title: Effects of cholecystokinin octapeptide on rat cardiac function and the receptor mechanism.
abstract: The aim of this study was to explore the effects of cholecystokinin octapeptide (CCK-8) on cardiac function and the receptor mechanism in anesthetized rats. The mean arterial pressure (MAP), heart rate (HR), the left ventricle systolic pressure (LVP) and the maximal/minimum rate of LVP (+/-LV dp/dt(max)) were measured. The results obtained are as follows. (1) Low dose of CCK-8 (0. 4 microgram/kg i.v.) caused tachycardia and slight increase in MAP, LVP and LV dp/dt(max) (P<0.01), while medium dose (4.0 microgram/kg i.v.) and high dose of CCK-8 (40 microgram/kg i.v.) elicited a bradycardia and marked increase in MAP, LVP and LV dp/dtmax (P<0.01). (2) Proglumide (1.0 mg/kg i.v.), a CCK-receptor (CCK-R) antagonist, significantly inhibited the pressor effects of CCK-8, whilst it reversed the bradycardic responses (P<0.01). (3) Using reverse transcription polymerase chain reaction (RT-PCR), CCK-A receptor (CCK-AR) and CCK-B receptor (CCK-BR) mRNA were expressed in myocardium of rats. The above results indicate that CCK-8 may enhance cardiac function in a dose-dependent manner and elicit a change in HR, which is likely induced by the activation of CCK-R on myocardium.
authors.affiliation: Department of Pathophysiology, Hebei Medical University, Shijiazhuang 050017, China. lingyiling@163.net
authors.forename: Xiao-Yun
authors.initials: XY
authors.lastname: Zhao
authors.forename: Yi-Ling
authors.initials: YL
authors.lastname: Ling
authors.forename: Ai-Hong
authors.initials: AH
authors.lastname: Meng
authors.forename: Bao-En
authors.initials: BE
authors.lastname: Shan
authors.forename: Jun-Lan
authors.initials: JL
authors.lastname: Zhang
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects*; D008297:Male; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011949:Receptors, Cholecystokinin / Q000187:drug effects*; D012844:Sincalide / Q000008:administration & dosage / Q000494:pharmacology*; D016277:Ventricular Function, Left / Q000187:drug effects*; D017725:Ventricular Pressure / Q000187:drug effects*
chemical_list: D011949:Receptors, Cholecystokinin; D012844:Sincalide