Three‐Dimensional Study of the Terminal Portion in Sprague‐Dawley Rat Ejaculatory Ducts

In mammals, a pair of ejaculatory ducts exists in the urethra at the seminal colliculus. The detailed anatomical structures of the distal end of the ejaculatory ducts of Sprague‐Dawley rats were investigated by the computer‐assisted three‐dimensional reconstruction analysis using light‐microscopic serial sections. A three‐dimensional reconstruction revealed that in adult rats, the ejaculatory sinus pair consists of two parts: the cranial section – a compartment region composed of a fusion of the ampullary gland duct and the seminal vesicle duct, and the caudal section – a grooved region composed of a long slitlike ejaculatory ostium that extends into the urethra on both sides of the seminal colliculus. But the sphincter structure was not observed. The long axis of the compartment region was approximately 58 μm in length, and that of the groove region was approximately 495 μm. Although many epithelial glands ducts were distributed throughout the ejaculatory sinuses, the prostate and coagulation gland ducts did not open in these sinuses. The urethra was composed of transitional epithelium, while the ejaculatory sinuses were composed of single to stratified cuboidal epithelium. The ejaculatory ducts continued to the ejaculatory ostium in male adult Sprague‐Dawley rat were composed of the seminal vesicle ducts received the ampullary gland ducts.     

Postnatal development of the mouse volatile papilla taste bud cells

In the present study, we examined specific markers for taste bud cells in the mouse and the postnatal development of volatile papilla taste bud cells in ddY mice. We examined the immunoreactivity of 4 types of carbonic anhydrase isoenzymes, CA I, CA II, CA III and CA VI, as specific markers for taste bud cells, and K8.13 cytokeratin antibody as a specific marker for the lingual epithelial cells. Of the carbonic anhydrase isoenzymes, only CA III immunoreactivity was clearly detected in the spindle shaped gustatory cells. CA VI immunoreactivity was detectable in suspentacular cells. CA I and CA II antibodies did not recognize any taste bud cell specifically. K8.13 cytokeratin immunoreactivity was detected in the lingual epithelial cells, but not in taste bud cells. At 7 days after birth, the suckling phase, very small taste buds developed from the anaplastic gustatory cells. At 14 days after birth, the taste buds showed larger size than those at 7 days after birth. At 21 days birth, after the weaning phase, taste bud structure approximated the mature structure. These results demonstrate the specificity of anti-CA III and anti-CA VI for gustatory cells and suspentacular cells, respectively. These markers should be useful for an analysis of taste bud development in mice.     

Immunohistolocalization of carbonic anhydrase isozyme (CA-VI) in bovine mammary glands

The localization of bovine carbonic anhydrase isozyme VI (CA-VI) was examined immunohistochemically in bovine mammary glands during early lactation period (after 2-3 days of postpartum) and dry period (at about 2 months preparturition in adults), and young calves (at 30 and 150 days after birth) using specific CA-VI antiserum. The immunoreaction for anti-CA-VI antiserum was very weak in the mammary glands in young (prepubescent) calves. In dry period, CA-VI was also weakly expressed in secretory epithelial (acinar) and ductal cells. In contrast, the reaction was intense in mammary gland cells in early lactation period. Dot blotting analysis indicated that anti-CA-VI reacted positively to beastings and mature saliva, but weakly or not at all to milk during the dry period or calf saliva, respectively. The intense expression of CA-VI in the mammary glands in early lactation period might compensate for low levels of secretion from functionally and structurally immature salivary glands in young calves.     

Cleavage line patterns in beagle dogs: as a guideline for use in dermatoplasty

We prepared a map of the cleavage lines for beagle dogs, as a guideline for use of cleavage lines in dermatoplasty. The cleavage lines at the head resembled the orientation of the underlying muscles. Although the cleavage lines in the trunk were perpendicular to the body axis, those in the thoraco-abdominal region were parallel to the body axis. The cleavage lines at the limbs were parallel to the long axis of the limb on the cranial surface, but were perpendicular to the long axis of the limb on the lateral and caudal surfaces. Also, we recorded in detail the cleavage lines in the distal regions of the limbs.     

Distribution of apoptotic cells and apoptosis-related molecules in the developing murine palatine rugae

Distribution of apoptotic cells and expression of the apoptosis-related factors p53, bcl-2 and bad during morphogenesis of the murine palatine rugae (PR) were examined histochemically using the terminal deoxynucleotidyl transferase-mediated UTP nick end-labeling (TUNEL) technique and specific antibodies against apoptosis and cell cycle-related molecules. Formation of the PR rudiment was controlled by cell proliferation and apoptosis in the palatal epithelium. TUNEL-positive cells were detected only at the epithelial placode area at 12.5-13.5 days post coitus (dpc), but only a few cells were positive at the protruding PR area at 14.5-16.5 dpc. Bcl-2 protein was expressed mainly in the areas outside of those containing TUNEL-positive cells at 15.5 -6.5 dpc. P53 protein was not detected throughout gestation. Bad was detected in the epithelial layer at 13.5 and 15.5 dpc and overlapping the apoptotic area at 13.5-15.5 dpc. Apoptosis of palatal epithelial cells might therefore involve spatiotemporally regulated expression of bad during murine PR development.     

Immunohistochemical localization of carbonic anhydrase isoenzymes in salivary gland and intestine in adult and suckling pigs

Localizations of carbonic anhydrase isoenzymes (CA I, CA II and CA III) were investigated immunohistochemically in the salivary glands and intestine of mature and suckling pigs. Carbonic anhydrase isoenzymes were not detected in the salivary glands of sucklings, but were present in the adult. Bicarbonate ion in saliva might be important for the digestion of solid foods in mature pigs, but unnecessary for the digestion of milk in sucklings. Expressions of CA I and CA II were detected strongly in the large intestine of the adult and sucklings, and faintly only at duodenum in the small intestine. CA I and CA II isoenzymes in the large intestine may be involved, at least in part, in ion absorption and water metabolism during digestion and absorption of milk in suckling pigs. In addition, CA I and CA II expression in the duodenal villus enterocyte may support the process of bicarbonate absorption in the duodenum.     

The time course of lymphatic routes emanating from the peritoneal cavity in rats

The lymph drainage routes from the abdominal cavity in rats were observed at 3 min, 1, 2 and 4 h after India ink was administered intraperitoneally. Four systems of lymph drainage routes from the peritoneal cavity were observed. Three minutes after injection, the drainage route travelled via the intrathoracic lymph vessels located along the internal thoracic artery and returned to the anterior mediastinal lymph nodes. One hour after injection, the drainage route travelled via the lymph vessel located along the left phrenic nerve in addition to the drainage route observed at 3 min. Two and four hours after injection, in addition to the above-mentioned routes, the drainage that had travelled via the thoracic duct continued along the right side of the aorta and was also observed in the lateral lymph vessel located on the vertebra. These findings suggest that lymph or cells absorbed into the peritoneal cavity at first travel towards the anterior mediastinal lymph nodes in the thorax via the ventral lymphatic channels, and then gradually course through the dorsal lymphatic channels. These routes may serve as a route for transporting cancer cells and other cells from the peritoneal cavity.     

Changes in the skeletal dimensions of the digits of the thoracic limb of Holstein cows after maturation

The 12 left digits of the thoracic limb of Holstein female cows were obtained from a slaughterhouse, and 13 linear measurements of skeletal specimens of the digits of the thoracic limb were used in this study. Bivariate plots, regressions and correlation analyses were performed to assess the relationships between osteometric data and age, and between osteometric data and body size. The geometric mean (GM) of the metacarpal size was used as a proxy of body weight. The results of the regression analysis demonstrated that the length and the width of the distal phalanx were significantly correlated with age, whereas those of other bones were not. In addition, the correlations of the distal phalanx tended to be higher with age than with the GM of the metacarpal size, and their skeletal measurements tended to be longer in older animals than in younger animals. These findings suggest that the distal phalanx is slightly elongated and enlarged in its solear aspect with increasing age in skeletally mature cows. Moreover, although the side difference in the distal phalanx between the lateral and medial digits did not increase significantly with age, the solear aspect of the distal phalanx tended to be rougher, and deformation of the flexor tubercle tended to be more pronounced in the medial digit compared with the lateral digit. Therefore, in the distal phalanx of the front feet, the skeletal deformation with age and asymmetrical bone development might be related to the pathogenesis of claw horn lesions, as in the hind feet.