Increase of cardiac M2-muscarinic receptor gene expression in type-1 but not in type-2 diabetic rats.
Changes of cardiac M2-muscarinic receptor (M2-mAChR) gene expression was investigated in type-1 like diabetic rats induced by intravenous injection of streptozotocin (STZ) and type-2 like diabetic rats induced by fed with fructose-rich chow. Systolic blood pressure (SBP) in STZ-diabetic rats was significantly lower than that in age-matched non-diabetic rats, while the SBP in type-2 like diabetic rats was higher than in non-diabetic rats. Also, the mRNA or protein level of cardiac M2-mAChR in STZ-diabetic rats was markedly higher than non-diabetic rats, but it was not observed in type-2 like diabetic rats as compared to age-matched non-diabetic rats. Arecaidine propargyl ester (APE), the agonist of M2-mAChR, produced a marked reduction of heart rate in STZ-diabetic rats but made less influence on heart rate in fructose-fed rats or non-diabetic rats. The results suggest that cardiac M2-mAChR gene expression is raised in type-1 like diabetic rats but not in type-2 like diabetic rats, this difference mainly due to hyperglycemia, for the production of hypotension in diabetic disorders.
Lee
Liang-Ming
LM
Department of Urology, College of Medicine and Wan Fang Hospital, Taipei Medical University, Taipei City, Taiwan, ROC.
Chang
Cheng Kuei
CK
Cheng
Kai-Chun
KC
Kou
Dai-Huang
DH
Liu
I-Min
IM
Cheng
Juei-Tang
JT
D000818:Animals; D001115:Arecoline / Q000031:analogs & derivatives / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D003922:Diabetes Mellitus, Type 1 / Q000139:chemically induced / Q000473:pathology*; D003924:Diabetes Mellitus, Type 2 / Q000209:etiology / Q000473:pathology*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005632:Fructose / Q000009:adverse effects; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D043585:Receptor, Muscarinic M2 / Q000235:genetics / Q000378:metabolism*; D013311:Streptozocin
D012333:RNA, Messenger; D043585:Receptor, Muscarinic M2; C015000:arecaidine esters; D005632:Fructose; D001115:Arecoline; D013311:Streptozocin