Biomedical subjects

G Aumüller

Publications and source records attributed to G Aumüller.

At least 73 records · Page 4Linked to original sources

PubMed1994

Hormonally induced changes in apocrine secretion of transglutaminase in the rat dorsal prostate and coagulating gland.

Coagulating gland and dorsal prostate of the rat are peculiar in secreting transglutaminase, a protein-cross linking enzyme that is released in an apocrine fashion. To elucidate whether or not the intracellular pathway and the unusual extrusion mechanism proceed constitutively or were differentially regulated, transglutaminase immunoreactivity was studied both at the light and electron microscopic levels. In addition, ultrastructural morphometry and scanning densitometry were applied to quantitate hormone-dependent distribution of transglutaminase. Coagulating glands and dorsal prostate, respectively, from sexually active rats were compared to those from sexually inactive, castrated, estradiol-treated or testosterone-substituted castrated animals. In intact, sexually active animals, no labeling of the cisternae of rough endoplasmic reticulum was seen, but instead the hyaloplasm was labeled. In the supranuclear portions of the cells an increase in labeling density of the hyaloplasm subjacent to the plasma membrane was found, whereas no labeling of either Golgi stacks or vesicles was observed. Apical blebs projecting into the acinar lumen were densely labeled. In castrated animals, epithelium showed a reduction of rough endoplasmic reticulum, loss of secretory blebs, and a decrease in cell size. Morphometric analysis of immunolabeling of coagulating gland epithelium from experimental animals resulted in a highly significant reduction of labeling of the hyaloplasm and apical blebs which was reversed by testosterone supplementation of castrated animals. After estrogen treatment, the reduction in immunolabeling was less pronounced, but morphology of apical blebs was obviously changed. Results from scanning densitometry of Western blots correlated with quantitative immunoelectron microscopical findings. Northern blot analysis using a secretory transglutaminase cDNA probe showed characteristic changes at the RNA levels. Our results indicate that apocrine secretion of transglutaminase in rat coagulating gland and dorsal prostate is a hormonally controlled process, where androgen deprivation results in impaired biosynthesis and release of transglutaminase, whereas estradiol treatment only partially inhibits secretion, but changes morphological features of the glandular epithelium, especially apocrine bleb formation.

Animals↗

PubMed1993

Effects of androgen deprivation and estrogen treatment on the structure and protein expression of the rat coagulating gland.

The effects of androgen deprivation and estrogen stimulation on rat coagulating gland were determined by immunohistochemistry and morphometric quantification of different tissue compartments. In castrated or estrogen-treated or estrogen-treated castrated animals, the reduction of the glandular lumen is the most obvious morphological alteration, which is accompanied by an increase in stromal tissue, especially within the lamina propria. Regressive changes occur most rapidly in castrated animals (already by the end of the first week), slower in estrogen-treated castrated animals, and still slower in estrogen-treated normal animals. In castrated animals, epithelium shows a reduction of rough endoplasmic reticulum, loss of secretory blebs, and a decrease of cell size and immunoreactivity for secretory transglutaminase. The reduction of glandular lumen results from an impressive increase in connective tissue of the lamina propria. Smooth muscle cells become atrophic in castrated animals, less so in estrogen-treated animals and in castrated estrogen-treated animals. A relative increase in thickness of the smooth muscle cell layer occurs in all experimental groups and is most obvious in estrogen-treated normal animals. The proportion of myofilament and intermediate filament proteins (smooth muscle-specific actin and desmin immunoreactivities) remains nearly unaltered in these cells after hormonal challenge. A redistribution of intermediate filaments occurs forming thicker bundles within the cells. No indication for increased mitotic activity of estrogenized smooth muscle cells has been found. After castration, and after estrogen treatment, the fibroblasts and the smooth muscle cells, respectively, appear responsible for the architectural changes within the coagulating gland. Reactions of the stroma are differentially regulated after estrogen treatment and androgen deprivation. No indication for increased biosynthetic activities of smooth muscle cells has been observed in any of the experimental conditions.

Animals↗

PubMed1993

Influence of hormone application by subcutaneous injections or steroid-containing silastic implants on human benign hyperplastic prostate tissue transplanted into male nude mice.

To study the influence of androgens and estrogens on human benign prostatic hyperplasia (BPH) tissue, BPH fragments were grafted subcutaneously (s.c.) into male nude mice. Testosterone alone (group I) or in combination with 17 beta-estradiol (group III) were administered either by s.c. injections as oil suspensions or continuously by s.c. implanted steroid-containing Silastic implants (groups II and IV). Intact mice without transplants and treatment served as a control (group V). After 4 weeks of treatment, animals were exsanguinated, transplants were removed, and serum was obtained. Ninety-six percent of the BPH fragments were located; they displayed histologically typical BPH acini and stroma. In transplants of all treatment groups, the majority of secretory, as well as basal, cells displayed a proliferation comparable to the original tissue. In glandular cells of all transplants, prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) could be demonstrated immunohistochemically. Specimens removed from animals bearing testosterone implants displayed a very well preserved ultrastructure that was found less frequently in samples from injection-treated animals. Acini-bearing metaplastic epithelium were more often present in transplants treated by steroid injections and seemed to be due to lower androgen or higher estrogen serum levels. Endogenous serum testosterone levels (ng/ml +/- SD; n) were lower and more variable (i.e., higher standard deviation) in groups treated by injections (group I: 3.68 +/- 2.12; n = 5 and group III: 3.86 +/- 1.13; n = 5) and were similar to those seen in intact controls (3.93 +/- 1.62; n = 6) compared with groups treated by Silastic implants (group II: 5.11 +/- 1.14; n = 10 and group IV: 10.20 +/- 0.52; n = 4). These results indicate that by application of steroids via Silastic implants, reproducible hormone effects can be obtained on BPH tissue transplanted into male nude mice, thus providing a reliable new model system for study.

Acid Phosphatase↗

PubMed1993

Tissue-type transglutaminase expression in the Dunning tumor.

Transglutaminases with different functions and tissue distribution patterns can be distinguished by specific antibodies and by inhibition of enzyme activity in the presence of guanosine triphosphate (GTP). The most common form is the so-called tissue-type transglutaminase that is apparently involved in membrane stabilization processes, e.g. during apoptosis, and can be inhibited by incubation with GTP at low calcium concentrations. A secretory transglutaminase that cannot be inhibited by GTP is synthesized in an androgen-dependent manner in the dorsal prostate of the rat, the site suggested to represent the origin of the Dunning tumor used as an experimental model in prostate cancer research. Here we studied the expression of transglutaminases in different Dunning tumor lines--mainly in the highly differentiated H subline--and characterized the enzyme both biochemically and immunocytochemically. A very high enzyme activity was found only in the less well differentiated HI-F tumor line. Immunohistochemical reactions and Western blot analysis showed that there is no secretory transglutaminase present in any of the Dunning tumor lines studied. Transglutaminase activity of the Dunning tumor results from the so-called tissue-type enzyme that is non-organ specific. The absence of a secretory form of transglutaminase does not support the contention of a prostatic origin of the Dunning tumor.

Animals↗

PubMed1993

Functional properties of isolated stroma and epithelium from rat ventral prostate during androgen deprivation and estrogen treatment.

To identify the functional activities of prostatic stroma under different hormonal conditions, isolated stroma and epithelium from rat ventral prostate (RVP, intact or one week castrated or estrogen-treated), were studied in metabolic labeling experiments. Using a semiquantitative stereological procedure, the relative proportion of the epithelial and stromal compartment was determined in situ. In addition, the distribution of the androgen receptor was visualized by in situ hybridization and by immunocytochemistry. In castrated animals protein biosynthesis of the stroma and epithelium exceeded the control value by a factor 7 and 5, respectively. In estrogen-treated animals protein biosynthesis was reduced, reaching only between one tenth and one fifth of the control value. The amount of stroma obtained from these animals was very low. These results were confirmed by stereological findings and indicate a differential regulation of prostatic stroma and epithelium after estrogen challenge and androgen deprivation. Estrogen receptor was induced in epithelium and stroma in estrogenized animals whereas the androgen receptor was reduced in experimental specimens. During estrogenization the biosynthetic activity of both stroma and epithelium is depressed, while estrogen responsivity of the epithelium in terms of estrogen receptor expression is increased. Androgen withdrawal results in active transformation of the gland through increased stromal biosynthetic activity and epithelial regression.

Androgens↗

PubMed1993

Stromal and epithelial cells from rat ventral prostate during androgen deprivation and estrogen treatment--regulation of transcription.

To identify the functional capacities of prostatic tissue, the expression of steroid hormone receptors, growth factors, oncogenes and particular enzymes was studied at the RNA level in isolated stromal and epithelial cells of rat ventral prostate (RVP) under different hormonal conditions (androgen deprivation, estrogen treatment). Slot blot and Northern blot analyses of isolated RNA resulted in characteristic changes: In the control prostate, androgen receptor (AR) mRNA was high in epithelium of intact prostate, but low in stroma. Its level was increased after castration in the epithelium during the initial 24 hours, whereas an only slight increase occurred in stroma after one week castration. The AR signal was not altered by estradiol treatment in epithelium and stroma. Conversely, the estrogen receptor (ER) mRNA, predominant in stroma and very low in epithelium, decreased after castration in stroma and epithelium within 24 hours and was absent one week later. After estrogen treatment the ER signal increased considerably in stroma. mRNA of both basic fibroblast growth factor (bFGF) and transforming growth factor beta (TGF-beta) were exclusively found in stroma. Both were low in controls and responded in a different way to castration and estrogen treatment within 24 hours. bFGF was increased in estrogen-treatment animals, while TGF-beta was induced by castration. Shortly after castration (2 hours) v-fos expression increased and reached a maximum after 6 hours, but was no more detectable after 12 hours in epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Androgens↗

PubMed1993

Change in location and processing of inhibin alpha-subunit precursors during sexual maturation of the Djungarian hamster testis.

Immunohistochemical location and immunoblot of inhibin alpha-subunit peptides were analyzed in the testis of the Djungarian hamster from days 0-31 of postnatal development using a specific antibody. An intense immunoreaction was observed in the centrally located T1 prespermatogonia at day 0. The staining intensity decreased gradually in the spermatogonia when they make contact with the basal lamina at days 8-10. At days 13 and 15 there is no staining. Thereafter the immunoreactivity in Sertoli cells as well as in A spermatogonia gradually increased, being highest in sexually mature animals. The intensity of alpha-subunit staining in the seminiferous tubules was stage specific, being strongest at stages III and IV. Immunoblot analysis of testis homogenates with the anti-INH alpha 1-32 antibody showed several bands: 88K, 80K, and 43K in immature hamster testis (0-, 2-, 6-, 8-, or 10-day-old). In the adult hamster (31-day-old) 88K, 80K, 28K, and 20K bands were seen, but no 43K band. Dimeric inhibin was not detected. The 43-44K band most likely corresponds to the pro-alpha N alpha C, the 28K band to intermediate forms between alpha N alpha C and alpha C (alpha I alpha C), and the 20K band to mature alpha-subunit (alpha C). The shift from the immature pattern to mature occurs at about 20 days of age. Freezing of the samples was deleterious to alpha C, since it could be detected only in freshly homogenized samples. The results suggest that prespermatogonia produce predominantly monomeric alpha-subunit precursor pro-alpha N alpha C, whereas the mature Sertoli cells as well as A spermatogonia contain mainly monomeric alpha I alpha C. The alpha-inhibin precursors may act as auto-/paracrine regulators of spermatogenesis. Our results suggest that different alpha-subunit precursors, pro-alpha N alpha C and alpha I alpha C, might be involved in the differentiation and maintenance of spermatogenesis, respectively. The posttranslational processing of alpha-subunit precursors seems to play an important role in the physiology of reproduction.

Aging↗

PubMed1993

[Current aspects on morphology and functions of the prostate].

The human prostate has a dual function in that it produces a number of secretory compounds conditioning the urethral surface for sperm passage and acting on spermatozoa as well as on vesicular coagulation proteins (semen liquefaction). In addition to differentially distributed and regulated steroid hormone receptors in epithelium and stroma, the prostate contains a large number of growth factors and their receptors. An incompletely understood paracrine regulation of growth and differentiation exists between epithelial cells, such as secretory, basal and neuroendocrine cells, as well as the underlying stroma (smooth muscle cells, fibrocytes). The presently available (malignant and non-malignant) prostatic cell lines have a number of disadvantages that render them of limited value in prostate cancer research.

Animals↗

PubMed1992

Intermediate filaments in Sertoli cells.

Using immunohistochemical techniques both at light and electron microscopic levels, the arrangement and distribution of intermediate filaments in Sertoli cells of normal testis (in rat and human), during pre- and postnatal development (in rabbit, rat, and mouse) and under experimental and pathological conditions (human, rat), have been studied and related to the pertinent literature. Intermediate filaments are centered around the nucleus, where they apparently terminate in the nuclear envelope providing a perinuclear stable core area. From this area they radiate to the plasma membranes; apically often a close association with microtubules is seen. Basally, direct contacts of the filaments with focal adhesions occur, while the relationship to the different junctions of Sertoli cells is only incompletely elucidated. In the rat (not in human) a group of filaments is closely associated with the ectoplasmic specializations surrounding the head of elongating spermatids. Both in rat and human, changes in cell shape during the spermatogenic cycle are associated with a redistribution of intermediate filaments. As inferred from in vitro studies reported in the literature, these changes are at least partly hormone-dependent (vimentin phosphorylation subsequent to FSH stimulation) and influenced by local factors (basal lamina, germ cells). Intermediate filaments, therefore, are suggested to be involved in the hormone-dependent mechanical integration of exogenous and endogenous cell shaping forces. They permit a cycle-dependent compartmentation of the Sertoli cell into a perinuclear stable zone and a peripheral trafficking zone with fluctuating shape. The latter is important with respect to the germ cell-supporting surface of the cell which seems to limit the spermatogenetic potential of the male gonad.

Animals↗

PubMed1992

Estrogen-induced morphological and immunohistochemical changes in stroma and epithelium of rat ventral prostate.

Prostatic smooth muscle cells have been regarded to play a major pathogenetic role during the development of benign prostatic hyperplasia (BPH) in elderly men. Altered hormonal signals (increased estrogen) have been made responsible for the "metabolic" transformation of prostatic smooth muscle cells, which were thought to produce increased amounts of connective tissue fibers observed in BPH. In order to find out the role of metabolically "activated" smooth muscle cells, hormone stimulation experiments were performed in male rats. The effects of androgen deprivation and estrogen stimulation were recorded by semiquantitative analysis of intermediate and myofilament proteins in stromal smooth muscle cells. In castrated or estrogen-treated or estrogen-treated and castrated animals, the reduction of the glandular lumen is the most obvious morphological alteration, accompanied by an increase in connective tissue. Regressive changes occurred most rapidly in castrated animals (already within the first week), slower in castrated estrogen-treated animals and still slower in normal estrogen-treated animals. Regression of the epithelium was accompanied by a marked decrease in immunoreactivity for prostatic binding protein (PBP) in castrated animals, while PBP immunoreactivity in estrogenized animals was retained for up to 6 weeks. Smooth muscle cells became atrophic in castrated animals. This effect was attenuated in estrogen-treated animals. There was no indication for enhanced collagen synthesis by smooth muscle cells. Actin and desmin-immunoreactivity were only slightly altered in experimental animals and showed a changed distribution pattern. Prostatic smooth muscle cells respond less markedly to hormonal alterations than do the fibroblasts.

Animals↗

PubMed1992

Sulfhydryl oxidase immunoreactivity in seminiferous tubules of infertile men.

Sulfhydryl oxidase (SOx) immunoreactivity was investigated in the seminiferous epithelium of human biopsy material from the testes of 33 adult men with disturbed fertility. SOx immunoreactivity was expressed in normal seminiferous epithelium in type-A spermatogonia (27 +/- 4% of all spermatogonia) (n = 4), in spermatocytes and round spermatids. Mature spermatozoa as well as Sertoli cells were unlabelled. Within the interstitium, Leydig cells were immunopositive. In biopsies of oligozoospermic men showing hypospermatogenesis (n = 24), an increase in labelled spermatogonia up to more than 90% was observed in biopsies, where seminiferous epithelia revealed only spermatogonia and Sertoli cells. Within the group of oligozoospermic patients there was a significant increase of labelled spermatogonia from 43 +/- 13% (greater than 20 mill/ejaculate) (n = 7) to 55 +/- 16% (less than 20 and greater than 10 mill/ejaculate) (n = 6) to 68 +/- 8% (less than 5 mill/ejaculate) (n = 11) and a significant (P = 0.01) decrease of score count from 7.0 +/- 2.7 to 2.0 +/- 1.8. In this group the increase of labelled spermatogonia was correlated with sperm concentrations in the ejaculate (correlation coefficient: r = -0.6). In biopsies of azoospermic patients showing maturation arrest at the level of spermatocytes or spermatids (n = 5) the percentage of labelled spermatogonia was within the range of 24% to 59%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Arguments against the prostatic origin of the R-3327 Dunning H tumor.

The Dunning tumor, originally described as a carcinoma of the rat dorsal prostate, has for long been used as an experimental model of prostatic cancer. We have recently presented a number of morphological findings that are incompatible with the prostatic origin of the H-subline of the Dunning tumor. In this paper, biochemical and immunohistochemical markers of rat prostate and mammary gland are studied in the R-3327 Dunning H tumor. Pieces of the H tumor were inoculated in male or lactating female rats. The electrophoretic protein pattern of Dunning tumor extracts was more similar to that of the mammary gland than the dorsolateral prostate. Proteins selectively appearing after metabolic labeling in Dunning tumors grown in lactating rats corresponded to labeled proteins in mammary glands from the same animals. Secretory proteins typical of the lateral prostate (SVS II) and dorsal prostate (transglutaminase) could not be detected immunohistochemically in the Dunning tumor. Western blot studies of tumor extracts and slot blot analysis of RNA preparations from the tumor confirmed the absence of SVS II and prostate specific transglutaminase from the Dunning tumor. On the other hand, the presence of mammary gland proteins such as milk fat globule membrane proteins, lactoperoxidase and lactalbumin were detected in the Dunning tumor by immunohistochemistry and Western blotting, but were absent from the dorsolateral prostate. Transferrin-mRNA, expressed in the male urogenital tract and also in the liver and other tissues, was detected in the mammary gland and Dunning tumor, but not in the dorsolateral prostate. The absence of mammary gland secretory beta-casein in the Dunning tumor was related to the elevated Ha-ras oncogene expression in the tumor, previously reported to suppress casein expression. The findings clearly demonstrate that the prostate cannot be the origin of the Dunning tumor, presently being used in prostatic cancer research. The designation prostatic adenocarcinoma for this tumor is therefore invalid. Furthermore, the data support our view that mammary gland might be the origin of the Dunning tumor, although the derivation from the bulbourethral or the parotid glands cannot strictly be excluded.

Adenocarcinoma↗

PubMed1992

Immunological identification of G protein alpha- and beta-subunits in tail membranes of bovine spermatozoa.

Heterotrimeric G proteins are believed to play important roles as signal transducing components in various mammalian sperm functions. To assess the distribution of G proteins in bovine sperm tails, we purified membranes by hypoosmotic swelling of bovine spermatozoa followed by disruption of plasma membranes in a homogenizer and various centrifugation steps. Electron microscopy revealed highly purified membranes of bovine sperm tails. Subsequently, antisera against synthetic peptides were used to identify G proteins in immunoblots. An antiserum directed against the C-terminal decapeptide of Gi3 and detecting all known pertussis toxin-sensitive alpha-subunits, reacted specifically with a 40-kDa protein. In contrast, various other specific peptide antisera against alpha-subunits did not detect any G protein in enriched tail membranes. An antiserum recognizing the beta 2-subunit of G proteins and an antiserum reacting with both beta 1- and beta 2-subunits identified a 35-kDa protein in sperm tail membranes. In contrast, antisera against the 36-kDa beta 1-subunit did not detect any relevant proteins in the membrane fraction. Neither G protein alpha-subunits nor G protein beta-subunits were found in the cytosol. Our results suggest that G proteins in membranes of tails of bovine spermatozoa most likely belong to a novel subtype of G protein alpha-subunits, whereas the putative beta-subunit could be identified as a beta 2-subunit.

Adenosine Diphosphate Ribose↗

PubMed1992

[Benign prostatic hyperplasia and growth factors: mechanisms and hypotheses].

The aetiology and pathogenesis of benign prostate hyperplasia (BPH) are still unresolved questions, although a number of hypotheses have been developed, most of which have still not been confirmed by experimentation. BPH has been regarded as a kind of adenoma, as a stromal disease, as the result of either hormonal imbalance (altered oestrogen/testosterone ratio) or testosterone or dihydrotestosterone stimulation, and finally as the result of oestrogen stimulation, perinatally or involutionally. More recently, scientific interest has focused on the presence and possible function of growth factors and their receptors in the human prostate and their autocrine or paracrine stimulatory effects in BPH development. Hypotheses on their hormonal regulation as well as their interplay during epithelial-stromal interaction have been developed. The intact human prostate produces epithelial (EGF) and basic fibroblast (bFGF) growth factors. Normally, they do not appear to have autocrine or paracrine effects. In androgen deficiency, however, as shown experimentally in castrated rats, the stromal cells express increased amounts of TGF beta, of TGF beta receptor, and of bFGF. Platelet-derived growth factor (PDGF), but not the corresponding receptor, has been shown in prostate. The growth factor receptor-associated tyrosine protein kinase is present in the human prostate in two different forms, but its functional significance in BPH development has not yet been elucidated. A more significant role may be attributed to the recently described growth factors in cultured human stromal cells, which exert multifarious mitogenic and non-mitogenic effects on prostatic epithelium as well as neuronal and non-neuronal cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Division↗

PubMed1992

SVS II--an androgen-dependent actin-binding glycoprotein in rat semen.

Rat seminal vesicles and the lateral prostate secrete a glycoprotein designated as SVS II in an androgen-dependent manner. SVS II, which has a M(r) of 49,000 and a pI of 10.5, is an actin-binding protein. G- and F-actins cosediment with SVS II at a ratio of 2:1 (actin:SVS II). SVS II affects the kinetics of actin polymerization in the same way as do barbed end capping proteins. Interaction with actin is specific for the skeletal and cardiac muscle isoforms and there is no corresponding interaction with cytoplasmic actins. The binding site is close to the C-terminus of actin. Monospecific polyclonal antibodies directed against the N-terminus of actin cross-react with SVS II, but there is no cross-reaction by a monoclonal antibody directed against a C-terminal epitope on actin. Recent sequence analysis of SVS II shows a sequence of about 14 residues that is repeated 13 times between residues 86 and 298. The consensus sequence based on these repeats is homologous to residues 10 to 25 of actin; this may account for the immunological cross-reactivity. Like actin, SVS II binds and inhibits the activity of DNase I, but SVS II has no effect on the ATPase activity of myosin subfragment 1. Thus, SVS II is an actin-binding protein which retains some properties of actin itself.

Actins↗

PubMed1991

Purification and molecular characterization of a secretory transglutaminase from coagulating gland of the rat.

A transglutaminase (TGase, EC 2.3.2.13) was isolated from the secretion of rat coagulating gland (CGS-TGase). The protein consists of a single polypeptide chain and has a molecular mass of 65 kDa. During purification the net charge changes from pI 7.6 in the crude extract to pI 8.5-8.7 for the purified protein. Nearly equal numbers of glutamyl- and lysyl-residues were detected by amino acid analysis. The protein therefore represents an appropriate substrate of autocatalytic crosslinking. The total number of cysteine residues is 18-19, six of which being present in free form. One of the thiol groups is essential for the enzymic activity. The protein core is glycosylated with mannosyl residues and in addition substituted with saturated acyl residues and phosphoinositol. The phosphoinositol anchor was demonstrated by use of a specific antibody. Removal of the acyl- and glycosyl-residues or of the total anchor group results in autoaggregation and decrease of enzymic activity. In contrast to tissue-type TGases, Ca2+ dependent enzymic activity of CGS-TGase is not inhibited by GTP. The secretory TGase shows no immunological cross-reactivity to tissue-type enzyme or blood factor XIII.

Amino Acids↗

PubMed1991

Basal cells of H-Dunning tumor are myoepithelial cells. A comparative immunohistochemical and ultrastructural study with male accessory sex glands and mammary gland.

Recent immunohistochemical studies have shown that basal cells in human prostatic epithelium are not myoepithelial cells. Since in the literature the Dunning tumor, originally described as a rat prostate carcinoma derived from the dorsolateral prostate of a Copenhagen rat, was reported to have myoepithelial cells, a comparative immunohistochemical and ultrastructural study was performed in the H-, HIF- and AT3-lines of the Dunning tumor, the male accessory sex glands (ventral, dorsal, lateral prostate, coagulating gland, bulbourethral gland) and the mammary gland of both Copenhagen and Wistar rats. Mono- and polyclonal antibodies directed against intermediate filament proteins (cytokeratin, desmin, vimentin) and the contractile proteins (alpha-actin, muscle type specific myosin, tropomyosin) were used along with phalloidin decoration of F-actin. As in the human prostate, none of the rat prostate lobes in either strains did contain basal cells expressing cytokeratin along with alpha-actin, myosin and tropomyosin Cells representing fully differentiated myoepithelial cells, however, were present as anticipated in the mammary gland, the bulbourethral gland and the H-tumor line of the Dunning tumor. This finding is difficult to reconcile with the contention of a prostatic origin of the H-Dunning tumor. Further studies are required to classify the epithelial parental tissue in order to define the true origin of the H-Dunning tumor and the tumor lines derived thereof.

Actin Cytoskeleton↗

PubMed1991

Immunohistochemical distribution of sulfhydryl oxidase in the human testis.

Sulfhydryl oxidase (SOx) is an enzyme that catalyzes the oxidation of sulfhydryl compounds. It is present in mitochondria of certain testicular cells at specific stages of functional activation. In the mature human testis moderate SOx immunoreactivity is found in Leydig cells, and lacking in Sertoli and in peritubular cells. The Adark spermatogonia usually contain immunoreactive mitochondria, while in Apale spermatogonia immunoreactivity is mostly low. In stage V of spermatogenesis, Apale spermatogonia were found containing immunoreactive material. Leptotene (stages IV and V) and zygotene (stage VI) primary spermatocytes display a moderate immunoreaction. It is strongest in pachytene spermatocytes of stages I-IV, decreases in stage V, and is low during diakinesis and in secondary spermatocytes. Late spermatids usually show a stronger immunoreactivity than early spermatids. At stage V of spermatogenesis the late spermatids contain only few immunoreactive particles. Spermatozoa are free of SOx-immunoreactive mitochondria. In residual bodies small amounts of SOx-immunoreactive particles are seen. Compared to rat and hamster testis, SOx immunoreactivity of the human testis is less clearly stage-dependent and it is not confined to certain germ cell stages. As deduced from the findings in patients with spermatogenic disorders, the SOx immunoreactivity of spermatogonia in human testis seems to be of diagnostic relevance.

Adult↗