Mutation Research 498 (2001) 1–6 DNA damage induced by copper deficiency in cattle assessed by the Comet assay S.J. Picco a , J.C. De Luca a , G. Mattioli b,c , F.N. Dulout a,∗ a Facultad de Ciencias Veterinarias, Centro de Investigaciones en Genética Básica y Aplicada (CIGEBA), Universidad Nacional de La Plata, 60 y 118, CC 296, B1900AVW La Plata, Argentina b Facultad de Ciencias Veterinarias, Servicio de Nutrición Mineral, Cátedra de Fisiolog´ ıa, Universidad Nacional de La Plata, 60 y 118, CC 296, B1900AVW La Plata, Argentina c Facultad de Ciencias Veterinarias, Centro de Diagnóstico e Investigaciones Veterinarias (CEDIVE), Universidad Nacional de La Plata, Salta y Alvear, Chascomús, Argentina Received 6 December 2000; received in revised form 22 May 2001; accepted 30 May 2001 Abstract Cattle hypocuprosis is a well-known endemic disease in several parts of the world. In a previous paper, the clastogenic effect of copper deficiency in cattle has been described although the occurrence of DNA damage was not directly tested. For this reason, the relation between DNA damage assessed by the Comet assay and Cu plasma concentration was studied in Aberdeen Angus cattle. Blood samples were obtained in heparinized Vacutainer ® tubes from 28 female Aberdeen Angus cows during pregnancy or immediately after to give birth. Each sample was divided into two aliquots for Comet assay and Cu plasma determination, respectively. From the 28 cattle sampled, 17 were normocupremic and 11 were hypocupremic. Results obtained showed that whereas the average plasma Cu level in normocupremic cattle was 67.6 g/dl, in hypocupremic cattle it was 32.1 g/dl. The increase of DNA damage was mostly evidenced by the decrease of comet degree 1 cells and an increase of comet degree 2 cells. Correlation analysis comparing plasma Cu levels and degree 1 cells showed a correlation coefficient 0.72 (P< 0.01). The comparison between plasma Cu levels and comet degree 2 cells was -0.65 (P< 0.01). The comparison between plasma Cu levels and the comet length-head diameter medians determined in 23 out of 28 animals showed a correlation coefficient of -0.54 (P< 0.01). The induction of DNA damage was clearly supported by the fact that the decrease of plasma Cu levels was correlated with the increase of comet length-head diameter. These findings could be considered as a contribution to the hypothesis that DNA and chromosome damage are a consequence of the higher oxidative stress suffered by hypocupremic animals. © 2001 Elsevier Science B.V. All rights reserved. Keywords: Copper plasma levels; DNA damage; Comet assay 1. Introduction Cattle hypocuprosis is a well-known endemic disease in several parts of the world, causing severe ∗ Corresponding author. Fax: +54-221-421-1799. E-mail address: dulout@fcv.medvet.unlp.edu.ar (F.N. Dulout). economical loses through loss of condition, diar- rhoea, spontaneous fractures in calves, sudden death in adult animals and impairment of inmunological response [1]. In Argentina, the Salado’s river basin in Buenos Aires Province is one of the most charac- teristic regions in the country with copper deficiency, affecting well over 3 million heads of beef cattle [2]. 1383-5718/01/$ – see front matter © 2001 Elsevier Science B.V. All rights reserved. PII:S1383-5718(01)00242-X