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)

The proteins of epididymal tissues and fluids recovered from different regions of the mouse epididymis from a natural population and an inbred line were examined by polyacrylamide gel electrophoresis under denaturing conditions. Two epididymal specific peptides on the order of 88 and 20 Kilodaltons (Kd), undetected in serum and testicular extracts, were identified in the initial segment, caput, corpus and cauda. Another specific 30 Kd peptide was localized in the cauda tissue and fluid. Castration caused the disappearance of the three specific epididymal bands and of a non-specific 34 Kd band. In contrast, a new band appeared at 14.5 Kd. Testosterone propionate administration only restored the three specific epididymal bands and had no effect on the 14.5 peptide. Variations in the staining intensity of the four bands, which were suppressed in castrated animals, were observed after ductuli efferentes ligation.
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PMID:Characterization and hormonal regulation of tissue and fluid proteins in the mouse epididymis. 325 99

The ultrastructure of epididymal basal cells in adult castrated and castrate-androgen supplemented rhesus monkey was studied. Due to reduction in the height of the epithelium, three months after castration their number appeared to have increased. In the initial segment dark basal cells occupied more area in the epithelium and their cytoplasm showed the presence of large vacuoles. Cells that resembled dark basal cell were found at all heights of the epithelium. In all the segments, dark basal cells developed pseudopod-like structures. Pale basal cell cytoplasm was filled with lipofuscin pigment granules. Androgen replacement therapy for 30 days prior to autopsy at 90 days did not bring about any significant changes in the ultrastructure of both the types of basal cell. However, the size of the dark basal cell appeared to have decreased. The possible role of basal cells in the disposal of products accumulated in the principal cells under normal and altered endocrine conditions in discussed.
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PMID:Epididymal basal cells in rhesus monkey (Macaca mulatta): ultrastructural changes after castration and androgen replacement therapy. 345 79

Androgen binding activity (ABP) was determined in two different fractions of developing rat testicular homogenates: in cytosol (cABP) and in a particulate fraction isolated by differential centrifugation (pABP). Homogenates were prepared under stabilization conditions by adding 350 nM testosterone to the homogenization buffer. cABP and pABP concentrations were maximal in 22- to 32-day-old animals, to decrease thereafter during sexual maturation. However, both cABP and pABP increased with age when results were expressed on a per organ basis. pABP could be solubilized under conditions in which it could retain its binding activity. It was then photoaffinity labeled and chromatographed on a Sephadex G 200 column using cytosolic epididymal ABP as a control. Similarities between cABP and pABP include not only the same androgen binding characteristics but also the same exclusion volume after Sephadex G 200 chromatography. Since pABP is only present in Sertoli cells, it might represent ABP before being secreted. Because of its intracellular localization, it could play a role in the compartmentalization of androgens within the testis.
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PMID:Variations in soluble and particulate ABP of rat testis during sexual development. 350 72

At 2 weeks of age, 11 isoenzymes were expressed and similar banding patterns on vertical polyacrylamide gel electrophoresis (PAGE), stained by alpha- or beta-naphthyl acetate as a substrate, were obtained for tissues or fluids from the proximal and the distal parts of the mouse epididymis. After this period, the emergence of new bands or the disappearance of certain others led to a regional differentiation which appeared progressively in tissues and fluids, earlier in the distal part than in the proximal part. The changes occurring during epididymal differentiation affected the isoenzymes specific to the epididymis more than those common to testis and serum. Castration of adult mice induced a decrease in esterase activity and changes in the number of isoenzymes, leading to the loss of regional specificity of the banding patterns. The dedifferentiation process modified the electrophoretic profiles of the distal part only. Androgen replacement restored the regional specificity of cytosol banding patterns after 2 weeks of treatment and the normal intensity of bands after 4 weeks. Some differences in the fluid isoenzymes nevertheless persisted. The androgen-dependence of esterase isoenzymes can be attributed to circulatory hormones rather than to androgens from the testis via the rete testis as shown by efferent ductule ligation which did not modify the epididymal esterase profiles.
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PMID:Postnatal differentiation and endocrine control of esterase isoenzymes in the mouse epididymis. 357 78

Androgen binding protein (ABP) was detected in both the testis and epididymis of golden hamsters exposed to a long photoperiod (16L:8D). The concentration of ABP in the testis rose from 0.1 pmol/g testis in 2-week-old animals to attain maximum values (3.9 pmol/g testis) at 6-7 weeks, then declined to adult values (1.8 +/- 0.4 pmol/g testis) after 10-11 weeks of age. In contrast, the ABP concentration of the caput epididymidis reached maximum values at 4-7 weeks of age (14 pmol/g tissue) and declined to adult values (4.8 +/- 1.5 pmol/g tissue) by 10-11 weeks of age. ABP content of the corpus epididymidis was maximal (1.0 pmol/g tissue) at 2 weeks of age and thereafter declined to below detectable levels by 10-11 weeks. No ABP could be detected in the cauda epididymidis from animals of any age examined. Hamster ABP analysed by steady-state polyacrylamide gel electrophoresis had a relative mobility (Rf) of 0.33 compared to 0.41 for rabbit ABP. Sucrose gradient analysis of hamster ABP indicated a sedimentation coefficient of about 4 S. The binding of [3H]5 alpha-dihydrotestosterone [( 3H]5 alpha-DHT) to hamster ABP was very rapid with equilibrium occurring within 10 min. The dissociation of [3H]5 alpha-DHT from hamster ABP was also rapid (t1/2 = 2.77 min). Saturation analysis of ABP from mature animals yielded an apparent dissociation constant of 6.4 nM and an ABP concentration of 1.2 +/- 0.2 pmol/mg protein. The binding of [3H]5 alpha-DHT to hamster ABP was inhibited by 5 alpha-DHT greater than testosterone greater than greater than greater than oestradiol greater than cyproterone acetate. Exposure of mature hamsters to a short photoperiod (8L:16D) for 3 weeks resulted in a 42% drop in epididymal ABP levels (10.3 to 4.3 pmol/g tissue). Epididymal ABP further declined so that after 15 weeks in a short photoperiod it was 4% (0.4 pmol/g) of initial values. Accompanying this decrease in epididymal ABP concentrations was a decline in the fertilizing ability of spermatozoa from the distal cauda. When hamsters were transferred from a short to a long photoperiod (16L:8D), epididymal ABP content returned to about 50% of control values within 3 weeks. However, the fertilizing ability of spermatozoa from the cauda epididymidis of these animals did not return to control values after a 9-week exposure to a stimulatory photoperiod.
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PMID:Effects of photoperiod on androgen-binding protein and sperm fertilizing ability in the hamster. 366 63

Androgen binding protein (ABP) was measured in the serum, testes and epididymides of adult rats up to 105 days after the induction of reversible impairment of spermatogenesis by a single injection of busulphan. This treatment decreased testicular and epididymal weights within 7-21 days after treatment, reaching a minimum at 63 days with partial recovery by 105 days. The testicular and epididymal content of sperm was unchanged up to 42 days after busulphan administration, was reduced considerably at 63 days and thereafter increased towards control values. The serum and testicular concentrations of testosterone were normal at all times after treatment, even though serum LH levels were increased at 42 and 63 days. Serum levels of FSH were also increased at 43 and 63 days after treatment. A biphasic pattern in the serum levels of ABP was observed. Concentrations were low up to 43 days post treatment when only the early germ cell types were depleted from the seminiferous epithelium and when the testicular and epididymal contents of ABP were normal. Serum levels of ABP increased as the more mature germ cells were depleted in numbers and the testicular and epididymal contents of ABP declined. It is concluded that bidirectional secretion of ABP into the interstitium (serum) and into the seminiferous tubular lumen by Sertoli cells is influenced considerably by the population of germ cells that are present in the seminiferous epithelium.
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PMID:Evidence suggesting that germ cells influence the bidirectional secretion of androgen binding protein by the seminiferous epithelium demonstrated by selective impairment of spermatogenesis with busulphan. 369 18

Androgen metabolism in human epididymis was studied by incubating tissue fragments with isotopically labeled testosterone (T) and androstenedione (A) under batch and superfusion conditions. Epididymides were obtained from 16 patients with prostatic cancer, 5 of them treated with diethylstilbestrol (2.5 mg/d) for several months prior to castration. Results from batch incubations with [3H]T (100 nM) for 2 h at 25 degrees C indicated a markedly lower 5 alpha-reductase activity in tissues from estrogen-treated patients, as evaluated by measuring the amounts of radioactive 5 alpha-dihydrotestosterone, 5 alpha-androstanediols and 5 alpha-androstanedione present in tissue and medium at the end of the incubation period. Superfusion experiments confirmed this estrogen effect and also showed a shift of the interconversion between A and T towards the reductive direction and a diminished tissue retention of DHT after estrogen treatment. These effects may contribute to the marked regression of the epididymal epithelium that was noted in the estrogen-treated patients, which is thought to be mainly the result of the inhibition of androgen biosynthesis caused by chemical hypophysectomy.
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PMID:Androgen metabolism in the human epididymis. Effect of in vivo estrogen administration. 374 23

Radioimmunoassays were established for the measurement of total androgens and the specific measurement of testosterone and 5 alpha-dihydrotestosterone in peripheral plasma of the brush-tail possum. Androgen concentrations were measured in blood collected from indwelling jugular cannulae to determine whether the normal pattern of androgen secretion in this species was episodic and to attempt to relate total androgen and the pattern of testosterone secretion to the changes previously reported in prostatic, but not epididymal, weight in the breeding season. Blood was collected from restrained animals at varying time-intervals during daylight hours and darkness. Despite an apparent good adaptation to the sampling procedure there was generally a progressive decline in plasma androgen level during the collection period. This was true for animals bled during or out of the breeding season. There was no significant seasonal effect on the androgen concentration in the initial blood sample. When less restraint was used, two of three animals showed fluctuations in androgen levels over the 7-h sampling period. Testosterone levels in blood obtained by cardiac puncture were four- to nine-fold higher than those of 5 alpha-dihydrotestosterone but levels of these androgens in samples obtained during the breeding season were not significantly different from those obtained out of season. The results do not argue for a pulsatile release of testosterone in the possum but do demonstrate a marked capacity for changes in the peripheral androgen concentration. There was a poor correlation between testosterone and 5 alpha-dihydrotestostosterone levels and prostatic weight.
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PMID:Peripheral androgen levels in the male brush-tail possum (Trichosurus vulpecula). 398 24

Androgen-binding protein (ABP) can be detected in the blood of sexually immature male rats by its ability to specifically bind [3H]5 alpha-dihydrotestosterone (5 alpha-DHT). Since the androgen-binding site is functional, we consider this ABP to be biologically active. ABP can be detected (641 +/- 107 ng/ml; n = 5) in plasma by the 15th day of postnatal life, it reaches a maximum concentration (1631 +/- 323 ng/ml; n = 5) on day 20 of age, and is no longer detectable after day 40. ABP can be detected in the testes of all age groups studied (15 days to adult). However, no ABP is detectable in the epididymis until the animals are 25 days old. Plasma ABP comigrates on nondenaturing gels with photolabeled ABP from the adult or immature rat epididymis. Serum that had been treated with Affigel blue to remove albumin and with hydroxylapatite to decolorize it was photolabeled using [3H]17 beta-hydroxy-4,6-androstadien-3-one. Photolabeled serum ABP migrated on polyacrylamide gels containing sodium dodecyl sulfate as 60,000 and 48,000 dalton androgen-specific peaks. In contrast, photolabeled adult epididymal ABP exhibited the 47,000 and 41,000 dalton peaks characteristic of ABP subunits. When photolabeled plasma and epididymal ABP were combined and electrophoresed on the same gel under denaturing conditions, prominent 60,000 and 47,000 dalton peaks were obtained, indicating that the two species of ABP retained their identities when combined. Photolabeled epididymal ABP from 25-day-old rats exhibited similar subunit mol wt in the same ratios as ABP from the adult. When epididymal ABP from the two age groups was combined and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the resulting pattern was identical to that obtained when the samples were run individually, except that there was an increase in peak height. These data indicated that there is no significant difference in the subunit mol wt of epididymal ABP from the two age groups.
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PMID:The ontogeny of biologically active androgen-binding protein in rat plasma, testis, and epididymis. 404 Aug 48

The hypothesized relationship between androgen-binding protein (ABP) and sperm maturation was investigated using a mutant rodent: the restricted rat. The seminiferous epithelium of these animals undergoes a spontaneous degeneration, but changes are progressive. Restricted rats in the transition to infertility were used to determine if changes in ABP were related to the decreased fertility found in these animals. Fertilizing ability was determined by insemination of cauda epididymal spermatozoa into hormonally primed female rats and examination of ova for evidence of fertilization 48 h later. Epididymal and testicular tissues were analyzed for ABP using a charcoal assay. Androgen levels were determined by RIA. Testicular weights were significantly reduced compared to those of normal littermates in restricted rats at all ages; epididymal weights were significantly reduced in rats 140 days and older. Among restricted rats, sperm fertilizing ability was variable, but was significantly lower than that in normal littermates; it was consistently highest at 90 days of age. Epididymal ABP content (picomoles per organ) was significantly reduced in restricted rats at all ages; peak values occurred at 90 days. Testicular ABP content was significantly reduced only in the youngest and oldest animals. Plasma testosterone levels were not statistically lower than those found in normal littermates, and ventral prostate weights were maintained at normal levels in all four groups of animals. A significant positive correlation existed between sperm fertilizing ability and epididymal ABP, but not between sperm fertilizing ability and plasma testosterone. Since ABP is an index of Sertoli cell function, these data indicate that sperm fertilizing ability is closely related to Sertoli cell function and/or ABP.
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PMID:Investigations on the relationship between sperm fertilizing ability and androgen-binding protein in the restricted rat. 653 77


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