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An amine oxidase activity distinguishable from MAO, which is inhibited by carbonyl reagents is present in rat epididymal WAT. This enzyme, referred to as semicarbazide-sensitive amine oxidase (SSAO), appears concentrated in adipose cells. Close homologies between WAT SSAO and the circulating plasma BAO are discussed.
Sixteen proteinase inhibitors were tested for their ability to compete with the natural seminal inhibitor for binding to the surface of murine epididymal sperm. The most effective competitors, 4-methylumbelliferyl-p-quanidinobenzoate (MUGB) and p-nitrophenyl-p-guanidinobenzoate (NPGB), are also effective inhibitors of both murine acrosin and in vitro fertilization of mouse gametes. The data support the suggestion that the inhibition of fertilization by these inhibitors may be effected by their action on the sperm surface rather than binding to enzymes located within the acrosome. Since the surface acceptor molecule recognizes a number of inhibitor types, as well as substrates for such enzymes as trypsin and acrosin, the acceptor's binding site may be similar to the active site on the enzyme.
The ability of a long-acting androgen, testosterone buciclate (TB), to induce suppression of testicular and epididymal sperm functions when given in combination with a potent GnRH antagonist (Antide) either on day 1 or 45 of Antide administration (days 1-90) as well as the ability of TB to maintain Antide-induced suppression of spermatogenesis were evaluated in adult bonnet monkeys. A group of untreated animals (group I) acted as controls. All animals given Antide and androgen simultaneously (group II) became azoospermic but at different times. When androgen administration was delayed 45 days after start of Antide treatment (group III), the mean sperm concentration remained in the normospermic range and only three animals became azoospermic. Antide given alone (group IV) induced azoospermia in three animals and oligospermia in the remaining animals; spermatogenesis recovered when Antide was withdrawn and TB was injected. In all Antide-treated animals (groups II-IV), non-motile spermatozoa or sperm with non-progressive motility and poor gel penetrability were seen in the ejaculate.
In the rat vas deferens there are prejunctional A1 receptors mediating inhibition of transmitter release and post-junctional A1 and A2 receptors mediating enhancement and inhibition of contractions respectively. In this study the distribution of adenosine receptors in the prostatic and epididymal portions of the bisected rat vas deferens was investigated. The pre- and post-junctional A1 receptors were present on both portions of the bisected tissue. However, post-junctional A2 receptors appear to be present only in the prostatic region, showing that adenosine receptors are differentially distributed along the length of the rat vas deferens.
In vivo expression of P-glycoprotein in isolated rat brain microvessels is compared with that in vitro in primary cultures of brain endothelial cells. More P-glycoprotein is detected by Western immunoblotting in microvessels than in cultured endothelium. RT-PCR with isoform-specific primers and immunoblotting with a mdr1b-specific antibody reveals only mdr1a in vivo but both mdr1a and mdr1b in vitro. Thus mdr1a decreases whereas mdr1b increases during culture. P-Glycoprotein activity is evident in vitro, with resistance modulators, e.g. verapamil, producing increases in intracellular [3H]vincristine accumulation. Endothelial cells cultured from epididymal fat pad microvasculature and aorta contain little or no P-glycoprotein. Here, resistance modulators are less effective.
Estrogen binding activity was investigated in the epididymis of the turtle, Chrysemys picta using DNA-cellulose affinity chromatography. A component binding estradiol-17 beta specifically with high affinity (Kd:8.0 X 10(-10) M) and limited capacity (20 fmol/mg protein) was demonstrated in the epididymal cytosol. In addition, binding of estradiol-17 beta was sensitive to excess (100-fold) diethylstilbestrol or natural estrogens (estradiol-17 beta, estrone, and estriol) but not to progesterone or androgens (testosterone and 5 alpha-dihydrotestosterone). The specific estrogen binding macromolecules eluted from DNA-cellulose columns sedimented at 4-5 S in linear 5-20% sucrose gradients. These characteristics suggest the presence of an estrogen receptor in this androgen target organ.
During the annual cycle of the lizard Lacerta vivipara dramatic changes in the secretory activity of the epididymis were observed. These changes and changes in morphology correlate with the plasma and epididymal testosterone concentrations. The secretory proteins contain a major group of immunorelated components referred to as LI to L1X. They consist of a group of nine proteins Mr 19,000 which can be separated according to pI 3.5 to 8.7. Post-translational modifications may be responsible for their pI diversity. All the L proteins are glycosylated (fucose, N-acetylgalactosamine and or N-acetylglucosamine) but only LVI glycosylation was inhibited with tunicamycin. Phosphorylation is unique to LV protein and none of the L proteins are sulfated. All L proteins appeared sequentially during the annual cycle and in organotypic culture when incubated in the presence of testosterone (150, 500, 1000 nM) in a time dependent manner.
The existence of a microsomal acetyl-CoA carboxylase in the rat epididymal adipose tissue was demonstrated in vitro in the present study. Its specific activity was of the same order of magnitude as that of the cytoplasmic acetyl-CoA carboxylase. The effect of several experimental conditions on the enzymatic activities of both enzymes were tested; fasting for 24 hr strongly increased (2.5-4 times) the activity of the microsomal enzyme while the cytoplasmic enzyme remained unchanged. Palmitoyl-CoA (1 and 5 microM), an inhibitor of acetyl-CoA carboxylase, had a greater effect on the cytoplasmic (33 and 88% inhibition) than on the microsomal enzyme (0 and 37% inhibition).
1. In the present study, we isolated the two forms of proacrosin from acid extracts (pH 3.0) of cauda epididymal bovine spermatozoa by ammonium sulfate fractionation, gel filtration on Sephadex G-150 and affinity chromatography on Concanavalin A Sepharose 4B. The overall purification was 13-fold with respect to crude acid acrosomal extract. 2. The apparent molecular weight of the proacrosins determined by SDS-PAGE were 44,000 and 38,000. Both forms have proteinase activity on gelatin-SDS-polyacrylamide gel electrophoretic zymography. 3. The M(r) = 38,000 component was isolated by reverse phase HPLC. Thirty-nine amino acid residues at the N-terminus have about 72 and 77% sequence similarity with boar and human proacrosin, respectively. 4. The amino acid sequence of 14 amino acids at the N-terminus of the high molecular weight component (M(r) = 44,000) was determined after electroblotting on a polyvinylidene difluoride membrane. This portion of the molecule is identical with that of the low molecular weight component. 5. Proacrosin autoactivation followed the sigmoidal activation curve.
By means of specific radioimmunoassays unconjugated testosterone, 5 alpha-dihydrotestosterone, 5 alpha-androstane-3 alpha, 17 beta-diol, 5 alpha-androstane-3 beta, 17 beta-diol and estradiol-17 beta as well as testosterone-glucosiduronate were estimated in the plasma of the spermatic vein and artery simultaneously with the determination in peripheral venous and arterial plasma in ten male patients undergoing orchiectomy for prostatic cancer. The following results were obtained: A positive concentration gradient was found for all steroids. The testicular "secretion" of 5 alpha-androstane-3 beta, 17 beta-diol was established for the first time. The venous-arterial transfer of the mentioned steroids within the plexus pampiniformis yielded the following figures: 5.1%; 17.4%; 6.5%; 5.4% 5.1% and 6.5%, respectively. The testicular and/or epididymal origin of the different steroids was calculated to be of the following order of magnitude (mean values): Dihydrotestosterone 28%, 5 alpha-androstane-3 alpha, 17 beta-diol 45%, 5 alpha-androstane-3 beta, 17 beta-diol about 100% estradiol-17 beta 63% and testosterone-glucosiduronate 3%.
Purified rabbit epididymal androgen binding protein and serum testosterone estradiol binding globulin have been immunologically compared. A comparison using the steady state gel method of Ritzen et al. indicated immunological cross-reactivity. In order to further compare their immunological properties we developed a radioimmunoassay for both rbABP and rbTeBG using specific antisera directed against each. When these assays were compared, the extent or completeness of displacement proved to be the only parameter that was significantly different. This data obtained with homologous and heterologous radioimmunoassays is consistent with the idea that these two proteins contain minor antigenic determinants which are distinct.
Epididymal 4-ene steroid 5 alpha-reductase converts testosterone to 5 alpha-dihydrotestosterone. The enzyme is localized to the nuclear and microsomal fractions, and the activity can be altered by modifying the phospholipids in the membrane environment. To investigate the membrane dependence of 4-ene steroid 5 alpha-reductase, we have treated nuclear and microsomal membranes with combinations of phospholipase A2 and phospholipase C, and examined the effects on 4-ene steroid 5 alpha-reductase activity. Sequential addition of phospholipase A2 and phospholipase C to the nuclear fraction, reduced the 4-ene steroid 5 alpha-reductase activity to approx 25% of the control level. Neither the nature of the phospholipase, nor the sequence of addition altered the inhibition. When both phospholipases were added simultaneously, nuclear 4-ene steroid 5 alpha-reductase activity was inhibited in a linear fashion, and in tests for cooperativity, the effects of phospholipase A2 and phospholipase C were clearly additive. The microsomal enzyme responded differently to sequential phospholipase treatments; if phospholipase A2 was followed by phospholipase C, or phospholipase C followed by phospholipase A2, the 4-ene steroid 5 alpha-reductase activity was, respectively, 13 and 27% of the control. In contrast, sequential addition of the same phospholipase reduced the activity of 4-ene steroid 5 alpha-reductase to approx 40% of the control level. Furthermore, simultaneous addition of phospholipase A2 and phospholipase C to the microsomal fraction, resulted in non-linearity of 4-ene steroid 5 alpha-reductase activity with time, whereas when added individually, linearity of 4-ene steroid 5 alpha-reductase was maintained. Consequently, it was not possible to test for cooperative effects of phospholipases on the microsomal 4-ene steroid 5 alpha-reductase. These findings suggest that for the nuclear 4-ene steroid 5 alpha-reductase, the polar and non-polar regions of the membrane environment have similar functions, which are most likely involved in the maintenance of the structural integrity of the enzyme. For the microsomal enzyme, the polar and non-polar regions of the membrane appear to have different functions, not only for the maintenance of enzyme integrity, but also in the mechanism at the active site.
The normal development of adipose tissue lipolysis as measured by glycerol release was studied in epididymal fat pads of fed and fasted Sprague-Dawley rats between 15 and 128 days of age and correlated with changes in fat cell size. At 15 and 17 days of age, when fat cell size was small, glycerol release per cell was highest and decreased steadily to adult levels by 73 days of age. Between 85 and 128 days of age as fat cell size continued to increase, glycerol release per cell began to rise. Therefore, glycerol release per cell inversely correlated with fat cell size during early development and directly correlated with fat cell size after 73 days of age. The response to fasting was variable in the younger rats but was established by the third postnatal week. The possible early reciprocal and later complementary roles of lipolytic activity and lipoprotein lipase activity in the "setting" and regulation of fat cell size during postnatal adipose tissue development is discussed.
The equilibrium affinity constant for rat prostate androgen receptor and epididymal androgen binding protein (ABP) has been determined for thirty-four potential progestogens. Three A-nor-, four A,19-dinor-, and one A-homo-5 alpha-androstane derivative bind to the androgen receptor (KD less than 0.5 muM). Five of these compounds also bind to ABP with an affinity of the same order of magnitude. "Anordrin" (compound 24) and "Dinordrins" (compounds 10, 14, 15, 16, 17), which are potential female contraceptives, do not bind with high affinity to the androgen receptor or to ABP. The following modifications in A-nor derivatives favour binding to the receptor as compared to ABP: 19-nor substitution (compound 1), C-18 methyl homologation (compound 5), 2 alpha-ethinylation (compound 22). One 2 alpha-allenyl A-nor derivative (compound 25) and one A-homo derivative (compound 34) bind almost exclusively to ABP. The interaction with either binding protein is decreased by oxidation or esterification of the hydroxyl group at C-17, and by addition of a 17 alpha-ethinyl group. The latter modifications are likely to increase the specificity of androstane derivatives for receptors other than androgen binding proteins, such as the progesterone receptor.
A staining technique based upon the known ability of tannic acid to selectively stain the outer layer of the triple-layered plasma membrane was used, along with electron microscopic examination of stained, serial sections, to differentiate between surface invaginations, clusters of invaginations, free vesicles and tubular channels in epididymal fat pads from young, fed and fasted mice and from old, fed mice. A preliminary semiquantitative evaluation of the average number of each type of structure per cell was attempted. There were no significant numbers of free cytoplasmic vesicles of approximately 50 nm diameter (the dimension of most surface invaginations) under any conditions studied. Most apparent vesicles were stained by tannic acid and were, therefore, actually invaginations of the plasma membrane. There were no tubular channels of this size seen in any of the electron micrographs examined in serial sections. We estimated that there are about 50 single invaginations per micron2 of plasma membrane surface in both young and old fed mice. In addition there were about 20 invaginations/micron2 grouped as clusters of 2-15 per group (mean, 4 per group) in the fed mice. There was a tendency for the number of invaginations in clusters to increase during fasting; about 40% of the surface invaginations were grouped in clusters in adipocytes of fasted mice. Although there was no effect of ageing on the concentrations of surface invaginations or in their groupings as clusters, the total number of invaginations per cell must have increased almost 3-fold as the cells enlarged. The function of these surface invaginations and deeply penetrating groups of invaginations remains to be elucidated.
Insemination with the sperm of an epididymal reservoir three days after implantation of the prosthesis led to a successful pregnancy with subsequent delivery of five healthy sucklings. Alloplastic spermatocele can function longer than four months as proved by a successful pregnancy.
A case of epididymal metastasis from carcinoma of the prostate with an unusual presentation is reported. A review of the literature disclosed only 10 reported cases of this rare finding. A mechanism for the method of metastasis in this patient is proposed.
A case of epididymal metastasis from prostatic carcinoma is presented. The initial histologic findings were suggestive of adenomatoid tumor, but a diagnosis of metastatic adenocarcinoma of prostatic origin has been established by prostatic acid phosphatase and prostate-specific antigen immunoperoxidase staining.