A. Elhajouji et al., METABOLIC DIFFERENCES BETWEEN WHOLE-BLOOD AND ISOLATED LYMPHOCYTE-CULTURES FOR MICRONUCLEUS (MN) INDUCTION BY CYCLOPHOSPHAMIDE AND BENZO[A]PYRENE, Mutagenesis, 9(4), 1994, pp. 307-313
In order to study the metabolic differences between whole blood and is
olated lymphocyte cultures, two indirectly acting mutagens cyclophosph
amide (CP) and benzo[a]pyrene (B[a]P) were assessed for their potentia
l to induce micronuclei (MN) in the presence and absence of S9 microso
mal fractions. In isolated lymphocyte cultures supplemented with S9, C
P and B[a]P induced a statistically significant increase in MN which w
as not observed in whole blood cultures. However, the direct-acting ag
ent methyl methanesulphonate (which was used as a positive control) sh
owed an increase in MN frequency in a dose-dependent manner in both cu
lture methods. The effect of erythrocytes was then investigated by tre
ating isolated lymphocyte cultures simultaneously with CP and S9 mix i
n the presence of purified erythrocyte concentrate (PEC). A clear redu
ction in the MN frequency was observed compared to the frequencies of
MN induced in isolated lymphocyte cultures treated with CP and S9 mix
in the absence of PEC. Thus, isolated lymphocyte cultures mag represen
t a more sensitive test system for the evaluation of potential indirec
t-acting mutagens. However, whole blood cultures may reflect the 'real
life' situation more accurately as a consequence of the presence of e
rythrocytes.