L-arginine-induced current in portal venous smooth muscle cells.
In our previous report, we showed that L-arginine induced depolarization of smooth muscle cells of the rat portal vein with an increased contraction. To clarify the ionic mechanism of the membrane depolarization, the effect of L-arginine on the holding current was studied in freshly isolated smooth muscle cells of the rat portal vein. The whole-cell patch-clamp technique was used, with the membrane potential held at -60 mV. In the presence of Na+ in the perfusate, L-arginine 10 mM induced an inward current in about 50% of the cells. In Na+-deficient perfusate, L-arginine 10 mM increased the amplitude of the inward current in a Na+ concentration-dependent manner. BCH, an inhibitor of the Na+-dependent amino acid transporter, ceased the L-arginine-induced current. These results indicate that L-arginine induces an inward current via Na+-dependent mechanisms in rat portal venous smooth muscle cells.
Kimura
Shinichi
S
Department of Pharmacological Sciences, School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido 061-0293, Japan.
Ohashi
Atsuko
A
Tohse
Noritsugu
N
Kitamura
Kenji
K
Shimamura
Keiichi
K
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000502:physiology; D011169:Portal Vein / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology
D001120:Arginine