Modulation of Neonatal Rat Myeloid Kinetics Resulting in Peripheral Neutrophilia by Single Pulse Administration of Rh Granulocyte-Macrophage Colony-Stimulating Factor and Rh Granulocyte Colony-Stimulating Factor

Abstract

Rh granulocyte-macrophage (GM) colony-stimulating factor (CSF) and rh granulocyte (G) CSF have been demonstrated to induce proliferation and maturation of myeloid stem cells and release of mature polymorphonucleocytes (PMNs) from human and animal adult bone marrows. Unfortunately, reduced bone marrow progenitor cells, neutrophil storage pool (NSP) depletion and peripheral neutropenia are characteristic of human and animal newborn bone marrows. We investigated the effect of administering intraperitoneal rhGM-CSF and rhG-CSF to Sprague-Dawley newborn rats (less than 36 h). Newborn rats treated with intraperitoneal CSF (3.0 micrograms/kg) demonstrated significant leukocytosis at 6 and 24 h: rhGM-CSF vs. control, WBC (10(3)/mm3), at 6 h, 8.0 +/- 0.5 vs 4.3 +/- 0.9 (p less than or equal to 0.003), and at 24 h, 7.7 +/- 1.7 vs. 3.8 +/- 0.2 (p less than or equal to 0.008); rhG-CSF vs. control WBC (10(3)/mm3) at 6 h, 6.6 +/- 1.2 vs 4.3 +/- 0.1 (p less than or equal to 0.03), and at 24 h, 8.1 +/- 0.2 vs. 3.75 +/- 0.2 (p less than or equal to 0.003). The absolute neutrophil count was also significantly elevated at 6 h following intraperitoneal CSF (3.0 micrograms/kg): RhGM-CSF vs. control 1,827 +/- 25 vs. 379 +/- 10 (p less than or equal to 0.001); rhG-CSF vs. control, 1,698 +/- 40 vs. 371 +/- 10.1 (p less than or equal to 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)