Biphasic haematological response to nitrocellulose thinner vapour exposure and withdrawal in male Wistar rats

Abstract

Background: Nitrocellulose thinner, a commonly used industrial solvent mixture, contains aromatic hydrocarbons, which are known to have toxicological effects.

Objective: There is a dearth of information on haematological effects due to subchronic exposure and the extent of recovery following withdrawal. In this study, the effects of subchronic inhalation of nitrocellulose thinner vapour (NCTV) and its withdrawal on haematological parameters in male Wistar rats were evaluated.

Methods: Twenty-four male rats divided into 3 groups (n=8) were used for the study. Group I (control, no exposure), Group II (90-day NCTV exposure), Group III (90-day exposure with 90-day withdrawal). Haematological indices (white blood cell (WBC), red blood cell (RBC), platelet (PLT) counts, haemoglobin (HGB), haematocrit (HCT), and erythrocyte indices (MCH and MCHC) were evaluated using automated haematological analysis.

Results: Exposure to NCTV led to a significant (p < 0.05) increase in WBC count (19.85 ± 7.64). Following withdrawal, WBC levels reduced (13.56 ± 4.30). In contrast, there was no significant (p < 0.05) change in RBC and PLT counts due to exposure, but withdrawal led to a significant (p < 0.05) decline in both parameters. Also, MCH and MCHC were not significantly affected due to exposure, but withdrawal led to a significant (p < 0.05)   increase in both parameters.

Conclusion: Subchronic NCTV exposure induces a biphasic haematological response characterised by transient inflammation and delayed suppression of erythropoiesis and thrombopoiesis. These findings highlight the persistence of toxic effects beyond exposure and underscore the importance of post-exposure monitoring in solvent-exposed populations.