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

Mouse epididymal spermatozoa exposed to fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) immediately following dilution or after a 2-hour incubation period under fertilization conditions, were assessed by fluorescence microscopy for albumin adsorption. Motile spermatozoa exhibited light fluorescence in the midpiece and tail but not in the head. In contrast the majority of nonmotile spermatozoa displayed a strong and characteristic fluorescence in the post acrosomal region of the sperm head as well as the midpiece. Spermatozoa immobilised by short-term heat stress exhibited fluorescence in the post acrosomal region and midpiece as before but also in the acrosomal cap. The equatorial region failed to fluoresce. The significance of these observations on the involvement of albumin in capacitation is discussed.
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PMID:The relationship between motility and the FITC-BSA binding properties of mouse epididymal spermatozoa. 661 73

Loss of forward motility of rabbit epididymal spermatozoa in high K+ phosphate buffer is inhibited by taurine, hypotaurine, epinephrine and bovine serum albumin. Pyruvate and lactate also show this effect. The rate of lipid peroxidation in these spermatozoa, as measured by rate of formation of malondialdehyde, is also inhibited by these agents. A close linear correlation between percent inert spermatozoa and malondialdehyde was found, which was independent of the rate of peroxidation. Complete cessation of motility was observed at 0.5 nmol malondialdehyde/10(8) cells in the absence or presence of these agents, which is the same value found in other suspending media in a previous study [Alvarez and Storey (1982) Biol. Reprod. 27:1102-1108]. Albumin was the most effective agent in preventing loss of motility and inhibiting lipid peroxidation. Hypotaurine was the next most effective, followed by taurine, epinephrine, pyruvate and lactate. Hypotaurine reduces the amount of rate of superoxide production, as measured by the rate of reduction of acetylated ferricytochrome c by O(2), from rabbit sperm under these conditions and concomitantly reduces inactivation of the superoxide dismutase in these cells. Since superoxide seems to be the major inducer of lipid peroxidation in rabbit sperm, the protective effect of hypotaurine, which should be readily permeant to the plasma membrane, may be ascribed to scavenging of intracellular superoxide. The mechanism of the protective action of albumin is not known. Rabbit epididymal spermatozoa lose motility over time if Ca2+ or Mg2+ are omitted from the suspending medium.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Taurine, hypotaurine, epinephrine and albumin inhibit lipid peroxidation in rabbit spermatozoa and protect against loss of motility. 662 44

Three factors were studied for their effects on the first cleavage division of in vitro fertilized hamster eggs. Eggs from superovulated females were inseminated with precapacitated epididymal hamster sperm in medium containing either fatty acid-free (FAF) or fraction V (V) bovine serum albumin (BSA), in the presence or absence of cumulus cells. After incubation for 3 to 4 h with sperm, eggs were transferred to culture medium containing FAF- or V-BSA, with or without amino acids (glutamine, isoleucine, methionine, and phenylalanine), and the percentages of eggs cleaving to two cells were recorded after a further 20 h of incubation. Fatty acid-free BSA was found to support a significantly higher percentage of eggs cleaving than V-BSA and was used in all further experiments. The presence of cumulus cells during fertilization was found to have a beneficial effect on cleavage when no amino acids were added to the culture medium, but when amino acids were included, eggs fertilized with or without cumulus present cleaved equally well. These results represent another step toward defining the optimal environmental conditions for obtaining the first cleavage division of hamster eggs in vitro.
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PMID:The effects of amino acids, cumulus cells, and bovine serum albumin on in vitro fertilization and first cleavage of hamster eggs. 668 53

The heads of mouse spermatozoa obtained 5 min after release from the excised caudae epididymides showed a characteristic fluorescence pattern in the presence of the fluorophore chlortetracycline (CTC). There was uniform fluorescence over the entire head with about half the sperm population showing a brighter line of fluorescence across the equatorial segment; this fluorescence pattern was designated "F". After 90-min incubation in culture medium (CM) containing 2% (w/v) bovine serum albumin, most of the sperm heads showed a dark band of nonfluorescence over the equatorial and postequatorial segment, while the anterior portion of the head showed bright fluorescence. This fluorescence pattern was designated "B." The time course for the disappearance of pattern F matched the time course of the appearance of pattern B, with a half-time of 30 min. The transformation was complete in 90 min. At longer times of incubation in CM, the percentage of spermatozoa showing pattern B declined; fluorescence over the entire head was lost, characteristic of the pattern for acrosome-reacted sperm (P. M. Saling and B. T. Storey (1979). J. Cell Biol. 83, 544-555). Mouse sperm showing pattern B were able to undergo the acrosome reaction, either spontaneously or by induction with acid-solubilized zonae pellucidae from mouse eggs (H.M. Florman and B. T. Storey (1982). Dev. Biol. 91, 121-130). The latter reaction was blocked by its specific inhibitor 3-quinuclidinyl benzilate (QNB). Mouse sperm showing pattern F could not be induced to undergo the acrosome reaction by exposure to solubilized zonae. This implies that the change from fluorescence pattern F to fluorescence pattern B corresponds with changes in the sperm which make them susceptible to undergo the acrosome reaction. This change occurs during the time interval previously determined to be needed for capacitation of mouse sperm in vitro in CM (M. Inoue and D. P. Wolf (1975). Biol. Reprod. 13, 340-346). These results imply that spermatozoa showing CTC fluorescence pattern B can be considered to be capacitated and that a functional definition for capacitation is the acquired ability to undergo the acrosome reaction rapidly when treated with acid-solubilized zonae pellucidae. The CTC fluorescence assay provides for the first time a means to monitor the time course of epididymal mouse sperm capacitation in vitro.
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PMID:Determination of the time course of capacitation in mouse spermatozoa using a chlortetracycline fluorescence assay. 674 85

Microvessels isolated from rat epididymal fat exhibit differential vesicular ingestion rates for unmodified and non-enzymatically glycosylated rat albumin. While unmodified rat albumin is excluded from ingestion by endothelial micropinocytic vesicles, glycosylated albumin is avidly taken up by endocytosis. Interaction of albumin and glycosylated albumin with endothelium was studied with a double-label fluorescence assay of micropinocytosis. When glycosylated albumin was present at a concentration of 6% with respect to total albumin (the level found in "non diabetic" serum), only glycosylated albumin was ingested. At higher concentrations of glycosylated albumin (those found in diabetic serum), both albumin and glycosylated albumin are ingested. Glycosylation of endothelial membrane components results in stimulated ingestion of glycosylated albumin, persistent exclusion of unmodified albumin, and unaltered micropinocytic ingestion of native ferritin. These results indicate that nonenzymatic glycosylation of serum albumin may result in rapid vesicle-mediated extravasation of albumin. Chronic microvascular leakage of glycosylated albumin could contribute to the pathogenesis of diabetic microangiopathy.
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PMID:Micropinocytic ingestion of glycosylated albumin by isolated microvessels: possible role in pathogenesis of diabetic microangiopathy. 694 Dec 99

In an effort tao simulate the effects of insulin on fat cells prepared from fresh adipose tissue, pieces of epididymal adipose tissue were cultured in a medium containing charcoal-treated bovine serum albumin (BSA) with a gas phase of 100% O2. Using this system, the insulin effect on [1-14C]glucose oxidation was retained, in contrast to previous results in culture with untreated BSA in room air. Basal [1-14C]glucose oxidation was similar to fresh tissue, and insulin stimulated oxidation by 137%. In contrast to the effects of this culture system on [1-14C]glucose oxidation, tissue cultured with charcoal-treated BSA had lower basal rates of [U-14C]glucose utilization and 2-deoxyglucose uptake than either cells from fresh tissue or from tissue cultured with untreated BSA. The insulin effect on both of these measures was similar for the two culture systems and lower than for fresh tissues. Rates of lipolysis were increased in both types of cultured fat cells. Thus the improvement in [1-14C]glucose oxidation is presumably an effect on the pentose phosphate shunt, does not reflect a change in glucose transport or overall glucose utilization, and is not caused by a reduction in free fatty acid levels.
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PMID:Improved insulin responsiveness in rat adipose tissue pieces cultured with charcoal-treated albumin and oxygen. 704 80

Mouse seminal plasma (SP), a mixture of aqueous extracts of prostate, seminal vesicle, and epididymis, exerts potent immunosuppressive effects in vivo. The SP mixture completely suppressed both primary and secondary humoral immune responses in mice to low immunizing doses of antigen (bovine serum albumin or washed epididymal sperm), and also significantly suppressed the antibody response to high doses of immunizing antigen. The humoral immune response to epididymal sperm was also suppressed when sperm were incubated in SP and then washed before immunization and when SP was administered at a secondary site (i. p.) at the time of sperm immunization (subcutaneous). When SP components were tested individually in in vitro assays, all of them (prostate, seminal vesicle, and epididymis) suppressed mitogen-induced lymphocyte transformation. Prostatic fluid also inhibited complement-mediated hemolysis in a standard immune hemolytic assay. These data indicate that potent immunosuppressive factors are present at several locations within the male reproductive tract; these factors may serve to protect sperm from immunologic damage and prevent sensitization of females to sperm antigens after insemination.
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PMID:Immunosuppressive effects of mouse seminal plasma components in vivo and in vitro. 705 87

Hamster eggs with postovulatory oviduct contents were added to a simple defined medium, without serum albumin, but supplemented with different combinations of energy sources. They were then inseminated by epididymal spermatozoa. In a medium containing D-glucose but without pyruvate and/or lactate, high proportions of acrosome-reacted spermatozoa (78-94%) and eggs undergoing fertilization (89-96%) were obtained 9-9.5 h after insemination. With only pyruvate or lactate as substrates, or with both pyruvate and lactate, acrosome reactions occurred in only 2-4% of the sperm. When D-glucose ranging in concentration from 2.78 to 8.34 mM was added, a high proportion (82-95%) of the eggs inseminated were found to be fertilized. Substituting D-galactose, L-glucose, L-fucose, D-lactose, or D-saccharose for D-glucose resulted in very low numbers of acrosome-reacted sperm (0-12%) and fertilized eggs (0-7%). However, in the presence of metabolizable sugars, such as D-mannose or D-fructose, the acrosome reaction was seen in 78-85% of the sperm examined and 87-95% of the eggs tested were fertilized.
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PMID:The importance of the presence of metabolizable sugars in a medium for in vitro fertilization of hamster eggs with postovulatory oviduct contents. 707 70

After a 1-hour preincubation of epididymal mouse spermatozoa at a concentration of 2 X 10(6)/ml in 0.23 mM spermine, the proportion of F1(C57BL X CBA) mouse ova fertilized after 1 and 2 hours was significantly greater than with untreated spermatozoa. Spermine also significantly increased the proportion of ova fertilized at the sub optimal sperm concentration of 2 X 10(5)/ml. The stimulatory effect was lost when the protein source in the fertilization medium was changed from human serum albumin V (HSA) to HSA crystalline. This provides indirect evidence that albumin is directly involved in the capacitation process and that the crystalline is more potent than the fraction V preparation. At equimolar concentrations, spermidine was partially and putrescine was totally inhibitory to fertilization. Mechanisms whereby spermine may affect metabolic activity or sperm-zona binding are discussed. It is suggested spermine may also be present in ovulatory fluid and therefore could potentially be involved in fertilization in vivo.
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PMID:Effect of polyamines on fertilization of mouse ova in vitro. 708 89

Epididymal spermatozoa from rabbit and ram were washed either once or twice using an efficient washing procedure and were then diluted in various media to a final concentration of approximately 1.4 x 10(7) cells/ml and incubated at 30 degrees C for up to 12 hours. Bovine serum albumin (BSA), either untreated or defatted, was found to be better than polyvinylpyrrolidone, ovalbumin, or alpha-lactalbumin, both at stimulating and maintaining motility levels and at reducing the tendency of the washed spermatozoa to stick to glass. BSA was effective in all media tested, being independent of Ca2+, PO4(3-), HCO3-, and ionic strength). BSA has a reversible stimulatory effect on motility. If BSA was added to sperm suspensions 3 1/2 hours after they had been washed and diluted in protein-free medium, motility was stimulated to levels not significantly lower than those observed in samples that had been washed and diluted in the presence of BSA. However, samples washed into BSA and then washed free of it behaved essentially as though they had never been in contact with protein. The motility, survival, and response to BSA of twice-washed spermatozoa were the same as those of once-washed spermatozoa, showing that epididymal plasma factors are not required for survival in vitro. It was concluded that dilution is not essentially detrimental to rabbit and ram spermatozoa. However, severe dilution of semen may result in levels of male reproductive tract fluids insufficient either to stimulate motility or to prevent sticking of motile cells to container surfaces. Few motile spermatozoa are recovered from samples of such diluted semen.
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PMID:Bovine serum albumin, sperm motility, and the "dilution effect'. 711 5


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