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Query: KEGG:D01453 (caffeine)
 21,611 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this report the effect of caffeine, IBMX and Cholera toxin on ejaculated human spermatozoa was tested. It was found that caffeine was the most effective drug, and that Cholera toxin was ineffective. Caffeine stimulated motility, preserved viability and increased the glucose, fructose utilization and lactate production of sperm in whole semen and washed sperm. Oxygen consumption however was decreased. These results of the normokinetic ejaculates were defined as a basis for comparison with the response of hypokinetic sperm. A group of 11 hypokinetic ejaculated spermatozoa were treated by caffeine and only five responded to caffeine stimulation by a response, similar to that of normokinetic sperm. They were defined as "responsive." The other group of six patients who did not respond were defined as a "non-responsive" class. The possibility that the in vitro treated sperm of the responsive class ejaculate is suitable for artificial insemination to their wives, is discussed.
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PMID:Effect of caffeine on the motility, viability, oxygen consumption and glycolytic rate of ejaculated human normokinetic and hypokinetic spermatozoa. 1 19

Washed mature spermatozoa from bulls incorporate ribonucleoside triphosphates into RNA using an endogenous template. Maximum incorporation was observed at 31 degrees C in the presence of MgCl2, all four ribonucleoside triphosphates, beta-mercaptoethanol, and glycine sodium hydroxide buffer at pH 9.0. The amount of synthesis was linearly dependent upon the concentration of spermatozoa and continued for at least 4 h. Digestion studies revealed the RNA to be present in a protected (intracellular?) location in the spermatozoa. The RNA synthesis was inhibited by ethidium bromide, rifampicin, acriflavine, actinomycin D, and caffeine, but not by alpha-amanitine or rifamycin SV. Fractionation of the spermatozoa by sonication and separation of the heads and tails by centrifugation through a discontinuous gradient revealed that more than half of the total RNA polymerase activity was associated with the tail fraction.
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PMID:RNA polymerase activity in bovine spermatozoa. 2 Apr 46

The adenylate energy charge of human ejaculated spermatozoa was studied when the sperm motility was perturbed by varying pH, prolonged incubation, and caffeine. Between pH 8 and 9, which was optimal for the sperm motility, the energy charge was in the physiological range of 0.8 to 0.9. Above pH 9, the mobility, ATP content, and adenine nucleotide pool declined rapidly but the energy charge was maintained slightly below 0.8. Below pH 8, the motility also dropped drastically, but the ATP, nucleotide pool, and energy charge fell only slightly. Prolonged incubations of the spermatozoa decreased the motility, ATP, and nucleotide pool. However, the energy charge would remain above 0.6. Caffeine stimulation of the motility caused a rapid fall of ATP and the reduction of the physiological energy charge by 0.2 unit, unless glucose was added. Imidazole which reduced the caffeine-stimulated motility did not alter the physiological energy charge of the spermatozoa. The study showed that the spermatozoa could maintain the energy charge above 0.6 under stress.
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PMID:Stabilization of adenylate energy charge and its relation to human sperm motility. 2 Nov 88

Preservation of human semen in liquid nitrogen causes a significant impairment of sperm motility. Ejaculated human spermatozoa show an increased motility in the presence of caffeine, a phosphodiesterase inhibitor, and pancreatic kallikrein (EC 3.4.21.8), a kinin-producing proteinase. Hence, the effect of both substances on post-thaw motility, fructose consumption, and cervical mucus penetration of cryo-preserved human spermatozoa was investigated. The results indicate that both substances stimulate the motility of freshly ejaculated spermatozoa and also improve the motility pattern of cryo-preserved human spermatozoa, thus offering a possible means of improving the quality of freeze-preserved human semen.
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PMID:Effect of caffeine and kallikrein on cryo-preserved human spermatozoa. 3 76

Noradrenaline, adrenaline, and isoproterenol induce head-to-head association in bovine spermatozoa in a Tris-HCl-buffered medium. Noradrenaline was the most and isoproterenol the least efficient. This effect was stimulated by Ca2+, Mg2+ and Mn2+, Ca2+ being more efficient than the other two ions. At 2 X 10(-6) M Ca2+, oxidation products of adrenaline dissociated spermatozoa associated by washing; at 2 X 10(-5) M Ca2+, the dissociating effect was transformed into association. The induction of association by adrenaline was blocked by both alpha- and beta-adrenergic blockers at low concentrations (2 X 10(-7) M). Both cAMP and dibutyryl substituted cAMP (db-cAMP) induced association in the Tris-buffered medium at 2 X 10(-6) M Ca2+. Further increase in association was brought about by increasing the Ca2+ concentration to 2 X 10(-5) M. Prolongation of the treatment with cAMP increased association. When combined with cAMP under the same conditions as used in the combination with adrenaline, L-propranolol did not inhibit association induced by cAMP. In an identical experiment, performed in Tyrode solution, L-propranolol inhibited association induced by cAMP. At 2 X 10(-5) M, theophylline, caffeine, and papaverine induced association in the presence of 2 X 10(-5) M Ca2+. The results are compatible with the hypothesis that catecholamines act via receptors and formation of cAMP.
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PMID:Head-to-head association in bovine spermatozoa induced by catecholamines. 4 20

The motility of washed suspensions of human spermatozoa was completely inhibited by tetraphenylboron at concentrations that had little effect on sperm energy metabolism. The inhibition of motility was reversed by quaternary ammonium salts, albumin, caffeine, dibutyryl cyclic AMP and potassium ions. The addition of ouabain to cells redndered immotile by tetraphenylboron prevented reinitiation of motility by potassium but not by the other compounds. These observations, together with the effect of tetraphenylboron on the fluorescence of sperm suspensions treated with 1-anilinonaphthalene 8-sulphonic acid, suggest that the binding of tetraphenylboron to sites on the sperm plasma membrane is involved in the inhibition of sperm motility and the cyclic AMP may be involved in the regulation of ion transport across the plasma membrane.
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PMID:Reversible inhibition of the motility of human spermatozoa by tetraphenylboron. 17 68

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

Cytochalasin B inhibits the motility and metabolism of washed human spermatozoa at low concentrations (20 to 200 mum). Spermatozoal motility (primarily the frequency of flagellar contraction) declines slowly after addition of the antibiotic but is not abolished even after treatment for several hours. The addition of caffeine or dibutyrylcyclic adenosine 3' :5'-monophosphate to washed sperm suspensions increases the percentage of motile cells, the frequency of flagellar contraction, and the rate of glycolysis. These effects are blocked by cytochalasin B. However, cytochalasin B-treated spermatozoa regain their responsiveness to these agents when the antibiotic is washed out of supporting media. These effects are discussed in terms of an interaction of cytochalasin B with the sperm plasma membrane.
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PMID:Reversible inhibition of the motility of human spermatozoa by cytochalasin B. 19 48

Mann-fructose fluid (MF), MF plus caffeine, MF plus pentoxifylline, MF plus dibutyryl cyclic adenosine 3',5'-monophosphate (cAMP), MF plus propranolol, and MF plus propranolol plus dibutyryl cAMP were individually added to aliquots of semen samples obtained from 18 normal men to a final concentration of .6 mM to determine whether these drugs affected percentage, quality, and duration of activity of ejaculated human spermatozoa. At each observation time (30 minutes, 1, 2, and 4 hours), semen quality was evaluated by determining percentages of forwardly progressive, slowly progressive, in situ motile, live and nonmotile, and dead sperm. MF resulted in a decrease in motility and duration of activity compared with controls (P .001). Caffeine seemed to neutralize the deleterious effect, whereas pentoxifylline and cAMP seemed to increase duration of activity. Propranolol resulted in a dramatic decrease in motility, an effect that could not be neutralized by adding cAMP. The effects of adding cAMP seem to confirm that an increase of the intracellular content of this compound could determine a longer-lasting activity of ejaculated human spermatozoa.
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PMID:Effect of two phosphodiesterase inhibitors, cyclic adenosine 3':5'-monophosphate, and a beta-blocking agent on human sperm motility. 20 45

Boar spermatozoa incorporated more [14C]glycerol into lipid when incubated with 200 mM- than with 25 mM-glycerol. Measurements were made of the metabolism of spermatozoa while they were being prepared for frozen storage. [14C]-Glucose was converted to CO2 and lipid while the cells were cooling to 15 degrees C. Glycerol was added at 15 degrees C and during further cooling to 5 degrees C glucose metabolism was greatly reduced but [14C]glycerol was converted to CO2 and lipid. Under aerobic conditions spermatozoa accumulated lactate while cooling from 30 to 15 degrees C and from 15 to 5 degrees C. With essentially anaerobic conditions, although more lactate was accumulated this occurred only while the cells were cooling from 30 to 15 degrees C, and no further accumulation could be detected during cooling from 15 to 5 degrees C. When boar spermatozoa were incubated at 37 degrees C after storage in liquid nitrogen, metabolism of glycerol was greater than metabolism of glucose. It is suggested that this preferential use of glycerol during cooling and after storage may be one facet of its cryoprotective function. After storage, boar spermatozoa incorporated relatively less [14C]stearic and [14C]palmitic acids into phospholipids (especially phosphatidyl choline) than did freshly collected cells. Caffeine stimulated the oxygen uptake of freshly collected and thawed cells.
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PMID:Metabolism of boar spermatozoa before, during preparation for, and after storage in liquid nitrogen. 43 61


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