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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It was possible to demembrante and reactivate not only freshly collected testicular, cauda epididymal, and ejaculated ram sperm but also sperm that had been stored for several days at 0 degrees C and for several months at -196 degrees C in rete testis fluid or egg yolk citrate media. Sperm were usually washed free of seminal plasma before demembranation, but this was not essential for reactivation. Bovine serum albumin (1.0%) in the wash medium increased the survival of sperm, but more than 0.25% in the extraction medium decreased reactivation. A macro-molecular component of cauda epididymal fluid also inhibited the reactivation of testicular sperm. Triton X-100 concentrations between 0.01% and 1.00% in the extraction medium were satisfactory for demembranating the sperm. Rapid cooling (i.e., cold shock) mimicked the effect of detergent in making the sperm responsive to added ATP and demonstrated that damage to ram sperm in cold shock does not involve the axoneme. Ejaculated and cauda sperm were reactivated immediately on addition of ATP and activity persisted for up to 10 min. Testicular sperm, on the other hand, required about 4 min to become fully reactivated. The optimal ATP concentration for activation of sperm was 0.1-1.0 mM. Magnesium ions (0.1-1.0 mM) were important for reactivation, and testicular sperm required a higher magnesium concentration than did cauda or ejaculated sperm. Manganese ions were almost as effective as magnesium for reactivating cauda epididymal and ejaculated sperm. Cobalt and cadmium ions were much less active for cauda and ejaculated sperm and none of these ions were effective for testicular sperm. Fluoride (25-50 mM) inhibited reactivation. The presence of 50 microM cAMP in the extraction medium or preincubation of testicular sperm with theophylline or caffeine increased low levels of activation, but this was not evident with ejaculated or cauda sperm. We conclude that the motor apparatus is already functionally assembled in spermatozoa on leaving the testis, but some fine adjustment must take place during maturation in the epididymis.
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PMID:ATP-induced reactivation of ram testicular, cauda epididymal, and ejaculated spermatozoa extracted with Triton X-100. 395 35

Experiments were conducted to determine whether chronic caffeine consumption during early growth and development affected cardiac performance and development of adipose tissue. Dams were fed a nutritionally complete diet with or without the addition of 10 mg/kg caffeine during lactation. After weaning, the pups were maintained on this diet until they were sacrificed at 88 days of age. Body weight at the time of sacrifice was comparable for both groups. The hearts from caffeine-fed animals were significantly (P less than 0.05) larger based on both dry and wet weights although the dry weight/wet weight ratios were similar. Ventricular function curves were generated on each heart using an isolated working heart preparation. The isolated hearts of caffeine-fed rats exhibited a significant reduction in cardiac output, stroke volume, mean aortic pressure, and estimated myocardial work when compared to controls. The rats fed caffeine had greater plasma triglyceride levels with no significant differences in adipocyte size or number in the epididymal and perirenal depots. It is concluded that chronic caffeine intake from birth may alter cardiac function of the offspring.
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PMID:Effects of chronic caffeine ingestion on growth and myocardial function. 400 Nov 33

Sperm were collected over a period of months from a human alloplastic spermatocele implanted at the corpus/caudal epididymal junction and were evaluated for their maturity, motility, and ability to capacitate and acrosome react, as assessed by the hamster zona-free oocyte sperm penetration assay (SPA). A mean of 11 X 10(6) sperm were obtained with each aspiration, with 34% to 40% being mature, normal forms. Motility was poor; 15% +/- 5% showing nonprogressive movement. SPA results were 22% +/- 3% oocyte penetration. Addition of 7.5 mM caffeine markedly enhanced motility and improved the SPA results. After 30 minutes' exposure, the motility was 45% +/- 5%, with all spermatozoa exhibiting progressive movement. This stimulation was maintained over a 24-hour period. When caffeine was present during the 2-hour preincubation for the SPA, penetration rates increased to 50% +/- 10% (P less than 0.05). These results demonstrate that the poor-quality sperm retrieved from a human alloplastic spermatocele can be improved with exogenous stimulation and suggest that their fertilizing capacity may be enhanced by this treatment.
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PMID:Properties of human epididymal sperm obtained from an alloplastic spermatocele: motility assessment and penetration of zona-free hamster oocytes in the presence and absence of caffeine. 402 29

31P NMR signals assigned to intracellular adenine nucleotides and to inorganic phosphate were detected in dense suspensions of epididymal sperm obtained from bulls or hamsters. Similar adenine nucleotide signals and an additional large resonance peak, attributable to extracellular glycerylphosphorylcholine, were observed with whole bovine cauda epididymides. Provision of the glycolytic substrate fructose to such sperm suspensions promoted apparent conversion of intracellular ADP to ATP with a concomitant decrease in cellular inorganic phosphate (Pi) content. Subsequent treatment with the methylxanthine caffeine resulted in diminution of the intracellular gamma-P-ATP signal that was consistent with the decreased ATP and ADP contents previously demonstrated by chemical analyses of cellular extracts. Alternatively, treatment with fructose followed by the membrane-selective detergent digitonin produced loss of the nucleotide NMR signals, indicating release of ATP and Pi from the sperm cytosol with subsequent hydrolysis in the extracellular medium. Comparison of intracellular Pi and ATP resonance signals with those of ATP and Pi in vitro, in media of varied pH and cation composition, allowed calculation of a cytosolic pH of 6.5-6.6 and a cytosolic Mg2+ concentration of 0.5 mM for fresh suspensions of bovine cauda epididymal sperm. Intracellular Pi of hamster epididymal sperm reported a similar cytosolic pH. Other, more acidic compartments were not detected in these experiments. However, during prolonged incubation, the pH of the bovine sperm interior slowly decreased as the extracellular medium was acidified by extensive production of lactate. Intracellular ATP was detectable until cytosolic pH declined to approximately 5.5. Rapid intracellular acidification, resulting from exchange of internal K+ for H+, was observed after treatment with carboxylic acid ionophore nigericin. This lowering of internal pH was followed by a slower return toward initial internal pH values, probably as a consequence of secondary exchange of internal protons for other external monovalent cations, rather than as a result of the operation of a cellular homeostatic mechanism. Together, these studies utilizing noninvasive NMR techniques provide evidence that within the bovine epididymis sperm utilize an unknown energy source to phosphorylate adenine nucleotides and maintain a slightly acidic cytosolic pH.
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PMID:A 31P NMR study of the epididymis and epididymal sperm of the bull and hamster. 407 1

Caffeine stimulates a release of free fatty acids from adipose tissue and has been shown to enhance fat utilization during an acute bout of prolonged aerobic exercise. A previous study indicated that chronically ingesting caffeine prior to exercise in an aerobic training program may enhance the fat-reducing effects of exercise. In the present study, mature male rats were divided into four groups: two groups swam 90 min/day, 5 days/week for 10 weeks (caf-ex, no caf-ex), while two groups served as sedentary controls (caf-sed, no caf-sed). The groups that received caffeine were administered, by gavage, 5 mg caffeine/kg body weight, dissolved in saline, 45 min prior to the start of exercise. The no caf groups received saline only. After the training period, body fat weight was determined by petroleum ether extraction of the fat from a dried, homogenized sample in a soxhlet apparatus. Body weight, percent body fat, epididymal fat pad weight, and food intake were all significantly lower in the exercised groups than the sedentary groups (P less than 0.05). The exercised groups weighed approximately 50-70 g less, % BF was 3.4% lower, EFP were approximately 2.5 g lighter, and food intake was 49-66 g less. There was no statistically significant difference between the caffeine and no caffeine groups on any of the variables tested (P greater than 0.05). This study did not find that caffeine enhanced the fat-reducing potential of the aerobic exercise.
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PMID:Effects of caffeine and exercise on body fat levels of the rat. 407 59

1. The rise in clearing-factor lipase activity that occurs when epididymal fat bodies from starved rats are incubated in appropriate media in vitro is inhibited in the presence of 6-N-2'-O-dibutyryl-3',5'-(cyclic)-AMP (1mm). 2. Inhibition occurs at a concentration of glucose in the incubation medium of 1.3mg./ml. or less, but not at a glucose concentration of 2.4mg./ml., unless caffeine (1mm), an inhibitor of 3',5'-(cyclic)-nucleotide phosphodiesterase, is also present. Caffeine (5mm) alone inhibits the rise in clearing-factor lipase activity at a glucose concentration of 2.4mg./ml. of medium. 3. The concentration of free fatty acids in the epididymal fat bodies normally falls during incubations in vitro as the rise in clearing-factor lipase activity occurs. In the presence of 1mm-6-N-2'-O-dibutyryl-3',5'-(cyclic)-AMP, however, either the tissue free fatty acid concentration is increased or it does not fall to the same extent. The concentration of glucose in the incubation medium is important in determining the direction and extent of the changes in tissue free fatty acid concentration that occur in the presence of 6-N-2'-O-dibutyryl-3',5'-(cyclic)-AMP. 4. Free fatty acid concentrations in epididymal fat bodies in vivo rise as the clearing-factor lipase activity of the tissue falls during starvation. 5. The possibility that the concentration of 3',5'-(cyclic)-AMP in adipose tissue may regulate clearing-factor lipase activity, and that the regulation may occur through effects of the nucleotide on tissue free fatty acid concentrations, is discussed.
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PMID:Clearing-factor lipase in adipose tissue. A possible role of adenosine 3',5'-(cyclic)-monophosphate in the regulation of its activity. 430 48

Hamster spermatozoa were isolated from the caput, corpus and cauda epididymidis. They were observed in culture medium at 37 degrees C with a phase-contrast microscope and their motility recorded cinematographically. About 20 p. 100 of the caput epididymidis spermatozoa were motile and moved in a confined space with no forward progression. 30 p. 100 of the corpus epididymidis spermatozoa were motile, showing increased flagellar activity and moving in wide circles. 90 p. 100 of the cauda epididymidis spermatozoa were motile and moved forward. Forward motility was induced in immotile spermatozoa from the caput epididymidis by adding cyclic 3'-5' adenosine monophosphate (cAMP) phosphodiesterase inhibitors (caffeine, theophylline, IMX) and epididymal plasma. The best stimulation was initiated by 15 mM caffeine with 10 p. 100 of cauda epididymal plasma; a mean of 60 p, 100 of forward motility was obtained which lasted for one hour and then ceased. Cinematographic studies revealed that some induced sperm movements differed from the equivalent natural ones by the amplitude of the head movements. It is shown that during epididymal transit of hamster spermatozoa, the induction of forward motility requires not only an increased cAMP level but also factors from the cauda epididymal plasma. The idea that glycoprotein of epididymal origin initiates forward motility is discussed.
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PMID:Development and initiation of sperm motility in the hamster epididymis. 618 85

Capillaries isolated by collagenase digestion of hamster epididymal fat pads were used to examine the properties of endothelial adenylate cyclase and cyclic nucleotide phosphodiesterase. Adenylate cyclase activity in capillary homogenates was increased by 10 microM GTP or 100 microM isoproterenol. Lower concentrations of the catecholamine and 5.7 microM prostaglandin E1 did not stimulate endothelial adenylate cyclase activity unless GTP was included in the assay system. The effects of isoproterenol on capillary adenylate cyclase activity were blocked by propranolol, but were not affected by phentolamine. Phosphodiesterase activity in endothelial homogenates showed anomalous kinetic behavior with either cyclic AMP or cyclic GMP as the enzyme substrate. At substrate concentrations below 1 microM, capillary phosphodiesterase activity hydrolyzed cyclic GMP 2-6 times faster than cyclic AMP. However, at high substrate levels, e.g., 100 microM, cyclic AMP and cyclic GMP were degraded at similar rates. Hydrolysis of 1 microM cyclic AMP by capillary homogenates was stimulated by 0.1 and 1 microM cyclic GMP. Caffeine, 1-methyl-3-isobutylxanthine, papaverine and dipyridamole SQ 20009 were effective inhibitors of capillary phosphodiesterase activity. In contrast, imidazole enhanced the activity of the enzyme. The presence of adenylate cyclase and phosphodiesterase activities in hamster isolated capillaries is consistent with a role for cyclic AMP in the regulation of endothelial function. Moreover, the experiments described here indicate that hamster isolated capillaries are useful model systems for studying the metabolism of vascular endothelium.
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PMID:Properties of adenylate cyclase and cyclic nucleotide phosphodiesterase in hamster isolated capillary preparations. 624 1

The authors investigated the effect of moderate caffeine intake on overall cyclic adenosine monophosphate (AMP) metabolism in the rat and its relationship to growth and glucose metabolism in adipose tissue. Male Sprague-Dawley weanling rats were divided into control and treatment groups. The latter received caffeine via drinking water (0.06 mg/ml H2O) during a 4-week period whereas controls received water only. At weekly intervals, urinary cyclic AMP excretion, food intake and weight gain were measured. Plasma cyclic AMP caffeine and glucose were determined at moment of death and in vitro lipogenesis and glycogen synthesis from [6-14C]glucose in epididymal adipose tissue were assayed. Although urinary cyclic AMP excretion was negatively correlated to caffeine intake during the 2nd week of the experiment, this did not reach significant levels, nor did this trend continue into the 4th week. Growth pattern and food efficiency were similar in both groups as were blood glucose and cyclic AMP values at moment of death. In vitro glycogen synthesis from [6-14C] glucose in adipose tissue showed a 40% increase, this parameter being positively correlated with plasma caffeine concentration. Glucose uptake and lipogenesis were unaltered in epididymal fat pads. These data suggest that regular intake of a moderate dose of caffeine leads to homeostasis of overall cyclic AMP metabolism and of selected physiological parameters under study. Alteration of glycogen synthesis in adipose tissue is discussed in relation to documented effects of caffeine ingestion on catecholamine secretion.
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PMID:Physiological effects of caffeine in the rat: extracellular cyclic AMP status, growth pattern and glucose metabolism in adipose tissue. 626 Sep 14

Semiautomated capillary scanning was used to quantitate the migratory rate of hamster caudal epididymal (HCE) sperm populations from undiluted exudates into various defined media. The populations migrated through calcium-containing Tyrode's solution four times more rapidly than they did through buffered-glucose fortified saline or isotonic sucrose. This difference was partially eliminated by the addition to the saline or sucrose of the motility inducers, calcium ion or cyclic adenosine monophosphate (cAMP), and completely eliminated by the additional presence of the motility amplifiers, caffeine or spermine. The addition of the motility amplifiers, caffeine or spermine, alone to either calcium-saline or Tyrode's solution greatly stimulated the microscopically judged vigor of motility. However, this increase in flagellar activity was not coupled to increased forward velocity. Instead, as in the case of capacitated HCE sperm, the activation of motility resulted in significantly reduced forward velocities. Thus, it appears that under certain conditions caffeine, spermine, or capacitation can elevate sperm cAMP concentrations above those optimal for maximal forward progression.
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PMID:Migration of hamster sperm within capillaries: effect of agents elevating cyclic AMP. 627 60


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