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Van Loveren H, Vos JG, De Waal EJ. Testing Immunotoxicity of Chemicals as a Guide for Testing Approaches for Pharmaceuticals. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/009286159603000132] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- H. Van Loveren
- Laboratory for Pathology, National Institute of Public Health and Environmental Protection, Bilthoven, the Netherlands
| | - J. G. Vos
- Laboratory for Pathology, National Institute of Public Health and Environmental Protection, Bilthoven, the Netherlands
| | - E. J. De Waal
- Preclinical Assessment Group of the Medicines Evaluation Board, Laboratory for Medicines and Medical Devices, National Institute of Public Health and Environmental Protection, Bilthoven, the Netherlands
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Laudisi F, Sambucci M, Nasta F, Pinto R, Lodato R, Altavista P, Lovisolo GA, Marino C, Pioli C. Prenatal exposure to radiofrequencies: Effects of WiFi signals on thymocyte development and peripheral T cell compartment in an animal model. Bioelectromagnetics 2012; 33:652-61. [DOI: 10.1002/bem.21733] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 04/12/2012] [Indexed: 11/10/2022]
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3
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Collinge M, Burns-Naas LA, Chellman GJ, Kawabata TT, Komocsar WJ, Piccotti JR, Shenton J, Wierda D. Developmental immunotoxicity (DIT) testing of pharmaceuticals: Current practices, state of the science, knowledge gaps, and recommendations. J Immunotoxicol 2012; 9:210-30. [DOI: 10.3109/1547691x.2012.661486] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Differential effects of alprazolam and clonazepam on the immune system and blood vessels of non-stressed and stressed adult male albino rats. Interdiscip Toxicol 2011; 4:132-43. [PMID: 22058654 PMCID: PMC3203915 DOI: 10.2478/v10102-011-0021-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Revised: 07/01/2011] [Accepted: 07/21/2011] [Indexed: 01/21/2023] Open
Abstract
Benzodiazepines belongs to one of the most commonly used anxiolytic and anticonvulsant drugs in the world. Full description of toxic effects on different organs is lacking for nearly all the current benzodiazepines. The aim of the current work was to study the immunologic and vascular changes induced by sub-chronic administration of alprazolam and clonazepam in non-stressed and stressed adult male albino rats. Forty-two adult male albino rats were divided into 6 groups (I): (Ia) Negative control rats, (Ib): Positive control rats received distilled water, (II): Stressed rats, (III): Non-stressed rats received daily oral dose of clonazepam (0.5 mg/kg), (IV): Stressed rats received daily oral dose of clonazepam (0.5 mg/kg), (V): Non-stressed rats received daily oral dose of alprazolam (0.3 mg/kg). (VI): Stressed rats received daily oral dose of alprazolam (0.3 mg/kg). At the end of the 4th week, total leukocyte count (WBCs) and differential count were determined, anti-sheep RBC antibody (Anti-SRBC) titer and interleukin-2 (IL-2) level were assessed, thymus glands, lymph nodes, spleens and abdominal aortae were submitted to histopathological examination. Alprazolam was found to induce a significant increase in neutrophil count and a significant decrease in lymphocytes, anti-SRBC titer and IL-2 level with severe depletion of the splenic, thymal and nodal lymphocytes, accompanied by congestion and eosinophilic vasculitis of all organs tested in comparison to clonazepam treated rats. Stress enhanced the toxic effects. It was concluded that the immune system and blood vessels can be adversely affected to a greater extent by short-term chronic administration of alprazolam than by clonazepam, and these toxic effects are aggravated by stress.
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Sharkhuu T, Doerfler DL, Krantz QT, Luebke RW, Linak WP, Gilmour MI. Effects of prenatal diesel exhaust inhalation on pulmonary inflammation and development of specific immune responses. Toxicol Lett 2010; 196:12-20. [PMID: 20362647 DOI: 10.1016/j.toxlet.2010.03.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Revised: 03/18/2010] [Accepted: 03/24/2010] [Indexed: 12/23/2022]
Abstract
There is increasing evidence that exposure to air pollutants during pregnancy can result in a number of deleterious effects including low birth weight and the incidence of allergic asthma. To investigate the in utero effects of DE exposure, timed pregnant BALB/c mice were exposed to 0, 0.8 or 3.1 mg/m(3) of DE during gestation days (GD) 9 to GD 18. The number of successful pregnancies was 15/20 in the air controls and 10/20 in each of the diesel exposures. Immune function in the 6-week-old offspring as determined by development of delayed type hypersensitivity (DTH) reactions to bovine serum albumin (BSA), antibody titers to injected sheep red blood cells (SRBC), splenic T cells expressing CD45(+)CD3(+)CD8(+) and CD3(+)CD25(+), and mRNA expression of TNF-alpha, TLR2, SP-A, TGF-beta and Foxp3 in the lung were not affected by prenatal DE exposure. On the other hand, lung TLR4 mRNA expression, the number of neutrophils in the bronchoalveolar lavage fluid (BALF) and splenic T cells expressing CD45(+)CD3(+)CD4(+) and CD4(+)CD25(+) were differentially affected depending on the DE concentration and gender. When additional groups of mice were sensitized and challenged via the respiratory tract with ovalbumin to induce allergic airway inflammation, female mice had higher protein levels in the BALF compared to males and this was reduced by prenatal exposure to either concentration of DE. No other changes in allergen-induced immunity, lung function or severity of inflammation were noted. Collectively, the results show that in utero exposure to DE altered some baseline inflammatory indices in the lung in a gender-specific manner, but had no effect on development of specific immune responses to experimental antigens, or the severity of allergic lung inflammation.
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Affiliation(s)
- Tuya Sharkhuu
- Cardiopulmonary and Immunotoxicology Branch, Environmental Public Health Division, NHEERL, US Environmental Protection Agency (EPA), Research Triangle Park, North Carolina 27711, United States
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Sakai M, Fonseca ESM, Dagli MLZ, Palermo-Neto J. Diazepam effects on Ehrlich tumor growth and macrophage activity in mice. Life Sci 2006; 78:1777-83. [PMID: 16257421 DOI: 10.1016/j.lfs.2005.08.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2005] [Accepted: 08/11/2005] [Indexed: 11/23/2022]
Abstract
Besides the central gabaergic receptors described for benzodiazepines, peripheral type binding sites (PBR) were also identified for these molecules in endocrine steroidogenic tissues, immune organs and cells, such as macrophages and lymphocytes. PBR activation was reported to decrease innate immunity and host defense. The present experiment was designed to analyze the effects of diazepam on Ehrlich tumor growth, and on macrophage activity of Ehrlich tumor bearing mice. Results showed that diazepam (3.0 mg/kg/day, for 7 days) increased the number of Ehrlich tumor cells and the volume of tumor-induced ascitic fluid. These effects were not observed after smaller doses of diazepam, suggesting a dose-dependant effect. Furthermore, our results show that 3.0 mg/kg of diazepam, administered daily, for 2 days, decreased (1) the number of peritoneal leukocytes retrieved after injection of the Ehrlich tumor, (2) the percents of macrophage spreading, and (3) the levels of macrophage NO production. Diazepam (3.0 mg/kg/day for 2 days) had no effect on macrophage phagocytosis or on H2O2 production. The present data is discussed based on a direct and/or indirect action of diazepam. Particularly, our findings might be due to a direct effect of diazepam on PBRs present on macrophages and tumor cells, or could still be mediated by PBR stimulation within the hypothalamus-pituitary-adrenal (HPA) axis.
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Affiliation(s)
- M Sakai
- Applied Pharmacology and Toxicology Laboratory, School of Veterinary Medicine, University of São Paulo, São Paulo, SP, Brazil
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Luebke RW, Chen DH, Dietert R, Yang Y, King M, Luster MI. The comparative immunotoxicity of five selected compounds following developmental or adult exposure. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2006; 9:1-26. [PMID: 16393867 DOI: 10.1080/15287390500194326] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
It is well established that human diseases associated with abnormal immune function, including some common infectious diseases and asthma, are considerably more prevalent at younger ages. Although not established absolutely, it is generally believed that development constitutes a period of increased immune system susceptibility to xenobiotics, since adverse effects may occur at lower doses and/or immunomodulation may be more persistent, thus increasing the relative risk of xenobiotic exposure to the immunologically immature organism. To address this issue, a brief overview of immune maturation in humans is provided to demonstrate that functional immaturity alone predisposes the young to infection. Age-dependent differences in the immunotoxic effects of five diverse compounds, diethylstilbestrol (DES), diazepam (DZP), lead (Pb), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and tributyltin oxide (TBTO), which have undergone adult and developmental immunotoxicity testing in rodents, are then reviewed, as are human data when available. For all five chemicals, the developing immune system was found to be at greater risk than that of the adult, either because lower doses produced immunotoxicity, adverse effects were more persistent, or both.
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Affiliation(s)
- Robert W Luebke
- Immunotoxicology Branch, Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.
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Barrow PC, Ravel G. Immune assessments in developmental and juvenile toxicology: Practical considerations for the regulatory safety testing of pharmaceuticals. Regul Toxicol Pharmacol 2005; 43:35-44. [PMID: 16099567 DOI: 10.1016/j.yrtph.2005.06.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2005] [Indexed: 10/25/2022]
Abstract
The developing organism is considered to be more sensitive than the adult to immunotoxic agents. There is every reason, therefore, to include immune assessments in the regulatory testing for developmental toxicity of drugs that are intended to be used in young patients or pregnant woman. An effective strategy would be to incorporate immune assessments in the existing recommendations on pre- and post-natal toxicity study in the rat from the International Conference on Harmonisation. Immune assessments could also be included in juvenile toxicity studies to screen for effects resulting from post-natal exposure to the drug. Adequate testing methods are available to screen for developmental effects that result in immune depression. Routine immune assessments may comprise histopathological examination of the lymphoid organs/tissues and immunophenotyping of lymphocyte subsets in the blood, spleen, or thymus. These tests should be performed in rodents at various ages and at various stages of pre- and post-weaning development. Immunoglobulin and cytokine measurements, assessment of the T-cell dependent antigen response to sheep red blood cells or keyhole limpet haemocyanin antigens, and host resistance studies may be performed as apical tests at maturity. More research is required to develop methods for the detection of drugs that may render the developing organism more susceptible to hypersensitivity or autoimmunity.
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Affiliation(s)
- Paul C Barrow
- MDS Pharma Services, Les Oncins, 69210 Saint-Germain sur l'Arbresle, France.
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da Silva FR, Lazzarini R, de Sá-Rocha LC, Morgulis MSFA, de Oliveira Massoco C, Palermo-Neto J. Effects of acute and long-term diazepam administrations on neutrophil activity: a flow cytometric study. Eur J Pharmacol 2003; 478:97-104. [PMID: 14575793 DOI: 10.1016/j.ejphar.2003.08.046] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study analyzed the effects of acute and long-term diazepam treatments on rat peripheral blood neutrophil activity and cortisol serum levels. Rats were acutely and long-term (21 days, once daily) treated with diazepam (10 mg/kg) or its vehicle (1.0 ml/kg). Blood was collected 1 h after treatments for flow cytometric analysis of neutrophil oxidative burst and phagocytosis. Corticosterone and diazepam concentrations were also determined. Results showed that: (1) both diazepam treatments increased lipopolysaccharide (LPS) and phorbol myristate acetate (PMA)-induced neutrophil oxidative burst; (2) the increase in oxidative burst after Staphylococcus aureus induction in acutely treated animals was higher than that observed after long-term treatment; (3) phagocytosis is increased by acute diazepam treatment and decreased by a long-term regimen; (4) acute, but not long-term, diazepam treatment increased corticosterone levels; (5) diazepam plasmatic levels after acute and long-term treatments were not different. These results indicate the development of tolerance to diazepam effects on corticosterone serum levels but not on neutrophil activity.
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Affiliation(s)
- Fábio Ribeiro da Silva
- Applied Pharmacology and Toxicology Laboratory, School of Veterinary Medicine, University of São Paulo, São Paulo, SP, Brazil
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Massoco C, Palermo-Neto J. Effects of midazolam on equine innate immune response: a flow cytometric study. Vet Immunol Immunopathol 2003; 95:11-9. [PMID: 12969632 DOI: 10.1016/s0165-2427(03)00097-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Benzodiazepines (BDZ) are among the most frequently used class of psychotropic drugs employed in veterinary medicine in Brazil and worldwide due to their anxiolytic, muscle relaxant and anticonvulsant effects [J. Clin. Pharmacol. 33 (1993) 124]. Peripheral benzodiazepine receptor (PBR) sites were described in peripheral organs, endocrine steroidogenic tissues and immune organs and cells. Midazolam is a mixed-type agonist of PBRs. The present study is focused on the effects of midazolam on equine peripheral blood neutrophils, peritoneal macrophages and cortisol levels in plasma. Adult horses were treated with a single dose of midazolam (0.06 or 0.1 mg/kg) or with 0.9% NaCl. Immune cells were collected 24 h after treatment for flow cytometry analysis of Staphylococcus aureus-induced phagocytosis and oxidative burst. Plasma cortisol concentration was measured 30, 90, 180 and 360 min after midazolam treatment. Midazolam induced a dose-dependent reduction on: (1) peripheral blood neutrophil and peritoneal macrophage oxidative burst; (2) the capacity of both peripheral blood neutrophils and peritoneal macrophages to phagocyte S. aureus. Increments on plasma cortisol concentration were not found after 0.06 and 0.1 mg/kg of midazolam. The effects on oxidative burst of neutrophils and macrophages from horses treated with midazolam were interpreted as a consequence of an impairment of S. aureus-induced phagocytosis. The present data suggest that midazolam, most probably acting on PBRs present on equine macrophage and neutrophil membranes, might have changed some mechanisms related to both phagocytosis and oxidative burst. These results support the use of flow cytometry to identify functional properties and dysfunction of equine immune cells. They also confirm the notion that changes in the functional capacity of the immune system may represent an important hazard of exposure to drugs or chemicals.
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Affiliation(s)
- C Massoco
- Applied Pharmacology and Toxicology Laboratory, Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, School of Veterinary Medicine, Universidade de São Paulo, São Paulo, SP, Brazil
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Piersma AH, Verhoef A, Sweep CGJ, de Jong WH, van Loveren H. Developmental toxicity but no immunotoxicity in the rat after prenatal exposure to diethylstilbestrol. Toxicology 2002; 174:173-81. [PMID: 12007857 DOI: 10.1016/s0300-483x(02)00059-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Studies with dioxins and PCB's have shown that the developing immune system may be especially vulnerable to xenobiotics during the perinatal period. However, current guidelines for reproductive toxicity testing do not include immune parameters. In the present study, we have explored the usefulness of including immune parameters within the prenatal developmental toxicity study in rats, using the treatment protocol as described in the OECD 414 developmental toxicity test guideline. In addition, the experimental protocol was enhanced by including ten dose groups to facilitate dose-response analysis. Diethylstilbestrol (DES) was used as the model compound, as it is known to be toxic both for embryofetal development and for the immune system. The results show developmental toxicity in terms of decreased fetal survival and decreased pup body weight in the presence of reduced maternal food consumption and reduced body weight gain. However, immune parameters, including histopathology, hematology, and antibody responses to sheep red blood cells (SRBC) in pups at 4 weeks of age were uncompromised. It is speculated that rather than the prenatal exposure protocol used here, the generation study design with both pre- and postnatal exposure may be preferable as a general screen to detect developmental immunotoxic injury after xenobiotic exposure.
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Affiliation(s)
- A H Piersma
- Laboratories for Health Effects Research and for Pathology and Immunobiology, National Institute for Public Health and the Environment (RIVM), P.O. Box: 1, 3720 Bilthoven, The Netherlands.
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Portela CDP, Tibério IDFLC, Leick-Maldonado EA, Martins MA, Palermo-Neto J. Effects of diazepam and stress on lung inflammatory response in OVA-sensitized rats. Am J Physiol Lung Cell Mol Physiol 2002; 282:L1289-95. [PMID: 12003785 DOI: 10.1152/ajplung.00352.2001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The influence of stress and diazepam treatment on airway inflammation was investigated in ovalbumin (OVA)-sensitized rats. Animals were injected with OVA plus aluminum hydroxide intraperitoneally (day 0) and boosted with OVA subcutaneously (day 7). From the first to 13th day after sensitization, rats were treated with diazepam, and 1 h later they were placed in a shuttle box where they received 50 mild escapable foot shocks/day preceded by a sound signal (S). Response during the warning (S) canceled shock delivery and terminated the S. On day 14, rats were submitted to a single session of 50 inescapable foot shocks preceded by S and then were challenged with OVA. High levels of stress were detected in shocked animals, manifested as ultrasonic vocalizations. Morphometric analysis of stressed animals revealed a significant increase in both edema and lymphomononucleated cells in airways compared with controls. Diazepam treatment reduced edema in stressed and nonstressed rats. No differences were found in polymorphonucleated cell infiltration. Diazepam treatment reduced lymphomononucleated cell infiltration in stressed animals. These data suggest that stress and diazepam treatment play relevant roles in edema and lymphomononucleated airway inflammation in OVA-sensitized rats.
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Affiliation(s)
- Carlos De Paula Portela
- Applied Pharmacology and Toxicology Laboratory, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil
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Domingues-Junior M, Pinheiro SR, Guerra JL, Palermo-Neto J. Effects of treatment with amphetamine and diazepam on Mycobacterium bovis-induced infection in hamsters. Immunopharmacol Immunotoxicol 2000; 22:555-74. [PMID: 10946832 DOI: 10.3109/08923970009026012] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Tuberculosis is an example of an infection with an intracellular bacterium in which sensitivity is determined mainly by the host response. Macrophages are the architectural and functional units of the granulomas described in tuberculosis. Treatment with amphetamine (AMPH) and diazepam has been reported to decrease macrophage activity. The present experiment was undertaken to investigate the effects of AMPH and/or diazepam given alone or in combination on hamster resistance to Mycobacterium bovis. The effects of these treatments on serum cortisol levels were also studied. Adult hamsters were treated i.p. with AMPH (group E1 = 1.0 or 2.0 mg/kg/day), with AMPH (group E2 = 1.0 or 2.0 mg/kg/day) plus diazepam (2.0 mg/kg/day), with diazepam (group E3 = 2.0 mg/kg/day), or with control vehicles (1.0 ml/kg/day) for 40 days. Six days after the beginning of the treatments, the animals received identical inoculum concentrations of M. bovis. Hamsters treated with AMPH plus diazepam exhibited: 1) increased weight loss; 2) increased mortality; 3) increased scores of M. bovis colony forming units (CFU) isolated from liver, lung and spleen; 4) increased granuloma areas measured in the liver, lung and spleen. These effects were not induced by AMPH (1.0 or 2.0 mg/kg/day) given alone and were produced by diazepam (2.0 mg/kg/day) treatment per se. Furthermore, AMPH (2.0 mg/kg/day) and diazepam (2.0 mg/kg/day) given alone or in combination for 20 days increased the serum levels of cortisol in relation to control hamsters, with the effect being higher in the animals treated with both drugs. The present data, which demonstrate an impaired defense against M. bovis in hamsters treated with AMPH plus diazepam or with diazepam alone, were tentatively explained on the basis of a direct and/or indirect action of the drugs on macrophage/lymphocyte activity. In the former case, the effects may be related to stimulation of peripheral benzodiazepine receptor sites (PBR) present on macrophages/lymphocytes and/or to a direct effect of ACTH on immune cells, while in the latter they may be mediated by cortisol via PBR and ACTH stimulation of the adrenals.
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Affiliation(s)
- M Domingues-Junior
- Department of Preventive Medicine and Animal Health, School of Veterinary Medicine, University of São Paulo, Brasil
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Righi DA, Pinheiro SR, Guerra JL, Palermo-Neto J. Effects of diazepam on Mycobacterium bovis-induced infection in hamsters. Braz J Med Biol Res 1999; 32:1145-53. [PMID: 10464392 DOI: 10.1590/s0100-879x1999000900014] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The in utero exposure of hamsters to low doses of diazepam results in impaired host defense against Mycobacterium bovis during adulthood. Delayed developmental immunotoxicity, however, represents a specific situation that might not be general. The present experiment was undertaken to investigate the effects of diazepam on hamster resistance to M. bovis using adult animals. The effects of diazepam treatment on serum cortisol levels were also studied. Adult hamsters (N = 10 for each group) were treated with diazepam (E1 = 1. 0, E2 = 2.0 or E3 = 3.0 mg kg-1 day-1 subcutaneously) or with control solution (C) for 30 days. Seven days after the beginning of the treatment, the animals received identical inoculum concentrations of M. bovis. Hamsters treated with the higher (2.0 and 3.0 mg kg-1 day-1) doses of diazepam exhibited: 1) increased granuloma areas in the liver (C = 1.81 +/- 1.39, E2 = 10.29 +/- 4.64 and E3 = 15.80 +/- 4.82) and lung (C = 0.54 +/- 0.55, E2 = 6.28 +/- 3.85 and E3 = 6.31 +/- 3.56) and 2) increased scores of M. bovis colony-forming units isolated from liver (C = 2.0, E2 = 3.0 and E3 = 3.5), lung (C = 1.0, E2 = 3.0 and E3 = 3.5) and spleen (C = 1.0, E2 = 2.5 and E3 = 4.0). These effects were dose dependent, and were not detected or were less severe in animals treated with the lowest (1.0 mg/kg) dose of diazepam as well as in those of the control group. Furthermore, diazepam treatment (3.0 mg kg-1 day-1 for 30 days) increased (E3 = 71.32 +/- 2.99; N = 10) the serum levels of cortisol compared to control hamsters (C = 22.61 +/- 2.75; N = 10). The present data, that demonstrate an impaired defense against M. bovis in adult hamsters treated with diazepam, were tentatively explained on the basis of a direct and/or indirect action of diazepam on the cytokine network. The effects may be related to stimulation of peripheral benzodiazepine receptor binding sites (PBR) by macrophages and/or lymphocytes, or they may be mediated by PBR stimulation of the adrenals.
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Affiliation(s)
- D A Righi
- Laboratório de Farmacologia Aplicada e Toxicologia, Departamento de Patologia, Universidade de São Paulo, São Paulo, SP, Brasil
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Silva FR, Palermo-Neto J. Developmental, neuro and immunotoxic effects of perinatal diazepam treatment in rats. Immunopharmacol Immunotoxicol 1999; 21:247-65. [PMID: 10319279 DOI: 10.3109/08923979909052761] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In utero exposure of rats to low dosages of diazepam (1.0-2.0 mg/kg) has been found to result in depression of the cellular and humoral immune responses during adulthood. Behavioral dysfunctions were also reported in infants from mothers with high benzodiazepine (BDZ) intake during pregnancy. The present experiment was undertaken to reconsider the potential action of diazepam during ontogeny in order to obtain further information about developmental processes using a refined methodology. Time-pregnant rats were treated subcutaneously with diazepam (2.0 mg/kg/day,: group E1) or with diazepam vehicle (group C1) from gestational day 14 to 20. Other dams (group E2) received the same BDZ dose from the 1st to the 21st day of lactation (weaning) or were not treated, remaining undisturbed in their home cages (group C2). The following results were obtained for animals perinatally treated with diazepam compared to groups C1 and C2: 1--increased time for testis descent and decreased time for vaginal opening (group E2); 2--no changes in the dates for ear end eye opening, or incisor tooth eruption (groups E1 and E2); 3--increased locomotor activity in the open-field (group E2) and/or in the plus maze (groups E1 and E2); 4--decreased levels of anxiety measured in the plus maze (groups E1 and E2); 5--decreased macrophage spreading and phagocytosis (groups E1 and E2). These results, which occurred in the absence of overt signs of maternal or fetal toxicity, demonstrate developmental, neuro- and immunotoxic effects of perinatal diazepam treatment in rats.
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Affiliation(s)
- F R Silva
- Department of Pathology, School of Veterinary Medicine, University of São Paulo, Brasil
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Ugaz EM, Pinheiro SR, Guerra JL, Palermo-Neto J. Effects of prenatal diazepam treatment on Mycobacterium bovis-induced infection in hamsters. IMMUNOPHARMACOLOGY 1999; 41:209-17. [PMID: 10428649 DOI: 10.1016/s0162-3109(99)00031-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In utero exposure of rats to low dosages of diazepam has been found to result in depression of cellular and humoral immune responses during adulthood, with marked changes in macrophage spreading and phagocytosis. The present experiment was undertaken to investigate the resistance of adult hamsters to Mycobacterium bovis after prenatal exposure to diazepam. Time-pregnant hamsters were exposed to diazepam (1.0 or 1.5 mg kg(-1) day(-1) subcutaneously) or vehicle from gestational day 9 to 15. A total of 36 different litters (12 of them control and 12 for each experimental group) born after a 16/17-day gestation were used. One male from each litter was infected twice with identical inoculum concentrations of M. bovis at 75 and 107 days of age. This infection model involves the participation of macrophages and T and B cell populations. The animals prenatally exposed to the higher (1.5 mg/kg) dose of diazepam exhibited: (1) increased weight loss, (2) increased mortality, (3) increased granuloma areas measured in the liver, lung and spleen, (4) increased spleen weight, and (5) increased scores of M. bovis colony forming units (CFU) isolated from liver, lung and spleen. These effects were dose-dependent, and were not detected or were less severe in animals treated with the lower (1.0 mg/kg) dose of diazepam as well as in those of the control group. The present data demonstrate an impaired defence against M. bovis in adult hamsters after in utero exposure to a dosage of 1.5 mg/kg of diazepam.
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Affiliation(s)
- E M Ugaz
- Department of Pathology, School of Veterinary Medicine, University of São Paulo, Brazil
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Apomorphine-susceptible and apomorphine-unsusceptible Wistar rats differ in their susceptibility to inflammatory and infectious diseases: a study on rats with group-specific differences in structure and reactivity of hypothalamic-pituitary-adrenal axis. J Neurosci 1999. [PMID: 9065517 DOI: 10.1523/jneurosci.17-07-02580.1997] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Variability in susceptibility to diseases is a well known phenomenon that has been attributed to genetic and environmental factors. At the level of the immune system, the reactivity of two types of T helper cells (Th1 and Th2 cells) plays an important role in determining disease susceptibility. Inflammatory (autoimmune) diseases are stimulated by cytokines produced by Th1 cells. Th2 cytokines stimulate antibody production (e.g., IgE) and eosinophilia as observed in allergic reactions or during parasitic infections. We describe here that the reactivity in a Th1 or a Th2 disease model significantly differs between individual rats that show group-specific differences in reactivity of the hypothalamic-pituitary-adrenal (HPA) axis, as well as in their behavioral responses to stress. We used two outbred lines of Wistar rats, apomorphine-susceptible rats that have a relatively hyperreactive HPA axis (APO-SUS) and apomorphine-unsusceptible rats that have a relatively hyporeactive HPA axis (APO-UNSUS). APO-SUS, but not APO-UNSUS, rats generated a vigorous, Th2-dependent IgE response after infection with the nematode Trichinella spiralis. In contrast, APO-UNSUS, but not APO-SUS, rats were susceptible for Th1-mediated experimental autoimmune encephalomyelitis. Investigation of cytokine responses of splenocytes revealed that the ratio of mRNA expression for Th1-derived interferon (IFN)-gamma and mRNA expression of Th2-derived interleukin-4 (IL-4) was significantly smaller in APO-SUS than in APO-UNSUS rats. In conclusion, individual differences in structure and reactivity of the neuroendocrine system co-occur with group-specific differences in susceptibility to inflammatory and infectious diseases.
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de Waal EJ, van Loveren H, Vos JG. Practice of Tiered Testing for Immunosuppression in Rodents. ACTA ACUST UNITED AC 1997. [DOI: 10.1177/009286159703100432] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Schlumpf M, Parmar R, Bütikofer EE, Inderbitzin S, Salili AR, Schreiber AA, Ramseier HR, van Loveren H, Lichtensteiger W. Delayed developmental neuro- and immunotoxicity of benzodiazepines. ARCHIVES OF TOXICOLOGY. SUPPLEMENT. = ARCHIV FUR TOXIKOLOGIE. SUPPLEMENT 1995; 17:261-87. [PMID: 7786163 DOI: 10.1007/978-3-642-79451-3_22] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- M Schlumpf
- Institute of Pharmacology, University of Zürich, Switzerland
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