Effect of age on alpha-calcitonin gene-related peptide-mediated delayed cardioprotection induced by intestinal preconditioning in rats.
In the present study, we examined whether age-related reduction in cardioprotection of intestinal ischemic preconditioning is related to stimulation of the release and synthesis of calcitonin gene-related peptide (CGRP) in rats. Ischemia-reperfusion injury was induced by a 45-min coronary artery occlusion and 180-min reperfusion, and ischemic preconditioning was induced by six cycles of 4-min ischemia and 4-min reperfusion of the small intestine. The serum concentration of creatine kinase, infarct size, the expression of CGRP isoforms (alpha- and beta-CGRP) mRNA in lumbar dorsal root ganglia and CGRP concentration in plasma were measured. Pretreatment with intestinal ischemic preconditioning for 24 h significantly reduced infarct size and creatine kinase release concomitantly with a significant increase in the expression of alpha-CGRP mRNA, but not beta-CGRP mRNA, and plasma concentrations of CGRP at 6 months of age but not at 24 months of age. These results suggest that the delayed cardioprotective effect of intestinal ischemic preconditioning is decreased in senescent rats, and the age-related change is related to reduction of the synthesis and release of alpha-CGRP.
Hu
Chang Ping
CP
Department of Pharmacology, Xiang-Ya School of Medicine, Central South University, Hunan 410078, Changsha, China.
Peng
Jun
J
Xiao
Liang
L
Ye
Feng
F
Deng
Han Wu
HW
Li
Yuan Jian
YJ
D000367:Age Factors; D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000097:blood / Q000235:genetics / Q000502:physiology*; D003326:Coronary Circulation / Q000187:drug effects; D003402:Creatine Kinase / Q000097:blood; D005727:Ganglia, Spinal / Q000378:metabolism; D007422:Intestines / Q000098:blood supply*; D019194:Ischemic Preconditioning; D008297:Male; D009203:Myocardial Infarction / Q000473:pathology / Q000517:prevention & control*; D020033:Protein Isoforms / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000097:blood / Q000201:enzymology; D020133:Reverse Transcriptase Polymerase Chain Reaction
D020033:Protein Isoforms; D012333:RNA, Messenger; D003402:Creatine Kinase; D015740:Calcitonin Gene-Related Peptide