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

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Query: EC:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human spermatozoa with normal structure and with different axonemal deficiencies (absence of axoneme, of arms, or of central structures) were studied by electron microscopy, SDS-polyacrylamide gel electrophoresis, and ATPase activity measurements. Normal human sperm possess a complement of high molecular weight polypeptides with an electrophoretic migration similar to that of sea urchin and other mammalian sperm dyneins. Human high molecular weight bands are numbered one to four in order of increasing of electrophoretic mobility; all of them are absent in spermatozoa that lack axoneme. The absence of doublet arms, coincides with the absence of bands 2, 3, and 4; the absence of central structures coincides with a reduction in intensity of band 2. In the latter two abnormal conditions, band 1 has an increased intensity. The data are tentatively interpreted by attributing the polypeptides forming bands 3 and 4 to the arm structure, whereas band 2 is supposed to contain a mixture of polypeptides localized in the arms and in the central structures; these abnormal sperm contain modified polypeptides which gather in band 1. Histochemical ATPase stainings indicate that this enzyme is localized mainly in the doublet arms and, to a minor extent, in the central structures.
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PMID:Human dynein and sperm pathology. 645 31

Mg2+- and Ca2+-dependent ATPase activity, fructose and divalent cation concentrations were determined in seminal plasmas from men with oligozoospermic ejaculates and from those with normal sperm count. The mean activity of the Mg2+- and Ca2+-stimulated ATPase from the former was 59 nmol . 0.1 ml-1 . This is significantly (p less than 0.005) lower than for men with a normal sperm count (corresponding figure is 87 nmol . 0.1m1-1 . min-1). As regards the concentrations of Mg2+, Ca2+ and Zn2+ in the seminal plasmas from these two groups there was no significant difference. The same was also valid for the fructose concentrations. The Mg2+- and Ca2+-stimulated ATPase activity as well as fructose and divalent cation concentrations were also determined in seminal plasmas from men before and after vasectomy. After vasectomy, only the ejaculates devoid of spermatozoa were included in the comparative studies. No significant difference was observed between the seminal plasmas from men before and after vasectomy. These findings support the view that the Mg2+- and Ca2+-stimulated ATPase system does not derive from the spermatozoa. Possible explanations for the significantly lowered Mg2+- and Ca2+-dependent ATPase activity from patients with oligozoospermia are given.
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PMID:Reduced activity of Mg2+- and Ca2+-dependent adenosine triphosphatase in seminal fluid of patients with oligozoospermia. 645 23

Protein carboxylmethylase (S-adenosyl-L-methionine:protein O-methyltransferase, EC 2.1.1.24.) is believed to be involved in the regulation of sperm motility. To test this hypothesis, we investigated the effects of erythro-9-[3-(2-hydroxynonyl)]adenine (EHNA) which, in combination with adenosine and homocysteine thiolactone, inhibits protein carboxylmethylase activity in monocytes. This group of compounds inhibited sea urchin sperm motility. Unexpectedly, EHNA alone inhibited the motility., This observation was confirmed in intact spermatozoa from rats, rabbits, and humans. EHNA also inhibited the motility of demembranated, reactivated sea urchin and rat spermatozoa from which protein carboxylmethylase had been extracted. In these preparations, motility was restored by ATP. These observations suggested that EHNA arrests sperm motility by inhibiting the axonemal dynein ATPase on which motility depends. Kinetic analysis demonstrated that EHNA produced mixed inhibition of both the axonemal ATPase and the partially purified dynein 1 from sea urchin sperm tails, as well as the axonemal ATPase of rat sperm tails. These observations also provide evidence for the similarity of the active site of the dynein ATPase in sea urchin and rat spermatozoa.
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PMID:erythro-9-[3-(2-Hydroxynonyl)]adenine is an inhibitor of sperm motility that blocks dynein ATPase and protein carboxylmethylase activities. 645 42

Gossypol acetic acid at the dose of 5 mg/rat/day for 2 and 4 weeks did not cause any significant effect on the body weight, testis, epididymis, seminal vesicle and prostate weight, nor gossypol treatment had any significant effect on the activities of acid phosphatase and succinic dehydrogenase in the testis. Changes in the testis ATPase activity were, however, significant after gossypol treatment. During the course of present investigations no effect of gossypol treatment on 3H thymidine incorporation into DNA of testicular cells was observed, nor there were any changes in the DNA and total protein content of the testis after gossypol treatment. Gossypol treatment did not cause any effect on the plasma Na+ level. However, transient decrease in the plasma K+ level was observed; decrease in K+ level two weeks after gossypol treatment was restored to normal after 4 weeks of gossypol treatment. No changes in the histology of the testis were observed 2 weeks after gossypol treatment but marked inhibition of spermatogenesis was observed 4 weeks after gossypol treatment. Motility of vas deferens spermatozoa was also markedly inhibited 4 weeks after gossypol treatment. In the light of the present observations and those of others, there is a clear demonstration that gossypol acts directly on the spermatozoa and on the testis; at both the sites the drug interferes in the ATPase activity.
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PMID:Studies on the male antifertility agent--gossypol acetic acid. III. Effect of gossypol acetic acid on rat testis. 645 43

Regional differences in the proximal part of mouse epididymis were reported to provide a morphological baseline for studies on functional zonation of this part that is critical in sperm maturation. Macroscopical, histological, ultrastructural, and histochemical observations permitted us to subdivide this part into five segments, characterized by epithelial height, nuclear position, cytological and histochemical features of principal cells. Segment I corresponded to the initial segment previously described in rodents. Segment II differed from segment I by endoplasmic reticulum (ER) and dictyosomes aspect in principal cells, apical alkaline phosphatase and Ca2+-dependent ATPase activities. Segment III was characterized by spermatozoa package, high content of cells in multivesicular bodies, mitochondria shape, complex interdigitating membranes, and strong periodic acid-Schiff (PAS)-positive cell border. Segments IV and V presented the same cytological features but differed by their esterase activity. In the principal cells of each segment, dense spherical concretions were scattered in ER caveolae. Cells with apical nuclei were classified into two groups. The cells of the first group presented the same morphological and histochemical features as the adjacent principal cells and were scattered in the five segments ("apical cells"). The cells of the second group differed from the others by their goblet shape, a dense cytoplasm, and a high mitochondria succinate-D activity. They presented different cytological and histochemical features depending on their localization in segments I ("narrow cells"), II ("prominent cells"), or III, IV, V ("mitochondria goblet-cells"). The possible relationships between epithelium structure and epididymal functions were herein discussed.
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PMID:Regional differences of the proximal part of mouse epididymis: morphological and histochemical characterization. 646 30

Motility of sperm flagella as well as of cilia is mechanically based on the principle of 9 + 2-tubules. It functions essentially by coordinated action between microtubules and the adenosine-triphosphatase dynein and was already present at the beginning of the evolution of the eucaryotes. Experimentally induced mutations in algae have resulted in numerous variations of the flagellar 9 + 2-structure. A mutation of this kind is also found in man, as immotile cilia syndrome (ICS) where anomalies in spermatozoa and in cilia (e.g. of the respiratory tract) are observed. Clinical manifestations of the syndrome have long been known (chronic bronchitis, bronchiectasis, sinusitis and male sterility). In addition, half of the patients exhibit situs inversus viscerum, known as Kartagener's syndrome, a subgroup of ICS. Electron microscopy was used to investigate sperm flagella with reduced motility from 9 patients (one with ICS) with primary infertility. Cilia of the respiratory tract from 7 patients (several with ICS) with chronic bronchial problems were analyzed for motility (using video techniques) and ultrastructure. Reduced motility or immotility of spermatozoa and immotile or dyskinetic cilia were always accompanied by ultrastructural anomalies. In spermatozoa, lack of dynein arms, 9 + 0-configuration and extratubuli were most frequently observed. The fibrous sheath was always asymmetrical. Structural ciliary defects resulted in non-parallel arrangements, electron dense matrix substance, extratubuli and lack of radial spokes. In one case, ciliary microtubuli were found in microvilli. In two patients, cilia as well as spermatozoa were analyzed. In the first, immotile spermatozoa without dynein arms and structurally normal cilia were observed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Sperm flagella and cilia with pathologic motility and ultrastructure]. 650 61

Gossypol acetic acid was given to male rats at a dose of 7.5 mg/rat/day six days a week for ten weeks. After nine weeks of gossypol treatment no implantation sites were observed in the females mated with gossypol treated males. After ten weeks of gossypol treatment all the spermatozoa in the vas deferens were non-motile. Gossypol treatment did not affect the body weight and the weights of the accessory sex organs. Plasma LH and FSH levels, hCG binding in testis and succinic dehydrogenase (SDH) and adenosine triphosphatase (ATPase) activities in liver, kidney and testis were not affected by gossypol treatment. Histological observations of the testis revealed partial damage to the seminiferous tubules. Single high doses of gossypol did not induce significant changes in the body weight and weights of testis and accessory sex organs. ATPase activity in the testis was reduced significantly after gossypol treatment, the enzyme activity in liver and kidney, was however, affected at high doses only. Gossypol treatment had no effect on the histoarchitecture of the testis. Intratesticular administration of gossypol evoked localized damage in the testis. Gossypol treatment had no effect on I125 FSH binding to the rat testis homogenate in vitro.
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PMID:Studies on the male antifertility agent--gossypol acetic acid. V. Effect of gossypol acetic acid on the fertility of male rats. 716 22

Intact and Triton X-100 demembranated boar spermatozoa possess two main heavy chains with molecular masses (M(r)) of 430 and 460 kDa. These heavy chains were photo-cleaved within the axoneme under V1 conditions and produced two main fragments at 245 kDa and 185 kDa. Two minor fragments at 170 and 90 kDa were also obtained. In the presence of low Mg2+ (1 mM) a supplementary fragment of 200 kDa was also observed. The heavier chain was cleaved in the absence of ATP to give the 245 kDa fragment. The boar axonemal heavy chains cannot be directly extracted by high salt treatment of the demembranated sperm in presence of high level of protease inhibitors (HPI) but were extracted when the solution contained low protease inhibitor (LPI) concentrations. Electron microscopy showed that high salt treatment in presence of LPI extracted the outer arm mainly from the principal piece of the flagellum and less from the intermediate piece. Fractionation of the LPI high salt by chromatography or sucrose gradient allowed the obtention of a particle with ATPase activity, a size of 1.2 MDa and a sedimentation coefficient of about 20S. The particle was composed of two heavy chains of M(r) 320 and 340 kDa. These heavy chains can be photo-cleaved under V1 conditions and in absence of Mg2+. The sucrose gradient 20S fractions contained also two chains at 110 and 87 kDa which could be either intermediate chains or proteolytic fragments of the heavy chains. A chain at 63 kDa was also associated with the 20S fraction.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Characterisation of boar sperm dynein heavy chains by UV-vanadate dependent photocleavage. 760 16

Progesterone (P) has previously been shown to induce a rapid increase in [Ca2+]i as well as tyrosine phosphorylation of proteins in human spermatozoa. Both these effects are essential for induction of the acrosome reaction by P. We investigated a possible relationship between the P-induced calcium increase and tyrosine kinase activation, by evaluating the effect of the tyrosine kinase inhibitor genistein on these two effects. We found that preincubation with genistein abolished P-induced tyrosine phosphorylation of two sperm proteins of 97 and 75 kDa molecular weight and significantly inhibited the plateau phase of P-induced [Ca2+]i increase without affecting the peak phase. Conversely, the plateau phase was enhanced by the tyrosine phosphatase inhibitor Na3VO4. The effect of genistein was specific for P, since no inhibition was observed on the [Ca2+]i increase induced by thapsigargin, an inhibitor of endoplasmic Ca(2+)-ATPase previously shown to mobilize Ca2+ in spermatozoa. These results indicate that tyrosine kinase activation is involved in the generation of the plateau phase of Ca2+ influx induced by P, and suggest the possibility that two different pathways are involved in the induction of Ca2+ entry by P in human sperm.
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PMID:Tyrosine kinase inhibition reduces the plateau phase of the calcium increase in response to progesterone in human sperm. 775 May 49

Mammalian spermatozoa require extracellular Ca2+, some of which must be internalized, to undergo capacitation and acrosomal exocytosis. The mechanisms controlling the intracellular Ca2+ concentration are unclear, but current evidence suggests that a Ca(2+)-ATPase may be involved. Using treatments that potentially modulate enzyme activity, we investigated this possibility in human spermatozoa; the capacitation state and acrosomal integrity were monitored by chlortetracycline fluorescence. Incubation of cells in the presence of quercetin, a Ca(2+)-ATPase inhibitor, significantly accelerated the transition from the uncapacitated F pattern of chlortetracycline fluorescence to the capacitated, acrosome-intact B pattern within 1 h. This was followed by an increase in the number of cells displaying the capacitated, acrosome-reacted AR pattern. Since most Ca(2+)-ATPases in somatic cells are sensitive to calmodulin, we also investigated the effect of the calmodulin antagonist W-7 on chlortetracycline patterns. At 1-125 mumol l-1, W-7 significantly stimulated capacitation and acrosomal exocytosis. Furthermore, W-7 at 1 mumol l-1 proved to be more effective than W-5, a less potent antagonist, suggesting that the observed responses in human spermatozoa did reflect a calmodulin-sensitive mechanism. When the glucose concentration in the culture medium was varied (from 0 to 5.56 mmol l-1) to alter the availability of ATP for enzyme activity, it was found that a reduced concentration of glucose promoted capacitation more rapidly than did the standard concentration of 5.56 mmol glucose l-1. However, maximal changes, particularly in promoting the shift from the B to the AR pattern of chlortetracycline fluorescence, required millimolar concentrations of glucose during the last few minutes before assessment. Finally, the addition of partially purified mouse sperm decapacitation factor (proposed to activate a Ca(2+)-ATPase and thus maintain a low intracellular Ca2+ concentration) to capacitated human sperm suspensions caused a significant reversal in the capacitation state of cells (from the B to the F pattern). The F pattern of chlortetracycline fluorescence predominates in conditions favouring low concentrations of intracellular Ca2+. From these results, we suggest that a Ca(2+)-ATPase may play an important role during human sperm capacitation. A time-dependent decrease in endogenous enzyme activity would allow the intracellular concentration of Ca2+ to rise to a critical value necessary for initiation acrosomal exocytosis and subsequent successful fertilization.
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PMID:A possible role for Ca(2+)-ATPase in human sperm capacitation. 779 3


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