2024-03-28T08:48:09Z
https://niigata-u.repo.nii.ac.jp/oai
oai:niigata-u.repo.nii.ac.jp:00021093
2022-12-15T03:51:41Z
453:456
471:537:538:1176
Mechanisms of Adenosine 5'-Monophosphate-induced Relaxation in the Isolated Guinea Pig Thoracic Aorta
Adenosine 5'-monophosphate(AMP)のモルモット摘出胸部大動脈弛緩作用について
Adenosine 5'-monophosphate(AMP)のモルモット摘出胸部大動脈弛緩作用について
今井, 裕久
129367
guinea pig thoracic aorta
AMP
adenosine
5'-nucleotidase
AOPCP
モルモット胸部大動脈
アデノシン
In order to investigate whether a relaxation potency of adenosine 5'-monophosphate (AMP) is comparable to that of adenosine, isolated guinea pig thoracic aortas precontracted with phenylephrine were used. In order to examine the direct relaxant effect on the smooth muscle, all preparations were deprived of endothelial layer by rubbing. Adenosine induced concentrationdependent relaxations in the aorta with an ED_<50> value of 1.0×10^<-4>M. The concentration-relaxation curve for adenosine was shifted to the left with 2×10^<-5> M of erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA), an adenosine deaminase inhibitor. This concentration of EHNA caused 97% inhibition of adenosine degradation to inosine in the aorta. Relaxation by adenosine was inhibited with 8-phenyltheophylline (8-PT), a P_1 purinoceptor inhibitor. AMP caused concentration-dependent relaxations in the aorta with an ED_<50> value of 1.2×10^<-4>M, a value which was comparable to that of adenosine. AMP-induced relaxation was also potentiated by EHNA treatment. α, β-methylene adenosine diphosphate (AOPCP), an ecto-5'-nucleotidase inhibitor, caused no effect on adenosine-induced relaxation, while it inhibited AMP-induced relaxation around 80%. The concentration of AOPCP used in this experiment. inhibited AMP degaradation in the aorta by 50 to 85%. These results suggest that AMP-induced relaxation is due to adenosine produced through ecto-5'-nucleotidase pathway and the relaxation potency of AMP itself is very weak.
departmental bulletin paper
新潟医学会
1992-03
application/pdf
新潟医学会雑誌
3
106
188
195
新潟医学会雑誌
AN00182415
00290440
https://niigata-u.repo.nii.ac.jp/record/21093/files/106(03)_188-195.pdf
jpn