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 specific activities of three acid phosphatases were followed in the epididymis of growing rats. All activities were constantly rising but revealed two steeper parts probably corresponding to the increase of androgen secretion and the arrival of spermatozoa in the epididymis. Simultaneously an increase in the histochemical staining was obtained in all epididymal segments. Both biochemical and histochemical studies showed that castration reduced the activity of all acid phosphatases and this could be restored with testosterone-estradiol treatment. Estradiol had no effect on the activities in the castrated animal, but in the normal animal it caused an elevation of Enzyme I activity. In the histochemical study estradiol seemed to restore the acid phosphatase activity. Enzyme I reacted slower than the others to both castration and hormone treatment. Increased elimination caused by ligation of the epididymis caused a reduction in the activity of all enzymes within four days. It was greatest in the area of the corpus. This study, however, rendered no further elucidation for the assumption that acid phosphatases participate in the elimination of excessive and defective spermatozoa.
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PMID:Acid phosphatase of the rat epididymis. III. Histochemical and biochemical responses in experimental conditions. 59 63

The nuclear estrogen receptor was characterised in isolated rat adipocytes. The binding reaction with [3H]estradiol was performed with intact isolated rat adipocytes and the radioactivity associated with the nucleus was subsequently determined after cell lysis. The nuclear uptake of [3H]estrogen in rat adipocytes was temperature dependent and steroid specific. The steady-state binding was achieved after 30 min at 37 degrees C and was constant for several hours. Estradiol was found to bind to a homogeneous class of nuclear receptors in epididymal adipocytes with an apparent Kd of 3.1 +/- 0.76 nM and a Bmax of 7.98 +/- 1.11 fmol/10(6) cells corresponding to about 4800 receptors per nucleus. The estradiol binding exhibited regional variations in isolated adipocytes. In lean rats the highest receptor number was found in epididymal adipocytes, whereas there was a significantly lower number of nuclear binding sites in perirenal and subcutaneous adipocytes (P less than 0.05), unlike in older and more obese rats where the nuclear estradiol binding was greatest in adipocytes from the perirenal fat depot. Incubations with isoproterenol (10 microM) and dibutyryl-cAMP (2.5 mM) both reduced estradiol binding by 56% (P less than 0.005), while insulin (1 nM) enhanced the estradiol binding by 37% (P less than 0.01). In conclusion, a specific and high affinity nuclear estradiol receptor was demonstrated in rat adipocytes and regional differences in nuclear estradiol binding were detected. Furthermore, it was demonstrated that nuclear estradiol binding could be modulated by other agents known to affect adipocyte metabolism.
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PMID:Nuclear estradiol binding in rat adipocytes. Regional variations and regulatory influences of hormones. 164 50

Male Sprague-Dawley rats displayed significantly higher rates of triglyceride/fatty acid (TG/FFA) substrate cycling in subcutaneous, perigenital, and mesenteric white adipose tissue, compared to females. To investigate possible regulation via androgens and estrogens, male rats were treated with the androgen antagonist, cyproterone acetate (10 mg daily in subcutaneous injections), or estradiol polyphosphate (0.3 mg intramuscularly, given as a single dose). Estradiol treatment did not affect TG/FFA cycling. Treatment with cyproterone acetate significantly decreased TG/FFA cycling in perigenital (epididymal) tissue. This effect could however largely be ascribed to concomitant inhibition of food intake by cyproterone acetate. The effects of cyproterone acetate on the two axes of TG/FFA cycling (lipolysis and re-esterification) were further studied in vitro. Norepinephrine-stimulated glycerol release from perigenital adipocytes was inhibited, whereas activities of esterification enzymes (GPAT and PPH) was essentially unaffected. We conclude that androgens seem to affect TG/FFA cycling indirectly via the lipolytic axis.
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PMID:Sex difference in triglyceride/fatty acid substrate cycling of rat adipose tissue: indirect regulation by androgens. 183 7

A reproducible cell culture system is described that allows the study of adipose conversion in fibroblast-like cells isolated by collagenase digestion of epididymal and perirenal adipose tissue from male rats weighing 70-200 g. Adipose conversion as measured by lipid accumulation and increase in glycerophosphate dehydrogenase (GPDH) activity during differentiation strongly depends on the density at which cells are inoculated and starts only when cells are confluent and when physiological amounts of corticosterone and insulin are added. beta-Estradiol, testosterone, thyroxine, triiodothyronine, and growth hormone do not affect the differentiation process. Methylisobutylxanthine added during the first 2 days after confluence, added with insulin and corticosterone, potentiates the effect of insulin on GPDH activity and accelerates triglyceride accumulation. The effect of methyl-isobutylxanthine seems to be mediated by increased cyclic AMP concentrations, inasmuch as it may be replaced by forskolin.
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PMID:Hormonal regulation of the differentiation of rat adipocyte precursor cells in primary culture. 244 Sep 70

To obtain evidence of a physiological role for androgens and estrogens in the regulation of the epididymis of sexually immature rabbits, the effects of these hormones on [35S] methionine incorporation into epididymal proteins in vitro were examined. Two-dimensional polyacrylamide gel electrophoresis revealed that short term incubation with estradiol changed the patterns of radiolabeled proteins detected in tissue homogenates of epididymal segments from castrated rabbits compared to those in segments from castrated rabbits that were not exposed to exogenous estradiol. Most of the changes seen in corpus tissue affected proteins with a wide range of pI values and relatively high mol wt (greater than 40K). The effects on caput and cauda tissue proteins were seen over a wide pH and mol wt range. Castration abolished many of the regional differences in protein synthesis; these were restored by incubation with estradiol. Testosterone had little effect on the synthesis of tissue proteins, except for stimulation of the synthesis of a single protein (17K; pI 5.1) in all three segments and stimulation of a small group of proteins (less than 14K; pI 7.0-7.2) in the corpus. Estradiol had little effect on proteins secreted by epididymal segments. Testosterone, however, stimulated the synthesis of a number of unique proteins secreted by the caput and corpus and resulted in a pattern of radiolabeled proteins similar to that obtained with intact animals. Additional secretory proteins could be stimulated in caput, but not corpus, tissue minces from intact rabbits by exogenous testosterone. No androgen-specific synthesis of secretory proteins was detected in the cauda of either castrated or intact rabbits. Estradiol affected the synthesis of both secreted and tissue proteins in terms of influencing which epididymal segment was most active at incorporating [35S]methionine into radiolabeled proteins and which was least active. Testosterone had a similar influence on secreted proteins, but did not have any analogous effect on tissue proteins. These results indicate that testosterone and estradiol influence the synthesis of proteins by the immature rabbit epididymis and that both may, therefore, be important physiological regulators of epididymal development and/or function.
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PMID:Estrogen and androgen regulation of protein synthesis by the immature rabbit epididymis. 273 45

Bovine oocytes removed from follicles 2-5 mm in diameter were cultured for 24 h in the medium without hormone (control) and in the medium supplemented with 1 microgram FSH/ml, 1 microgram LH/ml, 250 ng oestradiol-17 beta/ml and 250 ng progesterone/ml. At the end of culture the zonae pellucidae were dissolved by pronase and the eggs were transferred to droplets of preincubated bovine epididymal spermatozoa. After incubation for 14-16 h, the number of penetrated oocytes, the average number of spermatozoa per one oocyte, and the stage of sperm nucleus chromatin decondensation were recorded. The highest number of penetrated oocytes (99.2%) was found in cultures with progesterone, but 83.7% oocytes were polyspermic and in 77.0% oocytes a normal male and a female pronucleus was formed, it was the highest incidence among all hormones tested. Oocytes cultured with oestradiol-17 beta were penetrated in 76.5% of cases, but in this group the largest number of monospermic oocytes with a female and a male pronucleus was seen. Also, the lowest number of spermatozoa per polyspermic oocyte was recorded. In cultures with FSH and LH, the percentage of fertilization was almost equal (62.2 and 61.1%, respectively). With FSH the lowest number of polyspermic oocytes was observed. From the results it follows that progesterone has a positive effect on the synthesis of MPGF in the cytoplasm of oocytes and on the number of penetrated oocytes. Oestradiol-17 beta and FSH probably participate in the formation of a polyspermic block via cortical granules.
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PMID:The effect of FSH, LH, oestradiol-17 beta, and progesterone on cytoplasmic maturation of bovine follicular oocytes in vitro. 311 99

We measured the 5 alpha-reductase activity in isolated cell preparations of rat adipose tissue using the formation of [3H]dihydrotestosterone from [3H]testosterone as an endpoint. Stromal cells were prepared from the epididymal fat pad, perinephric fat, and subcutaneous fat of male rats and from perinephric fat of female rats. Adipocytes were prepared from the epididymal fat pad and perinephric fat of male rats. Stromal cells from the epididymal fat pad and perinephric fat contained greater 5 alpha-reductase activity than did the adipocytes from these depots. Stromal cells from the epididymal fat pad contained greater activity than those from perinephric and subcutaneous depots. Perinephric stromal cells from female rats were slightly more active than those from male rats. Estradiol (10(-8) M), when added to the medium, caused a 90% decrease in 5 alpha-reductase activity. Aromatase activity was minimal, several orders of magnitude less than 5 alpha-reductase activity in each tissue studied.
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PMID:5 alpha-reductase activity in rat adipose tissue. 367 52

The possible physiological role of estrogen in the epididymis and ventral prostate of rat was investigated. In prepubertal rats castrated for 7 days, treatment with estradiol (1.0 micrograms) for 7 days (35-day-old at autopsy) resulted in a marked increase in the weight and content of glyceryl-phosphorylcholine and sialic acid in the epididymis; estradiol and dihydrotestosterone were equipotent in causing an increase in sialic acid concentration. Estradiol showed a synergistic effect in influencing the androgen action on the growth of the prepubertal rat prostate while no such synergism was evident in stimulating the secretory function of the epididymis. The duality of epididymal response to the two sex steroids suggests that the two hormones may be acting in concert at physiological levels as regulators of epididymal secretory function; the need for identifying estrogen specific biochemical indices in the epididymis is discussed.
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PMID:Biological response of the rat epididymis to estrogen. 378 Aug 62

The effects of estradiol-17 beta on androgen uptake, metabolism and binding were studied in rat epididymis in vivo in comparison with cyproterone acetate. Steroids (250 ug/100 g body weight) were injected 5 min prior to 3H-testosterone in castrate rats. Estradiol-17 beta inhibited 3H-testosterone uptake into epididymal cytosol by 58% as compared to 38% by cyproterone acetate. 3H-Testosterone uptake into epididymal nuclei was inhibited 95% by estradiol-17 beta and 83% by cyproterone acetate. Total bound radioactivity in cytosol fractions was reduced to a greater extent by estradiol-17 beta than cyproterone acetate when either 3H-testosterone or 3H-dihydrotestosterone was injected. Binding of 3H-dihydrotestosterone to nuclear receptors was completely abolished by estradiol-17 beta; whereas approximately 20% binding remained in the nuclear extract after cyproterone acetate treatment. Metabolism of 3H-testosterone in vivo was also altered by estradiol-17 beta, resulting in diminished conversion to 3H-dihydrotestosterone. Cyproterone acetate, on the other hand, did not affect 3H-testosterone metabolism. Estradiol-17 beta and cyproterone acetate inhibited in vitro binding of 3H-dihydrotestosterone to the intracellular cytoplasmic receptor, but not the intraluminal androgen binding protein (ABP). These data suggest that estradiol-17 beta may have a more potent antiandrogenic effect on the epididymis than cyproterone acetate due to inhibition of 5 alpha reduction of testosterone as well as binding to the androgen receptor.
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PMID:Estradiol-17 beta inhibition of androgen uptake, metabolism and binding in epididymis of adult male rats in vivo: a comparison with cyproterone acetate. 645 38

A dose-dependent increase in body length and weight can be induced in Snell dwarf mice by human, porcine and bovine growth hormones, ovine prolactin, bovine TSH, T4 and T3, and to a lesser extent by insulin. In contrast, porcine FSH, equine LH, testosterone, oestradiol and glucagon influenced neither body length nor weight. Beside body length and weight, the weight of many organs is stimulated by hormonal treatment. GH, T4 and T3 have a rather similar spectrum of effects, with exceptions for the skinfold and epididymal fat-pads. LH had no effect, but in contrast FSH had a strong effect on the seminal vesicles and a less pronounced one on the testis. Oestradiol induced a marked enlargement of the uterus, whereas testosterone increased the weights of the kidneys and seminal vesicles. The main action of insulin is probably localized on body fat. Glucagon, however, did not stimulate organ growth. These data illustrate again the complexity of hormonal regulation of growth.
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PMID:The effects of pituitary, thyroid, pancreatic and sexual hormones on body length and weight and organ weights of Snell dwarf mice. 672 29


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