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 studies were carried out to investigate the effect of recovery in rewarming using the esophageal thermal tube in the deep hypothermia(25+_1 degrees centigrade ; rectal temp) in rabbits. Fifteen rabbits were divided into control group(n=6), peritoneal dialysis group(n=5) irrigated with dialysate at 42+_1 degrees centigrade, and esophageal rewarming group(n=6), peritioneal dialysis group(n=5) irrigated with dialysate at 42+_1 degrees centigrade, and esophageal rewarming group(n=4) perfused with circulating water at 38+_1 degrees centigrade. Rewarming of the rabbits was performed for 5 hours. MAP, HR, RR, esophageal temp, rectal temp, pH, pCO2, pO2, Na+, and K+ were observed. The results obtained in these experiments were summarized as follows:Esophageal rewarming group(38+_1 degrees centigrade) had more effect on esophageal temperature than other groups. Peritoneal dialysis group(42+_1 degrees centigrade) had more effect on rectal temperature and pO2 than other groups. The both groups also had more effects on MAP, HR, RR, and pCO2 than control group. Three groups had no significant effect on pH, Na+, and K+. In conclusion, we found that the simple, safe, and non-invasive esophageal rewarming method had an effect on the treatment of profound hypothermia as well as the peritoneal dialysis method in spite of the temperature difference between the dialysate and the circulating water, and the circulating water at 38+_1 degrees centigrade for esophageal rewarming also had an effect on the recovery of deep hypothermia.

This study was carried out to investigate the effects of vitamin E on the prevention and treatment of Babesia gibsoni. fifteen mongrel dogs, uninfected with Babesia spp, were assigned to three groups according to vitamin E(alpha-tocopherol) concentrations in the RBC. The concentrations in each of the three groups were, respectively : alpha-tocopherol in RBC less than 30 micro gram/micro liter(Group I), 30 micro gram/micro liter-60 micro gram/micro liter(Group II), more than 60 micro gram/micro liter(Group III). Artificial infection was accomplished by injecting 2*10 7-2*10 8 erythrocyte of Babesia gibsoni-infected dog into the cephalic vein. We investigated the clinical sighs, vitamin E concentrations in RBC and serum, Vitamin A concentrations in serum, hematological values, white blood cell(WBC) viability and RBC membrane osmotic fragility after infection of Bavesia gibsoni for a period of 20 days at 5 day intervals. The results obtained are summarized as follows: 1. After infection by Babesia gibsoni, clinical examination revealed depression, anorexia, pale mucous membranes, dark brown urine and diarrhea in proportion as time went on. After 10 days of infection, one dog each of Groups I, II and III revealed depression and anorexia. Two dogs in Group I and one dog each of Groups II and III showed dark brown urine after 15 days. Diarrhea was observed in one dog in each of the 3 groups after 20 days of infection. 2. After 5 days of infection, two dogs in each of Groups I, II and III showed Babesia gibsoni in RBC of blood smear stained with Giemsa. At the 15th day after infection with Babesia gibsoni, they were observed in all experimental animals. After both 5 days and 10 days of infection, the rate of Babesia gibsoni parasitized RBC(permillage, %) was 1%, and increased as time went on. 3. After 5 days of infection by Babesia gibsoni, Group I, which had the lowest vitamin E concentration, showed significantly decreased RBC and PCV levels(p0.01). Group II and group III also showed significantly decreased RBC and PCV levels after 15 days of infection(p0.05). particularly after 10 days of infection, Group I showed lower values in RBC and PCV levels compared to Groups II and III. WBC, RBC, fibrinogen and total protein levels between the groups did not differ during experimental periods. 4. According to the WBC differential counts, the ratios of neutrophil to lymphocyte showed a tendency to be slightly higher in Group III(more than 60 micro gram/micro liter) than in Groups I and II. 5. WBC viability did not differ between the groups. 6. RBC membrane osmotic fragility did not differ between the groups.

Ontogeny, distributions and relative frequencies of somatostatin-immunoreactive cells were investigated in the proventriculus of the chicken embryos with incubation periods. Samples were taken from 10 groups(10 days of incubation to hatching) and studied by immunogistochemical methods. The findings were as follows. Somatostatin-immunoreactive cells were observed from 12 days of incubation in the proventricular glands and after that increased with incubation periods. The first observation time of these cells in the epithelium were at 15 days of incubation in the basal portion but in 16 and 17 days of incubation, no immunoreactive cells were observed in the epithelium but after that a few immunoreactive cells were observed in the basal portion and gastric gland regions. The shpaes of these cells were spherical to spindle in the proventricular glands and spherical to round in the epithlium and gastric gland.

From 2,373 slaughtered pigs examined, 1,899 of them had visible evidence of pulmonary lesion. The lungs with pulmonary lesion were examined by grossly, histopathological technique to investigate the prevalence accordint to season, severity ofpulmonary lesion, types of the pneumonia and relationship between rearing management and prevalence of pulmonary lesion. The results were as follows: 1. Prevalence of pneumonia according to season was 72.3 % to 85.9% and the higher prevalence was in winter. 2. In the severity of pulmonary lesion, rates mild, moderate and severe lesions were 38.3%, 47.0% and 14.7%, respectively. Prevalence of mild lesion was the highest in autumn. Prevalence of moderate and severe lesions was the hihgest in winter. 3. In the type of pneumonia, rates of interstitial pneumonia and bronchopneumonia fibrinous pneumonia were 23.6%, 13.0%, and 3.4%, respectively. Prevalence of interstitial pneumonia was high in spring and autumn while that of broncho-pneumonia and fibrinous pneumonia was high in winter and summer, respectively. 4. In relationship of pulmonary lesions according to severityo fpulmonary lesion and types of pneumonia, similarity was observed in prevalence of mild lesion and bronchopneumonia.

Alpha toxin of S aureus has cytolytic activity respectively. This antigen has been received the most attention since it is a major virulence factor in pathogenesis of staphylococcal mastitis. Thus, alpha toxin has been focused as potential candidate ofvaccine tominimize mastitis in cows. the purpose of this study was to develop a simple, efficient production and purification methods of sufficient amount of alpha toxin antigen from S aureus. Alpha toxin production measured by hemolytic activity was the highest at 18 hrs postinoculation in yeast extract culture medium supplemented with thiamine, nicotinic acid and casamino acid. Alpha toxin was purifed by ammonium sulfate precipitation (65%) and ultrafiltration. Molecular weight of the toxin was 33 kDa in the analysis with SDS-PAGE. Conclusionally, when alpha toxin was included in the vaccine, the optimal harvest time of alpha toxin was at 18 hrs after inoculation in yeast extract medium supplemented with thiamine and nicotinic acid.

To establish the protocol of a standardized exercise test for evaluating exercise intolerance and degree of fitness in Thoroughbred racehorses, we examined serum lactate concentrations related to exercise intensities using the high speed tradmill. Twelve clinically healthy Thoroughbred racehorses with or without previous training or racing history were assigned to two groups, fit and unfit group, respectively. The protocol used for the standardized exercise test was consisted of two stages:stage ofwarm-up and that of acceleration. During the warm-up, the horses exercised 5 min at 1.8m/s and 3 min 3.4m/s without inclination. At the acceleration stage, exercise test was performed at 10% slope and the speed was increased from the initial 5m/s to the maximal speed which each tested horse could keep up with. The speed was increased with incremental steps of 1 m/s every minute. During the last 15 sec of each step, blood samples were collected for serum lactate determination. V max (masimal treadmill speed which tested horses could keep up with) of the fit group (10.93+_0.33m/s, mean+_SE, n=6) was higher than that of the unfit group (9.52+_0.23m/s, mean+_SE, n=6). Serum lactate concentrations increased exponentially according to exercise intensities. V la4 (speed producing a serum lactate concentration of 4mmol/l) of the fit group, 6.45+_0.26m/s, was higher than that of the unfit group, 5.45+_0.23m/s. La peak (peak plasma lactate concentration during the exercise test) was lower in the fit group (20.34+_1.62mmol/l at 1 min after maximal intensity exercise) than in the unfit group (24.78+_1.09mmol/l at 2 min after maximal exercise step). t50% (time required for the recovery of lactate concentration to be one-half of La peak after maximal exercise) of the unfit group and the fit group were 40.0 and 18.0 min, respectively. Therefore, the protocol of the incremental standardized exercise test utilized in this study seems to be reliable for the assessment of fitness and exercise intolerance for the Thoroughbred racehorses.

To investigate the effect of diazepam on fetal development in pregnant rats, this experiment was performed in eighty Sprague-Dawley female rats which were 8 weeks old and grouped into two according to different diazepam treatment period during 5-9 days of gestation and 10-14 days of gestation. Both experimental groups were included by saline treated groups (control) and diazepam-treated groups (6mg, 12mg and 24mg), respectively. Diazepam was injected to pregnant rats subcutaneously, which were wacrified on 20 days of gestation and mean litter size, fetal body weight, fetal crown-rump length (CRL) and pathological findings were examined. 1. Concerning mean litter size, diazepam-treated groups showed lower mean litter size than control in both 5-9 days and 10-14 days of gestation groups(p0.05) without difference according to dosage of diazepam and day of gestation. 2. Concerning fetal body weight, diazepam-treated groups during 5-9 days of gestation showed lower fetal body weight than control and the other treated group during 10-14 days(p0.01) without difference according to dosage of diazepam. Diazepam-treated group during 10-14 days of gestation showed no difference among experimented groups. 3. Concerning fetal crown-rump length (CRL), diazepam-treated groups during 5-9 days of gestation showed shorter CRL than control and the other treated group during 10-14 days of gestation(p0.01) without difference according to dosage of diazepam. 4. Reduction of mean litter size, fetal body weight and CRL was shown from when treated by the dosage of 6mg/kg of diazepam. 5. Maternal mortality according to dosage of the 20mg/kg of diazepam were 30% and 20% in the treated group during 5-9 days and 10-14 days of gestation, respectively. These results indicated that diazepam treatment in pregnant rats caused considerable reduction of mean litter size, fetal body weight and fetal crown-rump length when treated during 5-9 days of gestation.

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.

Renal failure is one of the main causes of economic impacts in the poultry industry and complex syndrome with different severity of clinical signs caused by multiple nephropathogenic factors such as infectious bronchitis viral infection and excess salt and calcium in diet. To evaluate the correlation between severity of renal failure and the causative nephropathogenic factors, one-day-old specific patogen free chicks were treated with either single causative factor or multiple causative factors described as above. Each group was designed as control for non-treated control, IB for infectious bronchitis virus (IB virus) infectio, IBHNa for IB virus infection with high diet salt, IBHCa for IB virus infectio with high diet calcium, IBHNC for IB virus infection with high diet salt and calcium, HNa for high diet salt, HCa for high diet calcium and HNC for high diet salt and calcium. Chickens were inoculated with IB virus at 1-day-old and remained on their respective diets until 21 day of age. The high dietary salt feeding groups such as IBHNa, IBHNC, HNa, HNC increased water intake, watery diarrhea, general subcutaneous edema and the high dietary calcium feeding groups such as IBHCa and IBHNC showed severe visceral gout. Two more than treated groups caused high mortality in comparison with the single treated groups. In virus exposure significantly increased urate deposition and lymphocytic interstitial nephritis. Espcecially urate deposition dramatically increased when excess diet calcium was combined together. In excess diet salt treated groups enlarged edematous kidneys were observed and hypertrophy of glomeruli were showed. These results suggest that IB virus enhanced the incidence and severity on chicken renal failure clearly related to the quantity of salt and calcium.