Korean J Physiol Pharmacol.  1999 Feb;3(1):29-34.

Cholinergic activity related to cardiovascular regulation in rostral ventrolateral medulla of spontaneously hypertensive rats

• Lee SY
• Lee SB

Abstract

The hyperactivity of cholinergic system in the RVLM of spontaneously hypertensive rats (SHR) may contribute to the sustained elevation of blood pressure. However, the hyperactivity mechanisms of cholinergic system are controversial. Thus, to clarify the mechanisms of cholinergic hyperactivity in RVLM of the SHR, we studied the activities of enzymes that participate in the biosynthesis and degradation of acetylcholine (ACh) and the density of muscarinic receptors in RVLM of the 14- to 18-week-old SHR and age-marched Wistar Kyoto rats (WKY). Choline acetyltransferase activity was far greater in RVLM of SHR than that of WKY. (3H)ACh release from RVLM was also greater in SHR than in WKY. Acetylcholinesterase activity and (3H)NMS binding of RVLM slice of SHR were not significantly different from that of WKY. These results suggest that the enhanced cholinergic mechanisms in the RVLM of SHR is due to the enhanced presynaptic cholinergic tone rather than the altered postsynaptic mechanisms.

Keyword

SHR; Rostral ventrolateral medulla (RVLM); Cholinergic activity

MeSH Terms

Acetylcholine
Acetylcholinesterase
Blood Pressure
Choline O-Acetyltransferase
Rats, Inbred SHR*
Rats, Inbred WKY
Receptors, Muscarinic
Acetylcholine
Acetylcholinesterase
Choline O-Acetyltransferase
Receptors, Muscarinic