Mannfred A. Hollinger

Effect of antibody to transforming growth factor beta on bleomycin induced accumulation of lung collagen in mice.

BACKGROUND--Increased production of transforming growth factor beta (TGF-beta) seems to have an important role in the pathophysiology of bleomycin induced lung fibrosis. This is attributed to the ability of TGF-beta to stimulate infiltration of inflammatory cells and promote synthesis of connective tissue, leading to collagen deposition. METHODS--The study was designed to evaluate the antifibrotic potential of TGF-beta antibody in mice treated with bleomycin, which is a model of lung fibrosis. Under methoxyflurane anaesthesia, each mouse received intratracheally either 50 microliters sterile isotonic saline or 0.125 units bleomycin in 50 microliters. Within five minutes after the instillation, mice received into the tail vein 100 microliters non-immune rabbit IgG, TGF-beta 2 antibody, or a combination of TGF-beta 2 and TGF-beta 1 antibodies at various dose regimens. Mice were killed 14 days after the instillation and their lungs processed for morphological and biochemical studies. RESULTS--Administration of 250 micrograms of TGF-beta 2 antibody after instillation of bleomycin followed by 100 micrograms on day 5 and 100 micrograms on day 9 significantly reduced the bleomycin induced increases in the accumulation of lung collagen from 445.8 (42.3) micrograms/lung to 336.7 (56.6) micrograms/lung at 14 days. Similarly, the combined treatment with 250 micrograms TGF-beta 2 antibody and 250 micrograms TGF-beta 1 antibody after bleomycin instillation followed by 100 micrograms of each antibody on day 5 also caused a significant reduction in bleomycin induced increases in lung collagen accumulation and myeloperoxidase activity at 14 days. CONCLUSIONS--These results suggest that TGF-beta has an important role in the aetiology of bleomycin induced lung fibrosis; the neutralisation of TGF-beta by systemic treatment with its antibodies offers a new mode of pharmacological intervention which may be useful in treating lung fibrosis.

Handbook of Toxicology

Laboratory Animal Management, JC. Siglin and W.H. Baker Acute and Chronic Toxicology, C.S. Auletta Dermal Irritation and Sensitization, K.L. Bonnette, D.D. Rodabaugh, and C.W. Wilson Ocular Toxicology, B.J. Dunn Fundamental Inhalation Toxicology, P.E. Newton Applied Inhalation Toxicology, G.M. Hoffman Fundamental Neurotoxicology, G.E. Schulze Applied Neurotoxicology, R. Mandella Immunotoxicology: Fundamentals of Preclinical Assessment, R.V. House and P.T. Thomas Renal Toxicology, W.J. Powers, Jr. Reproductive Toxicology, D. J. Ecobichon Developmental Toxicology, K.M. MacKenzie and R.M. Hoar Endocrine Toxicology: Male Reproduction, S.C. Sikka and R.K. Naz Endocrine Toxicology: The Female Reproductive System, P.B. Hoyer and P.J. Devine Genetic Toxicology, R.H.C. San, R. vi Gudi, V.O. Wagner, R. Young, and D. Jacobson-Kram Carcinogenesis, M.J. Derelanko Animal Histopathology, J.C. Peckham Animal Clinical Pathology, B.S. Levine Metabolism and Toxicokinetics of Xenobiotics, M.B. Abou-Donia, E. Elmasry, and A.W. Abu-Qare In Vitro Methods for the Prediction of Ocular and Dermal Toxicity, J.W. Harbell and R.D. Curren Ecotoxicology, D.J. Hoffman, B.A. Rattner, G.A. Burton, Jr., and D.R. Lavoie Metal Toxicology, A. Yasutake and K. Hirayama Human Clinical Toxicology, J. Dolgin Risk Assessment, M.J. Derelanko Regulatory Toxicology in the United States: An Overview, M.J. Derelanko Regulatory Toxicology: United States EPA/Chemicals (TSCA), H.C. Fogle Regulatory Toxicology: United States EPA/Pesticides (FIFRA), J.E. Harris Regulatory Toxicology: United States FDA/Pharmaceuticals, W.J. Powers, Jr. Regulatory Toxicology: Medical Devices, S.J. Hermansky Regulatory Toxicology: Consumer Products, D.J. Nass Regulatory Toxicology: Notification of New Substances in the European Union, M.J. Derelanko Regulatory Toxicology: Notification of New Substances in Canada, Korea, Australia and China, H.C. Fogle Miscellaneous Information of Toxicological Significance, M.A. Hollinger and M.J. Derelanko

Toxicological Aspects of Topical Silver Pharmaceuticals

Silver is generally considered to present a relatively low toxic threat to humans because unintentional exposure to large doses of the noble metal is quite rare. However, as the intentional utilization of silver in pharmaceutical preparations and devices increases, subtle toxic effects of silver may be predictable and expected. The present review examines the scientific literature, primarily covering the past 10 years, dealing with reports describing various types of silver toxicity. These reports consist of both in vitro and in vivo data dealing with immunological, mesenchymal, neural, and parenchymal cell types. Particular emphasis is given to (1) the use of silver in topical antimicrobial preparations as toxicity relates to absorption through dermal wounds into the systemic circulation and possible effects on delayed wound healing, (2) possible local silver toxicity via iontophoretic devices, (3) current theories relating to the toxicological mechanism of action of silver.

Biochemical and structural alterations of hamster lungs in response to intratracheal administration of bleomycin

Abstract One unit of bleomycin was administered intratracheally to hamsters and an equivalent volume of saline to controls. Morphological changes within lungs of bleomycin-treated hamsters consisted of a diffuse hemorrhagic interstitial pneumonia at 7 days post-treatment. Lungs contained less hemorrhage and edema but increased numbers of mononuclear inflammatory cells and thickened interalveolar walls at 14 days post-treatment. A diffuse mononuclear cell infiltrate with multifocal areas of fibrosis later predominated. The protein, RNA, and DNA levels in bleomycin-treated hamsters were consistently and significantly elevated at 4 (except DNA), 7, 14, 21, and 28 days after treatment. The Ca 2+ levels in lungs of these animals at the corresponding times were increased by 158, 194, 36, 22, and 8% without any change in plasma Ca 2+ . Lung soluble collagen was increased by 124, 207, 121, and 30% at 7, 14, 21, and 28 days, respectively, after bleomycin treatment. The increases in insoluble collagen were 65, 108, 132, and 91% at the corresponding times. The lung cAMP levels at 4, 7, 14, 21, and 28 days were 176, 164, 132, 158, and 96% of control, respectively, and cGMP at the corresponding times were 50, 81, 222, 198, and 137% of control. These data suggest that shifts in the intracellular levels of cAMP, cGMP, and Ca 2+ are associated with early lung changes induced by bleomycin insult and may serve as indicators to gauge the severity and progression of lung damage.

The effects of diphenylhydantoin, phenobarbital, and diazepam on the penicillin-induced epileptogenic focus in the rat

Abstract Techniques are described for the injection of minute quantities of penicillin into discrete intracortical loci in freely moving rats. The time course and quantification of the penicillin-induced cortical afterdischarges and seizure activity were determined. 14 C-penicillin was used to test assumptions related to the spread of this agent from the intracortical site of injection. The degree of spread was limited to the ipsilateral hemisphere along the cortical surface and was verified by both scintillation counting and autoradiography. The effects of diphenylhydantoin (30, 60 mg/kg, po), phenobarbital (15, 30 mg/kg, po) and diazepam (15, 30 mg/kg, po) on the penicillin-induced focal seizures were not marked. None of the agents produced a significant decrease in the spiking frequency, the number of afterdischarges, the total amount of afterdischarge activity or the average length of afterdischarge, even though the higher doses of all three compounds produced signs of neurotoxicity.

Modification of dopaminergic receptor sensitivity in rat brain after amygdaloid kindling.

Alterations in dopaminergic receptor sensitivity in various brain areas have been demonstrated in the rat after the kindling of seizures by repeated amygdala stimulation. Using a radioligand binding assay with [3H]spiroperidol as the ligand and butaclamol as the specific antagonist in crude brain homogenates, high- and low-affinity receptor sites have been shown to be differentially affected in various brain areas with respect to both density of sites and affinity for ligand.

The effects of ozone and paraquat on PGF2α and PGE2 levels in plasma and combined pleural effusion and lung lavage of rats

Abstract The effects of lung toxins O 3 and paraquat on PGF 2α and PGE 2 levels of plasma and combined pleural effusion and lung lavage were studied in male Sprague-Dawley rats using radioimmunoassay. The plasma concentration of PGF 2α in rats exposed to 4 ppm O 3 for 2, 4, and 8 hr was increased by 186, 109, and 25%, respectively. The increases in PGF 2α level in pleural effusion-lung lavage of these rats at the corresponding times were 82, 0, and 65%. The plasma concentrations of PGF 2α and PGE 2 were increased in response to treatment with paraquat (45 mg/kg i.p.). The increases in plasma PGF 2α at 1.5, 3, 6, 12, 24, and 48 hr following paraquat treatment were 223, 128, 47, 270, 195, and 130%, respectively. The increases in plasma concentration of PGE 2 at the corresponding times were 9, 88, 279, 323, 325, and 66%. In view of a dramatic increase in the prostaglandin level of plasma and pleural effusion-lung lavage following exposure to O 3 and treatment with paraquat, it has been suggested that an increased level of prostaglandin in plasma and lung lavage (done in case of O 3 ) might offer some diagnostic value for the morphological and functional impairment of the lung.

The Effects of Paraquat and Superoxide Dismutase on Pulmonary Vascular Permeability and Edema in Mice

Intraperitoneal administration of 50 mg/kg paraquat dichloride to mice significantly increased pulmonary vascular permeability at 24 and 48 hr, as measured by 125I-albumin content of alveolar lavage. Lung edema, measured by lung weight as percent body weight, was significantly increased 48 hr after paraquat treatment. Intravenous administration of four doses of superoxidase dismutase at 12-hr intervals (i.e., one before and three after paraquat treatment) failed to inhibit paraquat-induced increased pulmonary vascular permeability and pulmonary edema. Superoxide dismutase treatment also failed to reduce mortality and had no significant effect on the death time course in animals challenged with paraquat. The results of this study suggest that acute toxic effects of paraquat, such as increased pulmonary vascular permeability and pulmonary edema, may not be mediated through the generation of superoxide anion.

Effect of paraquat on plasma enzymes, insulin, glucose, and liver glycogen in the rat

Abstract Paraquat dichloride was administered (45 mg/kg i.p.) to male Sprague-Dawley rats. The rats were sacrificed at different times after treatment. Blood was collected and plasma was used for various biochemical measurements. A significant increase in creatine phosphokinase activity was obtained at 12, 24, and 48 hr after paraquat treatment. The activities of glutamic oxaloacetic transaminase (GOT) and sorbitol dehydrogenase were also consistently elevated in paraquat-treated animals but a statistically significant increase was obtained only at 48 hr for GOT. Paraquat had no effect on glutamic pyruvic transaminase activity. Paraquat caused a marked increase in blood glucose and a marked depletion of liver glycogen that lasted for at least a period of 48 hr. The plasma insulin level in paraquat-treated animals was markedly depressed as compared to saline control. Various possibilities have been discussed for the hyperglycemic and liver glycogen-depleting effects of paraquat in the rat.

Effect of seizures kindled by subconvulsant doses of pentylenetetrazol on dopamine receptor binding and dopamine-sensitive adenylate cyclase in the rat.

Abstract Possible alterations in dopamine receptor regulation were assessed in pentylenetetrazol (PTZ)-kindled rats by examination of dopamine (DA)-sensitive adenylate cyclase activity and the specific binding of [ 3 H]spiroperidol in various brain regions. A reduction in [ 3 H]spiroperidol-labeled high-affinity binding sites in the amygdaloid-pyriform cortex followed the kindling of seizures by chronic administration of PTZ. Similarly, a reduction of low-affinity binding sites was observed in the frontal cortex of PTZ-kindled rats. No changes in the apparent affinity of both high- and low-affinity binding sites were found after kindling except in the amygdala-pyriform cortex. The affinity of the low-affinity binding site was significantly reduced in this brain region. The lack of significant changes in the number and affinity of binding sites after acute seizures induced by electroconvulsive shock or a convulsant dose of PTZ suggests that the changes in receptor binding after PTZ kindling were not related to seizure sequelae. Basal and DA-sensitive adenylate cyclase activities remained unchanged after PTZ kindling. In conjunction with our previous observations of significant alterations in [ 3 H]spiroperidol binding after amygdaloid kindling, the present findings suggest that altered DA receptor regulation may be a general mechanism involved in the development of increased seizure susceptibility.