The ability of isolated perfused hindlegs of vinblastine sulfate (VLB) treated rats to release leukocytes into leukocyte depleted blood was studied. Neutrophil release and bone marrow neutrophil population size were strongly correlated (r = 0.82) during the 17 day period after a subcutaneous injection of 0.7 or 1.0 mg VLB per kg body weight. During this period marrow neutrophils ranged from 0 on day 4 to 12.73 x 105/mg femoral marrow on day 10. Marrow lymphocyte population size and lymphocyte release were correlated (r = 0.70) during the first 6 days after VLB administration, when marrow lymphocyte numbers were depressed and starting to recover, but not during the subsequent 11 days. Unlike marrow neutrophils, marrow lymphocyte numbers did not rebound to above normal levels at any time during the 17 days studied, nor were they as severely depressed by VLB. They ranged from 1.56 x 105/mg femoral marrow on day 3 to a near normal level of 8.12 x 105/mg femoral marrow on day 17. Normal blood neutrophil numbers were maintained during the first 2 days after VLB but fell off sharply to less than 10% of normal on day 3. Apparently the marrow granulocyte reserve, although depleted to about 15% of normal on days 1 and 2, was nonetheless able to sustain normal circulating neutrophil numbers.
ASJC Scopus subject areas
- Physiology (medical)