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)

Spermatozoa were collected from the rete testis and vas deferens of conscious rams. The endogenous oxygen uptake of the spermatozoa was unaffected by alpha-chlorohydrin added in vitro, although this compound abolished the stimulation of oxygen uptake caused by the addition of glycerol. The metabolism of [14C]glycerol by testicular and epididymal spermatozoa was markedly reduced by alpha-chlorohydrin, CO2 production and lactate accumulation being almost totally inhibited. These effects were dependent upon a period of preincubation of the spermatozoa with alpha-chlorohydrin alone, since the presence of glycerol protected the spermatozoa from its action. Longer exposure and a higher concentration of alpha-chlorohydrin were needed with testicular than with epididymal spermatozoa to achieve a maximal effect. The metabolism of [14C]glucose by both sperm types was also inhibited by alpha-chlorohyrin. Spermatozoa of the ram are therefore susceptible to the action of alpha-chlorohydrin throughout the epididymis, although more mature spermatozoa are more affected. It is suggested that alpha-chlorohydrin is converted to an intermediate which is the agent responsible for the inhibition of glycolysis in spermatozoa.
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PMID:Effects of alpha-chlorohydrin on the metabolism of testicular and epididymal spermatozoa of rams. 99 97

To study the kinetics of glycerol utilization by adipose tissue in vitro as function of the concentrations of both glycerol and glucose in the incubation media, pieces of epididymal fat pad from fed rats were incubated for different times in Krebs Ringer bicarbonate supplemented with 1-14C-glycerol and purified albumin. An increase in the concentration of glycerol in the medium produces a decrease in the formation of 14CO2 and 14C-lipids from 1-14C-glycerol. When the decrease in the specific activity of the tracer is considered to calculate the respective velocities, it turns out that glycerol actually enhances the rate of synthesis of both CO2 and glyceride glycerol. Glucose enhances the rate of synthesis of CO2 and fatty acids from glycerol but decreases the rate of glyceride glycerol synthesis from the same substrate. While the Km of the glycerol effect is much lower that the physiological concentrations of glycerol the Ka and Ki of the glucose effects are above or close to its concentration in blood. The results are discussed in terms of the competitive effects of glucose and glycerol for the synthesis of alpha-glycerophosphate and the necessity of glucose for lipogenesis from glycerol in adipose tissue.
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PMID:Effects of glycerol and glucose on the kinetics of glycerol utilization by adipose tissue in the rat. 100 89

After unilateral separation of the rat epididymis from the testis, the metabolism of various substrates in vitro by tissue from the attached and separated caput and cauda epididymidis at 7 and 28 days after surgery was determined by radiorespirometry. Hourly collections of 14-CO2 were made during 5-hr incubations. The patterns of 14-CO2 evolution from glucose indicated that most of the metabolic activity followed the Embden-Meyerhof glycolytic and the Krebs cycle respiration pathways. The alteration of the rate of glycolysis was always greater than that of respiration. In all samples, the metabolism of (2-14C) glucose was approximately equal to that of (6-14C) glucose (G-6)and less than that of (1-14C) glucose (G-1). Pentose cycle activity was indicated in all tissues from the caput and cauda epididymidis by the preferential utilization of G-1 over G-6. At 7 and 28 days after surgery, respectively, the G-1:G-6 ratios of 14-CO2 evolution after incubation for 2 hr were 9.75 and 7.79 for the separated caput, 5.17 and 2.66 for the intact caput, 3.11 and 2.52 for the separated cauda and 3.73 and 2.84 for the attached cauda epididymidis. Although epididymal separation did not effect the metabolism of (U-14C) glucose or (U-14C) fructose, glucose appeared to be a more important epididymal substrate than fructose.
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PMID:Epididymal carbohydrate metabolism. III. Metabolism of the caput and cauda epididymidis after separation from the testis in the rat. 112 44

1. Administration of methoxyindole 2-carboxylic acid to rats caused an increase in circulating free fatty acids which was associated with rapid hypoglycemia in fasted rats and liver glycogenolysis without hypoglycemia in fed rats. 2. The incorporation of labeled glucose, pyruvate and acetate carbons into triacylglycerol-glycerol, triacylglycerol-fatty acids and CO2 was inhibited in epididymal fat pads from methoxyindole 2-carboxylic acid-treated rats and by the addition of methoxyindole 2-carboxylic acid in vitro. In contrast, palmitate esterification and oxidation were enhanced by methoxyindole 2-carboxylic acid. 3. The activity of enzymes associated with fatty acid synthesis was reduced to a varying degree in the presence of methoxyindole 2-carboxylic acid in the reaction mixture in concentrations lower than those used to inhibit glucose and pyruvate metabolism in the intact tissue in vitro. 4. 4-Pentenoic acid, a potent inhibitor of pyruvate and palmitate metabolism in the liver, was considerably less effective in adipose tissue. 5. The effect of the two hypoglycemic substances investigated on adipose tissue metabolism seems to be different.
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PMID:Effect of methoxyindole 2-carboxylic acid and 4-pentenoic acid on adipose tissue metabolism. 113 99

Several studies indicate that in rats changing the rhythm of feeding from nibbling to meal-eating results in hyperlipogenesis and higher body fat deposition. Among the factors influencing this phenomenon, the effects of age and duration of treatment are not yet clear. Male rats of 4, 6, 12 and 18 weeks have been meal-fed (two 1-hour meals per day) for 5, 10, 20 and 30 days. Pair-fed Nibblers were used as controls. Adipocyte diameters and number from epididymal adipose tissues were determined, and lipogenesis measured my glucose-U-14-C incorporation into lipids. The results show that cellularity, glucose-U-14-C incorporation into adipocyte lipids and CO2 and body fat deposition are not affected by short-term meal-eating treatment in growing animals. In the adult rats, only after 30 days do the parameters studied show significant higher values in the meal-eating animals. The results are discussed in view of the possible interrelationships among the different factors influencing animal response to modifications in feeding frequency.
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PMID:Effect of age and duration of meal-eating on body composition and on lipogenesis and cellularity of adipose tissue in male rats. 124 32

The distribution of carbonic anhydrase (CA) was studied in the testis and epididymis of mature, male rabbits using a cobalt precipitation method. CA was found only in the endothelium of the capillaries in the testis. The epididymal duct was divided into initial, middle and terminal segments. Strong cytoplasmic CA was present in the apical cells in the initial and middle segments. Vacuoles with CA staining in the membranes were found in the principal cells in the middle segment. Intensely stained basal cells were present in the terminal segment. In the last part of the terminal segment and the first of the ductus deferens the basolateral cell membranes were also stained. The function of the enzyme is discussed especially in relation to acidification of the epididymal fluid and facilitation of CO2 diffusion.
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PMID:Histochemical localization of carbonic anhydrase in the testis and epididymis of the rabbit. 163 93

We found that anion channel blockers such as phosphotungstate and 4,4'-diisothiocyanatostilbene-2,2'-disulfonate (DIDS) enhanced HCO3(-)-induced activation on porcine epididymal sperm. In the presence of these compounds, HCO3- increased the motility, respiration rate and especially the cAMP content of the sperm to a greater extent than did HCO3- alone. The enhancing effects were not observed in the absence of HCO3-, but were evident when the concentration of HCO3- was low. These compounds did not significantly alter the intracellular pH and did inhibit the adenylate cyclase activity of the sperm plasma membrane. When these compounds were added to sperm homogenate with ATP, the cAMP formed was reduced compared to the control. In addition, these compounds inhibited both the SO4(2-) influx and efflux of the sperm. From these results, we conclude that the anion channel blockers tested principally inhibit the efflux of endogenous HCO3- derived from metabolic CO2, so that HCO3- accumulates intracellularly and stimulates the adenylate cyclase of the sperm.
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PMID:The enhancing effects of anion channel blockers on sperm activation by bicarbonate. 169 90

Mature (224 g) male Sprague-Dawley rats received bilateral electrolytic (1 mA for 8 sec) lesions in the lateral hypothalamic area (LHAL) or sham operations (CON). One group of CON was allowed to eat ad lib (CON-ADLIB), a second CON group was pair-fed to the LHAL rats (CON-PF). Tap water was available ad lib. Two days after the operation/sham operation all rats were killed by decapitation. Body weight, body weight change, food intake, carcass fat, liver weight, epididymal fat pad weight, in vitro incorporation of U-C14-glucose into liver total lipid, glycogen and CO2 (oxidation) (DPM, DPM/mg protein) as well as oxidation in fat pad tissue, plasma glucose and insulin were significantly reduced in LHAL and CON-PF rats compared with CON-ADLIB. Glucose carbon incorporation into epididymal fat pad lipid and glycogen were normal in LHAL and CON-PF. Liver protein and plasma free fatty acids (FFA) were both higher in LHAL and CON-PF than in CON-ADLIB groups. Thus, many of the somatic and metabolic changes that appear in the first few days after lesion production are simply due to hypophagia. However, CON-PF rats also exhibited some significant differences from the LHAL group, i.e., their plasma glucose and incorporation of glucose carbon into liver glycogen (DPM) were significantly lower than in LHAL rats; alternatively, plasma FFA levels were higher in CON-PF than in LHAL rats. Also, liver weight/100 g body weight was lower and fat pad weight/100 g body weight was higher in CON-PF than in LHAL rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Metabolic-endocrine correlates of the lateral hypothalamic syndrome: the first 48 hours. 208 79

Six pregnant rats were made mildly hyperglycemic by intraperitoneal injection of streptozotocin on d 5 of gestation. Four control rats were injected with citrate buffer. Thirty pups born to experimental dams who had increased birth weight (birth weight greater than 1.7 SD of mean birth weight of pups from control dams) maintained accelerated growth through 10 wk of age. At 10 wk, oral glucose tolerance tests showed higher glucose and insulin levels than the controls (n = 37). In addition to the higher body weight, the experimental rats also had higher fat weight to body weight ratios. Adipocytes of epididymal fat from obese males and periovarian fat from obese females had higher lipid content with significantly larger cell size than the adipocytes of the controls. The adipocytes of macrosomic rats showed attenuated response to insulin-stimulated glucose conversion to total lipid and fatty acid when compared with the responses seen in the adipocytes of the control rats. Interestingly, although the insulin-stimulated glucose conversion to CO2 was similar in macrosomic and control males, the response in the macrosomic female was blunted when compared with that of the control females. Insulin receptor binding capacities of the macrosomic rats were lower than those of the controls, which is consistent with a phenomenon of down-regulation. However, the receptor affinities were higher in the experimental animals than in controls. Therefore, a postreceptor defect may account for the abnormality in glucose metabolism in the obese rats. In conclusion, the abnormal response to oral glucose loading in these experimental obese, hyperinsulinemic rats is due to peripheral tissue insulin resistance that is probably postreceptor in nature.
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PMID:Glucose metabolism in adipocytes of obese offspring of mild hyperglycemic rats. 228 63

When mouse epididymal spermatozoa were rapidly frozen in two steps (37 to -70 degrees C for solid CO2 and -70 to -196 degrees C for liquid nitrogen) as pellets, 18% raffinose provided the greatest protection to ICR mouse spermatozoa against cold-shock; sperm motility and fertilizing ability were 43% and 22.4%, respectively. A small proportion of spermatozoa frozen with 10% sucrose was motile but incapable of fertilizing ovulated oocytes. Glycerol and dimethylsulphoxide were less effective at any concentration examined. However, the fertilizing ability of frozen-thawed ICR spermatozoa was significantly improved (35.5%) by addition of glycerol (1.75% final concentration) to medium containing 18% raffinose. Spermatozoa from one outbred (ddY) and 5 inbred (C57BL/6N, C3H/HeN, DBA/2N, BALB/c and kk) strains of mice were successfully frozen in the presence of 18% raffinose and 1.75% glycerol, although the fertilization rates of frozen-thawed spermatozoa varied among strains (13% for C57BL/6N to 64% for DBA/2N). A small fraction of mouse eggs resulting from fertilization by frozen-thawed spermatozoa developed normally in vitro (37% in C57BL/6N to 71% in ICR) to the blastocyst stage and in vivo (19% for C57BL/6N spermatozoa and ddY oocytes) to Day 18 of gestation.
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PMID:Cryopreservation of mouse spermatozoa in the presence of raffinose and glycerol. 240 78


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