Decrease of muscarinic M2 cholinoceptor gene expression in the heart of aged rat.
It is well known that the baroreflex activity decreases with aging. However, the mechanisms of this change are still not clear. Thus, we investigated one of the parameters to see whether aging alters gene expression of muscarinic receptors in the heart of Wistar rat aged between 2 months (adult) and 24 months (aged). The mRNA level determination by Northern blot analysis for muscarinic M2 cholinoceptors in aged rat was decreased as compared to that in 2-month-old rats. Quantification of receptor protein using selective antibodies indicated that the level of muscarinic M2 cholinoceptor in the heart of 24-month-old rats was lower than that in 2-month-old animals. These results indicate the decrease of muscarinic M2 cholinoceptor in heart with aging that may contribute as one of the parameters for dysfunction in baroreflex activity.
Lo
S H
SH
Cardiology Division, Department of Internal Medicine, Taipei Municipal Chung-Hsin Hospital, Taipei City, Taiwan.
Liu
I M
IM
Huang
L W
LW
Cheng
J T
JT
D000375:Aging / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017704:Baroreflex / Q000502:physiology; D015870:Gene Expression / Q000502:physiology*; D006321:Heart / Q000502:physiology*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D043585:Receptor, Muscarinic M2; D011976:Receptors, Muscarinic / Q000235:genetics / Q000378:metabolism*
D008565:Membrane Proteins; D012333:RNA, Messenger; D043585:Receptor, Muscarinic M2; D011976:Receptors, Muscarinic