Immunophenotyping and spatio-temporal distribution of aortic cell clusters in the bovine embryo.

In the present study the temporal and spatial appearance of aortic cell clusters in bovine embryos is described. Aorta-associated c-kit-positive cell clusters can be observed first in 23 days post inseminationem (dpi) bovine embryos and disappear after 34 dpi. For the first time, it was shown that the immunophenotype of these aortic cluster cells changes during embryonic development. Aortic cell clusters are c-kit+/CD45-/STA-, when they are first detected in the 23 dpi embryo, and acquire a c-kit+/CD45+/STA- phenotype in 27-29 embryos and a c-kit+/CD45+/STA+ immunophenotype in 32-34-day-old specimens. Cell clusters are most prominent in the vicinity of lateral and ventral aortic branches, but rare in omphalomesenteric arteries and absent in Aa. umbilicales. Free c-kit-positive cells in an intravasal position are common, suggesting separation from the clusters in order to colonize subsequent hematopoietic organs, i.e., the liver and the mesonephros. Transmission electron microscopic analysis reveals the existence of primitive desmosomes between the clusters cells and adjacent endothelial cells as well as a fine basal lamina as a demarcation between the cluster cells and underlying mesenchymal cells. Material resembling extracellular matrix is found in large vacuoles in cluster cells of 23 dpi embryos. Immunocytochemistry reveals an intense accumulation of heparan sulfate proteoglycan and collagen IV in the aortic wall at the sites where cell clusters are attached. These observations suggest that the hematopoietic cell clusters induce the formation of a specific microenvironment within the aortic wall.

Dichloro[1,2-bis(4-hydroxyphenyl)ethylenediamine]platinum(II) complexes: an approach to develop compounds with a specific effect on the hormone-dependent mammary carcinoma.

Stereoisomeric dichloro [1,2-bis(4-hydroxyphenyl)ethylenediamine]platinum(II) complexes (meso-3a, (+/-)-3b, (+)-3c, (-)-3d) and their N,N'-dibutyl derivatives (meso-4a, (+/-)-4b, (+)-4c, (-)-4d) were synthesized and tested on antitumor activity. The most active compound, 3d, shows a modest inhibition of the [3H]estradiol receptor interaction and causes a marked effect on the growth of the hormone-dependent human MCF 7 breast cancer cell line. It is also active on the hormone-independent human MDA-MB 231 breast cancer cell line, on the ADJ/PC6 plasmacytoma of the Balb/C mouse, and on the L 5222 leukemia of the BD IX rat. Apparently the inhibition of the MCF 7 cell line is not mediated by the estrogen receptor system. Histopathological studies on 3d revealed very low toxicity.

Ring-substituted [1,2-bis(4-hydroxyphenyl)ethylenediamine]dichloroplatinum (II) complexes: compounds with a selective effect on the hormone-dependent mammary carcinoma.

[1,2-Bis(4-hydroxyphenyl)ethylenediamine]dichloroplatinum (II) complexes with one substituent in the 2-position (CH3, CF3, F, Cl, Br, I: meso- and d,l-1-PtCl2, meso-(3-5)-PtCl2, meso-(7 and 8)-PtCl2) or two substituents in the 2,6-positions (CH3, Cl: meso-2-PtCl2, meso- and d,l-6-PtCl2) in both benzene rings were synthesized and tested for estrogenic and cytotoxic activities. Two complexes (meso-6-PtCl2 and meso-7-PtCl2) possess both effects. In comparative tests on estrogen receptor positive and negative mammary tumors in cell culture (MCF 7, ER+ and MDA-MB 231, ER-) and in animals (MXT, ER+ and MXT, ER-, mouse), meso-6-PtCl2 shows a selective effect on the estrogen receptor positive mammary carcinoma. A further increase of efficacy was achieved with the water-soluble (sulfato)platinum(II) derivative (meso-6-PtSO4). On the DMBA-induced hormone dependent mammary carcinoma of the SD rat, meso-6-PtSO4 is significantly more active than its ligand (meso-6) and cisplatin.

Growth of mesometrial arteries in guinea pigs during pregnancy.

Massive growth was observed in mesometrial arteries supplying the placenta of the guinea pig in the first 60 days of pregnancy. The wet weight of the vessel wall increased 50 times, with an almost constant protein concentration. The DNA content rose 30 times. The length of the arteries increased 3.5 times and there was a 13-fold increase in the cross-sectional area of the wall. The changes in cross-sectional area were most pronounced in the peripheral part of the vessel. The observed changes followed an exponential time course. Histological sections showed proliferation, particularly of connective tissue with collagen fibres, while the synthesis of elastic material was suppressed. After parturition, involution with reduction of internal diameter occurred with a half-time of around five days.

Pregnancy-induced structural changes and trophoblastic invasion in the segmental mesometrial arteries of the guinea pig (Cavia porcellus L.).

Light microscopic, electron microscopic and histochemical studies were carried out on the segmental mesometrial arteries of non-pregnant guinea pigs and on pregnant ones at each of the nine weeks of gestation. Pregnant animals show drastic changes in arterial structure and dimensions. Hypertrophy and structural dilatation of the arterial wall are obvious. In midpregnancy, the elastic membranes begin to disappear; only small fragments remain. From the fifth week on, mononuclear cells appear in the media; they form aggregates and occasionally giant cells with signs of phagocytosis in the seventh week of gestation. In the eighth week further degenerative changes can be observed, resulting in widespread destruction of the arterial wall. Deposition of necrotic cell debris is obvious in the ninth week. By this time there appear in the endothelial layer conspicuous single cells, cell aggregates and giant cells with heavily folded nuclei, prominent nucleoli, abundant vesicles, free ribosomes, intracellular lacunae and the histochemical properties of placental trophoblast. These cells in the endothelium are distinctly different from the medial giant cells of mononuclear origin. According to these observations, the segmental mesometrial arteries of pregnant guinea pigs show cytological and structural changes similar to those described for the mesometrial arteries in the hamster and the spiral arteries in man. The results show that, beside structural dilatation, degenerative changes and apparent trophoblastic giant cell invasion occur in the arteries studied. Trophoblastic invasion occurs later than structural dilatation and obviously does not trigger or control the structural dilatation of the segmental mesometrial arteries.

3,4-bis(3'-hydroxyphenyl)hexane--a new mammary tumor-inhibiting compound. Studies on the mechanism of action on the DMBA-induced, hormone-dependent mammary tumor of the rat.

Biochemical properties, such as the activities of eight carbohydrate-metabolism-linked enzymes and four acid hydrolases, and histological characteristics of growing and regressing DMBA-induced mammary tumors of the SD-rat after ovariectomy or treatment of the host with hexesterol, tamoxifen, and 3,4-bis(3'-hydroxyphenyl)hexane were determined. Significant differences were found between growing and regressing tumors regardless of the treatment animals had been subjected to. Only few differences in biochemical parameters could be found within the group of tumors regressing due to the applied therapy. The histological signs of regressing tumors were very diverse, but no phenomenon typical of a specific treatment could be found. It cannot be decided whether the partial antiestrogen, 3,4-bis(3'-hydroxyphenyl)hexane unfolds its antimammary tumor activity by means of its estrogenic or its antiestrogenic potency. The hypothesis that estrogens inhibit mammary tumor growth by directing neoplastic cell metabolism toward secretion is not supported by these findings.

Morphogenesis of the bovine rete testis: the intratesticular rete and its connection to the seminiferous tubules.

The development of the intragonadal rete testis and the establishment of the connection between seminiferous and straight testicular tubules was studied using ultrastructural and histochemical methods in 60 bovine embryos and fetuses ranging from day 39 through day 225 post conceptionem. The methodology included a modified acetylcholinesterase (AChE) reaction as a selective marker for pre-Sertoli cells and a modified microsomal aminopeptidase (MAP) reaction as a selective marker for the epithelia of rete testis and straight testicular tubules. Between 40 and 45 days, the rete testis is predominantly an extratesticular rete situated in the cranial peduncle of the gonadal fold and in broad contact with the pro/mesonephric giant corpuscle. During this period, the intragonadal rete enters the gonad proper from its craniodorsal pole and extends into the cranial fourth of the testis. Between 60 and 110 days the rete testis attains its definitive position, extending into the central longitudinal axis as far as to the caudal fourth of the testis. For the caudal expansion of the rete testis the preceding proliferation of the mediastinal stroma is an important prerequisite. In the 40 to 45-day-old embryo the area of the testicular cords may be divided into two zones. A narrow outer zone contains plate-like cords with a thick diameter, and a larger central zone is filled with a network of thinner cords. Only the thick outer cords transform into the permanent seminiferous tubules, whereas the thinner cords in the central zone are transitory structures that disappear between 45 and 110 days. One important function of these transitory cords is to establish a continuous system of basal laminae that allows a direct connection between the central ends of the growing seminiferous tubules and the peripheral extensions of the rete testis (future straight testicular tubules). The first true straight testicular tubules become visible between 85 and 110 days. Due to a strong proliferation of the tubulus rectus-cells the straight testicular tubules elongate continuously, and the border between the rete system and the seminiferous tubules is slowly shifted towards the testicular periphery. This shift is not restricted to the prenatal period, but proceeds until after birth. At the cytological level, the formation and elongation of the straight testicular tubules is effected by proliferating cells that advance along the continuous basal lamina into the area of the seminiferous tubules. The pre-Sertoli and germ cells in this zone of invasion are separated from each other and overgrown by the tubulus rectus-cells. Exposed to the special milieu of the straight testicular tubules, pre-Sertoli and germ cells apparently cannot survive and finally disappear.

Morphogenesis of the bovine rete testis: extratesticular rete, mesonephros and establishment of the definitive urogenital junction.

The development of the extratesticular rete, the regression of the mesonephros and the establishment of the urogenital junction between rete testis and efferent ductules were investigated in 67 bovine embryos and fetuses collected in the period from day 29 through day 250 post conception. The results were obtained by immunohistochemistry and by the study of semithin sections. At about day 30, the large mesonephros contains a peculiar Malpighian body in its cranial part, generally referred to as the mesonephric giant corpuscle, which is connected to the Wolffian duct by a series of well-developed and functioning mesonephric tubules. This set of primary mesonephric tubules, however, will not participate in the formation of the definitive urogenital junction, but will regress and soon disappear completely. The efferent ductules in the bovine are represented by another set of secondary mesonephric tubules that grow out from the dorsal aspect of the mesonephric giant corpuscle at about day 50. Transiently, the lumina of the sprouting efferent ductules are plugged by invading intraductular blood vessels, probably representing rudimentary glomeruli. The proximal portions of the newly-formed efferent ductules establish side-to-end contacts with extensions of the extratesticular rete that has bypassed the regressing giant corpuscle. At 85 days, the efferent ductules have reached the Wolffian duct and open into it. At 150 days, the channels of the extratesticular rete display a patent lumen and now form end-to-end anastomoses with the efferent ductules. The proliferating mesenchymal cells surrounding the epithelia of the efferent ductules have arranged in several concentric layers at about 85 days. These mesenchymal cells are the precursors of the periductular musculature and are reached by the first nerve fibers at about day 130.

Prespermatogenesis and spermatogoniogenesis in the bovine testis.

The bovine male germ cell population was studied over the entire period from testicular differentiation in the embryo through onset of spermatogenesis in the pubertal calf. Germ cells were identified by protein gene product 9.5 immunohistochemistry and characterized by their ultrastructure. The proliferation pattern of germ cells was studied with immunohistochemical anti-Ki 67 and anti-proliferating cell nuclear antigen reactions. Germ cells with a high proliferation rate are observed from day 50 p.c. to day 80 p.c. These cells are in transition from primordial germ cells to prespermatogonia. From day 80 p.c. until approximately the 15th postnatal week the germ cells present are identified as prespermatogonia. From day 80 p.c. to day 200 p.c. germ cell multiplication decreases continuously; then the prespermatogonia enter a phase of relative mitotical quiescence that lasts until the 4th postnatal week. Between the 4th and the 15th postnatal week, testicular tubular diameters grow from 40 to 80 microm and the prespermatogonia resume their proliferation. In seminiferous tubules with diameters between 80 and 120 microm, found in animals between 18 and 27 weeks of age, a central lumen is normally still absent. During this period germ cell proliferation reaches a second maximum. The cells involved represent the members of the spermatogonia stem and precursor cell line kinetically interpolated between the prespermatogonia and the first differentiating A-spermatogonia. This second phase of prepubertal germ cell multiplication coincides with the period when the pre-Sertoli cells transform into adult-type Sertoli cells and enter the G0-phase for the rest of life.

Identification and temporospatial distribution of bovine primordial germ cells prior to gonadal sexual differentiation.

The temporospatial distribution of bovine primordial germ cells was studied in 34 embryos (18 to 39 days). For a reliable identification of bovine primordial germ cells in varying localizations and at different developmental stages the alkaline phosphatase reaction combined with the use of selected lectins was applied. The first potential primordial germ cells were identified in an 18-day-old trilaminar embryo in the caudal wall of the proximal yolk sac at a distance of less than 100 microm from the germ disc. These cells are alkaline phosphatase-positive. but do not yet react with lectins. From 18 through 23 days, morphogenetic folding converts the flat trilaminar disc into a cylindrical embryonic body. During this folding process primordial germ cells located in the proximal yolk sac area are incorporated into the embryo when this portion of the yolk sac becomes the hind- and mid-gut. Consequently, in 23- to 25-day-old embryos putative primordial germ cells (alkaline phosphatase- and lectin-positive) are situated predominantly in the axial body region at the level of the mesonephros. When the gonadal ridge develops in this region (about day 27) it contains a certain number of primordial germ cells present from the very beginning. Thus, the assumptions of a long-range chemoattraction of primordial germ cells by the gonadal ridge, of active immigration from an extraembryonic site. or of a passive transportation via the blood stream are not necessary to explain the initial settlement of bovine primordial germ cells in the gonadal ridge. Within the gonadal ridge (days 27-31) and later in the still sexually indifferent gonadal fold (32-39 days) the primordial germ cells are unevenly distributed. Extragonadal potential primordial germ cells (alkaline phosphatase-positive, but with reduced or no lectin staining) are regularly present in large numbers in bovine embryos with indifferent gonads. Such cells occur predominantly in the paraaortal tissue and in the liver, but also in the branchial arches. The different locations of extragonadal primordial germ cells are discussed in the light of recent evidence that germ cells and haematopoietic cells share common ancestors.

The significance of rudimentary nephrostomial tubules for the origin of the vertebrate gonad.

Initial gonadal development was studied in 30- to 40-day-old bovine embryos. The results were interpreted in conjunction with findings on pro- and mesonephric organization in larval forms of Ichthyophis kohtaoensis (Gymnophiona, Amphibia). In bovine embryos vestigial nephrostomial tubules are the immediate precursors of the blastemas for adrenocortical, rete, gonadal and Mullerian infundibular development. From the study of Ichthyophis it can be concluded that the vestigial nephrostomial tubules seen in the bovine embryo are pronephric and not mesonephric in nature. As a consequence, the indifferent mammalian gonad is defined as a modified homologue of the pronephros situated in the zone of pro-/mesonephric overlapping. Such an overlapping of the two kidney generations in the fully developed state is clearly seen in Ichthyophis. Overlapping of the mesonephros with the modified pronephros (gonad) is necessary to allow intercalation of mesonephric tubules (efferent ductules in mammals) into the male seminal excurrent duct system.

Establishment of the urogenital junction in the male bovine embryo: an ultrastructural study.

The ultrastructure of the developing extratesticular rete testis, the efferent ductules and the establishment of the urogenital junction were studied in bovine embryos and fetuses of 41 through 95 days post conceptionem. The efferent ductules originate as a new set of secondary mesonephric tubules from the dorsal aspect of the nephric giant corpuscle and grow in the direction of the Wolffian duct. Cytological differentiation of the efferent ductules proceeds in a proximo--distal direction. At about 50-60 days, the simple columnar epithelium of the proximal portions of the efferent ductules already consists of the two typical cell types, i.e. reabsorptive principal cells with an endocytotic apparatus and a brush-border and ciliated cells. The lumen of the proximal portion is temporarily filled with intraductular blood vessels and perivascular tissue which may represent vestigial rudiments of glomeruli associated with the efferent ductules. At 50 to 60 days, the extratesticular rete still has a blastema--like appearance and consists of irregular cells with abundant glycogen. Extensions of the extratesticular rete come into contact with the efferent ductules and create the first end-to-side anastomoses with the latter. Somewhat later, the separating basal laminas vanish and invading rete cells intermingle with the epithelium of the efferent ductules, thus establishing the urogenital junction.

Immunohistochemical demonstration of cytoskeletal proteins in the ovine testis during postnatal development.

The distribution pattern of actin, desmin, vimentin and tubulin in the ovine testis during postnatal development was investigated by means of immunohistochemical methods. The postnatal development of the ovine testis can be divided into five phases. Phases I through III represent the prepubertal period, phase IV puberty and phase V the postpubertal adult stage. In peritubular cells alpha-smooth muscle actin is present, its amount increasing with advancing age of the animals. Structural F-actin is localized in peritubular myoid cells and Sertoli cells, of the adult testis. In Sertoli cells structural F-actin-positive material is observed at the level of the Sertoli-Sertoli junctions, at contact sites of Sertoli cells with primary spermatocytes and in the immediate vicinity of elongating spermatid heads during the acrosome phase of spermiogenesis. Desmin is present in intertubular and peritubular cells during the early prepubertal period, but vanishes completely as soon as the animals reach puberty. Vimentin is present in the cytoplasm of prespermatogonia I, but disappears when these change into prespermatogonia II. In prepubertal supporting cells the vimentin content increases, and in the adult the positive filament bundles create a flame-like pattern around the unstained nucleus. Cyclical variations during the seminiferous epithelial cycle are not observed. Expression of alpha-tubulin is found in the cytoplasm of prespermatogonia I and to a lesser extent in prespermatogonia II and spermatogonia. The immunoreaction is also seen in the microtubules of the axonema and manchette of elongating spermatids. The histochemical demonstration of the high alpha-tubulin concentration in supporting and Sertoli cells is an excellent method for studying changes of cellular shape and size during ontogenesis as well as during the seminiferous epithelial cycle.

On the origin and prenatal development of the bovine adrenal gland.

Decisive steps of bovine prenatal adrenal development were investigated in 46 embryos and fetuses using histological, electron microscopical, immuno-, enzyme and lectin histochemical methods. About day 30, the intermediate mesoderm between the cranial mesonephros and coelomic cavity is segmentally organized. It consists of proliferating tissue complexes that are connected to the coelomic cavity by vestigial nephrostomial tubules. This segmental organization soon disappears, however, due to longitudinal fusion of the tissue complexes into a continuous joined blastema. This blastema of intermediate mesodermal (nephric) origin becomes positive for alkaline phosphatase at about 30 days, and slightly later also for acetylcholinesterase. The most cranial portions of this common blastema represent the adrenocortical anlage, the following portions the gonadal rete blastema. A reevaluation of the comparative anatomical record revealed that a nephric origin of adrenocortical or interrenal cells is a general feature of all vertebrates and that the erroneous assumption of the lateral plate-derived coelothelium as precursor of the adrenocortical (interrenal) blastema should be definitively abandoned. The first adrenomedullary precursor cells become visible in the bovine adrenal primordium at day 35. At 50 days, both components (medullary and cortical precursors) are present as interpenetrating plates and strands between large sinusoid vessels and exhibit a strong MIB-1 activity, indicative of a high proliferation rate. About day 60 the cellular proliferation slows down in some of the adrenocortical precursor cells, and the separation into a visible cortex and medulla is initiated. From about day 80 on, the medullary tissue coalesces into a large, continuous area in the interior of the gland, surrounded by a narrow cortical glomerulo-fasciculata that becomes positive for 3beta-hydroxysteroid dehydrogenase at about day 90. Autonomous nerves penetrate the blastemal region as early as day 31. When the separation into cortex and medulla starts, the nerves are more concentrated in the latter. From 130 days on, nerve fascicles reach the interior of the organ not only from its medial side, but also from the capsule surrounding the gland. The penetrating bundles traverse the zona glomerulo-fasciculata without ramification and split off at the border to the medulla. Here, in the outer zone of the medulla, they constitute a particularly dense plexus, whereas in the central medulla a less dense innervation is observed. Up until 90 days, cells with the characteristic features of primordial germ cells are present within the confines of the adrenal gland.

[Histochemical, analytical and thin layer chromatographical studies on bovine seminal vesicle lipids (author's transl)]. / Histochemische, analytische und dünnschichtchromatographische Untersuchungen an den Lipiden im Samenblasenepithel des Rindes

The lipids in the epithelium of seminal vesicles of 11 adult bulls were studied by means of histochemical methods and thin layer chromatography. In the large basal lipid vacuoles dominate cholesterol, esters of cholesterol and tryglycerides. Phosphatides are also present in the large basal lipid vacuoles as well as in the smaller apical lipid droplets of the columnar cells. The existence of alkyl diglycerides, neutral plasmalogens and methyl esters of fatty acids, proved by 2-dimensional chromatography, can be taken as evidence that fatty acids, cholesterol, triglycerides and phosphatides are synthesized within the seminal vesicle epithelial cells. Free fatty acids as well as those incorporated in mono-, di-, triglycerides and polar lipids of the seminal vesicle epithelium are predominantly unsaturated, thus pointing to rapid mobilization and turnover of their esters. The cholesterol in the basal lipid vacuoles of bovine seminal vesicle is possibly eliminated from the epithelium via the subepithelial capillaries for there is no evidence of lipid secretion into the glandular lumen nor of a continued steroid synthesis from cholesterol within the seminal vesicle.

[On the histotopochemistry of the uterovaginal region in the quail (Coturnix coturnix japonica) (author's transl)]. / Zur Histotopochemie der Uterovaginalregion bei der Wachtel (Coturnix coturnix japonica

The surface epithelium of vagina, uterovaginal region and uterus as well as the uterine and uterovaginal glands of 18 mature female quails were studied with histochemical methods. As in other avian species also in the quail a storage of spermatozoa in the lightly coiled uterovaginal glands takes place. The functional specialization of these glands is underlined by their distinct enzyme pattern. A strong reactivity of enzymes from oxidative pathways and of adenosine triphosphatase between epithelium and glandular luminal content. Alkaline phosphatase in the glandular epithelium was observed only when an egg is transported through the uterovaginal region. As in other vertebrate sperm storing sites also in the uterovaginal region of the quail the presence of a strong steroid dehydrogenase activity is registered.

[Histochemical and histological studies on the vagina of pigs with in various phases of the estrus cycle (author's transl)]. / Histochemische und histologische Untersuchungen an der Vagina von Schweinen in verschiedenen Zyklusstadien

During estrus (1st day) the vaginal epithelium is highly proliferated; its thickness amounts up to 20 cell layers and even more. During metestrus (3rd day) the epithelium measures 12 to 15 layers due to degeneration and desquamation. During diestrus a further decrease in height is noticed. During late diestrus (16th day) the epithelium reaches its minimal height with 3 to 5 layers. The stratum superficiale consists during this phase of tall columnar cells. Starting from day 18 proliferation begins again. During all phases of the genital cycle the presence of infiltrated leucocytes is highest during middle and late diestrus. Leucocytes are easily recognized by their strong reaction for alkaline phosphatase whereas the epithelium proper remains negative. Mucification in the porcine vaginal epithelium is but moderate. Mucous substances occupy from from proestrus to early diestrus the intercellular gaps in the adluminal half of the epithelium. During middle and late diestrus mucous substances are localized in the supranuclear region of the superficial columnar cells. Histochemical tests for enzymes of oxidative pathways give relatively uniform and weak results during the entire cycle. Fluctuations of epithelial esterase activity may be correlated with phases of proliferation and differentiation.

[Histochemical and histological investigations on the vagina of the beagle she-dog during various functional conditions (author's transl)]. / Histochemische und histologische Untersuchungen an der Vagina der Beagle-Hündin während verschiedener Funktionszustände

Histotopochemistry and histology of vaginal epithelium in female beagles were studied during oestrus, metoestrus-dioestrus, post partum period and at days 20, 30, 40, 50, 60 of pregnancy. During oestrus the epithelium is uniform throughout the whole vagina: it presents itself as a high, uncornified, stratified squamous epithelium with some glycogen and lipid droplets but devoid of leucocytes. The intercellular gaps of the stratum intermedium give strong reactions for ATPase and alkaline phosphatase. The activities of oxidoreductases studied decrease continuously from basal to apical. During gravidity, post partum period and metoestrus-dioestrus distinct morphological and histochemical differences can be stated between the cranial and caudal vaginal portions. Caudal vaginal epithelium outside oestrus remains of stratified squamous type. It exhibits strong mucification during pregnancy. The PAS-positive mucous substances prefer a position in the enlarged intercellular gaps of stratum intermedium and superficiale. During pregnancy the epithelium is relatively rich in acid and completely devoid of alkaline phosphatases. Outside oestrus the epithelium of the cranial vaginal region is a relatively flat, stratified columnar one and contains leucocytes with regularity. Also the cranial vaginal portion undergoes mucification during pregnancy with a maximum about day 33. The mucous material is situated intracellularly and not within the intercellular gaps. Further, larger intraepithelial mucus cysts are observed. Alkaline phosphatase is found during gravidity in the basal region and an adluminal border of the epithelium. The reactions for oxidoreductases are strongest in the columnar cell layer which shows more functional adaptations than the remainder of the epithelium. Histochemical tests for beta-D-glucuronidase and leucine aminopeptidase give negative results in the whole vagina during all different functional stages studied.

[Histotopic of glycosidases in the oviduct of the quail (Coturnix coturnix japonica) (author's transl)]. / Histotopik von Glykosidasen im Eileiter der Wachtel (Coturnix coturnix japonica).

The activities of 6 glycosidases (n-acetyl-beta-glucosaminidase, beta-galactosidase, beta-glucuronidase, alpha-galactosidase, alpha-fucosidase and alpha-mannosidase) in the oviduct of the quail (Coturnix coturnix japonica) were studied with histochemical methods. Alpha-galactosidase and alpha-fucosidase showed a weak to moderate activity in the surface epithelium and in most of the glands of the oviduct. A Distinct reactivity of beta-glucuronidase was observed in the surface epithelium of the whole oviduct and in the glands of the uterovaginal-region. A moderate to distinct reactivity of n-acetyl-beta-glucosaminidase cound be demonstrated in the epithelium and in the glands of all regions of the oviduct. The comparatively highest activity of this enzyme was found in the glands of the magnum and in the surface epithelium of the uterus. The possible functions of the glycosidases in the oviduct are discussed briefly.

Postnatal development of ovine seminiferous tubules: an electron microscopical and morphometric study.

Corresponding to the increasing testicular volume and the histological appearance of the testicular parenchyma, the postnatal ontogenesis of the ovine testis can be divided into five phases. During the prebubertal period (phases 1-III), seminiferous tubules are solid and contain supporting (pre-Sertoli) cells as well as up to three types of germ cells: prespermatogonia I, II and spermatogonia precursor cells. In phase I, only prespermatogonia I are present and can usually be observed at the center of the seminiferous tubules. During phase II, prespermatogonia I migrate towards the basal lamina, divide and become prespermatogonia II. Those prespermatogonia I which are not successful in establishing contact with the tubular basal lamina degenerate. In phase III, prespermatogonia II divide and differentiate into cells which function as stem cells for spermatogenesis. Morphometric data corroborate the assumption of two types of prespermatogonia in the postnatal prepubertal ovine testis. Prespermatogonia I have nuclear volumes of about 480 microns 3 and cellular volumes of about 1200 microns3. In prespermatogonia II both volumes increase to about 920 microns3 and 1800 microns3 respectively. Adult A-spermatogonia are significantly smaller and possess an average nuclear volume of about 340 microns3 and an average cellular volume of about 800 microns3. Concomitanty with the formation of the tubular lumen in puberty (phase IV), supporting cells differentiate morphologically into typical Sertoli cells. Developmental events in the germ cell population are not yet synchronized. Adulthood (phase V) is characterized by complete spermatogenesis with all stages of the seminiferous epithelial cycle.