[Toxicity studies of VP 16-213 (II)--Oral one-month subacute toxicity in rats].
ABSTRACT VP 16-213 (etoposide, abbr. to VP), an oncostatic drug, was administered orally to Crj : CD (Sprague-Dawley) rats of both sexes at dose levels of 3, 10, 30 and 100 mg/kg/day for one month with the object of examining its subacute toxicity and the reversibility of toxic effects. The summarized results obtained are as follows: VP 30 mg/kg suppressed body weight increase and feed intake, and brought soft stool. VP 100 mg/kg decreased body weight and feed intake, and induced diarrhea, depilation and so forth. Furthermore, half of the animals at this dose level died showing systemic debility and emaciation. VP 30 and 100 mg/kg predominantly decreased red blood cell count as well as white blood cell count accompanied with lowered lymphocyte fraction. VP 10 mg/kg and higher lowered total serum protein content and serum alkaline phosphatase activity, and elevated A/G ratio. VP 10 mg/kg and higher caused thymic atrophy and a decrease in testicular weight; 30 and 100 mg/kg brought suppression of spermatogenesis; and 100 mg/kg predominantly induced appearance of giant cells in epididymis, hypoplasia of bone marrow, ileocecitis, and atrophy of prostate, seminal vesicle and splenic germinal centers. Above-described changes excluding exacerbation of the findings on testis and epididymis were shown to be generally reversible. Based on these results, the no-effect dose level of VP under the present experimental condition was estimated to be 3 mg/kg/day against rats of both sexes.
Article: Chemotherapy induced gastrointestinal toxicity in rats: involvement of mitochondrial DNA, gastrointestinal permeability and cyclooxygenase -2.[show abstract] [hide abstract]
ABSTRACT: The gastrointestinal damage induced by xenobiotics is occurring more frequently and with greater toxicological significance than previously thought. Although there are some preliminary clinical studies and reports, there does not appear to be an extensive examination of gastrointestinal toxicity of various chemotherapeutic agents in the rat. This study was undertaken to examine the suitability of a rat model to detect the gastrointestinal damage after administration of various anti-neoplastic agents including etoposide, teniposide, melphalan, 5-fluorouracil, methotrexate and cisplatin. Acute toxic doses of indomethacin and chemotherapeutic agents were administered to rats. The urinary excretion of orally administered sucrose and 51(Cr)-EDTA were measured as markers of gastroduodenal and intestinal permeability, respectively. Cyclooxygenase-2 messenger RNA and mitochondrial DNA damage were measured as toxicological endpoints. Each anti-neoplastic agent examined induced appreciable and significant dose-dependent increase in gastrointestinal permeability that correlated with gross toxicological and pathological changes to the gastrointestinal tract including ulceration and bleeding. COX-2 mRNA was upregulated > 2 fold in intestinal mucosa with enteropathy and dose-dependent mitochondrial oxidative damage was apparent in gastric and intestinal mucosa. After administration of each drug, the rats presented with histological evidence of drug-induced gastroenteropathy, ulceration and increased cecal hemoglobin. The rat appears to be a suitable model to study gastrointestinal toxicity of chemotherapeutic agents and non-steroidal anti-inflammatory drugs. Damage to mitochondrial DNA occurs in both the gastric and intestinal epithelium after the administration of these agents and may be an important factor in the pathogenesis and resolution of gastrointestinal toxicity.Journal of pharmacy & pharmaceutical sciences: a publication of the Canadian Society for Pharmaceutical Sciences, Societe canadienne des sciences pharmaceutiques 6(3):308-14. · 1.65 Impact Factor