Toxicology and humoral immunity assessment of octamethylcyclotetrasiloxane (D4) following a 28-day whole body vapor inhalation exposure in Fischer 344 rats
| Autor: | J. A. Mccay, M. R. Woolhiser, T. W. Galbraith, Paal Christian Klykken, Kimber L. White, R. W. Mast, Albert E. Munson, M. R. Elwell, Gary B. Kolesar, Leigh Ann Burns-Naas, P. A. Jean |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Male
Urinalysis Siloxanes Health Toxicology and Mutagenesis Decamethylcyclopentasiloxane Enzyme-Linked Immunosorbent Assay Toxicology Octamethylcyclotetrasiloxane chemistry.chemical_compound Silicone Adjuvants Immunologic Administration Inhalation Toxicity Tests medicine Animals Antibody-Producing Cells Pharmacology Inhalation exposure Chemical Health and Safety Inhalation medicine.diagnostic_test Dose-Response Relationship Drug Body Weight Public Health Environmental and Occupational Health General Medicine Organ Size Rats Inbred F344 Blood Cell Count Rats chemistry Immunoglobulin M Liver Immune System Toxicity Antibody Formation Room air distribution Female Spleen |
| Zdroj: | Drug and chemical toxicology. 22(4) |
| ISSN: | 0148-0545 |
| Popis: | Octamethylcyclotetrasiloxane, D4, is a low viscosity, silicone fluid consisting of four dimethyl-siloxy units ((CH3)2SiO)4 in a cyclic structure. It is primarily used as a building block in the industrial synthesis of long chain silicone polymers. The combination of D4 with decamethylcyclopentasiloxane (D5) is commonly referred to as cyclomethicone which has a wide range of applications as a formulation aid in personal care products. To extend the existing database regarding the biological activities of D4, a 28 day whole body vapor inhalation study was conducted using Fischer 344 rats at 0 (room air), 7, 20, 60, 180 and 540 ppm for 6 hours/day, 5 days/week. Parameters measured included body weights, organ weights, gross pathology, histopathology, serum chemistries, and urinalysis. In addition to these standard toxicological endpoints, the ability of D4 exposed animals to mount an IgM antibody response was evaluated by a splenic antibody forming cell (AFC) assay and a serum enzyme-linked immunosorbant assay (ELISA). The results of this 28-day inhalation study indicate that D4 exposure caused no adverse effects on body weight, food consumption, or urinalysis parameters. In addition, there were no exposure related histopathological alterations at any site for any exposure group. A statistically significant increase in liver weight and the liver to body weight ratio was observed in both male (180-540 ppm) and female (20-540 ppm) rats, which was not observed in the 14-day recovery group animals. There were no other significant organ weight changes. Although statistically significant changes were observed in several hematological and serum chemistry parameters in both the terminal and 14-day recovery animals, the changes were marginal and within the normal range of values for the rat. Under these experimental conditions, there were no alterations noted in immune system function at any of the D4 exposure levels. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|