亚硒酸钠染毒对小鼠免疫功能的影响

[目的]观察实验性硒染毒对小鼠免疫功能的影响,为进一步揭示硒免疫损伤过程和机制提供科学依据。[方法]取昆明种健康成年小鼠72只,分为阴性对照组和亚硒酸钠0.28mg/kg(1/100LD50)、1.40mg/kg(1/20LD50)2个剂量组,每组雌雄各半,腹腔注射染毒,每周一次,共56d,分别于染毒后第7、28、56d采用断头断尾取血法采血,测定α-醋酸萘脂酶(acidα-naphthylacetateesterase,α-ANAE)阳性率、淋巴细胞转化率、脾胸腺系数、半数血清溶血素(hemolysin,HC50)数值。[结果]0.28、1.40mg/kg剂量组,α-ANAE阳性率、淋巴细胞转化率、脾脏系数和胸腺系数、半数血清溶血素值均有降低,呈免疫抑制现象,且与硒离子剂量及作用时间均具有相关性。[结论]染毒剂量亚硒酸钠对小鼠具有免疫毒性作用,且呈明显剂量-效应关系。     

Stimulation of immunotoxicity of chemicals metabolizing <Emphasis Type="Italic">in vivo</Emphasis> into highly toxic compounds by the monooxygenase system inductors

Oral treatment of experimental random-bred albino rats with inductors of the monooxygenase system phenobarbital (50 mg/kg) and benzenal (70 mg/kg) for 3 days until acute poisoning with toxins (methanol, ethylene glycol, and dichloroethane in doses of 1.0 LD₅₀) metabolizing in the body to compounds with higher toxicity (phenomenon of lethal synthesis) increased immunotoxicity of these inductors.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 10, pp. 416–419, October, 2004 Original article submitted February 17, 2004     

氟暴露工人免疫功能的检测及氟化钠对体外培养淋巴细胞转化的影响

将62名受检者分为3组,采用单向免疫扩散方法和~3H标记的胸腺嘧啶同位素测定法检测其血清中免疫球蛋白IgG、IgA、IgM含量和外周血淋巴细胞转化情况。发现A组工人(氟暴露时间大于20年)的血清IgG含量,外周血淋巴细胞转化功能明显低于B组工人(氟暴露时间2—3年)和C组工人(非氟暴露者)。同时观察氟化钠对体外培养的淋巴细胞转化的影响,发现氟离子浓度在5mg/100ml时,即可抑制淋巴细胞的转化,并随离子浓度增加而加强。实验结果提示,氟对机体的细胞免疫功能和体液免疫功能均有一定的抑制作用。     

硒对镉致大鼠肺巨噬细胞吞噬和Fc受体表达抑制的保护作用

用体外实验的方法,在观察镉化合物致大鼠肺巨噬细胞吞噬功能和Fc受体表达功能抑制的基础上,研究了硒对镉毒性的拮抗作用。结果表明,氯化偏的毒性是氧化镉毒性的10倍。硒可拮抗氯化镉致肺巨噬细胞的抑制效应。同时还对氯化镉与氧化镉的毒性差别和硒的保护作用进行了探讨。     

Evaluation of a 15-day screening assay using intact male rats for identifying antiandrogens.

An in vivo screening assay using intact adult male rats has been evaluated for its ability to detect six antiandrogenic compounds via oral administration. The test compounds included cyproterone acetate (CPA), flutamide (FLUT), p,p'-DDE (DDE), di-n-butyl phthalate (DBP), linuron (LIN), and vinclozolin (VCZ). Two of the test compounds (DDE and FLUT) have been previously evaluated in the 15-day intact male assay with compound administration via intraperitoneal injection (ip). For the current studies, male rats were dosed for 15 days via oral gavage and euthanized on the morning of test day 15. The endpoints evaluated included final body and organ weights (liver, thyroid gland, testes, epididymides, prostate, seminal vesicles with fluid, accessory sex gland unit [ASG]), serum hormone concentrations (testosterone [T], estradiol [E2], dihydrotestosterone [DHT], luteinizing hormone [LH], follicle stimulating hormone [FSH], prolactin [PRL], T(3), T(4), and thyroid stimulating hormone[TSH]), and histopathology of the testis, epididymis, and thyroid gland; positive results for each endpoint are described below. In addition, an evaluation of immune system endpoints (humoral immune function, spleen and thymus weights, and spleen cell number) was conducted on a subset of animals dosed with either DDE or FLUT. All six endocrine-active compounds (EACs) increased relative liver weight. FLUT and VCZ caused the typical pattern for an androgen receptor (AR) antagonist, although not all endpoints were statistically significant for VCZ: decreased ASG weights, hormonal alterations (increased T, DHT, LH, and FSH), and induced Leydig cell hypertrophy and/or hyperplasia. CPA caused effects consistent with its mixed AR antagonist/progesterone receptor agonist activity: it decreased ASG weights, caused hormonal alterations (increased T and E2; decreased FSH), and caused spermatid retention. DBP, a compound with antiandrogen-like activity via a nonreceptor mediated mechanism, caused hormonal alterations (decreased T, DHT, and E2; increased LH, FSH, and PRL) and induced general testicular degeneration. LIN, a weak AR antagonist, decreased ASG weights, caused hormonal alterations (decreased T, DHT, and LH; increased E2), and caused spermatid retention. Unlike the other AR antagonists evaluated, DDE, a weak AR antagonist, did not alter reproductive parameters. All six antiandrogens caused some effects on thyroid parameters, although only CPA, DDE, and VCZ caused results consistent with a potential thyroid-modulator. FLUT and DDE did not alter the primary humoral immune response to SRBC, spleen or thymus weights, or spleen cell number. In the current study, 5 of the six test substances were identified as endocrine-active substances consistent with their known/proposed mechanism(s) of action. The effects that were observed in the current study via oral (gavage) compound administration were similar to the responses that were observed by the ip route in previous studies for DDE and FLUT. This report, in addition to the > 20 compounds that have already been examined using the 15-day intact male assay, supports this assay as a viable screening assay for detecting EACs, and also illustrates that the ability to identify EACs using the intact male assay will be equivalent regardless of the route of compound administration.     

Evaluation of a 15-day screening assay using intact male rats for identifying steroid biosynthesis inhibitors and thyroid modulators.

An in vivo screening assay using intact adult male rats has been evaluated for its ability to detect four endocrine-active compounds (EACs) via oral (gavage) administration. The test compounds included the aromatase inhibitor fadrozole (FAD), the testosterone biosynthesis inhibitor ketoconazole (KETO), and the thyroid modulators phenobarbital (PB) and propylthiouracil (PTU). Three of the test compounds (KETO, PB, and PTU) have been previously evaluated in the 15-day intact male assay with compound administration via intraperitoneal injection (ip). For the current studies, male rats were dosed for 15 days via oral gavage and euthanized on the morning of test day 15. The endpoints evaluated included final body and organ weights (liver, thyroid gland, testes, epididymides, prostate, seminal vesicles with fluid, accessory sex gland unit [ASG]), serum hormone concentrations (testosterone [T], estradiol [E2], dihydrotestosterone [DHT], luteinizing hormone [LH,] follicle stimulating hormone [FSH], prolactin [PRL], T(3), T(4), thyroid stimulating hormone [TSH]), and histopathology of the testis, epididymis, and thyroid gland; positive results for each endpoint are described below. In addition, an evaluation of immune system endpoints (humoral immune function, spleen and thymus weights, and spleen cell number) was conducted on a subset of animals dosed with either KETO or PB. FAD and KETO decreased the weights for the androgen-dependent tissues and caused similar patterns of hormonal alterations (decreased serum T and DHT; increased serum FSH and/or LH). In addition, KETO caused spermatid retention. For FAD and KETO, effects on thyroid parameters were not indicative of thyroid toxicity. PB and PTU caused thyroid effects consistent with thyroid modulators (increased thyroid weight, decreased serum T(3) and T(4), increased serum TSH, thyroid follicular cell hypertrophy/hyperplasia, and colloid depletion). In addition, PB increased relative liver weight and altered reproductive hormone concentrations (decreased serum DHT, PRL, LH; increased serum E2). Orally administered KETO and PB did not alter the primary humoral immune response to sheep red blood cells (SRBC), although spleen weights were increased at the highest doses for both compounds. In the current study, all four test substances were identified as endocrine-active. The effects that were observed in the current study via oral (gavage) compound administration were similar to the responses that were observed by the ip route in previous studies for KETO, PB, and PTU. Overall, the sensitivity (i.e., the dose required to elicit similar magnitude responses) between the ip and oral routes of administration were similar for the three EACs that were examined by both routes of administration. This article, in addition to the > 20 compounds that have already been examined using the 15-day intact male assay, supports this assay as a viable screening assay for detecting EACs, and also illustrates that the ability to identify EACs using the intact male assay will be equivalent regardless of the route of compound administration.     

医用纤维蛋白胶亚急性毒性实验研究

按照GB／T16886．11医疗器械生物学评价第11部分全身毒性试验的方法，观察了医用纤维蛋白胶对大鼠的全身亚急性毒性反应，其目的是找出纤维蛋白胶毒副反应的靶器官，确定是否有潜在的毒性反应，研究发现纤维蛋白胶浸提液高低剂量连续大鼠腹腔注射给样14天，大鼠一般状况良好，体重增加。给供试品后高剂量雄性和低剂量雄、雌性大鼠的凝血时间与对照组比较明显延长。高、低剂量雌雄性大鼠脾脏系数与对照组比较有显著性差异。病理组织学检查不同剂量浸提液组大鼠脾肿大、充血及生发中心淋巴细胞增生。因此纤维蛋白胶毒性可能的靶器官主要是凝血系统和免疫系统的脾脏，提示可能有潜在的免疫毒性。     

Justification for routine screening of pharmaceutical products in immune function tests: a review of the recommendations of Putman et al. (2003)

In a recent publication by Putman et al. (2003), salmeterol, morphine/methadone and buprenorphine were quoted as examples of pharmaceutical drugs whose immunotoxicity has only been revealed by conduct of specific immune function tests in non-clinical studies. Review of the published non-clinical data for these drugs has shown that there is no clear evidence of immunotoxicity of salmeterol in these studies, and in addition, there are no clinical issues regarding adverse immunological effects of this drug. Of the opioid drugs, only very minor evidence of immunosuppression by morphine, and marginal evidence of slight immunostimulation by buprenorphine were detected in the non-clinical immune function assays performed at high doses. Methadone showed no effects on immune function assays in animals. As some immunomodulation by opioid drugs might have been expected based on the known pharmacological properties of this drug class, the marginal effects, or lack of effects observed in the immune function tests does raise a question about the sensitivity and specificity of the assays to detect clinically relevant changes. This review has suggested that, based on the cited examples, there is no strong case for routine non-clinical immune function testing of all new pharmaceutical products. A more rigorous evaluation of non-clinical immune function tests, and their ability to discriminate between clinically relevant and non-clinically relevant immunosuppression, is needed before definitive regulatory guidance in this area can be finalized.     

Expression of Th1/Th2 cytokines in human blood after in vitro treatment with chlorpyrifos, and its metabolites, in combination with endotoxin LPS and allergen Der p1

Exposure to organophosphate (OP) pesticides has been associated with respiratory symptoms and may be related to asthma; however, few studies have examined the molecular basis for these associations. Asthma and allergic disorders are characterized by elevated Th2 cytokines (IL-4, IL-5, IL-13), whereas the chronic inflammatory response in asthmatic airways is maintained by Th1 cytokine IFN-gamma. The goal of this in vitro study was to examine the effects of OP chlorpyrifos (CPF), and its metabolites chlorpyrifos-oxon (CPO) and 3,5,6-trichloro-2-pyridinol (TCP), singly, and in combination with endotoxin lipopolysaccharide (LPS) or house dust mite Dermatophagoides pteronyssinus (Der p1) allergen, on expression of IFN-gamma and IL-4, Th1 and Th2 signature cytokines, respectively. Cytokine expression was measured by ELISA and flow cytometry. Human blood cultures were treated with CPF/CPO/TCP (1-1000 microg ml(-1)) and LPS (1.5-2.5 microg ml(-1)) or Der p1 (200 AU ml(-1)) and supernatants were collected at 48 h. Pesticides CPF, CPO and TCP did not induce cytokine expression in vitro, while LPS and Der p1 induced IFN-gamma and IL-4 expression, respectively. Whole blood cultures treated with low doses of CPO (1 and 10 microg ml(-1)), in combination with LPS, expressed higher levels of IFN-gamma than LPS alone (P < 0.05). While CPO increased LPS-dependent induction of IFN-gamma, CPO treatment did not alter Der p1 induction of IL-4. The interaction between CPO and LPS, which results in an increased type 1 immune response, should be investigated further, particularly since the combination of OP pesticides and endotoxin is common in rural, agricultural communities.     

Effect of maternal exposure to ozone on reproductive outcome and immune,inflammatory, and allergic responses in the offspring

There is growing concern that exposure to air pollutants during pregnancy affects health outcomes in the offspring due to alterations in the development of immune and other homeostatic processes. To assess the risks of maternal inhalation exposure to ozone (O₃), timed pregnant BALB/c mice were exposed to different concentrations of O₃ (0, 0.4, 0.8, and 1.2?ppm) for 4?h/day for 10 days during gestation (GD9–GD18), and pulmonary inflammation and immune responses were assessed in the offspring at 6 weeks-of-age. Maternal O₃ exposure reduced the number of productive dams by 25% at the highest O₃ concentration (1.2?ppm) and decreased the rate of weight gain in the offspring. Delayed-type hypersensitivity responses to bovine serum albumin were suppressed in the female offspring by maternal exposure to the two highest concentrations of O₃, whereas humoral immune responses to sheep red blood cells were not altered in either sex. Maternal exposure to 1.2?ppm O₃ increased lactate dehydrogenase (LDH) activity in bronchoalveolar lavage fluid (BALF) of the offspring but did not affect the number of inflammatory cells or levels of total protein, IFN-γ, IL-17, and IL-4 cytokines in BALF, or CD4⁺, CD8⁺, CD25⁺, and TCRβ⁺CD1d⁺ T-cells in the spleen. Offspring born from air-exposed dams sensitized early in life (postnatal day [PND] 3) to ovalbumin (OVA) antigen and then challenged as adults developed eosinophilia, elevated levels of LDH activity and total protein in BALF, and increased pulmonary responsiveness to methacholine, compared with animals sensitized at PND42. Maternal O₃ exposure in the 1.2?ppm O₃ group decreased BALF eosinophilia and serum OVA-specific IgE in the female offspring sensitized early in life but did not affect development of allergic airway inflammation by offspring sensitized late in life. In summary, maternal exposure to O₃ affected reproductive outcome and produced modest decreases in immune function and indicators of allergic lung disease in surviving offspring.