Similar cytokine but different coagulation responses to lipopolysaccharide injection in D-galactosamine-sensitized versus nonsensitized rats.

To compare cytokine release and coagulation disturbances induced by administration of high versus low doses of endotoxin (lipopolysaccharide [LPS]), we used two endotoxin test systems similar in mortality but different in the degree of endotoxemia. One group of rats (n = 11) randomly received endotoxin (15.0 mg/kg of body weight intraperitoneally [i.p.]) and 1 ml of Ringer's solution (nonsensitized animals). The second group (n = 11) received 1 ml of D-galactosamine (500 mg/kg i.p.) and endotoxin (100 micrograms/kg i.p.) simultaneously (sensitized animals). Endotoxin levels in the plasma of nonsensitized rats were 1,000-fold higher than those in the plasma of sensitized rats (69.33 x 10(3) +/- 22.42 x 10(3) versus 75.8 +/- 27.08 ng of LPS per ml), leading to a mortality of 91% in nonsensitized rats versus 82% in the sensitized-rat model within 48 h postendotoxemia. Serum transaminase activity increased up to 100-fold in sensitized rats as a sign of hepatocyte damage. Despite the large difference in LPS levels in plasma, the time courses of the plasma tumor necrosis factor (TNF) increase were similar in the two groups, with a peak at 2 h (54 +/- 12 ng/ml in nonsensitized rats versus 43 +/- 12 ng/ml in sensitized rats), and also similar to that of a group of nonsensitized rats (n = 5) that received a low dose of LPS (100 micrograms/kg) only (52 +/- 21 ng/ml), while D-galactosamine alone did not induce TNF release. Despite similar TNF levels, a more pronounced coagulation disorder was observed at 4 h in nonsensitized rats (with the high LPS dose) as measured by platelet counts, plasma fibrinogen levels, and activated partial thromboplastin time prolongation (191 x 10(3) +/- 107 x 10(3) cells per microliter, 40 +/- 24 mg/dl, and 53 +/- 15 s, respectively) than in rats with the low LPS dose either sensitized (495 x 10(3) +/- 153 x 10(3), 95 +/- 49, and 38 +/- 16, respectively) or nonsensitized (439 x 10(3) +/- 62 x 10(3), 170 +/- 18, and 35 +/- 11, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)     

Mu 1 opioid receptor involvement in maternal behavior

Previous studies have demonstrated that morphine inhibits the display of maternal behavior in lactating rats. Whether morphine exerts its actions specifically at the mu receptor has not yet been determined. The present study examined this possibility by evaluating whether naloxonazine, an irreversible and selective antagonist of the mu 1 opioid receptor subtype, is able to attenuate morphine's disruptive effect on maternal behavior in primiparous lactating rats. Experiment 1 compared the ability of naloxonazine (AZINE) and naloxone (NAL) to block the action of morphine (MOR) on maternal care. Virgin, Sprague-Dawley rats were mated in our colony and on day 3 postpartum (parturition, day 0) all rats received jugular catheters. On day 6 the mothers received one of the following treatments: MOR alone (10 mg/kg, SC, N = 10); MOR (10 mg/kg, SC) 24 hr after AZINE pretreatment (10 mg/kg, IV, N = 10); MOR (10 mg/kg, SC) 24 hr after NAL pretreatment (10 mg/kg, IV, N = 8); or MOR (10 mg/kg, SC) immediately after NAL (0.5 mg/kg, SC, N = 10). MOR alone completely disrupted maternal behavior (0% responded) which was blocked by prior NAL administration (100%). AZINE pretreatment 24 hr earlier partially blocked MOR disruption of MB (40% responded; significantly different from MOR alone). The response of rats pretreated 24 hr earlier with NAL did not differ from MOR alone. AZINE blocked MOR's effect on pup retrieval to an even greater degree (70% responded vs. 10% in MOR alone). Experiment 2 determined the ability of AZINE to interfere with varying doses of MOR on maternal behavior.(ABSTRACT TRUNCATED AT 250 WORDS)     

Capillary endothelial thrombomodulin expression and fibrin deposition in rats with continuous and bolus lipopolysaccharide administration

We studied capillary endothelial injury, as demonstrated by fibrin deposition and changes in thrombomodulin (Tm) expression, in rats receiving continuous or bolus iv lipopolysaccharide (LPS). Rats were continuously infused with iv LPS (0.1, 0.2, 0.5, or 1.0 mg/kg/hr) for up to 6 hours. Others were given a bolus iv dose of LPS (20 mg/kg), and then the same dose of saline as a continuous infusion was administered for up to 3 hours. Harvested lungs, livers, and kidneys were examined immunohistochemically for thrombomodulin expression and fibrin deposition. Tm expression began to diminish dose- and time-dependently in lung, liver, and renal peritubular capillaries within 2 to 4 hours of the start of continuous LPS administration (1.0 mg/kg/hr) and had completely disappeared by 3 hours, although Tm remained in the glomerulus. The amount of fibrin deposition observed varied with the organ, dose, and duration of treatment in rats that received continuous LPS administration, but little was deposited in the lung. After bolus LPS administration, Tm in the endothelia of lung, liver, and peritubular capillaries diminished 20 to 40 minutes after treatment and then recovered 120 to 180 minutes after treatment, but the Tm activity of the glomerulus did not change. Fibrin deposition in the capillaries was observed in the liver, glomerulus, and peritubular capillaries, but not in the lung. Endothelial injury by LPS administration is dependent on the dose of LPS and the duration of treatment. The amount of fibrin deposition differs among organs and with the duration of contact between the endothelium and the endotoxin.     

［8F］FDG microPET在评价二次打击所致大鼠急性肺损伤中的应用

目的：对一次打击和二次打击进行深入的对比研究,应用［8F］-氟脱氧葡萄糖（FDG）小动物正电子断层扫描仪（microPET）对肺内的炎症反应进行评价。方法: 将33只SD雄性大鼠随机分为4组,分别为生理盐水 (NS) 组（n=3）：生理盐水1 mL/kg腹腔注射(ip)及16 h后生理盐水0.5 mL/kg气道内滴入（it）;脂多糖(LPS)组（n=10）：LPS 5 mg/kg ip及16 h后生理盐水0.5 mL/kg it;HCl组（n=10）:生理盐水1 mL/kg ip及16 h后HCl（pH=1.2,0.5 mL/kg,it）;二次打击 LPS-HCl 组（n=10）：LPS 5 mg/kg ip及16 h后HCl（pH=1.2,0.5 mL/kg,it）。在盐酸或生理盐水气道滴入前,所有大鼠戊巴比妥钠腹腔注射麻醉,行股动脉插管,连续监测平均动脉压（MAP）,并于it后0.5 h、1.5 h及4 h后抽血,查动脉血气分析,it后4 h行［8F］FDG micro PET 胸部扫描,然后处死动物,取肺组织进行组织病理学观察。结果: 血气分析显示LPS-HCl大鼠低氧血症和二氧化碳潴留显著;MAP在气道内滴入盐酸或生理盐水前无差异,但在滴入后,LPS-HCl 组中MAP较其它3组显著降低;microPET示感兴趣区（ROI）在右肺与右上肢肌肉之间的比值进行比较,LPS-HCl 组中此比值为 9.00±1.41,显著高于LPS组4.01±0.60（P<0.01)和HCl组3.33±0.55 (P<0.01);肺损伤病理评分在 LPS-HCl 组中为12.70±0.95,显著高于 HCl组8.40±1.26（P<0.01）和LPS组7.00±0.82 (P<0.01)。结论:二次打击可使机体肺内产生剧烈而且持久的炎症反应,比一次打击更容易诱发急性肺损伤;microPET作为一种无创的检测手段,能很好地评价急性肺损伤时肺内的炎症反应。     

丙酮酸乙酯对LPS致急性肺损伤大鼠肺组织NF-κB p65及TNF-α和IL-lβ的影响

目的:观察丙酮酸乙酯(EP)对内毒素性急性肺损伤(ALI)大鼠肺组织核转录因子-κB(NF-κB)p65表达及肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)含量的影响,探讨EP可能的肺保护机制。方法:雄性SD大鼠30只随机分为三组(n均=10):正常对照组,静脉注射与其它二组等量生理盐水;LPS组,静脉注射脂多糖(LPS)5mg/kg复制大鼠ALI模型;EP+LPS组,于静脉注射LPS前1h腹腔内注射EP(40mg/kg)。所有动物于注射LPS或生理盐水后4h颈动脉放血处死,取肺组织用Westernblot测定其NF-κBp65的表达,用ELISA测定其TNF-α和IL-1β的含量。结果:与对照组相比,LPS组、EP+LPS组肺组织NF-κBp65表达增加,肺组织TNF-α和IL-lβ含量升高(P0.05);与LPS组相比,EP+LPS组肺组织NF-κBp65表达降低,肺组织TNF-α和IL-lβ含量降低(P0.05)。结论:EP通过下调大鼠LPS诱导的肺组织NF-κBp65表达,降低了TNF-α和IL-lβ的释放。EP可减轻ALI大鼠肺的炎症反应。     

The effects of amrinone and glucagon on verapamil-induced cardiovascular toxicity in anaesthetized rats

The goal of this study was to compare the effects of glucagon and amrinone on mean arterial pressure (MAP) and heart rate, when used alone and in combination, in an anaesthetized rat model of verapamil toxicity. Rats were anaesthetized and the carotid artery was cannulated for MAP and heart rate measurements. Jugular and femoral veins were cannulated for drug administration. After verapamil infusion (15 mg/kg/h), control animals were given normal saline solution and the other groups received amrinone (0.1 or 0.2 mg/kg/min), glucagon (0.3 mg/kg bolus followed by 0.1 or 0.2 mg/kg/min infusion), glucagon plus amrinone (0.1 mg/kg/min and 0.1 mg/kg/min respectively) or glucagon plus amrinone (0.2 mg/kg/min and 0.1 mg/kg/min respectively). Glucagon (0.2 mg/kg/min) significantly increased MAP when compared to the control group ( P  < 0.01). The combination of glucagon and amrinone did not produce a synergistic effect for the recovery of MAP. Furthermore, this combination masked the positive effects of glucagon (0.2 mg/kg/min) on MAP.Glucagon (0.2 mg/kg/min) increased the heart rates compared with those of the control group ( P  < 0.05). Additionally, amrinone (0.1 mg/kg/min) plus glucagon (0.1 mg/kg/min) increased the heart rates ( P  < 0.05). Finally, glucagon dose dependently recovered MAP. While amrinone depressed MAP in combination with glucagon, it did not alter the positive chronotropic effect of high dose glucagon.     

右美托咪定联合乌司他丁减轻脂多糖诱导的大鼠急性肺损伤

 目的：研究右美托咪定（DEX）联合乌司他丁（UTI）对脂多糖（LPS）诱导的大鼠急性肺损伤（ALI）的影响。方法：健康雄性Wistar大鼠40只,随机分为5组：生理盐水对照组（NS组）、LPS模型组（L组）、右美托咪定治疗组（L+D组）、乌司他丁治疗组（L+U组）和右美托咪定+乌司他丁治疗组（L+D+U组）。对照组股静脉给予5 mL/kg生理盐水(NS);模型组股静脉给予LPS (10 mg/kg);右美托咪定治疗组股静脉给予LPS (10 mg/kg),即刻持续输注右美托咪定(1 μg·kg -1·h -1);乌司他丁治疗组股静脉给予LPS (10 mg/kg),即刻腹腔注射乌司他丁(50 000 U/kg);右美托咪定联合乌司他丁治疗组股静脉给予LPS后立即持续输注右美托咪定(1 μg·kg -1·h -1)及腹腔注射乌司他丁(50 000 U/kg)。在注射LPS或NS后6 h处死动物。血气分析检测动脉血氧分压（PaO 2）、pH和碱剩余（BE）;HE染色光镜下观察肺组织病理学变化并进行肺损伤评分;检测肺组织湿干重比（W/D）、髓过氧化物酶（MPO）活性、丙二醛（MDA）、肿瘤坏死因子α（TNF-α）、白细胞介素1β（IL-1β）、巨噬细胞炎症蛋白2（MIP-2）、一氧化氮（NO）及前列腺素E 2（PGE 2）的含量;检测支气管肺泡灌洗液（BALF）中白蛋白浓度;提取肺组织核蛋白,检测NF-κB p65的表达。结果：与NS组比较,L组动脉血PaO 2、pH和BE降低,肺组织水肿、出血、炎症细胞浸润程度及肺损伤评分上升,肺组织TNF-α、IL-1β、MIP-2、MDA、NO、PGE 2含量及W/D升高,MPO活性升高,肺组织 NF-κB表达明显升高。与L组相比,联合治疗组动脉血PaO 2、pH和BE上升,肺组织水肿、出血、炎症细胞浸润程度及肺损伤评分降低,TNF-α、IL-1β、MIP-2、MDA、NO、PGE 2含量及W/D降低,MPO活性降低,肺组织NF-κB表达降低;与L组相比,右美托咪定和乌司他丁单独治疗组上述指标没有明显变化。结论：右美托咪定联合乌司他丁能够减轻脂多糖诱导的大鼠急性肺损伤。     

P38 Mitogen Activated Protein Kinase Is Involved in the Downregulation of Granulocyte CXC Chemokine Receptors 1 and 2 During Human Endotoxemia

Chemokine receptors CXC receptor (CXCR) 1 and 2, and their ligands interleukin (IL)-8 and growth-related oncogene alpha (GRO alpha), are principal regulators of neutrophil activation and migration. To investigate the role of p38 mitogen activated protein kinase (MAPK) in the regulation of CXCR expression during an inflammatory response in vivo, 24 healthy volunteers received an intravenous injection with lipopolysaccharide (LPS) preceded (-3 hr) by a specific p38 MAPK inhibitor (BIRB 796 BS) at a high dose (600 mg) or a low dose (50 mg) or a placebo. The LPS-induced reduction of neutrophil CXCR 1 and 2 expression, as determined by fluorescence-activated cell sorter analysis, was inhibited in volunteers receiving the high dose of the p38 MAPK inhibitor. The kinase inhibitor also dose dependently diminished the LPS-induced rises in plasma IL-8 and GRO alpha levels. These results indicate a principal role for p38 MAPK in regulating factors essential for neutrophil activation and chemotaxis in vivo.     

In vivo effects of the antiglucocorticoid RU 486 on glucocorticoid and cytokine responses to Escherichia coli endotoxin.

The endogenous adrenocortical response to sepsis is critical for host survival. The in vivo interactions among the endogenous glucocorticoid response, the induction of cytokines, and host survival during endotoxemia were explored in this study by use of the glucocorticoid receptor antagonist RU 486. Male Lewis rats underwent sterile insertion of a right jugular venous catheter. After a 72-h recovery period, animals received a 50% lethal dose of Escherichia coli endotoxin (2.5 mg/kg) via the catheter after pretreatment for 30 min prior to lipopolysaccharide (LPS) treatment with (i) vehicle alone intravenously (i.v.) (-corticosterone [-Cort]/-RU 486/+LPS) (n = 10), (ii) the antiglucocorticoid RU 486 (10 mg/kg) i.v. (-Cort/+RU 486/+LPS) (n = 11), or (iii) RU 486 (10 mg/kg) i.v. in animals that had undergone subcutaneous implantation of a corticosterone pellet at the time of catheter insertion (+Cort/+RU 486/+LPS) (n = 10). Except in animals receiving corticosterone pretreatment, baseline plasma corticosterone levels were low in all groups. Plasma corticosterone levels increased significantly (P less than 0.001) above the baseline following LPS administration. Animals in the -Cort/+RU 486/+LPS-treated group exhibited significantly increased mortality (P less than 0.001), with only 9% of the animals surviving at 72 h, as well as significantly increased plasma interleukin-6 levels, compared with animals receiving the vehicle alone (-Cort/-RU 486/+LPS), which showed 50% mortality. Pretreatment with corticosterone and RU 486 (+Cort/+RU 486/+LPS) significantly (P less than 0.001) reversed the mortality observed with RU 486 pretreatment alone (-Cort/+RU 486/+LPS), with 70% of the animals surviving at 72 h, and significantly attenuated the peak plasma tumor necrosis factor and interleukin-6 responses to LPS, compared with those in the animals treated with vehicle alone. These data demonstrate that the blockade of glucocorticoid binding by RU 486 increases LPS-induced mortality. The reversal of this effect by the induction of hypercorticosteronemia prior to RU 486 and LPS exposure (+Cort/+RU 486/+LPS) improves survival and is further associated with significant attenuation of cytokine production. Therefore, these data suggest that the protective effect of the endogenous glucocorticoid response to acute endotoxemia may result from the down-regulation of a potentially lethal cytokine response.     

Growth hormone increases lung NF-kappaB activation and lung microvascular injury induced by lipopolysaccharide in rats

The purpose of this study was to examine the effects of growth hormone (GH) on nuclear factor kappa B (NF-kappaB) activation and organ injury induced by lipopolysaccharide (LPS) in rats. Male Wistar rats were divided into 6 groups treated with saline, LPS (5 mg/kg), LPS plus GH (0.5, 1.0, 2.0 mg/kg), or GH (2.0 mg/kg) alone for 2 or 4 hr. NF-kappaB activity and I-kappaB level in lung, lung accumulation of neutrophils, and lung microvascular injury were measured. LPS-challenged rats had increased NF-kappaB activity and decreased I-kappaB level in lung, compared to controls. GH dramatically enhanced NF-kappaB activation and I-kappaB degradation induced by LPS challenge. LPS plus GH treatment increased lung accumulation of neutrophils, compared with LPS treatment. Also, subsequently, GH treatment increased lung microvascular injury induced by LPS. These findings suggest that treatment with GH is harmful, instead of beneficial, to LPS-induced organ injury. Increased NF-kappaB activation may be a critical in vivo mechanism that mediates GH action on LPS-induced organ injury. Thus, it is appropriate to rethink GH administration in critical illnesses; further studies are required to evaluate the safety and clinical benefits of GH administration in such conditions.     

A novel animal model for motion sickness and its first application in rodents

The present work was designed to establish a novel animal model for motion sickness (MS) in rodents and to evaluate the effects of a combination of scopolamine and modafinil on MS with this novel method. It was found that the rats and mice presented several symptoms induced by rotation such as, piloerection, tremble, urinal and fecal incontinence. As the rats and mice are lack of emesis response to rotation, we used a score based on abovementioned symptoms as an index for the severity of MS in rodents. MS index was determined in 260 mice with this novel method. It was found that the distribution of MS index was normal (W=0.99; P=0.23. P>0.05 considered values' normal distribution). The effects of scopolamine on MS were studied in mice and rats. It was found that scopolamine significantly decreased MS index at the dose of 0.3 mg/kg in mice and 1.0 mg/kg in rats. Finally, the effects of a combination of scopolamine and modafinil were observed with this novel method in rats. It was found that the efficacy of the combination (5.0+5.0 mg/kg) was greater than the single drugs (10 mg/kg). Even the smallest dose of the combination (0.5+0.5 mg/kg) had a similar effect to large dose of scopolamine or modafinile when they were used alone. In conclusion, this animal model is suitable for MS study in rats and mice and the combination of scopolamine and modafinil might be a new method to treat or prevent MS.     

Hepatoprotective effect of 3-alkynyl selenophene on acute liver injury induced by D-galactosamine and lipopolysaccharide

The aim of this study was to investigate the hepatoprotective effect of 3-alkynyl selenophene (compound a), a selenophene compound, on acute liver injury induced by D-galactosamine (D-GalN) and lipopolysaccharide (LPS) in rats. The animals received compound a (25 and 50 mg/kg; per oral, p.o.) in the first day of treatment. In the second day, the rats received D-GalN (500 mg/kg; intraperitoneal, i.p.) and LPS (50 μg/kg; intraperitoneal, i.p.). Twenty-four hours after D-GalN/LPS administration animals were euthanized to the biochemical and histological analysis. Compound a (25 and 50 mg/kg; p.o.) protected against the increase in aspartate aminotransferase (AST) activity induced by D-GalN/LPS. Compound a at 50 mg/kg protected against the increase in alanine aminotransferase (ALT) activity induced by D-GalN/LPS. The inhibition of δ-aminolevulinic dehydratase (δ-ALA-D) activity and the decrease of ascorbic acid levels caused by D-GalN/LPS were protected by compound a (25 and 50 mg/kg). Glutathione S-transferase (GST) and catalase activities were not altered in all groups. The histological data showed that sections of liver from D-GalN/LPS-treated rats presented massive hemorrhage, the presence of inflammatory cells and necrosis. Compound a attenuated D-GalN/LPS-induced hepatic histopathological alterations. Based on the results, we demonstrated the hepatoprotective effect of compound a on acute liver injury induced by D-GalN/LPS.     

Acute and chronic administration of immunomodulators induces anorexia in Zucker rats

To investigate the possible involvement of leptin signaling in lipopolysaccharide (LPS) anorexia, we compared the anorectic effect of LPS in genetically obese (fa/fa) Zucker rats and in their lean (Fa/?) counterparts. The effects of interleukin-1beta (IL-1beta) and muramyl dipeptide (MDP) were also tested. LPS [100 microg/kg body weight (BW)], IL-1beta (2 microg/kg BW) and MDP (2.2 mg/kg BW) injected intraperitoneally (i.p.) at lights out reduced food intake similarly in obese and lean rats. LPS injection at 500 or 1000 microg/kg BW (i.p.) also reduced food intake and BW similarly in obese and lean rats, but obese regained BW faster than lean rats. LPS (2.45 microg or 9.8 microg/h/rat) administered chronically with i.p. implanted osmotic pumps reduced food intake similarly on experimental day 1, regardless of the genotype. After day 3, the lean rats' anorectic response and recovery were dose-dependent, whereas the anorectic response in obese rats was minimally affected by dose (significant dose effect only on day 3). Again, obese rats regained lost BW faster than lean rats. These results do not support a role for leptin as the sole mediator of anorexia induced by bacterial products (LPS and MDP) and IL-1beta.     

Lipopolysaccharide reduces sodium intake and sodium excretion in dehydrated rats

The objective of this study was to find out if lipopolysaccharide (LPS) administered intraperitoneally affects sodium and water intake and renal excretion in dehydrated rats. LPS (0.3-5 mg/kg b.w.) inhibited 0.3 M NaCl intake induced by subcutaneous injection of the diuretic furosemide (FURO, 10 mg/kg b.w.) combined with the angiotensin converting enzyme inhibitor, captopril (CAP, 5 mg/kg b.w.). Only the highest doses of LPS (2.5 and 5 mg/kg) inhibited water intake induced by FURO/CAP. LPS (0.6 mg/kg) reduced urinary volume and sodium excretion, but had no effect on mean arterial pressure or heart rate of rats treated with FURO/CAP. LPS (0.3-5.0 mg/kg) abolished intracellular thirst and reduced by 50% the urine sodium concentration of rats that received 2 ml of 2 M NaCl by gavage. LPS (0.3-5.0 mg/kg) also reduced thirst in rats treated with FURO alone (10 mg/rat sc). The results suggest that LPS has a preferential, but not exclusive, inhibitory effect on sodium intake and on intracellular thirst. The inhibition of hydro-mineral intake and the antinatriuresis caused by LPS in dehydrated rats may contribute to the multiple effects of the endotoxin on fluid and electrolyte balance and be part of the strategy to cope with infections.     

Ameliorative effect of vitamin C on the haematological changes induced by exposure of chlorpyriphos and lead acetate in Wistar rats

The present study was designed to evaluate the effects of chlorpyriphos, lead acetate and vitamin C alone and in combinations, on various haematological parameters in Wistar rats. Rats of 150–200 g body weight were divided into eight groups of six animals each and were subjected to various daily oral treatment regimes for 98 days. Group C served as control receiving only corn oil, group CP received chlorpyriphos at 5.5 mg/kg in corn oil and group L received lead acetate at100?ppm in water, whereas animals in group CP + L received a combination of chlorpyriphos at 5.5 mg/kg in corn oil and lead acetate at 100 ppm in water. Group VC received vitamin C at 100 mg/kg in water; group CP + VC received a combination of chlorpyriphos at 5.5 mg/kg and vitamin C at 100 mg/kg; group L + VC received lead acetate at 100 ppm in water and vitamin C at 100 mg/kg and group CP + L + VC received chlorpyriphos at 5.5 mg/kg, lead acetate at 100 ppm in water and vitamin C at 100 mg/kg. Blood samples were collected on days 0, 30, 60 and 98 post exposure and analysed for packed cell volume (PCV), total erythrocyte count (TEC), haemoglobin (Hb), erythrocyte sedimentation rate (ESR), total leucocyte count (TLC) and differential leucocyte count. A significant decrease in TEC, PCV and Hb and a significant increase in ESR values were observed. However, lead acetate caused an increase in TLC while chlorpyriphos resulted in a decrease in TLC. Both of these toxicants potentiated toxicity of each other. The study demonstrated that treatment of chlorpyriphos- and lead-treated rats with vitamin C significantly altered some of the important haematological parameters revealing the protective effect of this vitamin against haematological alterations induced by chlorpyriphos and lead.     

Endogenous production of tumor necrosis factor in normal mice orally treated with Deodan--a preparation from Lactobacillus bulgaricus "LB51".

The ability of orally administered Deodan, a product from the cell wall of Lactobacillus bulgaricus strain "I. Bogdanov patent strain tumoronecroticance B51" ATCC #21815, shortly called "LB51", to induce endogenous tumor necrosis factor-alpha (TNF alpha) production in normal mice was evaluated. The priming and triggering activities of the preparation were investigated in combination with lipopolysaccharide (LPS) and live BCG vaccine. Deodan was applied at a dose of 150 mg/kg and various treatment schedules were employed. The serum levels of TNF alpha in treated mice were quantified by ELISA. Oral administration of Deodan at a dose of 150 mg/kg for 1, 3, 10 or 20 consecutive days only enhanced serum TNF alpha levels in treated mice. Maximal TNF alpha levels were reached 6 h after the last application of Deodan. Deodan was effective in priming TNF alpha in mice triggered intravenously (i.v.) with LPS. Deodan triggered the production of TNF alpha in BCG-primed mice. The preparation, however, was not an effective trigger of mice primed intradermally (i.d.) with 1 microgram/mouse LPS. These findings suggest that Deodan is both a primer and trigger of endogenous TNF alpha. The advantages of treatment of neoplastic disease with agents which induce endogenous TNF alpha is discussed.     

Cytogenetic effects of commercial formulations of deltamethrin and/or isoproturon on human peripheral lymphocytes and mouse bone marrow cells

The cytogenetic effects of deltamethrin (DEL) and/or isoproturon (ISO) were examined in human lymphocytes and mouse bone marrow cells. Peripheral lymphocytes were exposed to DEL (2.5, 5, 10, or 20 microM), ISO (25, 50, 100, or 200 microM), or DEL + ISO (2.5 + 25, 5 + 50, 10 + 100, or 20 + 200 microM) and cytogenic effects were evaluated via chromosomal aberrations (CA) and the cytokinesis-block micronucleus assay (CBMN). Mice were orally gavaged to single dose of DEL (6.6 mg/kg), ISO (670 mg/kg), or DEL+ISO (6.6 + 670 mg/kg) for 24 hr or to DEL (3.3 mg/kg/day), ISO (330 mg/kg/day), or DEL + ISO (3.3 + 330 mg/kg/day) for 30 days and analyzed for CA. DEL induced a significant frequency of CA at 10 microM whereas ISO (25-100 microM) alone, or in combination with DEL, did not show any significant effect. Micronucleus (MN) induction was observed to be concentration-dependent though significant frequencies were observed at 5 microM DEL, 100 microM ISO, or 5 + 50 microM DEL + ISO. In mice, DEL inhibited the mitotic index (MI) significantly (P < 0.001) at 24 hr while ISO alone, or in combination with DEL, did not cause any statistically significant effect. Following a 24 hr exposure, DEL and ISO alone induced significant (P < 0.01) frequencies of CA, whereas DEL + ISO in combination did not. Furthermore, 30 days exposure of ISO significantly inhibited the MI (P < 0.02 or < 0.01) and induced CA while DEL alone, or in combination with ISO, resulted in no significant effect on CA or the MI. The present findings indicate that the in vitro and in vivo exposure of a commercial formulation of DEL can cause genotoxic effects in mammals. However, the coexposure of DEL and ISO did not show additive effects, but instead demonstrated somewhat reduced genotoxicity.     

盐酸戊乙奎醚抑制脂多糖致急性肺损伤大鼠肺组织p38丝裂原活化蛋白激酶的活化

目的:观察盐酸戊乙奎醚(PHC)对脂多糖(LPS)致急性肺损伤(ALI)大鼠肺组织p38丝裂原活化蛋白激酶(p38MAPK)、c-jun氨基末端激酶(JNK)活化的影响。方法:SD大鼠随机分为对照组、LPS模型组（5 mg/kg LPS,iv）和LPS+PHC高、中、低(3.0、1.0和0.3 mg/kg)3个剂量组,每组6只,进行PHC对肺组织p38MAPK、JNK表达的量效性分析;另取大鼠在注入NS后即刻0（对照组）和注射LPS后2 h、4 h、6 h和12 h共5个时点,每时点6只,进行肺组织p38MAPK、JNK表达的时效性分析。蛋白免疫印迹法检测肺组织p38MAPK、JNK的表达。结果:LPS模型组大鼠肺组织磷酸化p38MAPK、JNK的表达显著高于对照组（P＜0.05);PHC高剂量组显著抑制LPS诱导的大鼠肺组织磷酸化p38MAPK表达（P＜0.05);PHC在造模后6 h时最能有效抑制磷酸化p38MAPK上调。与LPS模型组相比,PHC高、中、低剂量组磷酸化JNK的表达均无显著差异(均P＞0.05);造模后不同时点,PHC对磷酸化JNK的表达均无抑制作用。结论:PHC抑制LPS诱导的ALI大鼠肺组织p38MAPK活化,但不能抑制JNK活化,PHC对LPS诱导大鼠ALI的拮抗作用可能与其抑制p38MAPK的活化有关。     

Pharmacokinetics of 125I-radiolabelled PEG-hemoglobin SB1

PEG-hemoglobin SB1 (SB1) is a polyethylene glycol (PEG)-modified hemoglobin-based oxygen carrier, intended for use as resuscitation fluid for brain stroke and as a blood substitute. An intravenous pharmacokinetics (PK) studies with SB1 was investigated in male albino Sprague-Dawley (SD) rats and male beagle dogs at doses of 5 and 12.5 ml/kg for rats and 10 ml/kg for dogs. Total hemoglobin in plasma and whole blood was determined by gamma scintillation counter-detecting 125I-radiolabelled SB1. In the 5 ml/kg rats (n = 9), the Cmax, t1/2, AUCt and Tmax were 9.055 mg equivalents/ml, 9.6 hr, 79.6 mg equivalents.hr/ml and 0.20 hr in the plasma and 4.954 mg equivalents/ml, 9.7 hr, 37.6 mg equivalents.hr/ml and 0.11 hr in the whole blood, respectively. Those parameters in the 12.5 ml/Kg of rats (n = 9) were 19.00 mg equivalents/ml, 10.6 hr, 223.5 mg equivalents.hr/ml and 0.33 hr in the plasma and 10.58 mg equivalents/ml, 16.1 hr, 99.0 mg equivalents.hr/ml and 0.33 hr in the whole blood, respectively. An increase in the dose level from 5 to 12.5 ml/kg resulted in the increase in both Cmax and AUC24, and the increases in these parameters appeared to be in proportion to the dose increment. Thus, following the 2.5-fold increase in administered dose, Cmax was increased by a factor of 2.1 in both plasma and whole blood, while AUC24 was increased by a factor of 2.8 for plasma and 2.6 for whole blood. In the dogs receiving 10 ml/kg (n = 3), the Cmax, t1/2, AUC168 and Tmax were 12.70 mg equivalents/ml, 47.2 hr, 425.7 mg equivalents.hr/ml and 0.083 hr in the plasma and 8.372 mg equivalents/ml, 50.3 hr, 241.3 mg equivalents.hr/ml and 1.003 hr in the whole blood, respectively. The present work provides an insight into the pharmacological behavior of a PEG-modified hemoglobin.     

异丙酚抑制脂多糖致大鼠脑损伤时p38 MAPK的活化

目的: 观察异丙酚对脂多糖(LPS)致大鼠脑损伤时脑组织p38丝裂原活化蛋白激酶(p38 MAPK)和诱导型一氧化氮合酶(iNOS)活化的影响。 方法: SD大鼠,雌雄不限,随机分为3组(n=24):对照组(C组)、LPS组(LPS组)和LPS+异丙酚组(LPS+P组),LPS组经左颈内动脉注射LPS(1 mg/kg)建立LPS性脑损伤模型,LPS+P组在给予LPS后立即通过腹腔注射给予异丙酚(100 mg/kg),C组给予等容量生理盐水。分别于注射异丙酚后6、24 、48和72 h处死6只大鼠,取大脑皮质组织,测定脑组织含水量、磷酸化p38 MAPK和iNOS表达水平,光镜下观察脑组织形态及病理变化。 结果: 与C组比较,LPS组各时点脑组织含水量升高,脑组织磷酸化p38 MAPK和iNOS表达水平均于6 h开始增加,24 h达高峰,48 h及72 h各指标仍高于C组(P<0.05);与LPS组相比,LPS+P组脑组织含水量、磷酸化p38 MAPK和iNOS的表达水平降低(P<0.05)。脑组织含水量与磷酸化p38 MAPK、iNOS水平呈正相关(r=0.603,r=0.727, P<0.05)。LPS+P组脑组织病理学损伤轻于LPS组。 结论: 异丙酚可减轻LPS所致的大鼠脑损伤,其机制可能与异丙酚抑制脑组织p38 MAPK活化,下调iNOS的表达,进而减轻炎性反应有关。