title: Possible physiological role of endogenous adenosine in defecation in rats.
abstract: Evacuated feces after intraperitoneal administration of selective adenosine receptor antagonists were evaluated in rats. The selective adenosine A1 receptor antagonists, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) (100-300 micrograms/kg i.p.) and (R)-7,8-dihydro-8-ethyl-2-(3-noradamantyl)-4-propyl-1H-imidazo[2,1 -i]purin- 5(4H)-one (KF20274) (30-300 micrograms/kg i.p.), significantly increased defecation, whereas the selective adenosine A2 receptor antagonist 4-amino-8-chloro-1-phenyl[1,2,4]triazolo[4,3-a]quinoxaline (CP-66,713) failed to cause a significant increase at up to 10 mg/kg i.p. The defecation caused by DPCPX (100 micrograms/kg) was markedly alleviated by (2S)-N6-(2-endo-norbornyl)adenosine ((S)-ENBA) (30-300 micrograms/kg s.c.), a selective adenosine A1 receptor agonist, but not influenced by 2-[p-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamidoadenosin e (CGS 21680) (30-1000 micrograms/kg s.c.), a selective adenosine A2 receptor agonist. These results suggest that endogenous adenosine plays a physiological role in sustained inhibition of defecation via adenosine A1 receptors.
authors: Department of Pharmacology, Kyowa Hakko Kogyo Co., Ltd., Shizuoka, Japan.
authors: A
authors: A
authors: Tomaru
authors: A
authors: A
authors: Ishii
authors: N
authors: N
authors: Kishibayashi
authors: J
authors: J
authors: Shimada
authors: F
authors: F
authors: Suzuki
authors: A
authors: A
authors: Karasawa
mesh_terms: D000241:Adenosine / Q000502:physiology*; D000818:Animals; D003672:Defecation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D051381:Rats; D017208:Rats, Wistar
chemical_list: D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D000241:Adenosine