The Effects Of Kisspeptin-10 On Serum Metabolism And Myocardium In Rats And The Intervention Of Kisspeptin-10 In Heat Stress-induced Myocardial Damage

Kisspeptin is a peptide encoded by the Kiss 1 gene and also named as metastin because of its function of inhibiting tumor metastasis.Later research found that Kisspeptin also played important roles in the process of puberty initiation,reproduction,contraction of blood vessels and adjusting the stress.In the present study,the cardiac histomorphology was observed through TEM(transmission electron microscope),HE and Masson staining to find the instinctive change.The levels of metabolites in serum were measured and analyzed based on GC/TOF-MS.Gene chip was employed to detect the variation of gene expression profile induced by Kisspeptin-10.RT-PCR and Western-blot were subsequently conducted to verify the relevant mRNA and protein expression respectively.In summary,these findings suggested that Kisspeptin-10 could have positive inotropic effects on myocardium and alter the serum metabolites and expression of genes and proteins in heart tissue.In today’s environment,high temperature could cause human and animal in a state of heat stress,resulting the body’s nervous,immune and endocrine turbulence easily.Symptoms such as shortness of breath,heart failure and inflammation appeared after being suffered heat stress and caused great threat to human health.In animal husbandry,heat tress led to reduce the animal immunity,feeding,productivity and reproductive capacity.Heat stress caused a huge obstacles to development in animal husbandry and was a big problem to be solved.It has been reported that cardiovascular system was the first and the most vulnerable part to be damaged after being suffered heat stress.Heat tress could result in cardiac compensatory reactions such as increased strength and accelerated heart rate.It could cause the happening and development of many secondary diseases when myocardial compensatory couldn’t bear the damage induced by heat stress.In the first part of our study,we obtained the energy and amino acid metabolism changes in serum,heart disease pathways related genes expression changes in heart tissues,and morphological changes in cardiomyocytes induced by Kisspeptin-10 treatment.Then,we expected to probe the way Kisspeptin-10 intervened in the process of heart injury induced by heat stress.In the heat stress study with Kissppetin-10 intervened,all the rats were divided into three groups randomly:the heat stress group(H),the heat stress with Kisspeptin-10 intervention(KH),the control group(N).This study intended to employ several approaches,including histomorphological observation,heart injury related genes mRNA expression levels detection,and relative protein expression levels detection,to find the effects of Kisspeptin-10 on heat stress induced heart injury.Histomorphological findings demonstrated that there were many fractures of cardiomyocytes and uneven stained cytoplasm through HE staining and increased fibrosis around the heart cells through Masson staining after heat stress.Additionally,the main changes in ultrastructure such as broken mitochondrial cristae could be observed with TEM after heat stress treatment.However,heat stress induced damages in heart tissue were relieved,including decreased fractures of cardiomyocytes,even stained cytoplasm,deceased fibrosis around the heart cells,and decreased broken mitochondrial cristae,with the Kisspeptin-10 intervention.In heart tissue,genes ITGB8,HIF-1,MYL7 and BNP mRNA expression increased very significantly(P<0.01)in the heat stress group and decreased after the Kisspeptin-10 intervention.The gene ITGA4 expression increased significantly(P<0.05)in the heat stress group and decreased after the Kisspeptin-10 intervention.Additionally,the key genes ITGB8 and BNP also displayed consistent protein expression levels in Western-blot result.In summary,our findings demonstrated that Kisspeptin-10 could alter the structure of myocardial cells,serum metabolite levels,and expression of genes and proteins in heart tissues.These findings suggested that Kisspeptin-10 could induce positive inotropic action and alter the energy metabolism,amino acid metabolism and the other metabolism.In the heat-stress rats,histomorphological and molecular biological studies suggested that Kisspeptin-10 might participated in many processes,including myocardial remodeling,mitochondria repairment,energy production,and myocardial fibers formation,and relieved heart damages after heat stress.