Korean Circ J.  2002 Oct;32(10):894-901. 10.4070/kcj.2002.32.10.894.

Role of Tyrosine Kinases in Norepinephrine-Induced Vascular Contraction in Renal Hypertensive Rats

• Yeum CH
• Jun JY
• Yoon PJ
• Shin MK
• Cho HH
• Jang JS
• Hong SP
• Yeum CH

• KMID: 1938830
• DOI: http://doi.org/10.4070/kcj.2002.32.10.894

Abstract

BACKGROUND AND OBJECTIVES: Protein tyrosine kinases appear to be involved in the signal transduction mechanisms, which result in vascular smooth muscle contraction, as well those required in cell growth. The present study was conducted to examine the role of tyrosine kinases in the norepinephrine-induced vascular smooth muscle contraction of isolated aortae from two-kidney, one clip (2K1C) hypertensive rats.
MATERIALS AND METHODS
2K1C hypertension was made by clipping the left renal artery of the rats, with age-matched rats receiving a sham treatment serving as controls. Thoracic aortae denuded of endothelium were mounted in tissue baths to measure the isometric tension.
RESULTS
The putative tyrosine kinase inhibitors, genistein and tyrphostin 25, significantly inhibited the contractile responses of the aorta to norepinephrine in the control rats, but not in the 2K1C rats. The protein tyrosine phosphatase inhibitor, sodium orthovanadate, selectively potentiated the contractile response to norepinephrine, but only in the controls. Genistein, tyrphostin 25 and sodium orthovanadate did not affect KCl-induced vascular contractions in either the 2K1C or the controls. The vascular contraction elicited by phorbol 12, 13 dibutyrate, in the presence and absence of genistein, did not alter in either the 2K1C or the controls.
CONCLUSION
These findings indicate that protein tyrosine kinases participate in the norepinephrine-induced contraction of rat aortic smooth muscle, where the role is attenuated in 2K1C renal hypertension.

Keyword

Protein-tyrosine kinase; Muscle, smooth, vascular; Norepinephrine; hypertension renal

MeSH Terms

Animals
Aorta
Aorta, Thoracic
Baths
Endothelium
Genistein
Hypertension
Hypertension, Renal
Muscle, Smooth
Muscle, Smooth, Vascular
Norepinephrine
Phosphotransferases*
Placebos
Protein Tyrosine Phosphatases
Protein-Tyrosine Kinases
Rats*
Renal Artery
Signal Transduction
Sodium
Tyrosine*
Vanadates
Genistein
Norepinephrine
Phosphotransferases
Placebos
Protein Tyrosine Phosphatases
Protein-Tyrosine Kinases
Sodium
Tyrosine
Vanadates