Role of nitric oxide in desmopressin-induced vasodilation of microperfused rabbit afferent arterioles.
We have previously reported that desmopressin (dDAVP) increased the lumen diameter of norepinephrine (NE)-constricted isolated microperfused rabbit afferent arterioles. In this study, we examined the role of nitric oxide in dDAVP-induced vasodilation of afferent arterioles. We microdissected a superficial afferent arteriole from the kidney of a New Zealand white rabbit. Each afferent arteriole was cannulated with a pipette system and microperfused in vitro at 60 mmHg. dDAVP increased the lumen diameter of NE-preconstricted rabbit afferent arterioles dose-dependently. dDAVP-induced vasodilation was abolished by pretreatment with NG-nitro-L-arginine (L-NNA, 10(-4)M) (L-NNA + NE, 6.7 +/- 1.1 microns; L-NNA + NE + dDAVP, 7.3 +/- 1.4 microns, n = 8). dDAVP increased the lumen diameter of NE-preconstricted afferent arterioles pretreated with L-NNA and L-arginine (10(-2)M) (L-NNA + L-arginine + NE, 6.1 +/- 1.1 microns; L-NNA + L-arginine + NE + dDAVP, 8.7 +/- 0.9 microns*; *p < 0.05, n = 6). Aspirin-DL-lysine (10(-4)M) did not influence dDAVP-induced afferent arteriolar vasodilation (aspirin + NE, 6.4 +/- 0.8 microns; aspirin + NE + dDAVP, 9.6 +/- 1.3 microns *; *p < 0.05, n = 5). These results suggest that nitric oxide may be responsible for dDAVP-induced afferent arteriolar vasodilation.
Kiyomoto
K
K
Department of Pharmacology, Kagawa Medical School, Japan.
Tamaki
T
T
Tomohiro
A
A
Nishiyama
A
A
Aki
Y
Y
Kimura
S
S
Abe
Y
Y
D000818:Animals; D001160:Arterioles / Q000187:drug effects; D001241:Aspirin / Q000031:analogs & derivatives / Q000494:pharmacology; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D066298:In Vitro Techniques; D008239:Lysine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009638:Norepinephrine / Q000494:pharmacology; D010477:Perfusion; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011817:Rabbits; D014655:Vascular Resistance / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects*
D004791:Enzyme Inhibitors; D007004:Hypoglycemic Agents; D010975:Platelet Aggregation Inhibitors; D014662:Vasoconstrictor Agents; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D003894:Deamino Arginine Vasopressin; D008239:Lysine; D001241:Aspirin; D019331:NG-Nitroarginine Methyl Ester; D009638:Norepinephrine; C010395:acetylsalicylic acid lysinate