Existance of cholinergic and purinergic receptor on the detrusor muscle of rat urinary bladder.
10.12701/yujm.1991.8.2.138
- Author:
Tae Su CHOI
;
Oh Cheol KWON
;
Jeoung Hee HA
;
Kwang Youn LEE
;
Won Joon KIM
- Publication Type:Original Article
- Keywords:
Stimulatory component;
Innervation;
Detrusor muscle;
Cholinergic;
Purinergic;
Independent
- MeSH:
Adenosine Triphosphate;
Animals;
Atropine;
Bethanechol;
Choline;
Cholinergic Agonists;
Cholinesterases;
Ganglion Cysts;
Hemicholinium 3;
Hexamethonium;
Myography;
Nerve Endings;
Neural Conduction;
Physostigmine;
Rats*;
Receptors, Purinergic;
Tetrodotoxin;
Urinary Bladder*
- From:Yeungnam University Journal of Medicine
1991;8(2):138-149
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
This study was aimed at investigation of the stimulatory innervations on the rat urinary bladder. Detrusor muscle strips of 15 mm long were suspended in isolated muscle chambers containing 1 ml of PSS maintained at 37℃ and aerated with 95% O²/5% Co². Isometric myography was performed, and the results were as followings: Muscle strips showed “on-contraction” by electric field stimulation (EFS) frequency-dependently. The EFS-induced contraction was not affected by hexamethonium, a ganglion blocker, but abolished by tetrodotoxin, a nerve conduction blocker. Physostigmine, a cholinesterase inhibitor enhanced the EFS-induced contraction which was inhibited by hemicholinium, an inhibitor of choline uptake at the cholinergic nerve ending. Such an EFS-induced contraction was antagonized by atropine only partially, and the atropine-resistant portion was completely abolished by the desensitization of purinergic receptors by prolonged incubating of the strips in the presence of high concentration of ATP. Bethanechol, a cholinergic agonist, elicited concentration-dependent contraction. Adenosine triphosphate (ATP), a purinergic agonist, induced a weak but concentration-dependent contraction of short duration. Bethanechol-induced contraction was not affected by ATP-desensitization, and ATP-induced contraction was not affected by tetrodotoxin. These results suggest that there are at least two main stimulatory components of innervations in the detrusor muscle, cholinergic muscarinic and purinergic; and those receptors are independent each other.
