Comparative Biochemistry and Physiology Part B 134 (2003) 515–518 1096-4959/03/$ - see front matter  2002 Elsevier Science Inc. All rights reserved. doi:10.1016/S1096-4959(03)00003-4 Distribution of rhodanese in tissues of goat (Capra hircus) Saeed Nazifi *, Mahmoud Aminlari , Mohammad Ali Alaibakhsh a, b b Department of Clinical Studies, School of Veterinary Medicine, Shiraz University, Shiraz 71345, Iran a Department of Biochemistry, School of Veterinary Medicine, Shiraz University, Shiraz 71345, Iran b Received 3 July 2002; received in revised form 12 November 2002; accepted 16 December 2002 Abstract Rhodanese (thiosulfate: cyanide sulfurtransferase, EC. 2.8.1.1) is a ubiquitous enzyme present in all living organisms, from bacteria to humans and plays a central role in cyanide detoxification. The purpose of this investigation is to determine and compare rhodanese activity in different tissues of adult male and female goats (Capra hircus). The results showed that the specific activity of rhodanese in different tissues was significantly different (P-0.05). The highest activity of rhodanese was in epithelium of rumen, followed by epithelia of reticulum and omasum and liver. No significant difference was observed when tissues of male and female goats were compared. The lowest specific activity of rhodanese was observed in spleen, urinary bladder, lymph node, ovary, skeletal muscle and pyloric muscle of abomasum. The results of this study may indicate the involvement of rhodanese in cyanide detoxification in goat tissues that have greater potential to be exposed to higher levels of cyanide.  2002 Elsevier Science Inc. All rights reserved. Keywords: Cyanide; Detoxification; Goat; Rhodanese; Tissues 1. Introduction Rhodanese (thiosulfate ycyanide sulfur transfer- ase) is an ubiquitous enzyme present in all living organisms from bacteria to man (Westley, 1973; Wood, 1975; Lettl, 1983, 1984; Drawbaugh and Marrs, 1987; Aminlari and Gilanpour, 1991; Hatz- feld and Saito, 2000). Rhodanese catalyzes the cyanide dependent cleavage of thiosulfate to form thiocyanate and sulfite (Westley, 1981). In spite of extensive studies, the true biological role of this enzyme is still an enigma. It is believed that rhodanese is involved in cyanide detoxification (Lang, 1933; Himwich and Saunders, 1948; Koj and Frendo, 1962; Wood, 1975; Drawbaugh and Marrs, 1987; Aminlari et al., 2000). However, *Corresponding author. Tel.: q98-711-6280703; fax: q98- 711-6280707. E-mail address: aminlari@shirazu.ac.ir (S. Nazifi). there is some evidence that the enzyme may be involved in other functions, including formation of iron sulfur centers (Cerletti, 1986), participation in energy metabolism (Ogata et al., 1989; Bonomi et al., 1997) and function as a thioredoxin oxidase (Nandi et al., 2000). The presence of rhodanese has been detected in many tissues of animals (Dudeck et al., 1980; Westley, 1981; Drawbaugh and Marrs, 1987; Aminlari and Gilanpour, 1991; Aminlari and Shahbazi, 1994; Aminlari et al., 1994, 2000, 2002), but almost no information is available on the activity of rhodanese in goat tissues. The aim of this investigation was to determine and compare the pattern of distribution of rhodanese in different tissues of adult male and female goats (Capra hircus). The results of this study will be discussed in terms of possible role of rhodanese in cyanide detoxification in these tissues.