Effects of angiotensin II on isolated rabbit afferent arterioles.
We examined the effects of angiotensin II (Ang II) on isolated rabbit afferent arterioles to assess the direct effect of Ang II at the resistance vessel level in the kidney. We microdissected the superficial afferent arteriole from the kidney of New Zealand White rabbits. The afferent arteriole was cannulated with a micropipette system, and the intraluminal pressure was set at 80 mmHg. Ang II did not change the lumen diameter of the afferent arterioles. After the afferent arterioles were pretreated with aspirin DL-lysine or indomethacin, Ang II (10(-7) M) caused transient vasoconstriction in the afferent arterioles. Ang II (10(-7) M) caused persistent constriction in the afferent arterioles pretreated with NG-nitro-L-arginine (10(-4) M). Physiological doses of Ang II decreased the lumen diameter of the isolated afferent arterioles pretreated with NG-nitro-L-arginine and aspirin DL-lysine. Dup753 (10(-6) M), an AT1-receptor antagonist, abolished the vasoconstrictor effects of Ang II. These findings suggest that the isolated rabbit afferent arteriole has AT1 receptors, and the vasoconstrictor response of Ang II is counteracted by vasodilatory prostaglandins and nitric oxide.
Yoshida
H
H
Department of Urology, Kagawa Medical School, Japan.
Tamaki
T
T
Aki
Y
Y
Kimura
S
S
Takenaka
I
I
Abe
Y
Y
D000804:Angiotensin II / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001160:Arterioles / Q000033:anatomy & histology / Q000187:drug effects; D001241:Aspirin / Q000031:analogs & derivatives / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D019808:Losartan; D008239:Lysine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011448:Prostaglandin Antagonists / Q000494:pharmacology; D011453:Prostaglandins / Q000494:pharmacology; D011817:Rabbits; D012079:Renal Circulation / Q000187:drug effects*; D013777:Tetrazoles / Q000494:pharmacology; D014655:Vascular Resistance / Q000187:drug effects; D019323:omega-N-Methylarginine
D000894:Anti-Inflammatory Agents, Non-Steroidal; D001713:Biphenyl Compounds; D007093:Imidazoles; D011448:Prostaglandin Antagonists; D011453:Prostaglandins; D013777:Tetrazoles; D000804:Angiotensin II; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine; D019808:Losartan; D008239:Lysine; D001241:Aspirin; C010395:acetylsalicylic acid lysinate; D007213:Indomethacin