Flow cytometric analysis of erythropoietic abnormality: changes in the cell maturity index of reticulocytes and retic distribution index are useful as indicators of erythropoietic toxicity in non-clinical studies.
We performed a flow cytometric (FCM) analysis of the maturity of reticulocytes using peripheral blood obtained from rats administered 5-fluorouracil (5-FU) at 10, 50 and 100 mg/kg or acethylphenyl hydrazine (APHZ) at 1 and 3 mg/kg to clarify whether the FCM method is useful for assessing toxicity. In the 5-FU-administered rats, a decrease and recovery of the immature reticulocyte fraction (Cell Maturity Index, CMI; Retic Distribution Index, RDI) was observed more rapidly (several days prior to changes in the reticulocyte ratio), and sensitively regarding dose-dependency (clear changes were observed at 10 mg/kg, whereas the reticulocyte ratio was only slightly affected). In addition, there was good agreement between the microscopic results obtained by counting Heilmyer's reticulocyte maturation groups, especially for type I and II, and CMI/RDI assessed by the FCM method after the administration of 50 and 100 mg/kg of 5-FU, the dose at which clear changes were obtained with the microscopic method. In the APHZ-administered rats, a dose-dependent increase in CMI/RDI coinciding with the enhancement of reticulocyte production was observed. The results suggested that the automated FCM method could be a useful and valuable tool to assess and predict impairments of erythropoiesis, especially for CMI and RDI, and could help in the diagnosis of hematological disorders in experimental animals.
Kakiuchi
Satoko
S
Pharmacology and Safety Research Department, Pharmaceutical Development Research Laboratories TEIJIN Pharma Limited, 4-3-2 Asahigaoka, Hino, Tokyo 191-8512, Japan.
Kobayshi
Mitsuru
M
Satomi
Yoshihide
Y
Miura
Daishiro
D
Kasahara
Yoshinori
Y
Kondo
Shiro
S
D000818:Animals; D000963:Antimetabolites / Q000009:adverse effects / Q000494:pharmacology; D001774:Blood Chemical Analysis; D001853:Bone Marrow / Q000187:drug effects; D016922:Cellular Senescence / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004920:Erythropoiesis / Q000187:drug effects*; D005434:Flow Cytometry / Q000379:methods*; D005456:Fluorescent Dyes; D005472:Fluorouracil / Q000633:toxicity*; D008297:Male; D010659:Phenylhydrazines / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017701:Reticulocyte Count / Q000295:instrumentation / Q000379:methods*; D012156:Reticulocytes / Q000166:cytology*
D000963:Antimetabolites; D005456:Fluorescent Dyes; D010659:Phenylhydrazines; C006384:N(1)-acetylphenylhydrazine; D005472:Fluorouracil