Tuyển tập các báo cáo nghiên cứu về bệnh thú y được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành thú y đề tài: Plasma Melatonin Levels in Relation to the LightDark Cycle and Parental Background in Domestic Pigs. | Acta vet. scand. 2001 42 287-294. Plasma Melatonin Levels in Relation to the LightDark Cycle and Parental Background in Domestic Pigs By H. Andersson Department of Clinical Chemistry Centre of Reproductive Biology in Uppsala Swedish University of Agricultural Sciences Uppsala Sweden. Andersson H Plasma melatonin levels in relation to the light-dark cycle and parental background in domestic pigs. Acta vet. scand. 2001 42 287-294. - To study porcine melatonin secretion in a stable environment 3 daytime - and 3 nighttime - plasma samples were collected by jugular venipuncture from 15 gilts 16 sows 3 boars and 48 piglets 24 females and 24 males from 8 litters and analysed for melatonin content. Nighttime melatonin concentrations were higher than daytime melatonin concentrations p whereas no effect of sampling order could be discerned. The 3 adult Hampshire boars had higher melatonin concentrations during the day and the night than the 31 adult Yorkshire females p . There was no clear difference between gilts and sows in plasma melatonin. The gilts from one of the litters had higher plasma melatonin concentrations than the gilts in 3 other litters p . Among the 48 piglets the increase of nocturnal melatonin secretion differed between litters p whereas the influence of father was not quite significant p . No difference in daytime melatonin concentrations between litters could be found and there was no difference in melatonin levels between the male and female piglets. In conclusion this study demonstrates that domestic pigs express a nocturnal increase of melatonin secretion in a standard stable environment. For some animals the amplitude of nighttime melatonin secretion was very low although always higher than the daytime base levels. Furthermore the levels of nighttime melatonin secretion differed between litters which suggests a genetic background. genetic. Introduction The circadian rhythm of pineal melatonin with an
