Resveratrol and genistein inhibition of rat isolated gastrointestinal contractions and related mechanisms.
OBJECTIVE
To investigate the effects and underlying mechanisms of resveratrol and genistein on contractile responses of rat gastrointestinal smooth muscle.


METHODS
Isolated strips of gastrointestinal smooth muscle from Spraque-Dawley rats were suspended in organ baths containing Kreb's solution, and the contractility of smooth muscles was measured before and after incubation with resveratrol and genistein, and the related mechanisms were studied by co-incubation with various inhibitors.


RESULTS
Resveratrol and genistein dose-dependently decreased the resting tension, and also reduced the mean contractile amplitude of gastrointestinal smooth muscle. Estrogen receptor blockades (ICI 182780 and tamoxifen) failed to alter the inhibitory effects induced by resveratrol and genistein. However, their effects were attenuated by inhibitions of α-adrenergic receptor (phentolamine), nitric oxide synthase (levorotatory-NG-nitroarginine), ATP-sensitive potassium channels (glibenclamide), and cyclic adenosine monophosphate (SQ22536). In high K(+)/Ca(2+)-free Kreb's solution containing 0.01 mmol/L egtazic acid, resveratrol and genistein reduced the contractile responses of CaCl2, and shifted its cumulative concentration-response curves rightward.


CONCLUSIONS
Resveratrol and genistein relax gastrointestinal smooth muscle via α-adrenergic receptors, nitric oxide and cyclic adenosine monophosphate pathways, ATP-sensitive potassium channels, and inhibition of L-type Ca(2+) channels.
Li-Xue Zhang, Shan Jin, Xing-Cheng Dou, Department of Physiology, College of Basic Medicine, Lanzhou University, Lanzhou 730000, Gansu Province, China.
Li-Xue
LX
Zhang
Li-Xue Zhang, Shan Jin, Xing-Cheng Dou, Department of Physiology, College of Basic Medicine, Lanzhou University, Lanzhou 730000, Gansu Province, China.
Hong-Fang
HF
Li
Li-Xue Zhang, Shan Jin, Xing-Cheng Dou, Department of Physiology, College of Basic Medicine, Lanzhou University, Lanzhou 730000, Gansu Province, China.
Long-De
LD
Wang
Li-Xue Zhang, Shan Jin, Xing-Cheng Dou, Department of Physiology, College of Basic Medicine, Lanzhou University, Lanzhou 730000, Gansu Province, China.
Shan
S
Jin
Li-Xue Zhang, Shan Jin, Xing-Cheng Dou, Department of Physiology, College of Basic Medicine, Lanzhou University, Lanzhou 730000, Gansu Province, China.
Xing-Cheng
XC
Dou
Li-Xue Zhang, Shan Jin, Xing-Cheng Dou, Department of Physiology, College of Basic Medicine, Lanzhou University, Lanzhou 730000, Gansu Province, China.
Zhi-Feng
ZF
Tian
Li-Xue Zhang, Shan Jin, Xing-Cheng Dou, Department of Physiology, College of Basic Medicine, Lanzhou University, Lanzhou 730000, Gansu Province, China.
Qin
Q
Ma
D000818:Animals; D020746:Calcium Channels, L-Type / Q000187:drug effects / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004386:Duodenum / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism; D005769:Gastrointestinal Motility / Q000187:drug effects*; D019833:Genistein / Q000494:pharmacology*; D066298:In Vitro Techniques; D054086:KATP Channels / Q000819:agonists / Q000378:metabolism; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D048789:Phytoestrogens / Q000494:pharmacology*; D017207:Rats, Sprague-Dawley; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000378:metabolism; D000077185:Resveratrol; D015398:Signal Transduction / Q000187:drug effects; D013267:Stilbenes / Q000494:pharmacology*; D013270:Stomach / Q000187:drug effects*
D020746:Calcium Channels, L-Type; D054086:KATP Channels; D048789:Phytoestrogens; D011942:Receptors, Adrenergic, alpha; D013267:Stilbenes; D009569:Nitric Oxide; D019833:Genistein; D000242:Cyclic AMP; D000077185:Resveratrol
Ca2+ channel; Gastrointestinal; Motility; Phytoestrogen; Smooth muscle