Magnesium(Mg2+) is one of the most abundant intracellular divalent cation. Although recent studies demonstrate that adrenergic receptor stimulation evokes marked changes in Mg2+ homeostasis, the regulation of Mg2+ by dopaminergic receptor stimulation is not yet known. In this work, we uwed dopaminergic agents to identify which type(s) of receptors were involved inthe mobilization of Mg2+ by dopaminergic receptor stimulation in the perfused rat gearts, isolated myocytes and circulating blood. The mg2+ content was measured by atomic absorbance spedtrophotometry. Dopamine(DA), apomorphine(APO) and pergolide stimulated Mg2+ efflux in the perfused rat hearts and these effects were inhibited by haloperidol or fluphenazine, nonselective dopaminergic antagonists. SKF38393, a selective doparminergic agonist, increased Mg2+ efflux from the perfused hearts in dose dependant manners and SKF38393-induced Mg2+ efflux was potentiated in the presence of sulpiride or eticlopride, D2-selective antagonist, from the perfused hearts. This increase of Mg2+ efflux was blocked by haloperidol or imipramine. DA or pergolide increased in circulating Mg2+ from blood. By contrast, PPHT stimulated Mg2+ influx(a decrease in efflux) from the perfused hearts and circulating blood. PPHT-induced Mg2+ influx was blocked by fluphenazine in the perfused hearts. DA-stimulated Mg2+ efflux was inhibited by dopaminergic antagoinst in the isolated myocytes. In conclusion, the flux of Mg2+ is modulated by DA receptor activation in the rat hearts. The efflux of Mg2+ can be increased by D1-receptor stimulation and decreased by D2-receptor stimulation, respectively.

The development of uterus in fetuses on 60, 90 and 120 days of gastation and neonates of Korean native goats was investigated by scanning electron microscopy. The results were summarized as follows; 1. in the 60-day-old fetuses, the short microvilli were sporadically observed on the luminal surface of the endometrium. 2. In the 90-day-old fetuses, the mucosal folds, polygonal microridges, numerous microvilli, flower-like-buds, and domeshpaed or crateriform area were also observed on the luminal surface of endometrium. 3. In the 120-day-old fetuse, the primordial caruncles(nodules) of the endometrium were developed conspicuously and long microvilli were developed densely. 4. In the neonates, thecaruncles and microvilli of the endometrium were more developed than those of 120-day-old fetuses.

Field infectious bursal disease viruses 9IBDVs) were isolated from IBDV-suspected commercial chickens. The variable region in VP2 gene of six Korean IBDV isolates (K-IBDVs) and IBD vaccines was examined using the reverse transcriptase/polymerase chain reaction-restriction fragment length polymorphism (RT/PCR-RFLP) assay. With all K-IBDVs and vaccine IBDVs, a 474-bp fragment of the VP2 gene was amplified and tested with various restriction enzymes. Resseriction enzymes BstNI and StyI differentiated K-IBDV isolates and IBD vaccines into four groups. Reseriction enzyme profiles of K-IBDV isolates were different from them of IBD vaccines. K-IBDV isolates except for 310 isolate had specific SspI and TaqI recognition sites, which were recognized in highly virulent IBDVs, but IBD vaccines had no those sites. This study showed that RT/PCR-RFLP assay was thought to be valuable tool for differentiation of IBDVs and identification of highly virulent IBDV.

Fifteen dogs with superficial pyoderma were investigated clinically. Dermatological signs were mainly consisted of papule (66.6%), pustule (86.6%), epidermal collrarette and patchy (40%), and hyperpigmentation (53.3%). Distribution of skin lesion were consisted of back (35.5%), abdomen (29.0%), axillary (6.4%), leg (3.2%), neck (3.6%) and foot (16.1%), respectively. In pustular cytology PMN cells and cocci were examined. Cephalexin was very effective antibiotics on superficial pyoderma at administration of 30mg/kg bid P.O.for 3 weeks. Hyperadrenocorticism and atopy were diagnosed as a primary cause on pyoderma in 2 dogs.

Hemal nodes and hemolymph nodes are lymphoid organs that share morphologic and functional characteristics of lymph nodes and spleens. The aim of the present study was to obtain new informations on the distinct morphological structures of hemal nodes and hemolymph nodes according to ages, andto get the basic data for their functions in Korean native goats. Goats were divided into 5 groups, consisting of 3 animals aged 1, 3, 6, 10 and 12 months, respectively. Ultrastructural features of the organs were observed by transmission and scanning electron microscopes. The sinuses of hemal nodes and hemolymph nodes were lined by enodthelial-like reticular cells which had euchromatin-rich nuclei and many cytoplasmic processes, surrounding collagen fibrils. Macrophages containing phagocytosed erythrocytes were often noted in the diffuse lymphatic tissues of hemal nodes and hemolymph nodes. Some mast cells were in contact with the plasma cells near the blood vessel. Hemal nodes and hemolymph nodes had venous sinusal-like vessels which were different from the deep sinus. The lymph vessels with valves were observed in the capsule of the hemolymph node. There were no ultrastructural differences of the organs in the age different groups of the animals. These results suggest that hemal nodes and hemolymph nodes may take part in hemopoiesis, blood filtration and immune reaction in Korean native goats.

The morphological studies on the cecal development in the 60-, 90-, and 120-day-old fetuses and the newborns of Korean native goats were investigated by scanning and transmission electron microscopy. The results were summarized as follows; Scanning electron microscopic studies: 1. In the 60-day-old fetuses, fold-like shpaes protrusion oon the cecal mucosa surface appeared. In the 90-day-old fetuses, the cecal villi appeared to be columnar shpaes. In the 120-day-old fetuses, the cecal villi showed variou tongue-like or columnar shpaes. In the newborns, only the rudimental trace of the villi and the intestinal glands were observed. 2. In the 60-day-old fetuses, the cecal epithelia were simple columnar in some areas and stratified columnar in others, and the epithelial cells contained nuclei, nucleoli, ER, mitochondria, Golgi complexes, zonula occuludens, desmosomes, digitiform intercellular junctions, and large masses of the glycogen granules. 3. In the 90-day-old fetuses, the cecal epithelia were simple columnar in some area and stratified columnar in other. The microvilli of the cecal epithelia became much larger and longer than those in the 60-day-old fetuses, and intercellular junctions were developed, and increased numbers of ER, mitochondria, Golgi complexes were observed and the goblet cells contained a lot of the secretory granules. 4. In the 120-day-old fetuses, the cecal epithelia were only columnar in all areas. Microvilli and cytoplasmic organelles were well developed and the irregular annular nuclei were observed. 5. In the newborns, the cecal epithelia were covered with extensive microvilli, and the goblet cells with secretory granules were protruded into lumen. And some goblet cells secreted the secretory granules into the lumen.

The fatty acid composition of muscle were investigated to compare muscle composition among the 9 domestic animals including cattle. In major domestic animals, analyzed the effects of age, part and sex of the animal on their fatty acid composition. The content of 4 types of major fatty acids of muscle was determined and calculated their ratio. Myristic acid and palmitic acid levels were high in chicken and sheep. Besides dog muscle contained a lot of stearic acid. Linoleic acid content showed evident difference in the content depending on the animal species. The ratios of linoleic acid/palmitic acid (L/P ratio) and linoleic acid/stearic acid(L/S ratio) were characteristically high in horse and pig, whereas the ratio of palmitic acid/stearic acid(P/S ratio) was 0.7+_0.17, showing very low level in dog. As for the content of steric acid, in cattle and chicken it was higher in young animal than adults. In duck, the contents of all fatty acids and ratio were increased by the age. As for the content of fatty acids according to the part of chicken, high level was shown in thigh than in breast and wing, while there was no remarkable variation by the part in other animal. The differences in the content of myristic acid, palmitic acid and linoleic acid among some animal could be verified in muscle lipid composition. The L/P ratio which maintained certain level regardless of age, part, sex shown distinctive pattern between the species.

The visceral dissemination of Borrelia burgdorferi in New Zealand White rabbits was evaluated following intradermal inoculation of 1*10 8 spirochetes. We inoculated Borrelia burgdorferi B31, B garinii KW1 and B afzelii S13, respectively, and monitored the dissemination in the experimentally infected rabbits for 28 days. In the B burgdorferi B31-challenged group, the spirochetes were com;oetely cleared in rabbits at day 1 and visceral dissemination was not demonstrated. However, B garinii KW1 and B afzelii S13 were found to successfully disseminate in visceral organs of rabbits during the experiment period of 28 days. And experimentally infection-derived immunological responses in rabbits were identified with enzyme-linked immunosorbent assay and immunoblot analysis. Based on these results, the differences in the virulence of Lymeborrelial strains were proved in rabbit model.

The regional distributions and relative frequencies of the gastrointestinal endocrine cells inthe gean goose (Anser fabalisLatham) were investigated by immunohistochemical methods using bovineSp-1/chromogranin (CG), serotonin, gastrin, cholecystokinin (CCK)-8, somatostatin and glucagon antisera. BCG-immunoreactive cells were widespread throughout the gastrointestinal tract (GIT) with moderated frequencies except for the gizzard and proventriculus which were a few frequencies. Serotonin-immunoreactive cells were detected throughout the GIT except for the proventriculus and gizzard. These cells wer observed inthe pylorus with rare frequencies but numerous cells wee cetected in the intestinal tract. Gastrin-immunoreactive cells were restricted to the gizzard, pylorus and duodenum. These cells were most predominant in the pylorus and a few or rare in the gizzard and duodenum, respectively. CCK-8-immunoreactive cells were observed from the gizzard to ileum. the highest frequencies of endocrine cells were observed in the duodenum. These cells were increased from the gizzard to duodenum but thereafter decreased. Somatostatin-immunoreactive cells were detected in the GIT except for the large intestine. In the proventriculus and pylorus, numerous immunoreactive cells were demonstrated but a few cells were present in the other regions. Glucagon cells were observed in the gizzard, pylorus, ileum, colon and rectum with a few or moderated numbers.

The localization of substance P(SP), calcitonin gene-related peptide(CGRP) and three calcium binding proteins, calbindin D-28k(CB), calretinin(CR) and parvalbumin(PA) was immunohistochemically examined in the myenteric and submucous plexuses of Korean native goat duodenum. In the neurons of myenteric and submucous plexuses of duodenum, immunoreactivities of SP, CGRP and CB were confirmed in both nerve cell bodies and fibers. In contrast, CR immunoreactivity was found only in nerve fibers of myenteric plexuses, while PA immunoreactivity was found only in nerve cell bodies of submucoun plexuses. In the inner circular muscle layer, dense SP-like immunoreactive fibers were prominent but only a few CGRP-like immunoreactivities were observed. Most of SP-and CGRP-like immunoreactive neurons of both plexuses colocalized with CB. This result showed that SP and CGRP may have a important role for the movement of small intestine. The colocalizations of CB with SP or CGRP in myenteric and submucous plexuses suggest that CB may serve neuromodulatory role for SP-and CGRP-immunoreactecd neurons on the movement of intestinal wall.