[Vasorelaxing role of vasonatrin peptide in human intramammary artery in vitro].
The purpose of this study was to investigate the vasorelaxing effect of vasonatrin peptide (VNP) on human intramammary artery (HIMA).The vasorelaxing effect of VNP on HIMA was measured by means of perfusion in vitro. The effects of HS-142-1, TEA, 8-Br-cGMP and methylene blue (MB) were also observed. It was found that VNP caused a concentration-dependent relaxation in HIMA which was independent of the endothelium. 8-Br-cGMP (0.1-1000 micromol/L) also caused a concentration-dependent relaxation in HIMA. The vasorelaxing effect of VNP disappeared in the presence of HS-142-1 (20 micromol/L), an antagonist of the natriuretic peptide guanylate cyclase (GC) receptor. MB (10 micromol/L), an inhibitor of GC, not only blocked completely the relaxation of HIMA, but also enhanced the vascular contraction induced by norepinephrine. TEA (1 mmol/L), an antagonist of calcium activated potassium channels (K(Ca)), reduced but not completely blocked the vasorelaxing effect of VNP. These findings suggest that VNP can relax HIMA, which is independent of the endothelium. This effect is possibly achieved by the binding of VNP with the natriuretic peptide GC receptors in the smooth muscle cells (SMCs), leading to an increase in intracellular cGMP level. Moreover, the vasorelaxing effect of VNP is associated with K(Ca).
Yu
Jun
J
Department of Physiology, Fourth Military Medical University, Xi'an, PR China.
Zhu
Miao-Zhang
MZ
Wei
Geng-Ze
GZ
Chen
Bao-Ying
BY
Lu
Shun-Yan
SY
Kang
Yun-Fan
YF
Guo
Hai-Tao
HT
Ma
Heng
H
Dong
Ming-Qing
MQ
D000368:Aged; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D066298:In Vitro Techniques; D008323:Mammary Arteries / Q000187:drug effects / Q000502:physiology*; D008875:Middle Aged; D024681:Potassium Channels, Calcium-Activated / Q000378:metabolism; D050705:Receptors, Guanylate Cyclase-Coupled / Q000378:metabolism; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*
D024681:Potassium Channels, Calcium-Activated; C068986:ventricular natriuretic peptide, eel; D009320:Atrial Natriuretic Factor; D050705:Receptors, Guanylate Cyclase-Coupled