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 objective of these studies was to optimize conditions for computer-assisted sperm analysis (CASA) of rat epididymal spermatozoa. Methodologic issues addressed include sample collection technique, sampling region within the epididymis, type of diluent medium used, and sample chamber depth. In addition, sources of variation were identified and accuracy of the analysis was examined. All samples in this report were analyzed using a Hamilton Thorn Motility Analyzer (HTM-2000; Hamilton Thorn Research, Danvers, MA). We found that allowing the sperm to swim out from cuts made in the distal cauda epididymidis yielded samples with percentages of motile sperm 60% higher than samples collected using an aspiration method. Furthermore, sperm isolated from the distal cauda epididymidis exhibited slightly but significantly greater percentages of motile sperm and swimming speeds than sperm isolated from the proximal cauda epididymidis. Of the four motility media examined, all maintained a high percentage of motile sperm over an hour-long incubation period, but Medium 199 and modified Hanks' Balanced Salt supported substantially greater sperm velocity than Dulbecco's Phosphate Buffered Saline (with Ca++ and Mg++), with or without glucose. Motility and velocity endpoints were comparable in 200-, 100-, or 40-micron deep chambers, but significantly lower in 20-micron-deep chambers. Since these and presumably other variables in the preparation and analysis of rat sperm do influence the assessed motility endpoints, it is important to standardize these methods and to consider these issues when interpreting CASA data.
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PMID:Rat sperm motility analysis: methodologic considerations. 180 55

Nuclear androgen binding sites were examined in late spermatids (stages 12-19) which resisted sonication of homogenized testes of mature male rats. The measurement of unoccupied binding sites in salt extract of purified spermatid heads by nuclear exchange at -10 degrees C was developed and validated. As in the prostate, unoccupied nuclear androgen binding sites in sonicated testes were in low concentration, were not artefactual, and could be occupied both in vivo and in vitro by exogenous androgens, and uniquely in hemicastrated rats by endogenously compensated androgens in the remaining testis. The properties of occupied binding sites in salt extract of purified spermatid heads (measured by nuclear exchange at 4 degrees C for 48 or more hours with 5 nM [3H]dihydrotestosterone) were almost identical to those of occupied binding sites in nuclei of the ventral prostate, except for their concentration. However, levels of specific binding activity approaching 50 fmol/mg DNA could be expected in salt extract of spermatid pellets, by use of a sulfhydryl reducing agent (dithiothreitol) prior to salt extraction, a protease inhibitor (phenylmethylsulfonyl fluoride) in all buffers, and optimization of the sonication protocol. Nuclear androgen binding sites of sonicated epididymal spermatozoa, collected by retrograde perfusion of the cauda epididymidis, were found to be completely salt-resistant. These binding proteins could be extracted by 0.4 M KCl if dithiothreitol and dihydrotestosterone were incorporated into the sonication buffer, if phenylmethylsulfonyl fluoride was added to all buffers, and if the purified epididymal sperm pellet was treated with sarkosyl, a non-ionic detergent, just before salt extraction. The salt extract of epididymal spermatozoa which were treated as described above contained two binding components: a soluble form which was eluted from hydroxylapatite by increasing concentrations of phosphate buffers, and a non-soluble form, free of DNA, which remained in the hydroxylapatite column, and which contained most of the androgen binding sites. Affinity (Kd) of dihydrotestosterone to the soluble and insoluble fractions of the steroid-binding protein complex was determined to be 0.7 and 0.1 nM, respectively. Salt-resistance of binding proteins in germ cells was shown to develop significantly in the last stages of spermiogenesis.
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PMID:Nuclear androgen binding sites in the male rat. III. Late spermatids and spermatozoa in the testis, with an introduction to epididymal spermatozoa. 674 45

The dye Procion Red HE3B immobilized on agarose and available as Matrex Gel Red A is shown to bind citrate synthase and succinate thiokinase from a number of diverse organisms. Salt-gradient elution removes the enzymes in high yields and with substantial purification. The elution profiles follow a pattern similar to that of the molecular size variations of the enzymes.
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PMID:Affinity chromatography of acyl-CoA utilizing enzymes on Procion Red-agarose. 684 76