Rho-Rho kinase pathway is involved in the regulation of myogenic tone and pump activity in isolated lymph vessels.
To evaluate whether or not Rho-Rho kinase pathway is involved in the regulation of mechanical activity of lymph vessels, effects of Y-27632 and okadaic acid on lymph pump activity and myogenic, pressure- and agonist-induced tone were examined in isolated rat lymph vessels. Y-27632 caused a significant dilation with a cessation of the lymph pump activity. Y-27632 also produced a dose-related dilation of the lymph vessels precontracted by norepinephrine (NE)-, U-46619- or 80 mM KCl. Okadaic acid significantly constricted the lymph vessels and reduced the frequency of the lymph pump activity. Okadaic acid also produced a dose-related constriction of the lymph vessels precontracted by NE or U-46619. The Y-27632-induced decrease of the frequency of lymph pump activity was significantly reversed by the pretreatment with okadaic acid. In the presence of Y-27632, the pressure-mediated tone of the lymph vessel was significantly decreased. On the other hand, okadaic acid significantly increased the pressure-mediated tone. These findings suggest that Rho kinase and myosin phosphatase activity in lymphatic smooth muscles may contribute to the regulation of lymph pump activity and may be also involved in the control of myogenic pressure- and agonist-induced tone.
The First Department of Physiology, Shinshu University School of Medicine, Shinshu University Graduate School of Medicine, Matsumoto 390-8621, Japan.
Kayoko
K
Hosaka
Risuke
R
Mizuno
Toshio
T
Ohhashi
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D000577:Amides / Q000494:pharmacology; D000818:Animals; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005905:Glyburide / Q000494:pharmacology; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D008208:Lymphatic System / Q000033:anatomy & histology / Q000502:physiology*; D008297:Male; D009129:Muscle Tonus / Q000502:physiology*; D009130:Muscle, Smooth / Q000033:anatomy & histology / Q000502:physiology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009638:Norepinephrine / Q000494:pharmacology; D019319:Okadaic Acid / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D020741:rho GTP-Binding Proteins / Q000502:physiology*; D054460:rho-Associated Kinases
D000577:Amides; D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D011725:Pyridines; D014662:Vasoconstrictor Agents; C108830:Y 27632; D019319:Okadaic Acid; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D019001:Nitric Oxide Synthase; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D020741:rho GTP-Binding Proteins; D005905:Glyburide; D019331:NG-Nitroarginine Methyl Ester; D009638:Norepinephrine; D007213:Indomethacin