Abstract
The synthetic pyrethroids deltametrin and alpha-cypermetrin were studied for effects on the immune system in 28-day studies in F344 male rats. Sixteen rats per group were dosed with either deltametrin 0, 1, 5, or 10 mg/kg body wt./day or alpha-cypermertin 0, 4, 8, or 12 mg/kg body wt./day in soy bean oil by gavage. Haematology, bone marrow cell counts, tests for natural killer (NK) cell activity and mitogen response (Con A and STM) as well as quantitation of lymphocyte subpopulations were performed. Spleen cells from immunized animals (six animals/group) were tested for antibody production (SRBC-PFC). Volumes of lymphoid compartments of mesenteric lymph nodes and thymus were estimated using stereological methods. In the deltametrin study an effect was found in the groups receiving 5 or 10 mg/kg body wt. The effects were: increased weight of mesenterial lymph nodes, decreased thymus weight in immunized animals and an increase in numbers of SRBC-PFC and splenic NK cell activity. An effect on relative adrenal weight was seen in the 10 mg/kg body wt. group. No severe effects on the immune system was found. The lowest effect level of alpha-cypermetrin was 12 mg/kg body wt./day based on increased relative adrenal weight.
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Toxicology |
| Vol/bind | 107 |
| Udgave nummer | 3 |
| Sider (fra-til) | 219-27 |
| Antal sider | 9 |
| ISSN | 0300-483X |
| Status | Udgivet - 18 mar. 1996 |