Abstract
The effect of xanthone on smooth muscle was studied in thoracic aorta isolated from rats. Xanthone relaxed the norepinephrine-induced contraction of rat thoracic aorta. This relaxing effect of xanthone persisted in endothelium-denuded aorta suggesting that the relaxation induced by xanthone is endothelium-independent. The norepinephrine and high-K+-induced vasoconstriction was inhibited dose dependently in aorta pretreated with xanthone with IC50 values of 60.26 ± 8.43 and 82.9 ± 13.21 μM, respectively. The inositol 1,4,5-trisphosphate formation induced by norepinephrine (3 μM) in rat aorta was not affected by xanthone (10-100 μM), suggesting that the vasorelaxant effect of xanthone was not exerted on the receptor. Xanthone concentration dependently inhibited the 45Ca2+ influx induced by either norepinephrine or high-K+, suggesting that xanthone might act as a blocker of both receptor-operated and voltage-dependent Ca2+ channels. Furthermore, xanthone caused an increase in the level of intracellular cyclic adenosine 3',5'-monophosphate (cAMP), but not cyclic guanosine 3',5'-monophosphate (cGMP) content. These data suggested that the mechanism of xanthone-induced vasorelaxation might involve the increase of intracellular cyclic adenosine 3',5'-monophosphate (cAMP) content and block of Ca2+ channels.
| Original language | English |
|---|---|
| Pages (from-to) | 23-28 |
| Number of pages | 6 |
| Journal | European Journal of Pharmacology |
| Volume | 336 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Oct 1 1997 |
| Externally published | Yes |
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Keywords
- Ca channel blocker
- cAMP
- cGMP
- Norepinephrine
- Thoracic aorta
- Vasorelaxation
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience
- Pharmacology
Cite this
Mechanism of vasorelaxation of thoracic aorta caused by xanthone. / Cheng, Yu W.; Kang, Jaw J.
In: European Journal of Pharmacology, Vol. 336, No. 1, 01.10.1997, p. 23-28.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Mechanism of vasorelaxation of thoracic aorta caused by xanthone
AU - Cheng, Yu W.
AU - Kang, Jaw J.
PY - 1997/10/1
Y1 - 1997/10/1
N2 - The effect of xanthone on smooth muscle was studied in thoracic aorta isolated from rats. Xanthone relaxed the norepinephrine-induced contraction of rat thoracic aorta. This relaxing effect of xanthone persisted in endothelium-denuded aorta suggesting that the relaxation induced by xanthone is endothelium-independent. The norepinephrine and high-K+-induced vasoconstriction was inhibited dose dependently in aorta pretreated with xanthone with IC50 values of 60.26 ± 8.43 and 82.9 ± 13.21 μM, respectively. The inositol 1,4,5-trisphosphate formation induced by norepinephrine (3 μM) in rat aorta was not affected by xanthone (10-100 μM), suggesting that the vasorelaxant effect of xanthone was not exerted on the receptor. Xanthone concentration dependently inhibited the 45Ca2+ influx induced by either norepinephrine or high-K+, suggesting that xanthone might act as a blocker of both receptor-operated and voltage-dependent Ca2+ channels. Furthermore, xanthone caused an increase in the level of intracellular cyclic adenosine 3',5'-monophosphate (cAMP), but not cyclic guanosine 3',5'-monophosphate (cGMP) content. These data suggested that the mechanism of xanthone-induced vasorelaxation might involve the increase of intracellular cyclic adenosine 3',5'-monophosphate (cAMP) content and block of Ca2+ channels.
AB - The effect of xanthone on smooth muscle was studied in thoracic aorta isolated from rats. Xanthone relaxed the norepinephrine-induced contraction of rat thoracic aorta. This relaxing effect of xanthone persisted in endothelium-denuded aorta suggesting that the relaxation induced by xanthone is endothelium-independent. The norepinephrine and high-K+-induced vasoconstriction was inhibited dose dependently in aorta pretreated with xanthone with IC50 values of 60.26 ± 8.43 and 82.9 ± 13.21 μM, respectively. The inositol 1,4,5-trisphosphate formation induced by norepinephrine (3 μM) in rat aorta was not affected by xanthone (10-100 μM), suggesting that the vasorelaxant effect of xanthone was not exerted on the receptor. Xanthone concentration dependently inhibited the 45Ca2+ influx induced by either norepinephrine or high-K+, suggesting that xanthone might act as a blocker of both receptor-operated and voltage-dependent Ca2+ channels. Furthermore, xanthone caused an increase in the level of intracellular cyclic adenosine 3',5'-monophosphate (cAMP), but not cyclic guanosine 3',5'-monophosphate (cGMP) content. These data suggested that the mechanism of xanthone-induced vasorelaxation might involve the increase of intracellular cyclic adenosine 3',5'-monophosphate (cAMP) content and block of Ca2+ channels.
KW - Ca channel blocker
KW - cAMP
KW - cGMP
KW - Norepinephrine
KW - Thoracic aorta
KW - Vasorelaxation
UR - http://www.scopus.com/inward/record.url?scp=0030734799&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030734799&partnerID=8YFLogxK
U2 - 10.1016/S0014-2999(97)01224-7
DO - 10.1016/S0014-2999(97)01224-7
M3 - Article
VL - 336
SP - 23
EP - 28
JO - European Journal of Pharmacology
JF - European Journal of Pharmacology
SN - 0014-2999
IS - 1
ER -