it from spermatozoa. Examination of other rodent caudal fluids revealed a related protein in rat caudal fluid of 32 kDa, and amino acid sequence analysis of MEP 7 showed a 68% sequence similarity with rat proteins AEG and D/E. MEP 9 immunolocalized within the cytoplasm of all principal cells of the distal caput. In a transition zone between the distal caput and the corpus, some principal cells were stained while others were not. Distal to the corpus, the principal cell staining gradually decreased. In the distal caput and proximal corpus, large heavily stained droplets associated with spermatozoa were seen in the lumen. The staining intensity of these droplets also decreased from corpus to cauda. The clear cells of the distal corpus and cauda did not stain with the antibody to MEP 9. Sequential extraction of caudal spermatozoa showed that some MEP 9 was extractable under low-salt conditions, whereas extraction with 0.1% Triton X-100 was required to remove all MEP 9, indicating it was firmly associated with spermatozoa. The antibody to MEP 9 cross-reacted with a 25-kDa protein present in rat caudal fluid. MEP 10 was localized within the cytoplasm of the principal cells, the stereocilia, and the lumen of the epididymis at the junction of the distal caput and corpus. In the distal corpus, a large number of clear cells were stained, but very few of these cells stained in the cauda. MEP 10 dissociated completely from caudal spermatozoa under low-salt conditions, indicating that it was not firmly bound to spermatozoa. The antiserum to MEP 10 cross-reacted with proteins present in rat and guinea pig caudal fluid. The related rat protein migrated at approximately 20 kDa. Amino acid sequence analysis of MEP 10 revealed an 86% sequence similarity with rat proteins B and C.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Isolation, immunolocalization, and sperm-association of three proteins of 18, 25, and 29 kilodaltons secreted by the mouse epididymis. 159 32

We investigated the reason for the high mortality we had observed in hypophysectomized-orchidectomized Golden Syrian hamsters that were anesthetized with intraperitoneal (i.p.) injections of chloral hydrate (CH). Intact male Golden Syrian hamsters were injected intraperitoneally with 0.1cc/100g BW of a 35% solution of CH, a 35% solution of sodium chloride, or double-distilled water. Equal numbers of hamsters in each group were injected on the right or left side of the abdomen. Within 10 days, 35% of the CH-injected hamsters were dead or had to be euthanized. Autopsy revealed severe peritonitis and adynamic ileus. CH-injected hamsters that survived gained weight at a rate similar to that of the controls. All surviving hamsters were killed 18 days after the injections. Among the surviving CH-injected hamsters, 84.6% had intra-abdominal adhesions, 61.5% had unilateral testicular atrophy, and 53.8% had a yellowish necrotic mass in the epididymal fat pad (EFP). All the lesions occurred on the side that was injected. The atrophied testes had been rendered cryptorchid due to involvement with intra-abdominal adhesions. In the water-treated controls, there were no abnormalities; whereas, in the saline controls, 75% had a mass in the EFP. Histology of the EFP mass was similar in hamsters injected with CH or hypertonic saline and suggested a diagnosis of fat necrosis. The results suggest that the mortality, the intra-abdominal adhesions, and the unilateral cryptorchidism were caused by a single i.p. injection of CH, but the fat necrosis in the EFP was probably caused by high concentrations of salt. The results further suggest that high concentrations of CH should not be injected intraperitoneally for anesthesia in chronic studies, particularly of the male reproductive system.
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PMID:Intraperitoneal injection of chloral hydrate causes intra-abdominal adhesions and unilateral testicular atrophy in golden Syrian hamsters. 161 72

Experiments have been carried out characterizing an Mr 22,000 protein present in the acrosomes of hamster and bull spermatozoa. The Mr 22,000 protein is resistant to solubilization in detergent solutions containing high or low salt and has a pI of -5.2. With various lectins, the protein from hamster sperm was shown to be sparingly glycosylated with N-acetylglucosamine, mannose, and galactose while that from the bull demonstrated a slight reactivity for galactose. Using a specific monoclonal antibody (MAB 4/18), the Mr 22,000 polypeptide has been localized exclusively to the acrosomes of mature testicular and epididymal hamster and bovine sperm. Acrosomal components of differentiating bovine and hamster spermatids in tissue sections did not react with the monoclonal antibody, although the protein was present in immunoblots of round spermatids. In bovine sperm, MAB 4/18-staining at the ultrastructural level with immunogold-labeled second antibody was present as a reticulum throughout the acrosomal cap and as punctate aggregates in the equatorial segment. In hamster sperm, MAB 4/18-reactivity was present along the periphery of the acrosome in conjunction with matrix components (M1 and M2), as well as along the inner acrosomal membrane. These observations indicate that the acrosomes of bovine and hamster sperm possess an immunologically related Mr 22,000 protein and suggest that differences in MAB 4/18-staining of spermatids and spermatozoa is a result of epitope modification and/or a change in accessibility of the epitope to the antibody probe during the course of spermiogenesis. Based on its localization and solubility properties, we suggest that the Mr 22,000 protein, in conjunction with other polypeptides, forms a structural framework to maintain acrosomal shape and/or compartmentalize acrosomal contents.
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PMID:Characterization of an acrosomal matrix protein in hamster and bovine spermatids and spermatozoa. 169 46


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