Molecular cloning and expression of 17ß-hydroxysteroid dehydrogenase type 2 gene in Hu sheep.

17ß-Hydroxysteroid dehydrogenase type 2 (17ß-HSD2) catalyzes the NADP+-dependent oxidation of the most potent estrogen 17ß-estradiol into the weak estrogen estrone, and the conversion of testosterone to androstenedione. It has been reported that 17ß-HSD2 was expressed in many tissues in human, rats, however, the full-length sequence of 17ß-HSD2 gene and its expression in ewe were still unknown. In this study, we cloned the full-length cDNA sequence and investigated mRNA differential expression in 28 tissues of 12 adult Hu-Sheep which were fed with high- and low- dietary intake. The 1,317 bp full-length cDNA sequence was first cloned. The coding region was 1,167 bp in length, and the monomer was estimated to contain 389 amino acid residues. It shares high AA sequence identity with that of bos Taurus (96.13 %), sus scrofa (77.06 %), canis lupus familiaris (70.44 %), Callithrix jacchus (65.72 %), Nomascus leucogenys (65.46 %), pan troglodytes (65.21 %), human (64.69 %), mus musculus (58.35 %), and a comparatively lower identity to danio rerio (37.85 %). 17ß-HSD2 gene was high expressed in gastrointestinal (GI) tract, liver, but weakly expressed in other tissues. No detected expression was examined in lung. 17ß-HSD2 gene expression was significantly difference in rumen, omasum, duodenum, cecum, hypophysis after high- and low- dietary intake. Results from the present study suggested that 17ß-HSD2 plays a crucial role in almost all tissues protecting against excessive levels of active steroid hormone, and GI tract maybe an important steroid hormone metabolizing organ in Hu-Sheep. This present study is the first to provide the primary foundation for further insight into this ovine gene.

Distribution of rhodanese in tissues of goat (Capra hircus).

Rhodanese (thiosulfate: cyanide sulfurtransferase, EC. 2.8.1.1) is a ubiquitous enzyme present in all living organisms, from bacteria to humans and plays a central role in cyanide detoxification. The purpose of this investigation is to determine and compare rhodanese activity in different tissues of adult male and female goats (Capra hircus). The results showed that the specific activity of rhodanese in different tissues was significantly different (P<0.05). The highest activity of rhodanese was in epithelium of rumen, followed by epithelia of reticulum and omasum and liver. No significant difference was observed when tissues of male and female goats were compared. The lowest specific activity of rhodanese was observed in spleen, urinary bladder, lymph node, ovary, skeletal muscle and pyloric muscle of abomasum. The results of this study may indicate the involvement of rhodanese in cyanide detoxification in goat tissues that have greater potential to be exposed to higher levels of cyanide.

Histochemistry of the forestomach epithelium of the reindeer calf.

Samples from the rumen, reticulum and omasum of 26 reindeer calves were taken during the winter season. Non-specific alkaline and acid phosphatases, cytochrome and amine oxidases as well as succinate, lactate and 3-hydroxybutyrate dehydrogenases were demonstrated in the epithelium histochemically. The phosphatases were usually present in all the epithelial layers, whereas the activities of the other enzymes decreased in the outer layers and could not be demonstrated in the stratum corneum. The activity of alkaline phosphatase seemed to be highest in the reticulum and lowest in the omasum. The reason for the higher activity of this enzyme in epithelial taps in the rumen and omasum and in the reticular and omasal papillae may be the greater need for effective vertical transcellular transport in these regions. There was a tendency for enzymes other than phosphatases to be more active in the rumen than in the other forestomachs, which probably reflects the higher metabolic activity of the ruminal epithelium. No clear differences between early and late winter could be demonstrated.

Immunohistochemical localization of carbonic anhydrase isozymes I, II and III in the bovine salivary glands and stomach.

The immunolocalization of carbonic anhydrase (CA) isozymes in bovine salivary glands and stomach were first investigated in order to discuss their biologic functions. In parotid glands, CA-II was located in serous acinar cells, whereas CA-III, in the duct segments. In contrast, a strong reaction was shown for both CA-II and CA-III in the duct segments of the submandibular gland, especially CA-III was selectively located in basal cells of the interlobular ductal epithelium; however, these glands essentially lacked CA-I. On the other hand, epithelial cells of the rumen, reticulum and omasum showed cytoplasmic reaction for CA-I, II and III in all layers of the epithelium, except the stratum coroneum. The parietal cells in the abomasal epithelium were more intensely stained for CA-II, but not for CA-I and CA-III. Immunolocalization of CA isozymes in serous cells in the parotid gland indicates their primary function in secreting macromolecules, whereas localization of CA in striated and excretory ducts in the parotid and submandibular gland suggests their traditional function in fluid and electrolytic transport. The biologic function of CA isozymes in the ruminal, reticular and omasal mucosa are postulated to influence the absorption and excretion of volatile fatty acid and NH4; the abomasal parietal cell is considered to be involved in ion transport.

Distribution of glutamate dehydrogenase and glutamine synthetase activity in the sheep and chicken digestive tract.

Glutamate dehydrogenase (GLDH, EC 1.4.1.3) and glutamine synthetase (GS, EC 6.3.1.2) activity were determined in the contents and tissues of the various parts of the sheep and chicken digestive tract, GLDH activity in the tissues of the sheep omasum, duodenum, rumen, reticulum, colon, caecum, jejunum and ileum ranged from 3.25+/-0.7 U (mumol/g dry weight . min) to 5.94+/-2.28 U; in the abomasum it was 9.67+/-1.27 U. GLDH activity in the contents of the ileum, abomasum, jejunum and duodenum varied from 0.85+/-0.19 U to 3.29+/-0.53 U and in the colon, caecum, reticulum, omasum and rumen from 6.34+/-2.64 U to 16.96+/-3.83 U. GS activity in the tissues of these parts of the digestive tract varied from 2.8+/-0.59 U to 8.6+/-1.4 U and their contents from 2.49+/-0.85 U to 10.76+/-2 U. GS activity in the contents of the colon was very low (0.26+/-0.07 U). In the tissues of the chicken duodenum, caecum, jejunum and ileum we found GLDH activity of 4.68+/-1.64 U to 7.96+/-1.73 U; in their contents it was 3.31+/-1.06 U to 3.8+/-0.73, but in the caecum it attained up to 66.7+/-24.3 U. GS activity was high from 57.6+/-2.0 U to 231+/-84 U in the tissues and 357+/-53 U to 383+/-76 U in the contents (in the caecum up to 2,500+/-233 U). The results show that conditions for the utilization of ammonia are present in the tissues and the contents in the whole of the sheep and chicken digestive apparatus. The hypothesis is confirmed that the different ability of ruminants and fowls to utilize ammonia formed from urea added to their feed, including ammonia formed by hydrolysis of blood urea, is due to the different GLDH and GS activity in their digestive tract as well as in their liver.