Studies On The Expression Of Ghrelin System And Its Effects On Cold Exposure In Lambs

Ghrelin is an endogenous ligand for growth hormone secretagogue receptors,which regulates growth hormone secretion,promotes ingestion and gastrointestinal motility,regulates energy balance and other physiological functions.Ghrelin plays a variety of biological functions primarily through its functional receptor(GHS-R1a),whereas Ghrelin N-terminal serine 3 acylation is its binding receptor and plays a biological role,Its acylation is mainly catalyzed by Ghrelin O-acyltransferase(GOAT).In this study,we studied the expression and localization of Ghrelin system(Ghrelin,GHS-R1 a and GOAT)in ruminants and the effects of Ghrelin on the physiological and biochemical indexes of cold exposed lambs.In order to investigate the effects of Ghrelin system on Ghrelin system,Regulating the biological function of ruminants and other aspects of research to provide a reference.1.The expression of Ghrelin in hypothalamus,pituitary,rumen,wrinkled stomach,cranial antrum,duodenum,jejunum,ileum,heart,liver,spleen,kidney,pancreas and testis were detected by Real-time PCR,GHS-R1 a and GOAT mRNA expression levels.Ghrelin and GHS-R1 a mRNA were expressed in the tissues of lambs,but Ghrelin and GOAT mRNA were the highest in the wrinkled stomach and GHS-R mRNA was expressed in the hypothalamus and pituitary.2.The level of protein in tissues of Xinjiang fine wool sheep was detected by Western blotting.The results showed that Ghrelin,GHS-R1 a and GOAT proteins were positive in the tissues of lambs,but Ghrelin and GOAT proteins had the highest expression level in wrinkled stomach,while GHS-R protein was high in pituitary.At the same time,the localization of Ghrelin system in Xinjiang was studied by immunohistochemical method.The results showed that Ghrelin immunoreactive cells were mainly distributed in the gastric mucosa,especially near the bottom of the fundus gland.The distribution of GHSR1 a and GOAT protein was found in the rounded or oval-shaped positive cells.There are positive areas in the bottom.3.The effects of acute cold exposure(air temperature-24.7?±0.2? for 2 h)and exogenous Ghrelin(10 ?g / kg body weight)on the lambs showed that at 8 h?16 h and 24 h after fasting.The respiratory rate,heart rate and blood glucose concentration were significantly lower than those before fasting(P<0.05).The rectal temperature was significantly lower than that before fasting at 16 h and 24 h after fasting(P<0.01),and the changes of blood physiological indexes(P<0.05).The heart rate and blood glucose concentration were significantly increased at 1.0 h?1.5 h and 2.0 h after freezing(P<0.05),and the respiratory rate of lamb was significantly lower than that of the control group(P<0.05).There was no significant difference in the rectal temperature between the two groups(P>0.05).The effect of Ghrelin on the laryngeal vein was not found in the jugular vein after cryopreservation(P>0.05).The results of this study suggest that the ruminant Ghrelin is mainly synthesized in the corpses and regulates the growth and development of the animals through the hypothalamus and the pituitary.The lambs can maintain their homeostasis by adjusting their own activities in fasting and low temperature conditions.Ghrelin may not be directly involved in the regulation process.