This study was designed to evaluate the effect of cyclophospaide(CY) on dietynitrosamine(DEN)-induced hepatic tumors in rats. Thirty five male of femal Sprague Dawley rats were continiously given water containing O.01% DEN for 10 weeks and then were give with CY 25mg/rat/day in water for 3, 5, 7 or 9 days. The livers of rats were removed and fixed in 10% buffered neutral formalin. The appearances of positive cells by immunohistochemical methods using proliferating cell nuclear antigen (PCNA) antibody, p53 antibody and apoptotic kit were investigated. The livers of rats given with CY were grossly brilliant, red-brown color, flexible, and thin border, and stainability of the liver cells were restored microscopically, and the vaccuolated and degenerated regions were differentiated from restored regions. These restored findings also were advanced in control group becouse of no DEN treatment but tended to be less avanced. In immunohistochemistry, positive cells to PCNA antibody appeared more numerous in control groups than that of CY treated groups. Appearance of positive cells in CY-treated group for 7 days and for 9 days were more numerous than those of CY-treated groups for 3 days and for 5 days, respectively. So these findings suggested that CY suppressed cell proliferations and effects of these action were decreased with CY-treated days. The numbers of positive cells to PCNA antibody were more prominent in hepatocelular carcinoma regions and cholangiocarcinoma regions, and then were ranked as order of large liver cell regions and normal liver cell regions. Also the numbers of the positive cells by apoptotic kit tended to be higher in hepatocelular carcinoma regions and cholangiocarcinoma regions but not uniformly in order in all regions nd were much less numbers than those of OCNA positive cells. So immunohistochemical methods using PCNA antibody together than using apoptotic kit alone when anti-carcinogen experiments. Rats with positive cells by p53 antibody were 11 of 15 rats(73.4%) in control groups and 12 of 18 rats(66.7%) in CY treated group, respectively. These positive cells appeared focally in early vacuole-occurring regions and were low in numbers.

Osteoporosis is defined as a decrease in bone mass that leads to an increased risk of fracture. The therapeutic effect of 1alpha,25 dihydroxycholecalciferol, the hormonal form of vitamin D3 that mediates calcium translation in intestine and bone, on the healing process of fracture has still been controversial. These studies were designed to understand the healing process of normal fibular fracture, the osteoporotic changes after ovariectomy, and the theraqeutic effects of 1alpha,25 dihydroxycholecalciferol on the osteoporotic fracture in rats. The simple transverse fractures of rat fibulae were produced with a rotating diamond saw. The changes of the biochemical and mechanical indices of rats were investigated. The mechanical study based on bending test revealed the healing of the fibular fracture in the 5th week after simple transverse fracture. The osteoporosis impaired more the healing of osteoporotic fibular fracture than normal non-osteoporotic fibular fracture. The healing process of osteoporotic fracture was facilitated by the treatment with 1alpha,25 dihydroxycholecalciferol, however was delayed more than the healing process of normal fracture. The bone strength based on the bending test also confirmed this tendency. The bone strengths in the 5th week after fracture of normal bone, osteoporotic bone, and 1alpha,25 dihydroxycholecalciferol-treated osteoporotic bone were 75%, 41% and 67%, respectively, in comparison with those of intact bone. In conclusion, 1alpha,25 dihydroxycholecalciferol was effective in promoting the osteroporotic fracture healing.

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.

We have studied, by a nonisotopic in situ end-laveling(ISEL) technique, frequency of apoptosis in the external granular layer(EGL) of the cerebellum of immature mice by Y-rays irradiation from 60Co or diagnostic ultrasound exposure. The total number of normal cells and cells showing morphological features of apoptosis were counted. The frequency of apoptotic cells was expressed as a percentage of the total number of cells in EGL. The extent of changes following 200 cGy(1090 cGy/min) was studied at 2, 4, 6, 8, 12, or 24 hours after exposure. The maximal frequency was found 6~8 hours after exposure. The immature mice that received 18, 36, 54, 108, 198, 396, cGY of y-rays or diagnostic ultrasound(7.5MHz, 4.2mW, Ispta=7.9mW/cm2, Ispta=114.3W/cm2) for 10 or 30 minutes were examined 6 hours after irradiation. Measurements performed after y-ray irradiation showed a dose-related increase in apoptotic cells in each of the mice studied. The dose-response curves were analyzed by a linear-quadratic model;frequency of apoptotic cell in the EGL was y=(0.1349+_0.01175)D+(-0.0001522+_0.0000334)D2+0.048(r2=0.981, D-dose in cGy). In the experiment of ultrasound exposure, the frequency of apoptotic cell was 0.106+_0.130(10 minutes exposure) and 0.167+_0.220(30 minutes exposure). We estimated the relative dose of the yield from the experiment with ultrasound by substituting the yield from ultrasound exposure into the curve from the y-irradiation. The relative dose of ultrasound exposure compared with y-irradiation were 0.432 cGY(10 minutes exposure) and 0.885 cGY(30 minutes exposure). We have found that there is no evidence to indicate that diagnostic ultrasound involves a significant risk.

In order to study the effects of Jengjengamiyjintang on the duodenal ulcer induced by HCI-aspirin in rats, the changes of histological profiles, goblet cells(PAS-positive cells), and the distribution and frequency of cholecystokinin(CCK)-8 and serotonin-producing gastro-entero-endocrine cells were observed after oral administration of Jengjengamiyjintang. Histologically, very severe injury to duodenal epithelium were observed in control groups and theses injuries were increased with time intervals. But in the Jengjengamiyjintang administrated groups, no gross lesion of ulcer were demonstrated and histologically minor injury to the mucosal epithelium were observed. PAS-positive cells were increased in the Jengjengamiyjintang administrated groups compared to that of control groups. Severe degranulation of CCK-8- and serotonin-immunoreactive cells were observed in control groups but these phenomenon was seldom in the Jengjengamiyjintang administrated groups. Serotonin-immunoreactive cells were significantly decreased in control groups but increased in Jengjengamiyjintang administrated groups compared with control groups. According to these result, it is suggested that Jengjengamiyjintang would accelarat the healing of the duodenal ulcer but the functional mechanisms were unknown.

The insulin-like growth factor-I(IGF-I) is an important metabolic factor involved in cell growth and metabolism. Although secretion of IGF-I in rat liver is regulated by growth hormone, the effects of forskolin, adenylate cyclase activator, on secretion of IGF-I have not been reported. Therefore, a modified perfused rat liver model was used to investigate the regulatory effects of forskolin on IGF-I secretion in this experiment. The results were summerized as follows: 1. Modified perfused rat liver model was not changed to aspartate aminotransferase(AST), alanine aminotransferase(ALT) and lactic dehydrogenase(LDH) secretion in time. 2. The IGF-I secretion in hepatic cell was increased by forskolin(10-5, 10-6 and 10-7M) in a dose-dependent manner as compared with those of the controls, and significantly increased by 10-5 and 10-6M forskolin(p0.05). 3. Secretion of glucose in hepatic cell significantly was decreased by 10-5M forskolin as compared with those of controls(p0.05). These results suggest that forskolin may be involved in the regulation of IGF-I secretion in the perfused rat liver.

This study was carried out to compare the distribution pattern of the bombesin immunoreactive neurons of the hypothalamic nucleus in the rat and Mongolian gerbil. The bombesin immunoreactive neurons in the rat were located in the dorsal part of the dorsomedial hypothalamic nucleus, but in the Mongolian gerbil inthe compact part of dorsomedial hypothalamic nucleus. From this results, we could get an evidence that there were some differences in the distrbution of peptidebetween rat and Mongolian gerbil.

Ischemic preconditioning (IPC), i.e., a preliminary brief episode of ischemia and reperfusion, has been shown to reduce the cell damage induced by long ischemia and reperfusion. Superoxide radical which is produced during reperfusion after ischemia was recongnized as a factor of the ischemic injury and it is dismutated into H2O2 and O2 by two types of intracellular superoxide dismutase (SOD), Cu,Zn-SOD in cytoplasm and Mn-SOD in mitochondria. Recently oxygen free radicals are suggested to induce the apoptosis, however mechanism of the reduced apoptosis by ischemic precondition was unknown, while many studies performed in mammalian heart indicated that ATP-sensitive K+(K atp) channel activation related with the protective effects. The aim of present study is toinvestigate 1)whether IP upregulate the Cu,Zn-SOD and Mn-SOD activities, and 2)whether ischemic preconditioning decreases apoptosis via K atp channel activation in timely reperfused skeletal muscle after long ishemia. The experimental animals, Sprague-Dawley rats weighing 250~300g, were divided into 8 group; 1)control group, 2)ischemic preconditioning only groups, 3)pinacidil, a K atp channel opener, treatment only groups, 4)glibenclamide, a K atp channel blocker, treatment only groups, 5)ischemia groups, 6)ischemia after IPC groups, 7)ischemia and pinacidil treatment groups, and 8)IP and ischemia after glibenclamide pretreatment groups. Animals of the control group were administered with the vehicle (DMSO) alone. Pinacidil (1mg/kg) was administred intravenously 5 minutes after initiation of ischemia, and glibenclamide(0.5mg/kg) was injected intravenously 20 minutes before IPC. In rats that were ischemic preconditioned, the left common iliac artery was occluded for 5 minutes followed by 5 minutes of reperfusion by three times usign vascular clamp. Ischemia was done by occlusion of the same artery for 4 hours. The specimens of left rectus femoris muscle were obtained immediately (0 hours), 12 hours, 24 horus after drug administrations, IP or ischemia and reperfusion. The immunoreactivities of SOD and its alterations were observed by use of sheep antihuman Cu,Zn-SOD and Mn-SOD antibodies onthe 10 micro meter cryosections. The incidencies of apoptosis were observed by TUNEL methods with in situ apoptosis detection kit on 6 micro meter paraffine section. The results obtained were as follows: 1. After IPC, immunoreactivities of Cu,Zn-SOD mainly in the small-sized fibers were increased by 24 hours, that of Mn-SOD at 0 hour and 24 hours. 2. No significant changes in immunoreactivities of SDO was observed in the pinacidil and in the glibenclamide treatment only groups, and in the ischemia only groups. 3. The immunoreactivities of the Cu,Zn-SOD were incresed in the ischemia after IPC groups and the ischemia and pinacidil treatment groups. 4. The immunoreactivities of the Cu,Zn-SOD in the IPC and ischemia after glibenclamide pretreantment groups were not increased except for the 12 hours reperfusion group. But, Mn-SOD immunoreactivities were incresed in to 0 hours, 12 hours and 24 hours after reperfusion. 5. In the control group, the IPC only groups, and the pinacidil treatment only groups, negative or trace apoptotic reactions were observed, but the positive apoptotic reaction occured in the glibenclamide treatment groups. 6. Moderate or many number of apoptosis were revealed in the ischemia groups, and also the IPC and ischemia after glibenclamide pretreatment group except for 12 hours and 24 hours after reperfusion. However, the incidence of apoptosis was decreased in the ischemia after IPC groups and in theischemia and pinacidil treatment groups. 7. There is a coincidence between the increase of Cu,Zn-SOD immunoreactivities and the decrease of apoptosis in thepresence of ischemia and reperfusion. These results suggest that the protective effects of ishemic preconditioing may related to the SOD activation, and the ischemic preconditioning decreases the apoptosis partially via K atp channel activation in timely reperfused rat skeletal muscle. It is also suggested that inhibition of apoptosis by IPC may related with the SOD activation.

The study was designated to investigate the electron microscopic findings following diethylnitrosamine (DEN) treatment in rats. Forty four male (Srague Dawley) rats were continuously given water containing 0.01% DEN for 13 weeks and livers of five rats with more tumor lesions at 16 and 17 weeks after initial treatment were used as EM materials. In transmission electron microscopic findings, most small-sized hepatocytes were active cells containing large mount of organelles, but light (pale staining) hepatocyte among small-sized hepatocytes were injured cells containg disorganized organelles. Tumor cells among small-sized hepatocytes were irregularly arranged and have ;leomorphic nuclei containing electron dense chromatin but the organelles in cytoplasm were swelled. Large-sized hepatocytes were active cells with condensed chromatin but the cytoplasm of these cells were pale due to be injured and dilated organelles. Dark hepatocytes were apoptotic cells with homogenous pyknotic nuclei and cytoplasm, and the cytoplasm of these cells contained dilated smooth endoplasmic reticulum (sER) but these sER were non-vesiculated. Cholangiocarninoma cells were crowed and were pale by far less number of organelles in cytoplasm and nuclei. In scanning electron microscopic findings, the lumens of portal veins, bile canaliculi, bile ductules, bile ducts and sinusoids were dilated and have irregular folded inner surface by protruded parenchyma.

The morphometrical characteristics such as external measurements and mandible size assessment in mice and rats have to be highly heritable and sufficiently variable between strains in order to calculate a strain specific profiles. The coat color of Korean wild rats were observed and morphometric analysis of external measurements were carried out on Korean wild rats compared to laboratory strains in order to clarify the genetic characteristics of Korean wild rats and to establish background data as a domestication of Korean wild rats for new laboratory strain. Korean wild rats were captured from Chunchon and Hoengsong. 4 inbred and 1 outbred strains of rats were used in this study for the comparison of genetic characteristics of Korean wild rats. Total body length, head length, tail length, hind foot length and ear length were measured and then statistical analysis were carried out by discrimiant analysis. The coat color of Korean wild rat showed golden white in ventral portion and dark agouti in dorsal portion. Korean wild rats could be distinguished from the other laboratory strains distinctly by morphogenetical analysis. There was sighificant variations among Korean wild rat compared to those of the other laboratory strains of rat. This study may provide that Korean wild rats have a unique genetic characterization compared to those other inbred strains of rats based on morphogenetical characteristics by external measurements.