Corash L, Mok Y, Levin J, Baker G
Department of Laboratory Medicine, University of California, School of Medicine, San Francisco 94143.
Exp Hematol. 1990 Mar;18(3):205-12.
We have examined the effects of variable degrees of acute thrombocytopenia on platelet levels, mean platelet volume (MPV), and buoyant density after induction of thrombocytopenia by platelet antiserum (PAS) in mice with or without spleens. Mice were studied serially 10-16, 36, 48, 60-64, 84, 108, 144, 180, 228, 276, 348-360, 372, and 516 h after PAS treatment. MPV and platelet count (PC) x 10(6)/microliters for normal intact mice (n = 136) were 4.7 +/- 0.3 fl (SD) and 1.69 +/- 0.52 (SD), respectively. Twelve hours after PAS-induced severe thrombocytopenia (PC less than 0.05 x 10(6)/microliters), MPV increased significantly (p less than 0.01) to 6.4 fl, was maximal at 36 h (8.2 fl), remained elevated until 144 h following PAS treatment, and then returned to normal. Platelet density decreased significantly (p less than 0.05) 64 h after PAS treatment and returned to normal at 144 h. Hematocrits of repeatedly bled intact control mice decreased from 45% to 30%, accompanied by thrombocytosis (maximal PC 2.24 x 10(6)/microliters) without significant changes in either MPV or platelet density. Moderate thrombocytopenia (PC 0.1-0.2 x 10(6)/microliters) in intact mice produced significantly (p less than 0.05) increased MPV, at 5.7 fl 12 h after PAS treatment, with a peak MPV of 7.6 fl (p less than 0.001) at 36 h; MPV returned to normal at 84 h. Platelet density decreased (p less than 0.001) 12 h after PAS treatment and returned to baseline at 228 h. Control splenectomized mice (n = 185) had an MPV of 5.0 fl +/- 0.7 fl and a PC of 2.14 +/- 0.6 x 10(6)/microliters. Comparably severe and moderate thrombocytopenia in splenectomized mice produced alterations in platelet count, MPV, and density similar to those in intact mice, although maximal MPV and the degree of rebound thrombocytosis after severe thrombocytopenia were more marked in splenectomized mice. In response to reduction of the platelet mass in both intact and splenectomized mice, MPV increased in proportion to the severity of thrombocytopenia, occurred as early as 4 h after induction, and persisted during early rebound thrombocytosis. Previous observations that megakaryocyte ploidy did not shift until 48 h after onset of thrombocytopenia confirm that both initial and maximal changes in MPV in response to this stimulus are regulated by processes other than alterations of megakaryocyte DNA levels.(ABSTRACT TRUNCATED AT 400 WORDS)
我们研究了不同程度的急性血小板减少对血小板水平、平均血小板体积（MPV）以及在有或无脾脏的小鼠中通过血小板抗血清（PAS）诱导血小板减少后血小板浮力密度的影响。在PAS处理后的10 - 16、36、48、60 - 64、84、108、144、180、228、276、348 - 360、372和516小时对小鼠进行连续研究。正常完整小鼠（n = 136）的MPV和血小板计数（PC）×10⁶/微升分别为4.7±0.3飞升（标准差）和1.69±0.52（标准差）。在PAS诱导严重血小板减少（PC小于0.05×10⁶/微升）12小时后，MPV显著增加（p小于0.01）至6.4飞升，在36小时达到最大值（8.2飞升），在PAS处理后144小时一直保持升高，然后恢复正常。血小板密度在PAS处理64小时后显著降低（p小于0.05），并在144小时恢复正常。反复采血的完整对照小鼠的血细胞比容从45%降至30%，伴有血小板增多（最大PC为2.24×10⁶/微升），而MPV和血小板密度均无显著变化。完整小鼠中的中度血小板减少（PC为0.1 - 0.2×10⁶/微升）在PAS处理12小时后使MPV显著增加（p小于0.05），达到5.7飞升，在36小时时MPV峰值为7.6飞升（p小于0.001）；MPV在84小时恢复正常。血小板密度在PAS处理12小时后降低（p小于0.001），并在228小时恢复至基线水平。对照脾切除小鼠（n = 185）的MPV为5.0飞升±0.7飞升，PC为2.14±0.6×10⁶/微升。脾切除小鼠中同等程度的严重和中度血小板减少导致血小板计数、MPV和密度的变化与完整小鼠相似，尽管脾切除小鼠中严重血小板减少后的最大MPV和血小板增多反弹程度更为明显。在完整和脾切除小鼠中，随着血小板数量的减少，MPV与血小板减少的严重程度成比例增加，最早在诱导后4小时出现，并在早期血小板增多反弹期间持续存在。先前的观察表明，巨核细胞倍性直到血小板减少开始后48小时才发生变化，这证实了对这种刺激的MPV的初始和最大变化是由巨核细胞DNA水平改变以外的过程调节的。（摘要截短至400字）
