Effects of intraperitoneal application of toluene dissolved in propylene glycol on erythropoiesis in Wistar rats

Abstract

The potential toxic effect of toluene on erythropoiesis was investigated during the enhanced erythropoietic activity provoked by application of propylene glycol (known as a mild hemolytic agent) in adult female Wistar rats. The animals were treated daily for 3, 7 or 11 days, with an intraperitoneal dose of toluene dissolved in propylene glycol (T+PG) or propylene glycol (PG) alone. The effects of T+PG and PG on some hematological parameters in peripheral blood and bone marrow were evaluated at the time of sacrifice. The number of red blood cells (RBC), reticulocytes (Rt), hematocrit values (PCV), and hemoglobin concentration (Hb) were determined in peripheral blood samples using standard laboratory procedures. Total bone marrow nucleated cells (TBMNC) were counted and the myelogram was analysed as well. The number of early bone marrow erythroid progenitor cells - Burst Forming Unit – Erythroid (BFU-E) was assessed using a colony forming assay on methylcellulose. Toluene dissolved in PG induced a decrease in RBC number, PCV and Hb concentration and an increase within the bone marrow BFU-E and precursor erythroid cell compartments, as well as the percentage of peripheral blood Rt, indicating enhanced erythropoietic activity. Very similar changes occurred when PG was administered alone. Therefore, it can be assumed that short-term application of a low dose of toluene (3 mg/kg) dissolved in PG did not have a toxic effect during PG induced enhanced erythropoietic activity.