Heat shock-induced augmentation of vascular contractility is independent of rho-kinase.
In a previous study, we demonstrated that heat shock augments the contractility of vascular smooth muscle through the stress response. 2. In the present study, we investigated whether Rho-kinases play a role in heat shock-induced augmentation of vascular contractility in rat isolated aorta. 3. Rat aortic strips were mounted in organ baths, exposed to 42 C for 45 min and subjected to contractile or relaxant agents 5 h later. 4. The level of expression of Rho-kinases in heat shock-exposed tissues was no different to that of control tissues, whereas heat shock induced heat shock protein (Hsp) 72 at 3 and 5 h. Heat shock resulted in an increase in vascular contractility in response to phenylephrine 5 h later. 5. The Rho-kinase inhibitors Y27632 (30 nmol/L-10 mmol/L) or HA 1077 (10 nmol/L-10 mmol/L) relaxed 1.0 mmol/L phenylephrine-precontracted vascular strips in a concentration-dependent manner; these effects were attenuated in heat shock-exposed strips. Pretreatment with Y27632 resulted in greater inhibition of the maximum contraction in control strips compared with those in heat shock-exposed strips. 6. The results of the present study suggest that Rho-kinases are unlikely to be involved in heat shock-induced augmentation of vascular contractility.
Department of Pharmacology, Kyungpook National University School of Medicine, Daegu, Republic of Korea.
YoungMi
Y
Seok
Jee In
JI
Kim
Masaaki
M
Ito
Yasuko
Y
Kureishi
Takeshi
T
Nakano
Si-Oh
SO
Kim
Dong Gun
DG
Lim
Wee Hyun
WH
Park
InKyeom
I
Kim
D000199:Actins / Q000096:biosynthesis; D000577:Amides / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000378:metabolism; D015153:Blotting, Western; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism; D006358:Hot Temperature; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D009126:Muscle Relaxation / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D018994:Myosin Light Chains / Q000378:metabolism; D010656:Phenylephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012769:Shock / Q000201:enzymology* / Q000503:physiopathology*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D054460:rho-Associated Kinases
D000199:Actins; D000577:Amides; D050884:HSP72 Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; D018994:Myosin Light Chains; D011725:Pyridines; D014662:Vasoconstrictor Agents; C108830:Y 27632; D010656:Phenylephrine; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases