Effects of tyrosine kinase inhibitor, genistein, and phosphotyrosine-phosphatase inhibitor, orthovanadate, on Ca(2+)-free contraction of uterine smooth muscle of the rat.
1. The effects of a protein-tyrosine kinase inhibitor, genistein, and a protein-tyrosine phosphatase inhibitor, orthovanadate, were tested on the Ca(2+)-free contraction of the estrogen-dominated rat, which has been proved to be induced mainly via protein kinase C entirely independently of Ca2+. 2. Genistein (30 microM) significantly inhibited the contraction indicating participation of tyrosine kinase activity in the contraction. 3. Orthovanadate caused contraction concentration-dependently and augmented the Ca(2+)-free contraction at concentrations of more than 1 microM. The contraction by orthovanadate was not inhibited so significantly by genistein (30 microM). 4. Possible participation of tyrosine kinase activity in Ca(2+)-free contraction is discussed in addition to the formerly reported participation of protein kinase C.
Gokita
T
T
Department of Molecular Pharmacology, Meiji College of Pharmacy, Tokyo, Japan.
Miyauchi
Y
Y
Uchida
M K
MK
D000818:Animals; D002118:Calcium / Q000502:physiology; D004347:Drug Interactions; D005260:Female; D019833:Genistein; D066298:In Vitro Techniques; D007529:Isoflavones / Q000494:pharmacology; D010121:Oxytocin / Q000494:pharmacology*; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D051381:Rats; D014590:Uterine Contraction / Q000187:drug effects*; D014638:Vanadates / Q000494:pharmacology*
D007529:Isoflavones; D014638:Vanadates; D010121:Oxytocin; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D017027:Protein Tyrosine Phosphatases; D002118:Calcium