经皮肤暴露四溴双酚A对Wistar雄性大鼠的毒性效应

尘/土以及含阻燃剂产品的皮肤接触是四溴双酚A(TBBPA)重要的人体暴露途径。为研究TBBPA经皮肤亚慢性暴露毒性效应,选择无特定病原菌级别(SPF级)Wistar雄性大鼠作为受试生物,分别设空白对照组(K)、溶剂对照组(Z),以及20mg·kg^(-1)(A)、60 mg·kg^(-1)(B)、200 mg·kg^(-1)(C)、600 mg·kg^(-1)(D)共4个不同剂量的TBBPA暴露组,采用皮肤接触的方式连续暴露90 d。暴露期间观察大鼠状态并称重,于第91天解剖大鼠,分离主要脏器称重计算脏器系数,并对暴露皮肤进行组织病理学检查。研究发现,经皮肤暴露TBBPA后,90 d暴露期间不同实验组Wistar大鼠在表观形态、行动、进食方面无差异,TBBPA暴露导致大鼠体重略微降低,但各处理组间大鼠体重无显著差异;90 d暴露后不同剂量组间大鼠的器官脏器系数没有显著的剂量-效应关系,不同剂量组大鼠皮肤暴露区域均有一定程度的炎症细胞浸润及部分组织胶原间隙增宽。研究结果表明,TBBP A 90 d亚慢性皮肤暴露对Wistar大鼠无明显毒性效应。

Protective Action of Acupuncture and Moxibustion on Gastric Mucosa in Model Rats with Chronic Atrophic Gastritis

Objective: To probe the mechanism of acupuncture and moxibustion in atrophic gastritis so as to provide a basis for clinical treatment. Method: Observe the effects of acupuncture and moxibustion at the points of Zusanli, Zhongwan and Tianshu on gastric mucosa in model rats with chronic atrophic gastritis. Results:Acupuncture and moxibustion can increase the contents of PGE2α, PGF2α and cAMP, and decrease the content of cGMP in the tissue of gastric mucosa. Conclusion: Acupuncture and moxibustion shows cytoprotection on gastric mucosa, so it is an effective method for treating chronic atrophic gastritis.

Gastrin,somatostatin,G and D cells of gastric ulcer in rats

AIM: To investigate the relationship among gastrin,somatostatin, G and D calls in gastric ulcer and in its healing process in rats.METHODS: Fourty-nine Wistar rats were divided into 7groups. The gastric ulcer model was induced by acetic acid successfully. The gastrin and the somatostatin in rat plasma, gastric fluid and antral tissue were measured by radioimmunoassay(RIA). G and D cells in antral mucosa were analyzed with polyclonal antibody of gastrin and somatostatin by immunohistochemical method and Quantimet 500 image analysis systemRESULTS: In gastric ulcer, the level of gastrin in plasma,gastric fluid, and antral tissue increased, that ofsomatostatin declined, and the disorder gradually recoveredto the normal level in the healing process.Immunohistochemical technique of G and D cells in antralmucosa demonstrated that the number of G cells increasedand that of D cells decreased, both areas of G and D cellsdeclined, the ratio of number and area of G/D increased ingastric ulcer, and the disorder gradually recovered in thehealing process.CONCLUSION: In gastric ulcer, the increased gastrinsecreted by G cells, the declined somatostatin secreted by Dcells, and the disordered G/D cell ratio can lead togastrointestinal dysfunction.

Relationship between lymphocyte apoptosis and endotoxin translocation after thermal injury in rats

AIM：To investigate the relationship between lymphocyte papotosis in peripheral blood,spleen and mesenteric lymph nodes(MLN)and endotoxin translocation after thermal injury in rats.METHODS:In a wistar rat model infilicted with 30% TBSA Ⅲdegree scalding,serum LPS levels in portal vein and vena cava were quantified by tachypleus amebocyte lysate(TAL) technique.The analysis of peripheral bolld lymphocyte was employed in in situ Cell Death Detection Kit and evaluated by flow cytometry.Apoptotic lymphocytes in paraffinembedded spleen and MLN sections were examined by histologic analysis,in situ deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)and peroxidase(POD) staining.The imagines were taken by Cooldccd camera system,and the count and optical density value (transmission light) of apoptotic lymphocytes were analyzed with software Spot and lmagine proplus 4.10a(IPP4.10a).RESULTS:In the Period of 3 to 48 postburn hours(PBHs) serum LPS level(×10%3EU.L^-1)in portal vein(2.11±0.02,5.66±0.20,3.70±0.22,2.56±0.28,0.90±0.11)was higher than that in vena cava(0.63±0.01,.1.53±0.18,0.83±0.32,0.52±0.12,0.23±0.02,P<0.01),but both increased sharply in postburn rats(P<0.01)and reached a peak at 6 PBH.Analysius of apoptotic lymphocytes showed that the proportion(%) of postburn apoptotic cells was much higher than that in healthy rats(8.34±1.53,8.13±1.81,20.77±3.94,23.90±3.92,11.23±1.35and 13.26±2.09at3,6,12,24,48and 72 PBH,respectively,vs 3.99±1.72,P<0.01)especially after 6 PBH.The concentrations of lymphocytic apoptosis at 12 and 24 PBH were markedly higher than that at other time points.Meantime,few apoptotic lymphocytes were found in normal MLN,but increased postburn obviously(3±1vs 546±83,285±39,149±30,58±10,36±11and 33±9in turn,P<0.01),especially at 3 PBH,whereas apoptotic lymphocytes were concentrated in splenic cortex before the burn and decreased obviously during 72PBHs(499±186vs12±8，19±15,12±7,100±15,123±25and 226±26in turn,P<0.01) though a slight rise was found in the medulla after 24 PHB Optical density of apoptotic lymplhocytes was significantly reduced in spleen in the 24 PBHs and raised in MLN during 48 PBHs than that prior to the burn,respectively.CONCLUSION:Gut-origin LPS is a major cause of endotoxemia taken place early in rate following severe thermal injury and could induce extensive lymphocyts apoptosis in blood and MLN,which suggests an immunosuppression state could follow the initial injury and favores a septic state based on apoptotic mechanism.

Hyperammonemia,brain edema and blood-brain barrier alterations in prehepatic portal hypertensive rats and paracetamol intoxication

AIM: To study the blood-brain barrier integrity, brain edema,animal behavior and ammonia plasma levels in prehepatic portal hypertensive rats with and without acute liver intoxication.METHODS: Adults male Wistar rats were divided into four groups. Group I: sham operation; II: Prehepatic portal hypertension, produced by partial portal vein ligation; III:Acetaminophen intoxication and IV: Prehepatic portal hypertension plus acetaminophen. Acetaminophen was administered to produce acute hepatic injury. Portal pressure, liver serum enzymes and ammonia plasma levels were determined. Brain cortex water content was registered and trypan blue was utilized to study blood brain barrier integrity. Reflexes and behavioral tests were recorded.RESULTS: Portal hypertension was significantly elevated in groups II and IV. Liver enzymes and ammonia plasma levels were increased in groups II, III and IV. Prehepatic portal hypertension (group II), acetaminophen intoxication (group III) and both (group IV) had changes in the blood brain-barrier integrity (trypan blue) and hyperammonemia. Cortical edema was present in rats with acute hepatic injury in groups III and IV. Behavioral test (rota rod) was altered in group IV.CONCLUSION: These results suggest the possibility of another pathway for cortical edema production because blood brain barrier was altered (vasogenic) and hyperammonemia was registered (cytotoxic). Group IV, with behavioral altered test, can be considered as a model for study at an early stage of portal-systemic encephalopathy.

Effect of Buyang Huanwu Decoction on Platelet Activating Factor Content in Arterial Blood Preand Post-Arterial Thrombosis in Rats

To explore the effect of Buyang Huanwu Decoction (BHD) on platelet activating factor (PAF) content in arterial blood pre- and post-arterial thrombosis in rats, male Wistar rats were randomly divided into 3 groups, the medicine group treated with BHD, the control group with dexamethasone liquid, and the blank group with distilled water. Oral administration was given for 14 consecutive days, once daily. Model of arterial thrombosis was established in the animals 2 hours after final medication, the blood content of PAF, dry weight (DW) and occlusion time (OT) of thrombus, and dry weight of thrombus/body weight (TW/BW) ratio were observed. Results indicated that BHD could markedly lower the arterial blood content of PAF after thrombosis, increase the OT of thrombus, reduce the dry weight of thrombus and the TW/BW ratio (P<0.05). It is suggested that BHD can inhibit the pathologic PAF metabolism and formation and development of arterial thrombus.

Characteristics and mechanism of enzyme secretion and increase in [ Ca^(2+)]_i in Saikosaponin.(I)stimulated rat pancreatic acinar cells

AIM:This investigation was to reveal the characteristics and mechanism of enzyme secretion and increase in [Ca^2+]i stimulated by saikosaponin(1)[SA(1)] in rat pancreatic acini.METHODS:Pancreatic acini were prepared from male Wistar rats.Isolated acinar cells were suspended in Eagle's MEM solution,After adding drugs,the incubation was performed at 37℃for a set period of time.Amylase of supermatant was assayed using starch-iodide reaction.Isolated acinar single cell was incubated with Fura-2/AM at 37℃,then cells were wasthed and resuspended in fresh sulution and attached to the chamber,Cytoplasm [Ca^2+]i of a single cell was expressed by fluorescence ratio F340/F380 recorded in a Nikon PI Cd^2+ measurement system.RESULTS:Rate course of amylase secretion stimulated by SA(I) in rat pancreatic acini appeared in bell-like shape,The peak amplitude increased depended on SA(I) concentration.The maximum rate responded to 1^10moll/L SA(I) was 13.1-forld of basal and the rate decreased to basal level at 30min.CCK-8 receptor antagonist Bt2-cGMP markedly inhibited amylase secretion stimulated by SA(I)and the dose-effect relationship was similar th that by CCK-8,[Ca^2+]i in a single acinar cell rose to the peak at 5min afer adding 5×10^-6mol/L SA(I) and was 5.1-fold of basal level.In addition,there was a secondary increase after the initial peak.GDP could inhibit both the rate of amylase secretion and rising of [Ca^2+]i stmulated by SA(I) in a single pancreatic acinar cell.

Protective effect of exogenous adenosine triphosphate on hypothermically preserved rat liver

AIM:To clarify the protective effect of exogenous adenosine triphosphate (ATP)on hypothermically preserved rat livers.METHODS: Establishment of continuous hypothermic machine perfusion model,detection of nucleotides in hepatocytes with HPLC, measurement of activities of LDH and AST in the perfusate, observation of histopathological changes in different experiment groups, and autoradiography were carried out to reveal the underlying mechanism of the protective effect of ATRRESULTS:The intracellular levels of ATP and EC decreased rapidly after hypothermic preservation in control group,while a higher ATP and EC level, and a slower decreasing rate were observed when ATP-MgCl2 was added to the perfusate (P<0.01). As compared with the control group, the activities of LDH and AST in the ATP-MgCl2 group were lower (P<0.05).Furthermore, more severe hepatocyte damage and neutrophil infiltration were observed in the control group. Radioactive [α-^32P] ATP entered the hypothermically preserved rat hepatocytes.CONCLUSION: Exogenous ATP has a protective effect on rat livers during hypothermical preservation. However, Mg^2+ is indispensable, addition of ATP alone produces no protective effect.The underlying mechanism may be that exogenous ATP enters the hypothermically preserved rat liver cells.

N-acetylcysteine attenuates alcohol-induced oxidative stress in the rat

AIM: There is increasing evidence that alcohol-induced liverdamage may be associated with increased oxidative stress.We aimed to investigate free-radical scavenger effect of n-acetylcysteine in rats intragastrically fed with ethanol.METHODS: Twenty-four rats divided into three groups werefed with ethanol (6 g/kg/day, Group 1), ethanol and n-acetylcysteine (1 g/kg, Group 2), or isocaloric dextrose(control group, Group 3) for 4 weeks. Then animals weresacrificed under ether anesthesia, intracardiac blood andliver tissues were obtained. Measurements were performedboth in serum and in homogenized liver tissues.Malondialdehyde (MDA) level was measured by TBARSmethod. Glutathione peroxidase (GSH-Px) and superoxidedismutase (SOD) levels were studied by commercial kits.Kruskal-Wallis test was used for statistical analysis.RESULTS: ALT and AST in Group 1 (154 U/Land 302 U/L,respectively) were higher than those in Group 2 (94 U/L and155 U/L) and Group 3 (99 U/L and 168 U/L) (P＝0.001 forboth). Serum and tissue levels of MDA in Group 1 (1.84 nmol/mL and 96 nmol/100 mg-protein) were higher than Group 2(0.91 nmol/mL and 64 nmol/100 mg-protein) and Group 3(0.94 nmol/mL and 49 nmol/100 mg-protein) (P＜0.001 forboth). On the other hand, serum GSH-Px level in Group 1(8.21 U/g-Hb) was lower than Group 2 (16 U/g-Hb) andGroup 3 (16 U/g-Hb) (P＜0.001). Serum and liver tissue levelsof SOD in Group 1 (11 U/mL and 26 U/100 mg-protein)were lower than Group 2 (18 U/mL and 60 U/100 mg-protein)and Group 3 (20 U/mL and 60 U/100 mg-protein) (P＜0.001for both).CONCLUSION: This study demonstrated that ethanol-induced liver damage is associated with oxidative stress,and co-administration of n-acetylcysteine attenuates thisdamage effectively in rat model.

STUDY ON PATHOGENIC MECHANISM OF EMOTIONS IN TRADITIONAL CHINESE MEDICINE—An Observation of Hydrogen Peroxide Releasing Function of Celiac Macrophages in Rats Under Stress State

The hydrogen peroxide releasing function of macrophages in rats under the stress state wasobserved with the animal model of“excessive anger impairing the liver”.The resultsshowed that the volume of hydrogen peroxide released from the macrophages in rats wasdecreased,while the corticosterone level in plasma increased after stress.It indicates thatstimulation of harmful emotions could cause inhibition of immunoreaction of the organism,which might be related to the enhancement in excitability of the hypothalamus-pituitary-adrenal axis and hypersecretion of glucocorticoid hormone.

Heparin improves organ microcirculatory disturbances in caerulein-induced acute pancreatitis in rats

AIM: Microcirculatory disturbances are important early pathophysiological events in various organs during acute pancreatitis. The aim of the study was to evaluate changes in rnicroperfusion of the pancreas, liver, kidney, stomach,colon, skeletal muscle, and to investigate the influence of heparin on the organ rnicrocirculation in caerulein-induced experimental acute pancreatitis.METHODS: Acute pancreatitis was induced by 4 intraperitoneal injections of caerulein (Cn) (15 μg/kg). The organ microcirculation was measured by laser Doppler flowrnetry. Serum interleukin 6 and hernatocrit levels were analysed.RESULTS: Acute pancreatitis resulted in a significant drop of microperfusion in all examined organs. Heparin administration (2×2.5 mg/kg) improved the rnicrocirculation in pancreas (36.9±4% vs75.9±10%), liver (56.6±6% vs 75.2±16%), kidney (45.1±6% vs79.3±5%), stomach (65.2±8% vs78.1±19%), colon (69.8±6% vs 102.5±19%),and skeletal muscle (59.2±6% vs 77.9±13%). Heparin treatment lowered IL-6 (359.0±66 U/mL vs 288.5±58 U/mL) and hematocrit level (53±4% vs 46±3%).CONCLUSION: Hepadn administration has a positive influence on organ microcirculatory disturbances accompanying experimental Cn-induced acute pancreatitis.

Management of carbon tetrachloride-induced acute liver injury in rats by syngeneic hepatocyte transplantation in spleen and peritoneal cavity

AIM: Acute hepatitis may seldom have a fulminant course.In the treatment of this medical emergency, potential liver support measure must provide immediate and sufficient assistance to the hepatic function. The goal of our study was to study the adequacy of hepatocyte transplantation (HCTx) in two different anatomical sites, splenic parenchyma and peritoneal cavity, in a rat model of reversible acute hepatitis induced by carbon tetrachloride (CCl4).METHODS: After CCl4 intoxication, 84 male Wistar rats used as recipients were divided in to four experimental groups accordingly to their treatment: Group A (n=24): intrasplenic transplantation of 10±10^6 isolated hepatoo/tes, Group B (n=24):intrapedtoneal transplantation of 20×10^6 isolated hepatocytes attached on plastic microcarriers, Group C (n= 18): intrasplenic injection of 1 mL normal saline (sham-operated controls),Group D (n=18): intraperitoneal injection of 2.5 mL normal saline (sham-operated controls). Survival, liver function tests (LIT) and histology were studied in all four groups, on d 2,5 and 10 post-HCTx.RESULTS: The ten-day survival (and mean survival) in the 4 groups was 72.2% (8.1±3.1), 33.3% (5.4±3.4), 0%(3.1±1.3) and 33.3% (5.4±3.6) in groups A, B, C, D,respectively (PAB＜0.05, PAc＜0.05, P80=NS). In the final survivors, LIT (except alkaline phosphatase) and hepatic histology retumed to normal, independently of their previous therapy. Viable hepatocytes were identified within splenic parenchyma (in group A on d 2) and both in the native liver and the fatty tissue of abdominal wall (in group B on d 5).CONCLUSION: A significantly better survival of the intrasplenically transplanted animals has been demonstrated,Intraperitoneal hepatocytes failed to promptly engraft. A different timing between liver injury and intraperitoneal HCTx may give better results and merits further investigation.

Effects of San Qi on Gastric Secretion and Protective Factors of Gastric Mucosa in the Rat with Precancerous Lesion of Stomach

In the model rat with precancerous lesion of stomach induced by the combined method of insertion of a spring into the pylorus and high salt hot paste, effects of San Qi (三七 Radix Notoginseng) on gastric secretion and protective factors of stomach were investigated.

Effect of Acupuncture on Free Radicals in Rats with Early Experimental Spinal Cord Injury

Effect of acupuncture on free radicals after spinal cord injury was observed in rats with experimental spinal cord injury (SCI). Results indicated that within 24 hours after SCI malondialdehyde (MDA) increased progressively, 2 hours after SCI it reached the peak; and the superoxide dismutase (SOD) activity decreased significantly at the same hours, the decrease being the most marked 2-6 hours after SCI. The MDA content in the acupuncture group was significantly lower (P<0.05) and the SOD activity higher (P<0.01) than that of the control group respectively. It is suggested that acupuncture inhibits production of MDA and increases the SOD activity.……

N-acetylcysteine attenuates alcohol-induced oxidative stess in rats

AIM: To investigate free-radical scavenger effect of nacetylcysteine in rats intragastrically fed with ethanol.METHODS: Twenty-four rats divided into three groups were fed with ethanol (6 g/kg/day, Group 1), ethanol and nacetylcysteine (1 g/kg, Group 2), or isocaloric dextrose (control group, Group 3) for 4 weeks. Then animals were sacrificed under ether anesthesia, and intracardiac blood and liver tissues were obtained. Measurements were made in both serum and homogenized liver tissues.Malondialdehyde (MDA) level was measured by TBARS method. Glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) levels were studied by commercial kits.Kruskal-Wallis test was used for statistical analysis.RESULTS: ALT and AST in Group 1 (154 U/L and 302 U/L,respectively) were higher than those in Group 2 (94 U/L and 155 U/L) and Group 3 (99 U/L and 168 U/L) (P=0.001for both). Serum and tissue levels of MDA in Group 1 (1.84nmol/mL and 96 nmol/100 mg-protein) were higher than that in Group 2 (0.91 nmol/mL and 64 nmol/100 mg protein)and Group 3 (0.94 nmol/mL and 49 nmol/100 mg-protein)(P＜0.001 for both). On the other hand, serum GSH-Px level in Group 1 (8.21 U/g Hb) was lower than that in Group 2(16 U/g Hb) and Group 3 (16 U/g-Hb) (P＜0.001). Serum and liver tissue levels of SOD in Group 1 (11 U/mL and 26U/100 mg-protein) were lower than that in Group 2 (18 U/mL and 60 U/100 mg protein) and Group 3 (20 U/mL and 60 U/100 mg-protein) (P＜0.001 for both).CONCLUSION: Ethanol-induced liver damage was associated with oxidative stress, and co-administration of n-acetylcysteine attenuates this damage effectively in rat model.

Japanese herbal medicine, Saiko-keishi-to, prevents gut ischemia/reperfusion-induced liver injury in rats via nitric oxide

AIM: To determine whether Saiko-keishioto (TJ-10), a Japanese herbal medicine, could protect liver injury induced by gut ischemia/reperfusion (I/R), and to investigate the role of NO.METHODS: Male Wistar rats were exposed to 30-min gut ischemia followed by 60 min of reperfusion. Intravital microscopywas used to monitor leukocyte recruitment. Plasma tumor necrosis factor (TNF) levels and alanine aminotransferase (ALT) activities were measured. T]-10 1 gl(kg.d) was intragastrically administered to rats for 7 d. A NO synthase inhibitor was administered.RESULTS: In control rats, gut I/R elicited increases in the number of stationary leukocytes, and plasma TNF levels and ALT activities were mitigated by pretreatment withT]-10. Pretreatment with the NO synthase inhibitor diminished the protective effects of TJ-10 on leukostasis in the liver, and the increase of plasma TNF levels and ALT activities. Pretreatment with TL-10 increased plasma nitrite/nitrate levels.CONCLUSION: TJ-10 attenuates the gut I/R-induced hepalJc microvascular dysfunction and sequential hepatocellular injury via enhancement of NO production.

Inhibitory effect and mechanism of acarbose combined with gymnemic acid on maltose absorption in rat intestine

AIM To compare the combinative andindividual effect of acarbose and gymnemic acid(GA) on maltose absorption and hydrolysis insmall intestine to determine whether nutrientcontrol in diabetic care can be improved bycombination of them.METHODS The absorption and hydrolysis ofmaltose were studied by cyclic perfusion ofintestinal loops in situ and motility of theintestine was recorded with the intestinal ring invitro using Wistar rats.RESULTS The total inhibitory rate of maltoseabsorption was improved by the combination ofGA (0.1 g/L 1.0 g/L) and acarbose(0.1 mmol/L 2.0 mmol/L) throughout theireffective duration (P＜0.05, U test of Mann-Whitney), although the improvement only couldbe seen at a Iow dosage during the first hour.With the combination, inhibitory duration of acarbose on maltose absorption was prolonged to 3 h and the inhibitory effect onset of GA was fastened to 15min. GA suppressed the intestinal mobility with a good correlation (r-0.98) to the inhibitory effect of GA on maltose absorption and the inhibitory effect of 2mmol/L (high dose) acarbose on maltose hydrolysis was dual modulated by 1 g/L GA in vivo indicating that the combined effects involved the functional alteration of intestinal barriers.CONCLUSION There are augmented effects of acarbose and GA, which involve pre-cellular and paracellular barriers. Diabetic care can be improved by employing the combination.

Pulmonary Toxicity of a Formulated Preparation of Fenvalerate in Rats Subchronically Exposed by Nose Only Inhalation for 90 Days

Objective The pulmonary toxicity of a commercially available formulated preparation of Fenvalerate (Fen), a synthetic pyrethroid has been studied in rats following subchronic nose only inhalation exposure route. Method Adult male rats were exposed to Fen for 4h/day, 5 days a week for 90 days by using Flow Past Dynamic Nose only Inhalation Chamber. Results Fen exposed rats showed a significant increase in enzymatic activities of lactate dehydrogenase (LDH), acid phosphatase (ACP), alkaline phosphatase (ALP) and γ-glutamyl transferase (γ-GT) which are considered as biochemical indicators of pulmonary damage. The concomitant histopathological examination of Fen exposed rats' lung revealed inflammatory changes viz., influx of mononuclear cells admixed with a few giant cells in alveolar lumen, hypetrophied bronchiolar and alveolar epithelial lining cells and presence of edematous fluid in alveolar lumen alongwith congested parenchymatous blood vessels. Conclusion These results for the first time indicate the pulmonary toxic effects of a commonly used formulated Fen preparation by using rat model and nose only inhalation as the route of exposure.

Acute Inhalation Toxicity Study of 2-Fluoroaceta mide in Rats

One of the most potent rodenticides is 2_fluoroacetamide (2_FA). Toxicity of this chemical is well documented. However, its inhalation toxicity data is not available in the literature. Hence, \{acute\} inhalation toxicity study was carried out by exposing male and female rats to aerosols of 2_FA at different concentrations for 4 h in a dynamically operated whole body inhalation exposure chamber. During and after the inhalation exposure the rats were less active, and showed mild tremors and convulsions. At higher concentrations the rats died after 2_3 days. The estimated 4_h LC 50 for male and female rats was 136.6 and 144.5 mg·m -3 respectively. Exposure to 0.7 LC 50 for 4 h duration showed an increase in the liver weight of male and female rats 7 days after exposure. Various haematological and biochemical variables determined were within the normal limits. However, histological findings showed injured lung as indicated by desquamation and necrosis of the epithelium of the respiratory tract. Marked hypertrophy of hepatocytes displaying strong acidophilic granulated cytoplasm was observed. Focal dilatation of renal proximal tubules in kidney with cytoplasmic vacuolation, and irregularly placed pyknotic nuclei were seen. The present study shows that 2_FA is a highly toxic chemical through the inhalation route based on the LC 50 value. Consequently necessary precautions should be taken during its handling.