Morphometric study of Rynchotus rufescens testis throughout the year.

The research aimed to study the morphologic variation of the testis, seeking to promote the selection and genetic control of those that present appreciable spermatic production throughout the year. Testis morphology of the Rynchotus rufescens partridge was investigated, analyzing the testis weight, the seminiferous tubules diameter, the thickness of the seminiferous epithelium, the amount of meiotic figures and the thickness of the tunica albuginea. Sixty male partridges were used, divided in 12 groups, and one group per month had the testis collected for the histological routine and the sections were stained using the Hematoxilin-Eosin technique. For the histological sections analysis, morphometric measures were taken, with the aid of an Image Analyzer and the resulting data were submitted to analysis of variance and to Tukey's test. Based on the histological modifications of the seminiferous epithelium and the morphometric analysis, the partridge testis morphology could be divided in four successive phases throughout the year. The reproductive phase occurred in the spring, characterized by the complete spermatogenesis process. The regression phase occurred in the summer, with the involution of the seminiferous epithelium. The rest phase took place in the fall, with spermatogonias presence and some spermatocytes beginning the meiosis. The phase of recrudescence occurred in the winter, with the recovery of the seminiferous epithelium and absence of spermatozoa. In conclusion, the characteristics analyzed revealed a variation over the year, with greater production of spermatozoa in the spring and less in the winter.

Ultrastructural features of the lining epithelium of the vas deferens of Agouti paca.

The epididymal epithelium of Agouti paca, a wild South American rodent, was basically formed by principal and basal cells. Principal cells were closely related to processes of adsorptive endocytosis, phase-fluid endocytosis and also secretion originating from their cytoplasmic ultrastructural features. Principal cells were also characterized by the presence of vesicles of several shapes, sizes and internalized content occurring in smaller pits, pale small vesicles next to the apical brush border of microvillus, as well as coated vesicles, smooth surface vesicles and great vesicles. Multivesicular bodies, endosomes and lysosomes were mainly observed in supranuclear position. Moreover, presence of an apocrine secretory process was demonstrated by the occurrence of apical cytoplasmic expansions projecting into the vas deferens luminal compartment. Basal flattened cells without luminal surface contact occurred next to the basement membrane of the ductus, and did no exhibit special ultrastructural features.

Morphologic study of the efferent ductules of the pigeon (Columba livia).

The efferent ductules of the pigeon are localized in the epididymal region and are topographically divided into proximal and distal, both portions being lined with stereociliated pseudostratified epithelium. Transmission electron microscopy shows five distinct cell types: light, dark, and angular non-ciliated cells with possible apocrine secretory role cells and halo cells, possibly intraepithelial leucocytes. The proximal efferent ductules have the widest diameter among all ductules in the epididymal region.

Architecture of the caudal vena cava wall of the dog at the level of the liver caudate lobe.

The vascular segment of the caudal vena cava of the dog at the level of the caudate lobe was shown to be intimately related to hepatic tissue through the hepatic capsule and parenchyma. The tunica adventitia of the caudal vena cava was formed mainly by smooth muscle cells with collagen and elastic fibers arranged in bundles. The thin tunica media of the vein was also formed by smooth muscle cells, collagen and elastic fibers arranged in bundles. The tunica intima presented an elastic subendothelial network. The hepatic segment of the caudal vena cava showed a myoconnective architecture and propulsive characteristics in terms of its hemodynamic pattern.

Morphology of the vas deferens of the budgerigar (Melopsittacus undulatus).

A morphological study of the budgerigar vas deferens was conducted to demonstrate the electron-microscopic features of its epithelial lining. The analysis showed that the vas deferens of the budgerigar was found to be of a tubular and serpentine structure, continuous with the epididymal region and lined with stereo ciliated pseudostratified epithelium, which contained folds projecting into the tubular lumen and a characteristic brush border. The epithelium consists of ciliated and non-ciliated cells with different electron densities. Ciliated cells were characterized by two morphologically distinct configurations: some cells were columnar and other ciliated cells were longer, thinner and dark. Non-ciliated cells showed apical cytoplasmic expansions, which projected into the tubular lumen as protrusions.

Testicular ultrastructure and morphology of the seminal pathway in Prochilodus scrofa.

The seminiferous tubules of Prochilodus scrofa present a coiled morphological arrangement with intertubular anastomoses and unrestricted spermatogonial distribution. The structural pattern of the seminiferous tubules is cystic, with cysts formed by cytoplasmic prolongations of Sertoli cells. Inside the cysts are observed different types of germ cells. The seminiferous tubules open individually on the ventral surface of the main testicular duct present in each testis. Each main testicular duct prolongs as a spermatic duct, fusing with the spermatic duct of the opposite side to form the common spermatic duct which opens into the urogenital papilla. The mature sperm cysts break and extravasate their content into the lumen of the seminiferous tubules from which the seminal fluid and the spermatozoa penetrate the main testicular duct, the spermatic duct and the common spermatic duct for semen ejaculation.

The ultrastructure of the guinea pig rete testis.

The chambers of the rete testis (RT) of guinea pig are lined by a simple epithelium, whose cells are squamous, cubical and columnar in shape. The epithelial cells with distinct shapes were counted and the quantitative analysis of the number of these cells showed relative predominance of cubical cells. The ultrastructural observations showed predominance of membrane interdigitations among the epithelial cells. These cells present common cytoplasmic organelles. The Golgi complex polarity is typical with observation of electronlucent vesicles on the Golgi cis face closely related to rough endoplasmic reticulum (ER) lamellae, mitochondria and large number of polysomes on the Golgi trans face. These related structures present in Golgi area of RT cells suggest secretory activity which maybe occurs in the RT epithelium. Endocytotic process also occurs in the RT and this function probably concerns the uptake of substances and resorption of seminiferous fluid. Apical cilia present in RT epithelium cells are related with fluid transport and perhaps with chemoreception. Presence of spermatozoa portions enclosed into the cytoplasm of some epithelium cells has been referred to as spermatophagy. The RT complex is mainly supported by loose connective tissue, with collagen fibres and some Leydig cells. Leydig cells are adjacent to the network channels of the septal part of the RT and apparently are able to secrete inside the RT lumen.

Ultrastructure of the spermatozoa of the domestic duck (Anas platyrhynchos sp.).

The ultrastructure of the spermatozoa of the domestic duck (Anas platyrhynchos sp.) was analysed by transmission and scanning electron microscopies and compared with the results obtained in preliminary studies involving other non-passerine birds. The spermatozoa were characterised by the presence of a short head, short midpiece and long principal piece. The head consisted of a reduced acrosome that contained moderately electron-dense homogenous material. The implantation fossa was observed between the base of the nucleus and the proximal centriole. The midpiece contained electron-dense material associated with the proximal centriole and nuclear membrane, and a long distal centriole surrounded throughout its length by 11-12 elliptical mitochondria. A dense annulus separating the midpiece from the principal piece was visible. Posterior to the annulus, the axoneme was formed surrounded by a dense fibrous sheath, representing the principal piece or flagellum, which was a long segment with a smooth surface and a smaller diameter than the midpiece. The spermatozoon of the domestic duck resembles that of other non-passerine birds, corresponding to a basic type of spermatozoon similar to that of reptiles, called sauropsid type.

Structure of the lining epithelium of the cauda epididymis of the golden hamster.

The ductus epididymis has roles in the maturation and storage of spermatozoa. The main function of the cauda epididymis is the storage of spermatozoa; however, this region exerts other morphophysiological roles. So, this study was aimed at investigating structural features of the cauda epididymis epithelium, which could indicate roles other than the storage. The relative percentages of the cell types in the epithelium were 74.9, 6.9, 12.5 and 5.6% of principal, clear, basal and halo cells respectively. Large intercellular spaces were seen among the lateral plasmatic membranes of adjacent principal cells or among these cells and others cell types. These spaces were found to be filled with multivesicular bodies, myelin figures, scrolls and debris of membranes or flocculent dense material. Clear cells had the cytoplasms filled with lysosomes ((3/4) of basal cytoplasm), and vacuoles and vesicles ((1/4) of apical cytoplasm). The observations allowed us to infer that clear cells could act in the process of endocytosis and also in water transfer from the lumen to the interstitium through the epithelium compartment. Moreover, transcytosis may occur at the cauda epididymis of Golden hamster.

A histological study of the seminal vesicle of the armoured catfish Corydoras aeneus.

Most species of Corydoras exhibited a reproductive behaviour called 'T-position', and exhibited an accessory gland in the male genital tract, called the seminal vesicle. It appeared that both the structure and the composition of the fluid varied considerably between the species investigated. Consequently, different opinions were proposed regarding the possible role of seminal vesicle on this particular reproductive behaviour. Male adults of Corydoras aeneus were collected, anaesthetized, and samples of seminal vesicle were fixed in Bouin's solution. The sections were stained with haematoxylin-eosin and periodic acid Schiff. The seminal vesicle showed a system of anastomosed secretory tubules, forming a vesicular collective network, which gave rise to the vesicular ducts. The latter fused with the testicular efferent ducts and formed the spermatic ducts. Considering this fusion, when the sperm cells reached the spermatic ducts, the fluid produced at the seminal vesicle covered them. Histochemical studies evidenced the presence of neutral and acid glycosaminoglycans in the seminal fluid. Considering the reproductive behaviour of C. aeneus, it is believed that the protection associated with the immobilization of the sperm cells assures the sperm integrity during the passage through female's intestine until fertilization.

Ultrastructural characteristics of spermiogenesis in the domestic duck (Anas platyrhynchos).

In this present study was observed that the spermatids underwent morphological differentiation and modifications, which primarily comprised nuclear elongation, during the process of spermiogenesis in the domestic duck. The acrosome was formed and the flagellum developed concomitantly with nuclear modifications. Thus, various modifications could be observed during this process, especially changes in the distribution of cytoplasmic organelles. Long cisternae of the rough endoplasmic reticulum present in the spermatid cytoplasm dissociated into vesicles and the distal centriole initiated the development of the flagellum in the cellular portion opposite to the acrosome. The ultrastructure of the spermatids of the domestic duck did not show the characteristic development of pre-acrosomal granules, but the acrosomal granule could be directly visualized in this species.

Regional histology of the epididymis of the dog. A light microscope study.

The aim of the present paper was the study of the epididymis of the dog, at the optimal microscope level. It was found that the epididymis of th dog has 3 distinct segments: initial, middle and terminal. Each segment could be readily distinguished on the basis its morphological appearance of the epithelial lining.

Definition of the stages of the cycle of the seminiferous epithelium of the opossum (Didelphis azarae, Temminck, 1825).

Spermatogenesis of the opossum (Didelphis azarae, Temminck, 1825) as revealed by the ferric hematoxylin technique is described. The spermiogenesis is subdivided in 15 steps characterized by changes observed in the nucleus and in the acrosomic structure of the spermatids. Using the morphological changes during the spermatids' maturation, a classification into 10 stages is proposed for the various cellular associations during the cycle of the seminiferous epithelium of the opossum.

[Cytochemical and ultrastructural characteristics of the lining epithelium of the distal part of the epididymis in hamsters (Mesocricetus auratus)]. / Características citoquímicas e ultraestruturais do epitélio de revestimento na parte distal do epidídimo do hamster (Mesocricetus auratus).

In the terminal segment of the hamster epididymidis there was some evidence of micro-merocrine protein secretion a the level of the principal cells and clear evidence of granular secretion in the light cells, presumable of glycoproteins. The PAS and protein cytochemistry reactivities observed in both these cells, of the ductus epithelial lining, but especially in the light cells, are suggestive of mucopolysaccharides and protein complexes synthesis and secretion. This secretion is carried out to the epididymal epithelium from the lumen and luminal content. A complex of small vacuoles and vesicles appeared to form from the Golgi complex is showed in the principal cells. It was suggested that this complex may represented merocrine secretory vacuoles and vesicles in these cells. Dense granules, at the TEM level, are observed in all the cytoplasm of the light cells, with correspondence to similar PAS-positive granules observed in these cells, at the light microscope level. These granules, at the TEM level, are actually secreted to the epididymal duct lumen, by the apical cytoplasms of the light cells. Signs of absorption were suggested to the principal and light columnar cells through the ultrastructural observations of micropinocytosis, apical multivesicular bodies or great membrane-bounded vacuoles in the adluminal cytoplasms.

[Helping factors of the occlusion and oppening mechanisms of gastric cardiac region in opossum. Comparative study to the man (author's transl)]. / Facteurs auxiliaries des mécanisms d'occlusion et d'ouverture du cardia chez la sarigue. Etude comparative avec ceux de l'homme.

The morphological factors that should work to help the cardial occlusion (esophageal and gastric mucosal folds) and are arranged to cooperate for the cardial oppening (smooth muscle fibres of the longitudinal layer of esophagus and stomach) are described in opossum (Didelphis albiventris), comparatively to the man. Also are comparatively discussed the anatomical disposition of diaphragm, esophageal hiatus of diaphragm, gastrophrenic ligament and phrenosophagical membrane.

The fine structure of the swine sweat gland. I. The acini.

The structure of the acini in the swine sweat gland is described here at the TEM level. The acini of the sweat gland in the pig is formed by 2 secretory cell types: dark seromucous cells and clear cells. The dark seromucous cells are actively secretory and their secretion is apocrine. The clear cells seem to be involved in an active transport of water and electrolytes through their cytoplasms.

Fine structure of the ductuli efferentes of the hamster (Mesocricetus auratus).

Structurally the ductuli efferentes of the hamster showed 2 distinct segments, a testicular and an epididymal. Both of these segments were lined by a pseudostratified epithelium, which showed basically non-ciliated and ciliated cells. In the testicular segment a 3rd type of oval dark cells was observed. The ultrastructural characteristics of these cells were presented and discussed in this report.

[Anatomical observations of the coronary artery vascularization in the guinea pigs (Cavia porcellus, L.)]. / Observations anatomiques sur la vascularisation artérielle coronarienne chez le Cobaye (Cavia porcellus, L.).

Through an examination of the subepicardial part of the heart in the guinea pig it was characterized a duality concerning to the origin and branching of the 2 coronary arteries which are represented by 4, and not by 2, aortic branches: the R. circumflexus sinister and the R. interventricularis paraconalis to the left coronary artery; the A. coronaria dextra and the R. coni arteriosi to the right coronary artery. The heart of the guinea pig was considered of the "left coronary pattern", but the whole characteristics of its arterial vascularization seem to be concerning to the "intermediate coronary pattern".

The fine structure of the swine sweat gland. II. The coiled ducts.

The duct of the swine sweat gland crosses the dermis and epidermis in sequence. The cells of the dermic segment seem to be related with cellular secretion and absorption. In the epidermic segment of the duct the whole morphology of the cells resembles the cellular morphology of the epidermic cells.

[Structure of the efferent ductules of the domestic pig (Sus scrofa domestica)]. / Structure des canaux efférents du porc doméstique (sus scrofa domestica).

The ductuli efferentes of the pig have 2 distinct and continuous segments: the proximal or intratesticular segment that is formed in sequence to the labyrinthic portion of the rete testis, on the cranial extremity of the testis, and the distal or epididymal segment that forms the Cani vasculosi or Lobuli epididymidis. The testicular ductuli are more thicker and the epididymal ductuli are more thin, long and flexuous. The last segment is very coiled and forms a bulboid structure that is placed in the head of the epididymis, in which the ductuli jumped into the initial segment of the epididymis. Each efferent duct is formed by a single and cuboidal/columnar epithelium in which are identified three cellular types: ciliated cells, non ciliated cells and intra-epithelial lymphocytes. The epithelial lining rests on a conspicuous basement membrane that is surrounded by collagen fibrils. Among the ductuli is identified a loose connective tissue.