Abstract Ovine pulmonary adenocarcinoma (OPA) is an infectious and neoplastic disease etiologically linked to the Jaagsiekte sheep retrovirus (JSRV), characterised by tumour lesions of the lung. Because of the economic losses it induces, OPA is of great importance for flock health. In this study, oxidative stress markers and adenosine deaminase (ADA) activity were quantified in lung tissue from sheep, both healthy and those naturally afflicted with OPA. Compared to healthy sheep, malondialdehyde (MDA), nitric oxide (NO ), ceruloplasmin (CP) and ADA concentrations/activities were significantly increased (P<0.05 and P<0.001) in fresh lung tissues from JSRV–infected sheep, while reduced glutathione (GSH) levels were significantly decreased (P<0.05). In conclusion, pronounced oxidative stress and increased ADA enzyme activity were detected in the JSRV–infected sheep. These findings suggest that ADA activity could serve as a biomarker for disease diagnosis.
KIZILTEPE et al. (2026) studied this question.