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.

Expression and distribution of myoepithelial cells in developing bovine parotid gland.

The expression and distribution of myoepithelial cells in relation to parotid acinar cells were studied immunohistochemically in bovine fetuses and neonates. Definitive myoepithelial cells first appeared as slender, brown short lines around the perimeters of developing secretion acini at four months of fetal age (in a 26 cm long fetus). At this time, parotid acinar cells possessed no distinct secretory granules in the supranuclear region. The differentiation of myoepithelial cells subsequently progressed during late gestation and birth. In neonates, the myoepithelial cells surrounded the secretory acini and parts of the intercalated ducts.

Distribution of chondroitin sulfate proteoglycans during bovine fetal ruminal papillae formation.

The present paper demonstrates the immunohistochemical distribution of proteoglycan (PG) molecules carrying chondroitin sulfate (CS) chains with 6-sulfated hexosamine residues, or CS and/or dermatan sulfate (DS) chains with 4-sulfated residues in the developing bovine ruminal papillae (RP) using monoclonal antibodies (mAbs) 3B3, 2B6, and MO225. These PGs carrying chondroitin 6-sulfate that were detected by mAb 3B3, and the glucuronic acid 2-sulfate-N-acetyl-galactosamine 6-sulfate unit that was detected by the mAb MO225 were distributed in the mesenchyme and epithelial basement membrane in the rumen, and were thus correlated to the outgrowth of the RP. The PG carrying DS was detected by the mAb 2B6 and was distributed in the lower region of the mesenchyme and intermuscular connective tissue during the development of the RP. These findings suggest that PGs carrying CS chains with 6-sulfation are involved in the outgrowth of the RP, and that PGs carrying DS are involved in organization in the mesenchyme.

Determination of carbonic anhydrase-III by enzyme-immunoassay in liver, muscle and serum of male rats with streptozotocin-induced diabetes mellitus.

Insulin has a plethora of metabolic effects but its action on carbonic anhydrase-III (CA-III), a key enzyme in acid-base regulation, has been little studied. The present studies examined the effects of streptozotocin induced diabetes on the concentrations of CA-III. The concentration of CA-III in the liver, muscles and serum of rats with experimental diabetes mellitus was measured by the method of enzyme-immunoassay. Streptozotocin-induced diabetes mellitus resulted in a reduction in concentration of CA-III in the liver and serum, but not in skeletal muscles, of adult male rats. A 98% reduction in hepatic CA-III content relative to control values was observed. The reduction in CA-III content in the liver was restored to control value by administration of insulin. The CA-III content in serum of diabetic rats declined to approx. 25% of control values, but the reduction was unaffected by administration of insulin. The concentration of CA-III in the liver and serum of diabetic rats was not influenced by administration of methyltestosterone. Although the content of CA-III in m. rectus femoris, m. tibialis craniaris and m. soleus differed, no significant difference of CA-III content was found between diabetes mellitus and control rats. The effect of chronic diabetes mellitus on CA-III content was obviously different between liver and muscle, suggesting that the regulation of CA-III biosynthesis differs between these two tissues. These results suggest that biosynthesis of CA-III in hepatocytes of rats is influenced by irregular patterns of GH secretion brought about by diabetes mellitus.

Determination of carbonic anhydrase III isoenzyme concentration in sera of racehorses with exertional rhabdomyolysis.

The concentration of carbonic anhydrase III isoenzyme (CA-III) in serum samples from 216 clinically normal Thoroughbreds was determined by use of an enzyme immunoassay. The concentration range of CA-III was from 16.0 to 254.5 ng/ml (mean, 56.5 +/- 11.9 ng/ml). Significant differences were not detected according to age or sex. To confirm whether serum CA-III concentration was high in horses with muscle disease, serum samples of 11 horses with exertional rhabdomyolysis were analyzed by enzyme immunoassay. Their serum CA-III concentration was about 56 times (3,136 +/- 2,610 ng/ml) that of healthy Thoroughbreds. Concentration of CA-III was higher in horses with rhabdomyolysis that had been transiently recumbent than in horses with mild disease that were reluctant to move. Blood samples obtained serially from 6 horses with exertional rhabdomyolysis were studied. Serum activities of aldolase, creatine kinase, aspartate transaminase, and lactate dehydrogenase were high. Increases and decreases in concentration of CA-III were more rapid than that for aldolase, creatine kinase, aspartate transaminase, and lactate dehydrogenase activities; thus, CA-III may be clinically applicable as a diagnostic marker for muscle disease in horses.

Developmental changes in the ferret ileum during the postnatal period.

The development of the ferret ileum was studied in order to determine the pattern of morphological maturation during the postnatal period. In the newborn, intestinal villi were short, and lined by simple columnar enterocytes with striated borders and small vacuoles. At one week old, the equivalent cell had large vacuoles that were shown on TEM to be related to a tubulovesicular system in the apical region of the cytoplasm. At two and three weeks old, the epithelial cells at the same site showed a more extensive tubulovesicular system, and vacuoles occupied major areas of both the supra- and subnuclear cytoplasm. At six weeks old (weaning), although the enterocytes contained a few small intracellular vesicles, they appeared histologically more mature than in previous stages. At nine weeks and in the adult, the villi were longer and the enterocytes no longer contained vacuoles. In TEM, the epithelial cells had long microvilli, and the apical tubulovesicular system and vacuoles had completely disappeared from the cytoplasm.

Subepithelial elastic system fibers of oblique mucosal folds in the rat proximal colon.

The proximal colon of the rat is characterized by a 'herring bone' pattern of oblique mucosal folds (OMF) which are arranged in a parallel array. By light and electron microscopy the OMF exhibited rich subepithelial elastic system fibers which bound the epithelial basement membrane and the smooth muscle cells of the lamina propria together. The elastic system fibers usually consist of elastic, elaunin and oxytalan fibers. However, the subepithelial elastic system fibers of the OMF were composed of relatively thin elastic fibers with a few microfibrils, and elaunin and oxytalan fibers which were almost indiscernible. Areas other than the OMF were quite poor in subepithelial elastic system fibers. The interpositions between each of the OMF were composed of typical components: elastic, elaunin and oxytalan fibers. The composition of the subepithelial elastic system fibers of the OMF does not correspond to that of any other organs previously reported. The present study suggests that the OMF of the rat proximal colon might be equipped in such a way to resist to distension or compression.

The ultrastructure of bovine ileal follicle-associated epithelial (FAE) cells during the perinatal period.

The ileal follicle-associated epithelial (FAE) cells in bovine fetuses and neonates were examined by light and electron microscopy. In 7-9 months old fetuses (68, 82 and 86 cm CRL) the dome epithelium was usually a little thinner than elsewhere and contained more intra-epithelial leucocytes. FAE cells were already distinguishable by their being more cuboidal and eosinophilic than the other epithelial cells. The cytoplasm of the FAE cells bulged noticeably into the lumen and contained numerous mitochondria and vacuoles. At 18 hours and 21 hours after birth, the dome epithelium was more columnar and eosinophilic than previously and contained more intra-epithelial leucocytes. The FAE cells showed characteristic bulging of large cytoplasmic processes into the lumen, as seen in the previous stage. In the cytoplasm, moderate numbers of mitochondria, numerous vesicles and microtubules could be seen. Frequently degenerated FAE cells could also be found among normal FAE cells in the epithelium. After this stage the cytoplasmic processes almost disappeared but distribution of the other organelles was similar to that seen at the previous stage except that multivesicular bodies were frequently seen in the apical cytoplasm. These histological results suggest that bovine ileal FAE cells are histologically and functionally mature by birth and that at birth they seem to be able to react against the penetration of pathogenic substances from the extrauterine environment.

Histological development of bovine abomasum.

The histological development of the bovine abomasum during fetal and neonatal periods was studied. The abomasum in a fetus of 2.3 cm in length (estimated to be 1 month old) was a separated compartment situated to be caudo-ventral to the primordium on the median plane. On the later stages, the primitive stomach became distinctly separated into rumen, reticulum, omasum and abomasum. The epithelium of abomasum was pseudostratified histologically, consisting of cells low differentiation. The stomach in a fetus of 13-14 cm in length (estimated to be 3 months old) displayed the morphological feature with nearly same proportion as an adult stomach. In this stage, abomasal epithelium had a shape of simple column and also formed gastric pits. Pyloric gland cells could be recognized earliest of all the gastric exocrine cells in fetuses of 16-18 cm in length (estimated to be 3-4 months old). Mucous neck cells could be found in fetuses 43-45 cm in length (estimated to be 5-6 months old). Pyloric gland cell and mucous neck cell contained neutral and sialo- or sulfo mucosubstances in neonates. Chief cells, could be noticed in fetuses 58-65 cm in length (estimated to be 6-7 months old), and were devoid of demonstrable mucosubstance as well as parietal cells. Main abomasal gland cells began to develop to increase rapidly in number in the latter half period of gestation. All the types of gastric cells became to be present and mature in form at birth.