Platelet Morphology After Administration of M-CSF
| Platelet Form . | Control (n = 8) . | Day 3 (n = 3) . | Day 5 (n = 3) . | Day 9 (n = 3) . |
|---|---|---|---|---|
| Discoid (%) | 91.6 ± 1.1 | 89.3 ± 1.3 | 94.0 ± 1.4 | 91.7 ± 0.7 |
| Elongated (%) | 6.9 ± 1.0 | 9.4 ± 1.3 | 4.5 ± 1.3 | 6.9 ± 0.9 |
| Beaded (%) | 1.6 ± 0.4 | 1.2 ± 0.1 | 1.6 ± 0.7 | 1.5 ± 0.1 |
| Total percent nondiscoid (proplatelets) | 8.5 ± 1.1 | 10.6 ± 1.3 | 6.1 ± 1.4 | 8.4 ± 0.7 |
| Proplatelets × 10−3/μL blood | 102.1 ± 13.0 | 63.0 ± 10.1 | 11.1 ± 5.0* | 199.8 ± 9.7* |
| Platelet count × 10−6/μL blood | 1.208 ± 0.028 | 0.587 ± 0.029 | 0.160 ± 0.055 | 2.413 ± 0.093 |
| Platelet Form . | Control (n = 8) . | Day 3 (n = 3) . | Day 5 (n = 3) . | Day 9 (n = 3) . |
|---|---|---|---|---|
| Discoid (%) | 91.6 ± 1.1 | 89.3 ± 1.3 | 94.0 ± 1.4 | 91.7 ± 0.7 |
| Elongated (%) | 6.9 ± 1.0 | 9.4 ± 1.3 | 4.5 ± 1.3 | 6.9 ± 0.9 |
| Beaded (%) | 1.6 ± 0.4 | 1.2 ± 0.1 | 1.6 ± 0.7 | 1.5 ± 0.1 |
| Total percent nondiscoid (proplatelets) | 8.5 ± 1.1 | 10.6 ± 1.3 | 6.1 ± 1.4 | 8.4 ± 0.7 |
| Proplatelets × 10−3/μL blood | 102.1 ± 13.0 | 63.0 ± 10.1 | 11.1 ± 5.0* | 199.8 ± 9.7* |
| Platelet count × 10−6/μL blood | 1.208 ± 0.028 | 0.587 ± 0.029 | 0.160 ± 0.055 | 2.413 ± 0.093 |
Mice were injected with M-CSF, 4 mg/kg/d, on days 1 to 5. On days 3, 5, and 9, blood was obtained by cardiac puncture using ACDE1 as anticoagulant. PRP was prepared by centrifugation, and the platelets immediately examined at 400× magnification using phase-contrast microscopy. Platelets were grouped according to Tong, Seth, and Penington30 into the following different classes of morphologic forms by phase-contrast microscopy: (1) discoid; (2) elongated-length three times greater than the width; or (3) beaded forms showing two or more well-formed cytoplasmic masses separated by slender cytoplasmic threads. The mean percentages ± 1 SE of each morphologic form are shown. n = the number of individual mice examined. Platelets examined per animal: 390 ± 21 (mean ± 1 SE); range, 186-562. There were no significant differences in the frequency of the various forms of platelets between the control group and any M-CSF treated group.
Indicates that the absolute concentrations of circulating proplatelets were significantly different from control, P < .05.