Anti-fracture Efficacy of Monthly Risedronate Compared with That of Weekly Risedronate in Postmenopausal Korean Women with Osteoporosis: A Nationwide Cohort Study / 가정의학회지

Background@#Intermittent dosing regimens for oral risedronate (once-monthly and once-weekly) were developed for patient convenience. While several studies have reported the anti-fracture efficacy of weekly dosing, few have assessed monthly dosing. The lower efficacy of monthly dosing has been previously suggested. The aim of this study was to compare the anti-fracture efficacy of monthly and weekly dosing. @*Methods@#We obtained information from the Korea National Health Insurance Service database from 2012 to 2017 of Korean women of ≥50 years of age who used weekly or monthly risedronate. We compared the time of occurrence of the first osteoporotic fracture after the first prescription of risedronate. Using a Cox proportional model, we assessed incidence rate ratios (IRRs) with 95% confidence intervals (CIs) for fractures at any site, and the hip, vertebral, and non-vertebral sites between both regimens. Propensity score weighting was used to balance the treatment groups. @*Results@#The study populations were distributed according to dosing frequency (monthly, 27,329; weekly, 47,652). There was no significant difference in the incidence rate of new fractures in any site (IRR, 1.008; 95% CI,0.963– 1.055; P=0.737), hip (IRR, 0.999; 95% CI, 0.769–1.298; P=0.996), vertebral (IRR, 0.962; 95% CI, 0.890–1.040; P=0.330), or non-vertebral (1.022; 95% CI, 0.968–1.078; P=0.439) sites between monthly and weekly risedronate. @*Conclusion@#The anti-fracture efficacy at any site and the examined individual sites was similar for the monthly and weekly risedronate regimens. Large-scale randomized controlled trials are required for confirmation.

Effect of Melatonin during Recovery of Tissue Injury after Intestine Ischemia-Reperfusion

PURPOSE: It is now well recognized that reperfusion of ischemic tissues initiates a complex series of reactions that can paradoxically injure tissues. Apoptosis occurs in select cell populations during morphologic development and during cellular injury, including oxygen radical exposure, ischemia-reperfusion, and sepsis. Thus, in this study, we examined relation of the melatonin effect to the injection time and the dose, and role of melatonin in apoptosis. METHODS: Intestinal ischemia-reperfusion injury was induced in rats by clamping the superior mesenteric artery for 30 minutes. After reperfusion injury for 30 minutes, the experimental group was administered melatonin (10 mg/kg) intraperitoneally and the control group received saline and ethanol. At 30 minutes, 60 minutes, and 90 minutes, 1) pulmonary histological assessments (interstitial PMNs/10HPFs and lung (alveolar) injury score), 2) alveolar microvascular permeability assessments (wet-weignt to dry-weight ratio and lipid peroxidation activity, malondialdehyde, MDA), and 3) western blotting assessments (p53, p21, Bax, and bcl-2) were made. For comparison, long- time (60-minute) reperfusion and double- dosage melatonin (20 mg/kg) were also studied. RESULTS: The lung injury score was 1.00+/-0 in the melatonin group at 90 minutes and 3.28+/-0.30 in the saline group (p0.05). A marked difference was found between the ischemia-reperfusion control group and the experimental group at 90 minutes regarding lipid peroxidation activity (Malondialdehyde, 16.45+/-0.19 micrometer vs 10.93+/-0.11 micrometer, p<0.01). In the melatonin group, p21 expressions were found to be much more than in the control group. But, p53, bcl-2, and Bax expressions were found to be in the control group. CONCLUSION: Melatonin injection within 60 min after reperfusion may promote recovery of reperfusion injury, but double-dose melatonin injection was inefficacious. Also, melatonin inhibit apoptosis by p21 expression.

Caffeine Induces Apoptosis in Human Neuroblastoma Cell Line SK-N-MC

Caffeine is one of the most widely consumed neuroactive drugs, coming mostly from everyday beverages such as coffee and tea. To investigate whether caffeine induces apoptosis in the central nervous system, 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, flow cytometric analysis, DNA fragmentation assay, and caspase-3 enzyme assay were performed on SK-N-MC human neuroblastoma cells. Cells treated with caffeine at concentrations as high as 10 mM exhibited several characteristics of apoptosis. In addition, caffeine was shown to increase the caspase-3 activity. These results suggest that high-dose of caffeine induces apoptosis in human neuroblastoma cells, probably by increasing the caspase-3 enzyme activity.

Comparison between Spiral CT and MR Imaging in Evaluation of Focal Hepatic Masses

PURPOSE: The main aim of this study was to compare spiral CT and MR imaging in the detection and characterization of focal hepatic masses. MATERIALS AND METHODS: Seventy-nine patients with 155 focal hepatic masses confirmed pathologically, or radiologically and clinically [hepatocellular carcinoma(HCC) (n =52), hemangioma (n=36), cysts (n =35), metastasis (n =27), intrahepatic cholangiocarcinoma (n =5)], underwent two- or three-phase spiral CT, and T1-, T2- weighted, and dynamic contrast-enhanced MR imaging. The detection and characterization of focal hepatic masses by these modalities were evaluated and compared. RESULT: The detection rates of spiral CT and MR imaging, respectively, were as follows: HCC, 81%(42/52) and 94%(49/52); hemangioma, 75%(27/36) and 100%(36/36); cysts, 80%(28/35) and 100%(35/35); metastasis, 67%(18/27) and 100%(27/27); and intrahepatic cholangiocarcinoma, 100%(5/5) and 100%(5/5). MR imaging was superior to spiral CT in mass detection of HCC, hemangioma, cysts, and metastasis (p < .05). The characterization rates of spiral CT and MR imaging, respectively, were as follows: HCC, 52%(27/52) and 71%(37/52); hemangioma, 67%(24/36) and 100%(36/36); cysts, 63%(22/35) and 100%(35/35); metastasis, 37%(10/27) and 100%(27/27); and intrahepatic cholangiocarcinoma, 40%(2/5) and 80%(4/5). In the mass characterization of HCC, hemangioma, cysts, and metastasis, MR imaging was superior to spiral CT (p< .05). CONCLUSION: In the detection and characterization of focal hepatic masses, including hepatocellular carcinoma, hemangioma, hepatic cyst and metastasis, MR imaging is superior to spiral CT.

The Change of Portal Hemodynamics before and after Transjugular Intrahepatic Portosystemic Shunt according to Variceal Type: Gastric and Esophageal varix

PURPOSE: To investigate the changes occurring in portal hemodynamics in patients with esophageal and gastric varices, according to variceal type, before and after TIPS. MATERIALS AND METHODS: Between January 1994 and June 1999, we evaluated 22 of 44 patients who had undergone TIPS and endoscopy on admission. In these 22, hepatic venous and main portal venous pressure were measured. On the basis of endoscpic findings, the esophageal and gastric varices were classified as one of three types. Changes in portal hemodynamics in relation to the diameter of the portal vein, mean portosystemic gradient before and after TIPS, delta MPSG, and the presence of hepatic encephalopathy and gastrorenal shunt were all evaluated. RESULTS: Endoscopy indicated that there were ten Type-I cases, nine Type-II, and three Type-III. The diameter of the main portal vein was 14.95 +/-1.79 mm in Type I cases, and 13.35 +/-1.59 mm in Type II. Before TIPS, main portal venous pressure was 31.40 +/-6.79 mmHg (Type I) and 22.80 +/-4.26 mmHg (Type II), and the mean portosystemic gradient was 16.10 +/-7.0 mmHg (Type I), and 11.20 +/-5.36 mmHg (Type II). After TIPS, the pressure readings were 25.70 +/-7.60 mmHg (Type I) and 17.80 +/-6.52 mmHg (Type II), while those relating to were 10.80 +/-4.94 mmHg (Type I) and 5.25 +/-3.67 mmHg (Type II). delta MPSG was 6.04 +/-2.98 mmHg (Type I) and 5.91 +/-3.98 mmHg (Type II). Angiography revealed that the gastrorenal shunt was Type I in 10% of cases, Type II in 77%, and Type III in 33%. Hepatic encephalopathy after TIPS occured in three Type-I cases, three-Type- II, and two Type-III. CONCLUSION: The diameter of the main portal vein was significantly smaller, and portal venous pressure and mean portosystemic gradient before and after TIPS significantly lower in patients with dominant gastric varices than in those with dominant esophageal varices (p<0.05). Gastrorenal shunt was more frequent among patients with dominant gastric varices. No difference in the incidence of hepatic encephalopathy after TIPS was noted between those with dominant gastric varices and those with the esophageal variety.

The Effect of Melatonin on Mouse Jejunal Crypt Cell Survival and Apoptosis / 대한방사선종양학회지

PURPOSE: To evaluate protective mechanism of melatonin against radiation damage and its relationship with apoptosis in mouse jejunum. MATERIALS AND METHODS:' 168 mice were divided into 28 groups according to radiation dose and melatonin treatment. To analysis crypt survival, microcolony survival assay was done according to Withers an (l Elkind's method. To analysis apoptosis, TUNEL assay was done according to Labet-Moleur's method. RESULTS: Radiation protection effect of melatonin was demonstrated by crypt survival assay and its effect was stronger in high radiation dose area. Apoptosis index with 8 Gy irradiation was 18.4% in control group and 16.5% in melatonin treated group. After 18 Gy, apoptosis index was 17.2% in control group and 15.4% in melatonin treated group. Apoptosis index did not show statistically significant difference between melatonin treated group and control group. CONCLUSION: Melatonin shows clear protective effect in mouse jejunum against radiation damage but it.', protective effect seems not to be related with apoptosis protection effect.

Superselective Embolization with Microcoil in Acute Gastrointestinal Hemorrhage

PURPOSE: To evaluate the efficacy and safety of superselective arterial embolization using the microcoil in acute gastrointestinal hemorrhage. MATERIALS AND METHODS: We evaluated 11 of 42 patients who had undergone diagnostic angiography and tran-scatheter arterial embolization due to acute gastrointestinal hemorrhage and subsequently underwent superselective arterial embolization using the microcoil. Nine were males and two were females, and their age ranged from 33 to 70 (mean, 51) years. The etiologies were bleeding ulcer (n=5), pseudoaneurysm from pancreatitis (n=3), and postoperative bleeding (n=3). The symptoms were melena, hematemesis, and hematochezia, and the critical signs were decreased hemoglobin and worsening of vital signs. All patients underwent superselective embolization using the microcatheter and microcoil. RESULTS: Bleeding occurred in the gastroduodenal artery (n=5), inferior pancreaticoduodenal artery (n=2), left gastric artery (n=2), right hepatic artery (n=1), and ileal branch of the superior mesenteric artery (n=1). All cases were treated succesfully, without complications. In one case in which there was bleeding in the right he-patic artery, reembolization with a microcoil was needed because of persistent melena. During follow up, three patients died from complications arising underlying diseases, namely disseminated intravascular coagulopathy, chronic renal failure, and adult respiratory distress syndrome. Procedural complications, such as ischemia or infarction were not noted. CONCLUSION: Superselective arterial embolization using the microcoil is a safe and effective method for the treatment of acute gastrointestinal bleeding, and does not lead to complications.

MR Imaging Finding of Xanthogranulomatous Cholecystitis: A Case Report

We describe a case of xanthogranulomatous cholecystitis in which there was close correlation between MR andhistopathological finding and review the previous literature. On both T1-and T2-weighted MR images, multiplegallstones and diffuse wall thickening of the gallbladder were seen, with multiple hyperintense intra-muralnodules. The nodules were pathologically confirmed as anthogranuloma.

Transcatheter Arterial Embolizations of Arterial Bleeding in Patients with Pelvic Bone Fracture

PURPOSE: To evaluate the usefulness of transcatheter arterial embolization (TAE) of arterial bleeding in patients with pelvic bone fracture. MATERIALS AND METHODS: We retrospectively evaluated 13 injured arteries of seven patients with pelvic bone fracture. In order to evaluate the sites and types of arterial injuries, angiography was performed, followed by TAE using Gelfoam and a coil. The parameter of technical success is non-visualization of extravasation and pseudoaneurysm in injured arteries. We investigated (1) the survival rate and complications of TAE; (2) the relationship of arterial injuries to findings, as seen on plain film; and (3) the influence of BP on arrival and the time interval between trauma and TAE on prognosis. RESULTS: Angiography revealed (1) extravasation of contrast media in four patients; (2) extravasation and pseudoaneurysm in two; and (3) extravasation and abrupt cut-off of an artery in one. The injured arteries involved( n=13), were the internal iliac (n=3), superior gluteal (n=3), inferior gluteal (n=2), obturator (n=2), ili-olumbar (n=2), and internal pudendal (n=1). TAE was technically successful and in no case were there complications. Vital signs improved in four patients, but three others died due to hypovolemia. In five patients the site of arterial injury, as seen on plain films, was consistent pelvic bone fracture but in one patient more severe arterial injury was noted at the contralateral side of more severe pelvic bone fracture, and in one other arterial injury was observed only at the contralateral side of pelvic bone fracture. In this study, BP at arrival was a more important prognostic indication than was the time interval between trauma and TAE. CONCLUSION: For the management of arterial bleeding after blunt pelvic trauma, TAE is the procedure of choice.

The Effects of UVB Irradiation and Sunscreen Agents on Photoaging of Hairless Albino Mouse Skin / 대한피부과학회지

BACKGROUND: Photoaging skin is clinically characterized by wrinkled, dry, inelastic and irregularly pigmented skin, skin tumor and histologically by increased epidermal thickness, nurnerous fibroblasts, mast cells and inflammatory cells in the upper dermis, elastosis, degeneration of collagen fibers, increased proportion of type III collagen fibers in the dermis and increased numbers of keratinizing cysts in the lower dormis of hairless albino mouse skin. Chronic exposure to UVB induces photoaging skin and sunscreen agents are used to prevent photodamage to skin and reduce the incidence and extent of the chronic photoaging effects. OBJECTIVE: To evaluate the photoaging effects of UVB on the skin and to assess the ability of sunscreen agents to protect the skin from photoaging, we examined the clinical, histological and quantitative changes in collagen in the skin of Albino hairless Skh: HR-1 mice. MATERIALS AND METHODS: The experimental animals were male Albino hairless Skh: HR-1 mice, 12 weeks old. The control group was a chronologically aging group which had not been affected by UVB irradiation. The non-protected group was irradiated with UVB, a half of MED, 3 times weekly(Monday, Wednesday, Fr iday), for 12 weeks. To assess the photoprotective effects of sunscreen agents, the control group, the non-protected group and the sunscreen agent-applicated groups were compared to each other clinically, histologically, and by quantitative collagen analysis. An early increase in type III collagen during UVB irradiation was determined by cyanogen bromide digestion of the whole skin, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and densitometry. RESULTS: Clinically, the skin of the mice in the non-protected group showed mild changes caused by photoaging. Histoloically, the non-protected group showed increases in the size and number of keratinizing cysts in the lower dermis and increases in the mast cells in the upper dermis compared with the control group. However, no significant findings of increased epidermal thickness, inflammatory cell infiltration, elastic fiber change or degeneration of collagen fibers were shown. By the 12th week, four of the total of nine mice in the non-protected group developed at least one tumor. The sunscreen agent applicated groups showed slightly photoprotected effects clinically and histologically. In the collagen analysis, the proportion of type III collagen was significantly increased in the photoaging skin of mice in the non-protected group compared with the control group. Mice in the sunscreen agent applicated groups showed a significantly decreased proportion of type III collagen compared with the non-protected group. CONCLUSION: To summarize, UVB exposure of the skin induces photoaging. The number and size of keratinizing cysts increased in the photoaging skin of hairless albino mice. There was also a quantitative change in the collagen fibers. The use of sunscreen agents decreases the photoaging effects of UVB on the skin.

The Effects of UVB Irradiation and Sunscreen Agents on Photoaging of Hairless Albino Mouse Skin / 대한피부과학회지

BACKGROUND: Photoaging skin is clinically characterized by wrinkled, dry, inelastic and irregularly pigmented skin, skin tumor and histologically by increased epidermal thickness, nurnerous fibroblasts, mast cells and inflammatory cells in the upper dermis, elastosis, degeneration of collagen fibers, increased proportion of type III collagen fibers in the dermis and increased numbers of keratinizing cysts in the lower dormis of hairless albino mouse skin. Chronic exposure to UVB induces photoaging skin and sunscreen agents are used to prevent photodamage to skin and reduce the incidence and extent of the chronic photoaging effects. OBJECTIVE: To evaluate the photoaging effects of UVB on the skin and to assess the ability of sunscreen agents to protect the skin from photoaging, we examined the clinical, histological and quantitative changes in collagen in the skin of Albino hairless Skh: HR-1 mice. MATERIALS AND METHODS: The experimental animals were male Albino hairless Skh: HR-1 mice, 12 weeks old. The control group was a chronologically aging group which had not been affected by UVB irradiation. The non-protected group was irradiated with UVB, a half of MED, 3 times weekly(Monday, Wednesday, Fr iday), for 12 weeks. To assess the photoprotective effects of sunscreen agents, the control group, the non-protected group and the sunscreen agent-applicated groups were compared to each other clinically, histologically, and by quantitative collagen analysis. An early increase in type III collagen during UVB irradiation was determined by cyanogen bromide digestion of the whole skin, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and densitometry. RESULTS: Clinically, the skin of the mice in the non-protected group showed mild changes caused by photoaging. Histoloically, the non-protected group showed increases in the size and number of keratinizing cysts in the lower dermis and increases in the mast cells in the upper dermis compared with the control group. However, no significant findings of increased epidermal thickness, inflammatory cell infiltration, elastic fiber change or degeneration of collagen fibers were shown. By the 12th week, four of the total of nine mice in the non-protected group developed at least one tumor. The sunscreen agent applicated groups showed slightly photoprotected effects clinically and histologically. In the collagen analysis, the proportion of type III collagen was significantly increased in the photoaging skin of mice in the non-protected group compared with the control group. Mice in the sunscreen agent applicated groups showed a significantly decreased proportion of type III collagen compared with the non-protected group. CONCLUSION: To summarize, UVB exposure of the skin induces photoaging. The number and size of keratinizing cysts increased in the photoaging skin of hairless albino mice. There was also a quantitative change in the collagen fibers. The use of sunscreen agents decreases the photoaging effects of UVB on the skin.

Anesthetic Management of a Patient with Pheochromocytoma - A case report / 대한마취과학회지

The anesthetic management of patients with pheochromocytoma presents many difficult problems, such as hypertension, cardiac arrhythmias, and hypotension. A 21 year-old male underwent resection of pheochromocytoma under general anesthesia with isoflurane and fentanyl. Hypertensive crisis during induction of anesthesia and surgical manipulation of the tumor were managed with phentolamine and sodium nitroprusside drips. Anesthesia was maintained wtih nitrous oxide : oxygen, 50% : 50%, isoflurane, 0.5-2% and supplemented with fractional doses of fentanyl and vecuronium for muscular relaxation. We also used propranolol for the cardiac arrhythmia. An endotracheal semi-closed circle absorption technique with controlled ventilation was employed. Fentanyl does not release histamine, and has stable hemodynamics. Isoflurane has also advocated on the grounds that arrhythmias are less esaily provocated by circulating catecholamines than with other volatile agents, and has been shown to be a satisfactory agent. Vecuronium does not provoke catecholamine release, does not release histamine, has no autonomic effects at clinical plasma concentrations, and is clearly the neuromuscular blocking agent of choice in this case. Optimal pre-operative preparation, smooth induction of anesthesia, adequate alveolar ventilation, proper cardiovascular control, and good communication between surgeon and anesthesiologist are most important for the anesthetic management of pheochromocytoma.

The Effects of Halothane, Enflurane, and Regional Anesthesia on SGOT and SGPT / 대한마취과학회지

When halothane was first introduced into the clinical anesthesia in 1956, it was acclaimed as the ideal anesthetic agent. Soon after its clinical introduction, reports were published regarding jaundice and hepatic necrosis following its use. Stock and Strunin group the etiologic factors as biotransformation, hypersensitivity (immune-related), hypoxia and pharmacogenetic. In contrast, Calahan and Mangano list as possible causes hypoxia, trauma, viral hepatitis and toxic injury. A few cases of hepatitis following enflurane anesthesia have been described and a diagnosis of enflurane hepatitis was made. However, it is much rare than halothane hepatitis and the case remains unproven. Regional anesthesia with local anesthetic agent (lidocaine or bupivacaine) does not cause hepatic injury, even patients with moderate hepatocellular disease may well be able to metabolize durgs normally. Decrease in hepatic blood flow in healthy individuals will cause no problems with regional anesthesia, as the blood flow and cardiac output can be reestablished with the use of fluids or appropriate vasoconstrictors. This study was undertaken to evaluate the effects of halothane, enflurane, and regional anesthesia with lidocaine or bupivacaine on liver function, particularly with serum glutamic oxaloacetic and pyruvic transaminases (SGOT and SGPT) values which are the most frequently determined indicators of possible liver disease. Whereas SGOT is present in a variety of tissues, SGPT appears to be the liver-specific transaminase. We studied randomly-selected 219 patients, ASA class I or II, aged 15-68 yr, scheduled for elective surgery. They had no history of liver disease, and preoperative liver function tests were within normal limit. And we excluded blood transfused cases in this study. They were divided into three groups according to the anesthetic agent used; Group I: Halothane anesthesia (116 cases). Group II: Regional anesthesia (50 cases). Group III: Enflurane anesthesia (53 cases). We also divided subgroups according to the duration of anesthesia in each group; Subgroup A (Subg-A): under 2 hours of anesthesia. Subgroup B (Subg-B): more than 2 hours of anesthesia. SGOT and SGPT were measured before surgery, and on 1st, 3rd and 5th postoperatine days. The results we as follows: 1) The values of SGOT and SGPT were increased (p<0.01) in both Subg-A and B of Group I. However, on the 1st post-operative day they were more prominently elevated than the other postoperative days (P<0.05), but clinically the change of values was all within normal limits. 2) The values of SGOT were increased (P<0.05) in Subg-B of Group II on the 3rd postoperatine day hut clinically were within normal limits. The values of SGPT in Group II were slightly increased within normal ranges. 3) The values of SGOT were increased in Subg-A (P<0.05) and Subg-B (P<0.01) of Group III on the 1st postoperatine day, but clinically were within normal limits. The values of SGPT in Group III were slightly increased within normal ranges. 4) In comparing Group I and Group II, the value of SGOT in Group I was significantly increased than Group II (P<0.05), but clinically was within normal limits, and the change in that of SGPT was not significant. 5) In comparing Group II and Group III, the value of SGOT in Group II was significantly increased (P<0.01) on the 5th postoperatine day than Group III, but clinically was within normal limits, and changes of SGPT were not significant. 6) In comparing Group II and Group III, the values of SGOT and SGPT were not significantly different. 7) The results show that the effect of halothane on liver function (SGOT, SGPT) is not significantly different from those of enflurane and regional anesthesia with local anesthetics.

An Experimental Study on the Effect of Thiopental on Glutamic Oxaloacetic Transaminase Isozyme in Adult Rabbit Brain / 대한마취과학회지

In order to determine the enzyme activity, as expressed in Reitman-Frankel unit, of GOT isozyme present in whole homogenate, mitochondrial fraction and supernatant fraction were prepared from brain tissues of normal adult rabbit, by a differential centrifugal method. The effect of thiopental on the GOT isozyme activity in each fraction was determined and the following results were obtained. 1) The activity of GOT isozyme in whole homogenate of normal rabbit brain tissues was found to be 545+/-2.608 units/mg of wet weight whereas the corresponding figure for the supernatant GOT isozyme was 512+/-3.081 and the value for the mitochondrial GOT isozyme was found to be 34.9+/-1.224. 2) The supernatant GOT isozyme existing in a floating status within the cytoplasm accounted for 94 percent followed by 6.35 percent of mitochondrial GOT isozyme. 3) The activated-peak of mitochondrial GOT isozyme contained in the whole homogenate of adult rabbit brain tissues was found to be at #15 on the tube of elution in comparison to that of #73 for supernatant GOT isozyme, as analyzed by the DEAE-Cellulose column chromasography. 4) The supernant GOT isozyme from the thiopentaltreated brain was proportionaly distorted while mitochondrial GOT isozyme was not influenced. Fro example, treated with thiopental, the supernatant GOT isozyme was divided to be #63 & #73 on the tube in comparison to #15 for the mitochondrial GOT isozyme. 5) The activity of supernatant isozyme was proportionaly reduced as the concentration of thiopental. 6) Fifty percent inhibition dose(1se) of thiopental on the supernatant GOT isozyme was found to be 0.63mM. 7) The inhibitory effect of thiopental on the supernatant GOT isozyme was very high significantly by the statistics. 8) The mchanism by which thiopental inhibits the supernatant GOT isozyme in the adult rabbit brain was found to bh uncompetitive inhibition as its Michaelis-Menten constant Km=58.07mM demonstrated. In view of the above finding it is suggested that the thiopental inhibited selectively the activity of supernatant GOT isozyme of the adult rabbit brain tissues while it did not inhibitnificantly by the statistics. 8) The mechanism by which thiopental inhibits the supernatant GOT isozyme in the adult rabbit brain was found to bh uncompetitive inhibition as it Michaelis-Menten constant of Km=58.07 mM demonstrated. In view of the above findings it is suggested that the thiopental inhibited selectively the activity of supernatant GOT isozyme of the adult rabbit brain tissues while it did not inhibit that of mitochondrial GOT isozyme. The GOT isozyme of adult rabbit brain tissues was divided into thiopental-sensitive GOT isozyme(supernatant GOT isozyme) and thiopental insensitive GOT isozyme(mitochondrial GOT isozyme) Furthermore, it is suggested that the cellular function of the brain can be somewhat hindered, when thiopental is injected into the brain cell, while mitosis of the brain cell is not influenced.