Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Daily rhythm of salivary and serum urea concentration in sheep. | Journal of Circadian Rhythms BioMed Central Short paper Daily rhythm of salivary and serum urea concentration in sheep Giuseppe Piccione1 Augusto Foà2 Cristiano Bertolucci 2 and Giovanni Caola1 Open Access Address 1Dipartimento di Morfologia Biochimica Fisiologia e Produzione Animale Laboratorio di Cronofisiologia Veterinaria Facoltà di Medicina Veterinaria Università di Messina 98168 Messina Italy and 2Dipartimento di Biologia ed Evoluzione Università di Ferrara via L. Borsari 46 44100 Ferrara Italy Email Giuseppe Piccione - Augusto Foà - foa@ Cristiano Bertolucci - bru@ Giovanni Caola - Corresponding author Published 23 November 2006 Received 23 October 2006 Accepted 23 November 2006 Journal of Circadian Rhythms 2006 4 16 doi 1740-3391-4-16 This article is available from http content 4 1 16 2006 Piccione et al licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background In domestic animals many biochemical and physiological processes exhibit daily rhythmicity. The aim of the present study was to investigate the rhythmic pattern of salivary and serum urea concentrations in sheep. Methods Six 3-year-old female sheep kept in the same environmental conditions were used. Sheep were sampled at 4 hour intervals for 48 consecutive hours starting at 08 00 of the first day and finishing at 04 00 of the second day. Blood samples were collected via intravenous cannulae inserted into the jugular vein saliva samples were collected through a specific tube the Salivette . Salivary and serum urea concentrations were assayed by means of UV