Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Circadian variations in salivary chromogranin a concentrations during a 24-hour period in dogs | J. Vet. Sci. 2008 9 4 421-423 JOURNAL OF Short Communication Veterinary Science Circadian variations in salivary chromogranin a concentrations during a 24-hour period in dogs Kazutaka Kanai Mariko Hino Yasutomo Hori Ruriko Nakao Fumio Hoshi Naoyuki Itoh Seiichi Higuchi Department of Small Animal Internal Medicine School of Veterinary Medicine Kitasato University Towada Aomori 034-8628 Japan The purpose of this study was to determine if salivary chromogranin a secretion in dogs exhibits a circadian rhythm. Saliva sampling was performed during three different sessions occurring in three nonconsecutive 24-h periods. Sixteen healthy adult beagle dogs 8 males and 8 females were moved to a sampling room and housed individually in cages. Saliva samples were obtained every 4 h from 12 00 . to 12 00 . the following day. In the interest of habituation saliva was obtained hourly from each dog 3 h before the experiment was started. Salivary chromogranin A concentrations were measured using an enzyme-linked immunosorbent assay. No circadian rhythm was detected for salivary chromogranin A secretion and no differences in salivary chromogranin A concentrations measured every 4 h were demonstrated during the 24-h cycle in dogs. Keywords chromogranin A circadian variations dog saliva Chromogranin A CgA exists in chromaffin granules of the adrenal medulla and is co-released with epinephrine or norepinephrine 2 3 . Currently CgA is known to be stored in secretory granules in wide ranging neurons and endocrine paraneurons along with neurotransmitters or hormones 8 18 . It has been shown that CgA is stored in the acinar cells of the salivary glands in rats and horses 14 and that it is released by sympathetic nerve stimuli in saliva 9 . Human salivary CgA has also been shown to be produced by the submandibular gland and secreted into saliva 13 . Nakane et al. 12 reported that salivary CgA had promise as a sensitive index of psychosomatic stress. Akiyoshi et al. 1 reported that .
