Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.15.1 (ACE)
 18,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A semiquantitative colorimetric micromethod (APIZYM) was used to study the enzyme profiles of seminal plasma and of spermatozoa. Reactions with 65 different substrates are simultaneously tested in a single specimen. These substrates (principally naphtolic) allow the detection of hydrolytic enzymes (esterases, phosphatases, and peptidases) and of dehydrogenases potentially involved in sperm metabolism and in the process of fertilization. The usual sperm enzymes were regularly observed: C3-C4 esterases, amino acid arylamidases, acrosine, phosphatases, glutamyl transpeptidase, and various osidases. Among the dehydrogenases we observed a striking predominance of the enzymes of the hexose monophosphate shunt and of LDH. Seminal plasma has an enzyme pattern very similar to that of spermatozoa except for the absence of acrosine and of some dehydrogenases. This unexpected similarity is discussed. The gametes from subfertile donors do not at first sight differ in their enzyme pattern from those from fertile donors. Moreover, we found no marked differences between zymograms of seminal plasma from normal, subfertile, or even azoospermic patients. Deep freezing does not modify the hydrolytic enzymes of human sperm either quantitatively of qualitatively, but the dehydrogenases of the hexose monophosphate shunt are adversely affected (60% loss of activity for G 6 PDH, and 30% for 6 PGDH); LDH is not affected. The consequences on fertilizing capacity of frozen semen are discussed.
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PMID:Enzyme comparative study of spermatozoa and seminal plasma in normal and subfertile man. 51 8

All four components of the kallikrein-kinin system--kininogens, tissue kallikreins, kinins, and kininases--have been found in human male genital secretions. Kinins are continuously released from seminal plasma kininogens through limited proteolysis by kininogenases like tissue kallikrein from prostate and sperm acrosin. Kinins are the terminal effectors of the kallikrein-kinin system and increase sperm motility and sperm metabolism at nanomolar concentrations. Recent investigations indicate that these effects are possibly mediated by a specific sperm membrane integrated bradykinin receptor, subtype B2. The two major kininase that are present in seminal plasma are kininase II and neutral metallo-endopeptidase. Kininase II, which is identical with angiotensin-converting enzyme, is also involved in the renin-angiotensin system as it converts angiotensin I into angiotensin II and thus is the connecting enzyme of both systems. Apart from the observed effects of kinins on sperm motility, the kallikrein-kinin system is thought to be involved in the regulation of spermatogenic functions of the testis: in the rat, kallikrein activates Sertoli cell function, increases the relative number of spermatocytes and the [3H] thymidine incorporation of testicular tissue, enhances glucose-intake, and increases testicular blood flow. Clinical trials showed that systemic administration of kallikrein may be particularly useful for treatment of infertile men suffering from asthenozoospermia and/or oligozoospermia. During kallikrein therapy, the number of spermatozoa and both quantitative and qualitative sperm motility increased, and a significant improvement of the conception rate was achieved. An increased sperm number was also observed after application of the specific kininase II inhibitor captopril.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Possible effects of the kallikrein-kinin system on male reproductive functions. 131 46

Recently it has been observed that ejaculated human sperm possess high angiotensin converting enzyme (ACE) activity and that this enzyme is released during the process of capacitation. This observation raises the possibility that ACE may be involved in the fertilization process. To verify this hypothesis, we tested the effects of a potent ACE inhibitor, Captopril, on acrosome reaction induced by capacitating medium (3.5% HSA-added BWW) and on ability of human capacitated spermatozoa to penetrate zona-free hamster oocytes. Addition of Captopril (100 nmol l-1) modified neither sperm motility nor viability at any time considered, but significantly reduced the acrosome reaction percentages of sperm incubated in capacitating medium. Furthermore, Captopril significantly reduced the percentage of penetrated oocytes. The mean penetration rates both in the absence and presence of Captopril were 65.5 +/- 4.9% and 26.9 +/- 2.3% (P less than 0.001) respectively. These findings provide evidence that sperm release of ACE during capacitation may have a physiological role in the regulation of the mechanisms that allow sperm acrosome reaction and thus fertilizability.
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PMID:Evidence for the involvement of sperm angiotensin converting enzyme in fertilization. 166 81

Healthy adult cocks were administered through the intramuscular route with 1 or 15 mg cyproterone acetate (CyA)/kg b. wt. or testosterone at the rate of 1.5 mg/kg b. wt. daily for a period of 25 days. High doses of CyA and testosterone caused severe suppression (P less than 0.01) of semen volume, sperm concentration, sperm motility and angiotensin converting enzyme activity (ACE EC 3.4.15.1). Fertilizing ability of spermatozoa was also reduced drastically at the end of treatment period. No loss of sexual behaviour was observed in treated birds as compared to controls. Recovery in all parameters from deleterious effects of these drugs was rapid after cessation of treatment. Lower doses of CyA did not affect the parameters of semen. The results are discussed in relation to the possible mechanism of action of CyA and testosterone.
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PMID:Effects of cyproterone acetate and testosterone treatments on some physical parameters, angiotensin converting enzyme activity and fertilizing ability of spermatozoa of domestic cocks (Gallus domesticus). 217 66

The angiotensin converting enzyme inhibitor, enalapril, reduced the motility of washed human spermatozoa. The concentrations producing 50% inhibition were: (percentage motility) 11.6 +/- 2.6 mM, (average forward velocity) 8.0 +/- 1.5 mM and (motility index) 8.5 +/- 2.1 mM (mean + s.e.m.). Enalapril 20 mM prevented all forward movement and reduced percentage motility to an extremely low level. Motility was reduced within 20 sec of addition and little further change occurred during a 60-min incubation period. Inhibition of percentage motility by enalapril was reversible with a 5-min washing procedure following a 5-min incubation period, but not following a 60-min incubation period. Enalapril 20 mM did not impair plasma membrane integrity (hypoosmotic swelling test) or viability (nigrosin-eosin stain). It is concluded that the antimotility effects of enalapril are not caused by inhibition of angiotensin converting enzyme, but may be of interest in the search for new spermicidal agents.
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PMID:Effects of enalapril on human sperm motility. 231 7

Daily oral administration of gossypol acetic acid (40 mg/kg body weight daily) resulted in a gradual decrease in the semen volume and sperm concentration. Fertility dropped to zero at the end of the treatment period. Activities of acrosin, hyaluronidase and angiotensin converting enzyme were also drastically decreased by the end of the treatment period. A loss of appetite, loss of body weight and morphological abnormalities in spermatozoa were noticed in the treated cocks. At 4 weeks after cessation of the treatment, full recovery of the above measures was recorded. Healthy chicks were hatched and were observed for several months.
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PMID:Studies on antifertility effects of gossypol acetic acid in domestic cocks. 253 13

The purpose of this study was to investigate the influence of several pharmacological compounds on the motility and velocity of washed human spermatozoa. Results were evaluated by multiple exposure photography and computer-aided picture analysis. The motility-inhibiting effect of the antifertility drug gossypol was confirmed. Gossypol proved to be a potent inhibitor of the angiotensin converting enzyme (ACE) detectable in high concentrations in seminal plasma. However, human sperm motility was not inhibited during incubation with two other specific ACE-inhibitors (captopril, enalapril). On the contrary, high concentrations of captopril even showed a slight motility-stimulating effect. These results indicate no direct involvement of ACE in the regulation of sperm motility but suggest a direct interaction of gossypol with the plasma membrane of spermatozoa. To clarify whether or not gossypol blocks membranous ion transport, the effect of well-defined ion transport blocking agents on sperm motility was investigated. It was determined that the acetylcholine receptor blocker alpha-bungarotoxin and trifluoperazine, a specific calmodulin antagonist, inhibit sperm motility completely. Since stimulation of sperm motility by captopril may be due to an alpha-mimetic action of this compound, the influence of two alpha receptor blockers (bromocriptine, lisuride) on sperm motility was studied. Although lisuride inhibited sperm motility completely, bromocriptine revealed no influence. A temporary and reversible intervention with membrane transport processes could be a suitable way to regulate human sperm motility and male fertility.
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PMID:Effect of ace-inhibitors, calmodulin antagonists, acetylcholine receptor blocking, and alpha receptor blocking agents on motility of human sperm. 290 25

The localization of angiotensin converting enzyme (ACE) in the gonads of the normal rabbit was studied by immunofluorescence and immunoelectron microscopy. The enzyme is present in the cytoplasm of testicular spermatids and of epididymal and ejaculated spermatozoa, and on the surface of follicular and tubal oocytes. These findings support the hypothesis that ACE has a role in gamete maturation and in fertilization.
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PMID:Gametes contain angiotensin converting enzyme (kininase II). 300 98

The plasma level of angiotensin I-converting enzyme (ACE) has been shown to be under genetic control. An insertion/deletion polymorphism in the ACE gene is associated with differences in the level of ACE in the plasma and inside T-lymphocytes. An ACE isoform is present in large amounts in spermatozoa and is expressed under an alternative, germ cell-specific promoter, whereas ACE present in the seminal fluid is the somatic form of ACE. We have investigated the effect associated with the I/D polymorphism on the level of ACE in seminal fluid and in spermatozoa. No differences in the level of ACE measured in the seminal fluid or in the spermatozoa were associated with the ACE I/D genotypes. We conclude that the modulation of expression associated with the I/D polymorphism is restricted to the somatic ACE promoter. These results also suggest that if one allele modulating the expression of ACE was under positive selection pressure, it was not through an effect on the semen concentration of ACE.
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PMID:A genetic study of angiotensin I-converting enzyme levels in human semen. 776 33

Of the nine biological trace elements, zinc, copper and selenium are important in reproduction in males and females. Zinc content is high in the adult testis, and the prostate has a higher concentration of zinc than any other organ of the body. Zinc deficiency first impairs angiotensin converting enzyme (ACE) activity, and this in turn leads to depletion of testosterone and inhibition of spermatogenesis. Defects in spermatozoa are frequently observed in the zinc-deficient rat. Zinc is thought to help to extend the functional life span of the ejaculated spermatozoa. Zinc deficiency in the female can lead to such problems as impaired synthesis/secretion of (FSH) and (LH), abnormal ovarian development, disruption of the estrous cycle, frequent abortion, a prolonged gestation period, teratogenicity, stillbirths, difficulty in parturition, pre-eclampsia, toxemia and low birth weights of infants. The level of testosterone in the male has been suggested to play a role in the severity of copper deficiency. Copper-deficient female rats are protected against mortality due to copper deficiency, and the protection has been suggested to be provided by estrogens, since estrogens alter the subcellular distribution of copper in the liver and increase plasma copper levels by inducing ceruloplasmin synthesis. The selenium content of male gonads increases during pubertal maturation. Selenium is localized in the mitochondrial capsule protein (MCP) of the midpiece. Maximal incorporation in MCP occurs at steps 7 and 12 of spermatogenesis and uptake decreases by step 15. Selenium deficiency in females results in infertility, abortions and retention of the placenta. The newborns from a selenium-deficient mother suffer from muscular weakness, but the concentration of selenium during pregnancy does not have any effect on the weight of the baby or length of pregnancy. The selenium requirements of a pregnant and lactating mother are increased as a result of selenium transport to the fetus via the placenta and to the infant via breast milk.
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PMID:Zinc, copper and selenium in reproduction. 803 70


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