An Immunohistochemical Investigation of Renal Phospholipidosis and Toxicity in Rats.

Immunohistochemical staining for the lysosome-associated membrane protein 2 (LAMP-2) has been proposed previously as an alternative to electron microscopy to identify hepatic phospholipidosis. This study used LAMP-2 immunohistochemistry (IHC) to diagnose phospholipidosis in rats exhibiting renal tubular injury. Rats were administered toreforant, a histamine H4 receptor antagonist by oral gavage at a dose of 3, 10, or 100 mg/kg/d for 6 months. Hematoxylin and eosin staining revealed renal tubular epithelial cell vacuolation, hypertrophy, degeneration, and luminal dilation in the 100 mg/kg/d group animals. Renal tubular injury was confirmed using kidney injury marker 1 (KIM-1) IHC. The involvement of phosopholipidosis in the renal injury was investigated by LAMP-2. Adipophilin IHC was included to differentiate phospholipidosis from lipidosis. Increased LAMP-2 staining was observed in the 100 mg/kg/d group animals when compared to vehicle group animals. Lysosome-associated membrane protein-2 staining was most prominent in the outer stripe of the outer medulla where KIM-1 staining was also most prominent. By contrast, adipophilin staining was not increased. Phospholipidosis was also confirmed by electron microscopy. These data support the use of LAMP-2 IHC as a diagnostic tool and suggest an association between phospholipidosis and the renal tubular injury caused by toreforant.

Genotoxicity and carcinogenicity studies of antihistamines.

This review provides a compendium of the results of genotoxicity and carcinogenicity assays performed on marketed antihistamines. Of the 70 drugs examined, 29 (41.4%) have at least one genotoxicity and/or carcinogenicity test result: 12 tested positive in at least one genotoxicity assay, six in at least one carcinogenicity assay, and four gave a positive response in both at least one genotoxicity assay and at least one carcinogenicity assay. Of 19 drugs with both genotoxicity and carcinogenicity data, eight were neither genotoxic nor carcinogenic, two were carcinogenic in at least one sex of mice or rats but tested negative in genotoxicity assays, five tested positive in at least one genotoxicity assay but were non-carcinogenic, and four gave a positive response in at least one genotoxicity assay and in at least one carcinogenicity assay. Only 12 (17.1%) of the 70 drugs examined have all data required by present guidelines for testing of pharmaceuticals, but it should be considered that a large fraction of them were developed and marketed prior the present regulatory climate.

Can ocean warming alter sub-lethal effects of antiepileptic and antihistaminic pharmaceuticals in marine bivalves?

The negative effects induced in marine organisms by Climate Change related abiotic factors consequences, namely ocean warming, are well-known. However, few works studied the combined impacts of ocean warming and contaminants, as pharmaceutical drugs. Carbamazepine (CBZ) and cetirizine (CTZ) occur in the marine environment, showing negative effects in marine organisms. This study aimed to evaluate the impacts of ocean warming on the effects of CBZ and CTZ, when acting individually and combined (drug vs drug), in the edible clam Ruditapes philippinarum. For that, drugs concentration, bioconcentration factors and biochemical parameters, related with clam's metabolic capacity and oxidative stress, were evaluated after 28 days exposure to environmentally relevant scenarios of these stressors. The results showed limited impacts of the drugs (single and combined) at control and warming condition. Indeed, it appeared that warming improved the oxidative status of contaminated clams (higher reduced to oxidized glutathione ratio, lower lipid peroxidation and protein carbonylation levels), especially when both drugs were combined. This may result from clam's defence mechanisms activation and reduced metabolic capacity that, respectively, increased elimination and limited production of reactive oxygen species. At low stress levels, defence mechanisms were not activated which resulted into oxidative stress. The present findings highlighted that under higher stress levels clams may be able to activate defence strategies that were sufficient to avoid cellular damages and loss of redox homeostasis. Nevertheless, low concentrations were tested in the present study and the observed responses may greatly change under increased pollution levels or temperatures. Further research on this topic is needed since marine heat waves are increasing in frequency and intensity and pollution levels of some pharmaceuticals are also increasing in coastal systems.

Chronic toxicity of diphenhydramine hydrochloride and erythromycin thiocyanate to daphnia, Daphnia magna, in a continuous exposure test system.

Diphenhydramine hydrochloride (DH; Benadryl™, an over-the-counter antihistamine) and erythromycin thiocyanate (ET; a commonly used macrolide antibiotic) are pharmaceutical compounds whose chronic toxicity to Daphnia magna had not been characterized. Continuous exposure to DH concentrations about 5 times greater than the maximum reported environmental concentration of 0.023 µg/L for 21 days or to ET concentrations about 40 times the maximum reported environmental concentration of 6 µg/L for 21 days did not significantly impact D. magna survival and production. In this study the no observable effect concentration for DH was 0.12 µg/L and for ET was 248 µg/L.

Diphenhydramine abuse and detoxification: a brief review and case report.

Many medicines available over the counter from pharmacies are known to have abuse potential, including diphenhydramine (DPH), an antihistamine with antimuscarinic properties used for the treatment of insomnia. We present a brief review of the literature describing DPH abuse, and report the case of GF, a 56 year old woman who was admitted to an inpatient addictions unit for detoxification from DPH. A literature search revealed five case reports of DPH abuse including a total of six patients, published between 1986 and 2001. All reported cases exhibited features of DSM-IV criteria for substance dependence, and there was an apparent link with antipsychotic usage. GF was treated with antipsychotics, and was using up to thirty 50 mg DPH tablets each day. She described feeling 'good and calm' and 'it stopped the tremors'. GF tolerated a gradual dose reduction schedule, and completed the detoxification programme relatively comfortably. She was discharged from the inpatient detoxification unit as planned, and had not relapsed at six months. The described case report highlights the importance of enquiring about non prescribed medication when taking a drug history. Similarly community pharmacists and GPs should be vigilant to excessive requests for DPH, particularly in patients with a psychotic illness.

pH-Dependent Uptake and Sublethal Effects of Antihistamines in Zebrafish (Danio rerio) Embryos.

Reported off-target effects of antihistamines in humans draw interest in ecotoxicity testing of first- and second-generation antihistamines, the latter of which have fewer reported side effects in humans. Because antihistamines are ionizable compounds, the pH influences uptake and toxicity and thus is highly relevant when conducting toxicity experiments. Zebrafish embryo toxicity tests were performed with the 3 first-generation antihistamines ketotifen, doxylamine, and dimethindene and the 2 second-generation antihistamines cetirizine and levocabastine at pH 5.5, 7.0, and 8.0. We detected effects on survival, phenotype, swimming activity, and heart rate for 4 antihistamines with the exception of levocabastine, which did not show any lethal or sublethal effects. When compared to lethal concentrations, effect concentrations neither of phenotype malformation nor of swimming activity or heart rate deviated by more than a factor of 10 from lethal concentrations, indicating that all sublethal effects were fairly nonspecific. First-generation antihistamines are weak bases and showed decreasing external effect concentrations with increasing neutral fraction, accompanied by increased uptake in the fish embryo. As a result, internal effect concentrations were independent from external pH. The pH-dependent toxicity originates from speciation-dependent uptake, with neutral species taken up in higher amounts than the corresponding ionic species. Cetirizine, which shifts from a zwitterionic to an anionic state in the measured pH range, did not show any pH-dependent uptake or toxicity. Environ Toxicol Chem 2019;00:1-11. © 2019 SETAC.

Antiallergic and antihistaminic actions of Ceasalpinia bonducella seeds: Possible role in treatment of asthma.

ETHNOPHARMACOLOGICAL RELEVANCE: Seed kernel of the plant Ceasalpinia bonducella Linn (Caesalpiniacaeae) are used for the treatment of asthma in folk medicine and ancient books. AIM OF STUDY: To assess the pharmacological efficacy of the plant in asthma and to confine and describe the synthetic constituents from the seeds that are in charge of the action. MATERIAL AND METHODS: The viability of petroleum ether, ethanol extract and ethyl acetate fraction from ethanol extract of C. bonducella seeds were screened for the treatment of asthma by various methods viz. effect of test drug on clonidine and haloperidol induced catalepsy, milk-induced leukocytosis and eosinophilia, mast cell stabilizing activity in mice and studies on smooth muscle preparation of guinea pig ileum (in-vitro). Column chromatography of active extract was done to pinpoint the active compound followed by structure elucidation by FTIR, GCMS and NMR spectroscopic methods. RESULTS: Ethyl acetate fraction from ethanol extract of C. bonducella seeds exhibited antihistaminic activity at the dose of 50 and 100 mg/kg, inhibited clonidine-induced catalepsy but not haloperidol-induced catalepsy. Ethyl acetate fraction from ethanol extract significantly inhibited increased leukocyte and eosinophil count due to milk allergen and showed maximum protection against mast cell degranulation by clonidine. The results of guinea pig ileum indicated that the compound 2 methyl, 1 hexadecanol isolated from ethyl acetate fraction of ethanol extract relaxed significantly the ileum muscle strips pre-contracted by which suggests the involvement of ß2-agonists on the relaxation of the tissue. All the results are dose dependent. Active ethyl acetate fraction from ethanol extract showed presence of anti-asthmatic compound, 2-methyl, 1-hexadecanol. CONCLUSION: The ethyl acetate fraction from ethanol extract of seeds of the plant C. bonducella can inhibit parameters linked to asthma disease.

Embryonic cardiac arrhythmia and generation of reactive oxygen species: common teratogenic mechanism for IKr blocking drugs.

In the adult organism, it is well established that hypoxia followed by reperfusion may be fatal and result in generation of reactive oxygen species (ROS) and subsequent tissue damage. There is also considerable evidence that temporary decrease or interruption in oxygen supply to the embryo and ROS generation during reperfusion result in tissue damage in embryonic tissues. A wide spectrum of different malformations by transient embryonic hypoxia could be produced, depending on the duration, extent, and timing of the hypoxic event. It is the contention of this paper that drugs that block the potassium channel IKr, either as an intended pharmacologic effect or as an unwanted side-effect, are potentially teratogenic by a common ROS related mechanism. Drugs blocking the IKr channel, such as almokalant, dofetilide, phenytoin, cisapride and astemizole, do all produce a similar pattern of hypoxia-related malformations. Mechanistic studies show that the malformations are preceded by embryonic cardiac arrhythmia and periods of hypoxia/reoxygenation in embryonic tissues. Pretreatment or simultaneous treatment with radical scavengers with capacity to capture ROS, markedly decrease the teratogenicity of different IKr blocking drugs. A second aim of this review is to demonstrate that the conventional design of teratology studies is not optimal to detect malformations caused by IKr blocking drugs. Repeated high doses result in high incidences of embryonic death due embryonic cardiac arrhythmia, thus masking their teratogenic potential. Instead, single dosing on specific days is proposed to be a better way to characterize the teratogenic potential of Ikr blocking drugs.

Genotoxicity of 4-(piperazin-1-yl)-8-(trifluoromethyl)pyrido[2,3-e][1,2,4] triazolo[4,3-a]pyrazine, a Potent H4 Receptor Antagonist for the Treatment of Allergy: Evidence of Glyoxal Intermediate Involvement.

BACKGROUND: 4-(piperazin-1-yl)-8-(trifluoromethyl)pyrido[2,3-e][1,2,4]triazolo[4,3-a]pyrazine (1) is a small-molecule which demonstrated a sub-nM inhibitory potency toward the histamine H4 receptor (H4R). However, it was found to be mutagenic in an in vitro Ames assay. Metabolic bioactivation of 1 could potentially arise from the piperazine moiety by forming reactive intermediates such as glyoxal, aldehyde-imine and/or iminium ion, which could all lead to genotoxicity. The aim of this study was to investigate bioactivation of 1 to determine the potential causes of the genotoxicity and mitigate liabilities in this scaffold. METHODS: 1 was investigated for its genotoxicity in phenobarbital and ß-naphthoflavone induced Sprague Dawley rat liver S9 fractions. Trapping agents such as o-phenylenediamine was used postincubation. RESULTS: Following metabolic profiling of 1, two oxidative metabolites were observed and identified in phenobarbital- and ß -naphthoflavone induced Sprague Dawley rat liver S9 fractions. Metabolic pathway of 1 was primarily mediated by the metabolism of the piperazine moiety. The trapped glyoxal was identified by using high resolution LC-MS instrument. Structural characterization of the trapped glyoxal was determined by comparison of retention time, accurate mass measurement and Collision Induced Dissociation (CID) spectra to authentic standard. CONCLUSION: In the present investigation, a novel method was developed to trap glyoxal, which may potentially be liberated from piperazine moiety. These findings led to modifications on the piperazine ring to mitigate the bioactivation pathways leading to mutagenicity. Subsequently, the next generation compounds with modified piperazine moiety, retained H4R inhibitory potency in vitro and were not genotoxic in the Ames mutagenicity assay.

P21 (Cdc42/Rac)-activated kinase 1 (pak1) is associated with cardiotoxicity induced by antihistamines.

Astemizole, a non-sedating histamine H1 receptor blocker, is widely known to cause cardiac arrhythmia, which prolongs the QT interval. However, the precise molecular mechanism involved in antihistamine-induced cardiovascular adverse effects other than hERG channel inhibition is still unclear. In this study, we used DNA microarray analysis to detect the mechanisms involved in life-threatening adverse effects caused by astemizole. Rat primary cardiomyocytes were treated with various concentrations of astemizole for 24 h and the corresponding cell lysates were analyzed using a DNA microarray. Astemizole altered the expression profiles of genes involved in calcium transport/signaling. Using qRT-PCR analysis, we demonstrated that, among those genes, p21 (Cdc42/Rac)-activated kinase 1 (pak1) mRNA was downregulated by treatment with terfenadine and astemizole. Astemizole also reduced pak1 protein levels in rat cardiomyocytes. In addition, astemizole decreased pak1 mRNA and protein levels in H9c2 cells and induced an increase in cell surface area (hypertrophy) and cytotoxicity. Fingolimod hydrochloride (FTY720), a pak1 activator, inhibited astemizole-induced hypertrophy and cytotoxicity in H9c2 cells. These results suggest that antihistamine-induced cardiac adverse effects are associated with pak1 expression and function.

Effects of an antihistamine on carbon and nutrient recycling in streams.

In stream ecosystems, microbes and macroinvertebrates consume leaf litter deposited from the riparian vegetation, and thereby recycle resources tied up in the litter. Several environmental variables influence rates of this recycling, but it is not well known if common pharmaceuticals, such as antihistamines, originating from wastewater effluent, have additional impacts. Exposure to dilute concentrations of antihistamines may adversely influence aquatic detritivorous invertebrates, because invertebrates use histamines for neurotransmission, resulting in hampered recycling of resource tied up in leaf detritus. In this study, we therefore investigated if the antihistamine fexofenadine, at a concentration of 2000ngl(-1), alters rates of leaf litter decomposition in stream microcosms. Stonefly larvae (n=10, per microcosm), together with natural microbial communities, served as main decomposer organisms on alder leaf litter. First, we used 30 microcosms containing fexofenadine, while the other 30 served as non-contaminated controls, and of each 30 microcosms, 14 contained stonefly larvae and microbes, while the remaining 16 contained only microbes. We found, in contrast to our hypothesis, that fexofenadine had no effect on leaf litter decomposition via impacts on the stonefly larvae. However, independent on if stoneflies were present or not, concentrations of organic carbon (TOC) and nitrogen (N) were strongly affected, with 20-26 and 24-31% lower concentrations of TOC and N, respectively, in the presence of fexofenadine. Second, in a scaled down follow-up experiment, we found that microbial activity increased by 85%, resulting in a 10% decrease in pH, in the presence of fexofenadine. While the antihistamine concentration we used is higher than those thus far found in the field (1-10ngl(-1)), it is still 100 times lower than the predicted no-effect concentration for fexofenadine. As such, our results indicate that low µg l(-1) levels of antihistamines can have an effect on carbon and nutrient recycling in aquatic system.

Antihistamines modulate the integrin signaling pathway in h9c2 rat cardiomyocytes: Possible association with cardiotoxicity.

The identification of biomarkers for toxicity prediction is crucial for drug development and safety evaluation. The selective and specific biomarkers for antihistamines-induced cardiotoxicity is not well identified yet. In order to evaluate the mechanism of the life-threatening effects caused by antihistamines, we used DNA microarrays to analyze genomic profiles in H9C2 rat cardiomyocytes that were treated with antihistamines. The gene expression profiles from drug-treated cells revealed changes in the integrin signaling pathway, suggesting that cardiac arrhythmias induced by antihistamine treatment may be mediated by changes in integrin-mediated signaling. It has been reported that integrin plays a role in QT prolongation that may induce cardiac arrhythmia. These results indicate that the integrin-mediated signaling pathway induced by antihistamines is involved in various biological mechanisms that lead to cardiac QT prolongation. Therefore, we suggest that genomic profiling of antihistamine-treated cardiomyocytes has the potential to reveal the mechanism of adverse drug reactions, and this signal pathway is applicable to prediction of in vitro cardiotoxicity induced by antihistamines as a biomarker candidate.

Comparative pharmacology and toxicology of pharmaceuticals in the environment: diphenhydramine protection of diazinon toxicity in Danio rerio but not Daphnia magna.

Pharmaceuticals and other contaminants of emerging concern present unique challenges to environmental risk assessment and management. Fortunately, mammalian pharmacology and toxicology safety data are more readily available for pharmaceuticals than other environmental contaminants. Identifying approaches to read-across such pharmaceutical safety information to non-target species represents a major research need to assess environmental hazards. Here, we tested a biological read-across hypothesis from emergency medicine with common aquatic invertebrate and vertebrate models. In mammals, the antihistamine diphenhydramine (DPH) confers protection from poisoning by acetylcholinesterase inhibition because DPH blocks the acetylcholine receptor. We employed standardized toxicity methods to examine individual and mixture toxicity of DPH and the acetylcholinesterase inhibitor diazinon (DZN) in Daphnia magna (an invertebrate) and Danio rerio (zebrafish, a vertebrate). Though the standardized Fish Embryo Toxicity method evaluates early life stage toxicity of zebrafish (0-3 days post fertilization, dpf), we further evaluated DPH, DZN, and their equipotent mixture during three development stages (0-3, 3-6, 7-10 dpf) in zebrafish embryos. Independent action and concentration addition mixture models and fish plasma modeling were used to assist interpretation of mixture toxicity experiments. Though our primary hypothesis was not confirmed in acute studies with Daphnia magna, DPH conferred a protective effect for acute DZN toxicity to zebrafish when DPH plasma levels were expected to be greater than mammalian therapeutic, but lower than acutely lethal, internal doses. We further observed that timing of developmental exposure influenced the magnitude of DZN and DPH toxicity to zebrafish, which suggests that future zebrafish toxicity studies with pharmaceuticals and pesticides should examine exposure during developmental stages.

Gene expression analysis points to hemostasis in livers of rats cotreated with lipopolysaccharide and ranitidine.

Studies in rats have demonstrated that modest underlying inflammation can precipitate idiosyncratic-like liver injury from the histamine 2-receptor antagonist, ranitidine (RAN). Coadministration to rats of nonhepatotoxic doses of RAN and the inflammagen, bacterial lipopolysaccharide (LPS), results in hepatocellular injury. We tested the hypothesis that hepatic gene expression changes could be distinguished among vehicle-, LPS-, RAN- and LPS/RAN-treated rats before the onset of significant liver injury in the LPS/RAN-treated rats (i.e., 3 h post-treatment). Rats were treated with LPS (44 x 10(6) EU/kg, i.v.) or its vehicle, then two hours later with RAN (30 mg/kg, i.v.) or its vehicle. They were killed 3 h after RAN treatment, and liver samples were taken for evaluation of liver injury and RNA isolation. Hepatic parenchymal cell injury, as estimated by increases in serum alanine aminotransferase (ALT) activity, was not significant at this time. Hierarchal clustering of gene expression data from Affymetrix U34A rat genome array grouped animals according to treatment. Relative to treatment with vehicle alone, treatment with RAN and/or LPS altered hepatic expression of numerous genes, including ones encoding products involved in inflammation, hypoxia, and cell death. Some were enhanced synergistically by LPS/RAN cotreatment. Real-time PCR confirmed robust changes in expression of B-cell translocation gene 2, early growth response-1, and plasminogen-activator inhibitor-1 (PAI-1) in cotreated rats. The increase in PAI-1 mRNA was reflected in an increase in serum PAI-1 protein concentration in LPS/RAN-treated rats. Consistent with the antifibrinolytic activity of PAI-1, significant fibrin deposition occurred only in livers of LPS/RAN-treated rats. The results suggest the possibility that expression of PAI-1 promotes fibrin deposition in liver sinusoids of LPS/RAN-treated rats and are consistent with the development of local ischemia and consequent tissue hypoxia.

Effects of isopropanol on the development of inflammatory reactions in rats.

The effects of isopropanol on the development of inflammation were studied in rats. Isopropanol inhibited both the histamine-induced increase in cutaneous vascular permeability and the carrageenan-induced plasma exudation into the pleural cavity. The lipopolysaccharide-induced leucocyte emigration into the subcutaneous pouch was unaffected by isopropanol, but the leucocyte emigration of carrageenan-induced pleural inflammation was markedly inhibited by isopropanol. In contrast, when isopropanol was administered with an anti-inflammatory drug (indomethacin or dexamethasone), it enhanced the pleural inflammatory reaction. These results suggest that isopropanol may exert toxic effects through interference with the normal processes of inflammation and interaction with other agents that affect inflammatory reactions.

[Single dose toxicity studies of suplatast tosilate (IPD-1151T)].

Single dose toxicity studies of suplatast tosilate (IPD-1151T) were carried out in mice, rats and dogs of both sexes. The results were as follows: 1. The LD50 values of IPD-1151T were as follows: Mice, 12,500 (both sexes) mg/kg or more in oral route (maximum dose for technical manner); Mice 81 (male) and 96 (female) mg/kg in intravenous route; Rats, 10,000 (both sexes) mg/kg or more in oral route (maximum dose for technical manner); Rats, 96 (male) and 93 (female) mg/kg in intravenous route; Dogs, 2,124 (male) and 2,660 (female) mg/kg in oral route. On the LD50 values, no sexual difference was apparent in all species, but the species difference was noted between the rodent and dog. LD50 values of dog were lower level than those of rodent. 2. As toxic signs, mucous diarrhea with specific smell was noted in orally administered rodent. In addition, rats showed soiled fur in the perianal. In intravenous route, the rodent showed dyspnea, tonic convulsion and lateral position and deaths occurred within 10 min in mice and within 30 min in rats after administration. Dog showed toxic signs similar to those in rodents and deaths occurred within 3 hours. 3. In pathological examinations, dead mice and dogs administered orally showed lung congestion, liver fading or slight hemorrhage in the endo-and/or exocardium. Dead rodent administered intravenously showed only slight hemorrhage and congestion in the lung. Alive mice, rats and dogs showed no remarkable changes. 4. The main cause of deaths seemed to be respiratory disturbance in all species.

[A fifty two-week oral repeated dose toxicity study of suplatast tosilate (IPD-1151T) in dogs].

A 52-week oral repeated dose toxicity study of suplatast tosilate (IPD-1151T), a newly developed anti-allergic agent, was carried out in beagles by oral administration of 30, 90, 270 and 810 mg/kg/day for 52 weeks. The recovery study was carried out by the withdrawal for 5 weeks using control and the 810 mg/kg groups. The results are as follows: 1. Observation of general conditions revealed soft feces, mucous feces, and diarrhea in both sexes of the 270 and 810 mg/kg groups during the administration period, and these findings disappeared during the withdrawal period. One female of the 810 mg/kg group exhibited tremors in the legs and neck, staggering, a decrease of spontaneous motor activity, and clonic convulsions in Week 17 of administration and died on Day 118. One male of the same group exhibited whole body tremors and staggering from Week 32 to Week 52. 2. Body weight gain tended to be inhibited in males of the 810 mg/kg group during the administration period. The body weight of the female that died decreased rapidly after the appearance of neurological symptoms. The body weight of the male that exhibited neurological symptoms decreased after their appearance but later increased. 3. There were no abnormal changes in food consumption in all of the sacrificed dogs. The female that died did not eat at all after the appearance of neurological symptoms. The male that exhibited neurological symptoms did not eat at all for 1 week after their appearance, but the food consumption returned to normal thereafter. 4. Prothrombin times were prolonged in males of the 270 and 810 mg/kg groups at Week 26, and activated partial thromboplastin times were prolonged in males of the 810 mg/kg group at Week 52. 5. Plasma levels of alkaline phosphatase, GPT and LDH were elevated in some males and females of the 810 mg/kg groups. 6. No abnormalities due to IPD-1151T administration were found in urinalysis, opthalmological examination, electrocardiography, and fecal occult blood examination, or organ weights. 7. Autopsies including histopathological and electron microscopic examinations on the sacrificed dogs revealed no abnormalities. Subserosal hemorrhage in the base of the heart, congestion in the lungs, congestion and vacuolation in the liver and slight cell infiltration around vessels of the brain were found in the female that died.(ABSTRACT TRUNCATED AT 400 WORDS)

[A thirteen-week oral repeated dose toxicity study of suplatast tosilate (IPD-1151T) in dogs].

A 13-week oral repeated dose toxicity study of suplatast tosilate (IPD-1151T), a new anti-allergic agent, as well as a 5-week recovery study were carried out at dose levels of 0 (control), 50, 150, 450 and 1350 mg/kg/day using male and female beagle dogs. The results were as follows: 1. In general conditions, soft feces and diarrhea with specific smell were dose-dependently observed in males and females given 450 mg/kg/day or more. Both sexes given 1350 mg/kg/day, revealed reeling with dropped head, abnormal gait, dysstasia, lying at lateral or prone position, sedation, and tremor, and one male and one female in this group died after showing respiratory depression, collapse and cyanosis. 2. There were no significant or remarkable changes in body weight, food consumption, water consumption, ophthalmology, electrocardiogram, urinalysis, hematology, biochemistry, fecal occult blood test, and absolute and relative organ weights. 3. Pathological examination in dead animals revealed hemorrhagic change in the heart and slight vacuolar changes in hepatocytes. In survived animals, there were no pathological changes attributable to the IPD-1151T. 4. In electron microscopic examination, there were no abnormalities in the liver and kidney attributable to the IPD-1151T. 5. After 5-week recovery period, above-mentioned changes disappeared. 6. From the above results, the non-effective dose level and the toxic dose level were estimated to be 150 mg/kg/day and 1350 mg/kg/day, respectively, and no sex differences were found.

[A thirteen-week oral repeated dose toxicity study of suplatast tosilate (IPD-1151T) in rats].

A 13-week oral repeated dose toxicity study of Suplatast tosilate (IPD-1151T), a new anti-allergic agent, as well as a 5-week recovery study were carried out at dose levels of 0 (control), 200, 600, 1800 and 5400 mg/kg/day using male and female rats. The results were as follows: 1. In general conditions, salivation were observed in some rats of both sexes given 1800 mg/kg/day. Both sexes given 5400 mg/kg/day disclosed salivation and soft stool and then died after showing ataxic gait, hyperesthesia and convulsion of legs. 2. Inhibition of body weight gain in both sexes given 5400 mg/kg/day were observed from the early stage of the treatment period. 3. The food consumption was decreased from about 3-week and the water consumption was increased from the initiation of study to about 3-week in both sexes given 5400 mg/kg/day. However, both of them were remarkably decreased prior to death. 4. Fecal examination for occult blood showed an increasing tendency in the incidence of positive findings in both sexes given 1800 mg/kg/day. 5. Hematological examination showed slight decreases in erythrocytic parameters in both sexes given 1800 mg/kg/day. In both sexes given 5400 mg/kg/day hemoconcentration was observed, some animals showing decreases in leucocyte and lymphocyte counts and lymphocyte percentage. 6. Biochemical examination showed increases in total and free cholesterol levels in males given 600 mg/kg/day or more, an increased cholinesterase and decreased levels of triglyceride and cholesterol ester ratio in males given 1800 mg/kg/day. An increase in LDH was observed in both sexes given 5400 mg/kg/day and half of these animals also showed increases in GOT and Urea N. 7. The absolute weights of the pituitary, brain, thymus, heart, lungs and kidneys were increased. However, no histopathological lesion was observed in these organs. As treatment-related histological changes, atrophy in the thymus and spleen, dilation in digestive tracts, neuronal necrosis and necrotic foci in the central nervous system, necrosis of lymphocytes in the lymphoid organs and a decrease in bone marrow cell were observed in both sexes given 5400 mg/kg/day. 8. After a 5-week recovery period, above-mentioned changes had disappeared. 9. From the above results, the non-effective dose level was estimated to be 200 mg/kg/day in males and 600 mg/kg/day in females, and toxic dose level 1800-5400 mg/kg/day in both sexes.

[A fifty-two week oral chronic toxicity study of suplatast tosilate (IPD-1151T) in rats].

A 52-week oral repeated dose toxicity study of suplatast tosilate (IPD-1151T), a new anti-allergic agent, as well as a 5-week recovery study were carried out at dose levels of 0 (control), 50, 300 and 1800 mg/kg/day using male and female rats. The results were as follows: 1. In general conditions, transient salivation after each administration and excretions with peculiar smells were noted in both sexes given 1800 mg/kg/day. Since one male and six female rats given 1800 mg/kg/day showed bradypnea, clonic/tonic convulsions, lying on the belly and/or side, subnormal temperature, abnormal gait, paralysis of extremities, they were sacrificed in moribund. 2. The body weight was lowered from the early stage of administration period in both sexes given 1800 mg/kg/day. 3. There were no remarkable changes in food consumption, urinalysis, fecal examination, hematology and ophthalmology. 4. Biochemical examination revealed a decrease in triglyceride in males given 300 mg/kg/day or more. 5. In pathological examination, the animals sacrificed in moribund showed necrosis and degeneration of neurons and/or sponge-like change of neuropile in nucleus caudatus of the cerebrum, necrosis and partial disappearance of granular cells and Purkinje's cells, and swelling of Bergmann's cells in the cerebellum. In survived animals, the relative organ weight in the liver increased in males given 300 mg/kg/day or more and females given 1800 mg/kg/day, and histopathological examination revealed slight vacuolization, hypertrophy of centrilobular hepatocytes in males given 1800 mg/kg/day. Furthermore, in some females, similar changes of the cerebrum and the cerebellum, as mentioned above, were slightly observed. In electron microscopic examination, slight proliferation of smooth endoplasmic reticulum in hepatocytic cytoplasm was observed in males given 1800 mg/kg/day. The necrobiotic changes, such as condensation of nuclear chromatin, increased electron density of cytoplasm and nuclei, mitochondrial accumulation and vacuolization, in the cells possibly derived from small granular cells in the cerebellum were observed in females given 1800 mg/kg/day. The mitochondrial swelling, decreased and dilated rough endoplasmic reticulum, and increased electron density of cytoplasm and nuclei with formation of cytoplasmic vacuole and membranous degenerated structure in neurons of cerebral temporal lobe cortex were observed in females given 1800 mg/kg/day. 6. In a recovery study, electron microscopic examination revealed a slight degeneration of myelinated nerve fibers in the cerebellum in males given 1800 mg/kg/day. On the contrary, there were no remarkable changes in general condition, body weight and various clinical parameters. It was noted that these changes induced by IPD-1151T seemed to be reversible changes.(ABSTRACT TRUNCATED AT 400 WORDS)