TY - JOUR
T1 - Possible mechanism of the vasodepressor effect of endokinin A/B in anesthetized rats
AU - Abdelrahman, Aly Mohamed
AU - Syyong, Harley
AU - Tjahjadi, Anindita
AU - Pang, Catherine Cheuk Ying
PY - 2005/9
Y1 - 2005/9
N2 - We investigated the mechanism of the vasodepressor effect of endokinin A/B. An intravenous (IV) bolus of endokinin A/B (0.05-0.3 nmol/kg) dose-dependently decreased mean arterial pressure in thiobutabarbital-anesthetized rats. The magnitude of the response was unaffected by IV pretreatment with N G-nitro-L-arginine methyl ester (L-NAME, inhibitor of nitric oxide synthase), methylene blue (inhibitor of soluble guanylyl cyclase), indomethacin (cyclooxygenase inhibitor), or tetraethylammonium (TEA, nonspecific K + channel blocker). L-NAME reduced the half-recovery time of the vasodepressor effect of endokinin A/B relative to responses in rats pretreated with either saline or norepinephrine, which caused a similar pressor effect as did L-NAME. Methylene blue, but not TEA or indomethacin, reduced the recovery time of the vasodepressor effect of endokinin A/B. Therefore, the vasodepressor effect of endokinin A/B is mediated via the nitric oxide/L-arginine pathway and activation of soluble guanylyl cyclase but not by production of prostanoids or opening of TEA-sensitive K+ channels.
AB - We investigated the mechanism of the vasodepressor effect of endokinin A/B. An intravenous (IV) bolus of endokinin A/B (0.05-0.3 nmol/kg) dose-dependently decreased mean arterial pressure in thiobutabarbital-anesthetized rats. The magnitude of the response was unaffected by IV pretreatment with N G-nitro-L-arginine methyl ester (L-NAME, inhibitor of nitric oxide synthase), methylene blue (inhibitor of soluble guanylyl cyclase), indomethacin (cyclooxygenase inhibitor), or tetraethylammonium (TEA, nonspecific K + channel blocker). L-NAME reduced the half-recovery time of the vasodepressor effect of endokinin A/B relative to responses in rats pretreated with either saline or norepinephrine, which caused a similar pressor effect as did L-NAME. Methylene blue, but not TEA or indomethacin, reduced the recovery time of the vasodepressor effect of endokinin A/B. Therefore, the vasodepressor effect of endokinin A/B is mediated via the nitric oxide/L-arginine pathway and activation of soluble guanylyl cyclase but not by production of prostanoids or opening of TEA-sensitive K+ channels.
KW - Blood pressure
KW - Endokinin A/B
KW - Inhibitor of nitric oxide synthase
KW - K channel
KW - Prostanoids
KW - Soluble guanylyl cyclase
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U2 - 10.1097/01.fjc.0000175236.41573.2a
DO - 10.1097/01.fjc.0000175236.41573.2a
M3 - Article
C2 - 16116330
AN - SCOPUS:24344440223
SN - 0160-2446
VL - 46
SP - 269
EP - 273
JO - Journal of Cardiovascular Pharmacology
JF - Journal of Cardiovascular Pharmacology
IS - 3
ER -