Absence of significant effects by levamisole on circulating neutrophil levels in normal mice treated with 5-FU.
When B6C3F1 mice were given a single intravenous (i.v.) injection of 150 mg/kg 5-fluorouracil (5-FU) their levels of circulating neutrophils plummeted, reaching a nadir at 6 to 7 days postdosing and then gradually increasing to normal and above-normal levels. Neutropenia (actual neutrophil count (ANC) below 100 ANC/microliters) extended until 8.7 +/- 0.2 days after 5-FU injection. When these mice were also given levamisole (2.5 mg/kg, po) on days 0-2 the mean time to ANC recovery greater than 100/microliters was 7.7 +/- 0.3 days, (p < 0.05 vs. controls), while IL-1 (2 micrograms/day, ip) positive controls yielded a mean time to > 100 ANC of 6.5 +/- 0.2 days. Although levamisole-treated mice attained normal neutrophil levels one day faster than controls did and this more rapid recovery led to their neutrophil levels being between 2- and 3-fold greater, these differences were not statistically significant. Effects were only manifested on neutrophil recoveries. There were no differences between levamisole-treated mice and controls when recovery rates for platelets, monocytes or lymphocytes were examined. These results demonstrate that levamisole has, at best, only weak myelopoietic properties against 5-FU-induced myelotoxicity in mice.
Oncology and Endocrinology Research, Janssen Research Foundation, Spring House, PA 19477.
E S
ES
Kimball
M C
MC
Fisher
D000818:Animals; D001855:Bone Marrow Diseases / Q000139:chemically induced / Q000188:drug therapy; D005472:Fluorouracil / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D007978:Levamisole / Q000494:pharmacology*; D051379:Mice; D009503:Neutropenia / Q000139:chemically induced* / Q000188:drug therapy*
D007978:Levamisole; D005472:Fluorouracil