Effects of efonidipine hydrochloride on renal arteriolar diameters in spontaneously hypertensive rats.
Efonidipine, a calcium antagonist, has been reported to dilate not only afferent but also efferent arterioles, thereby reducing glomerular hydrostatic pressure. We investigated the effect of chronic treatment with efonidipine or lisinopril on the afferent and efferent arteriolar diameters by the vascular cast technique. Four-week-old spontaneously hypertensive rats (SHR) were divided into three groups: untreated, efonidipine (25 mg/kg/day)-treated, and lisinopril (3 mg/kg/day)-treated. At 22 weeks of age, the renal vasculatures were fixed at the maximally dilated condition. The morphometrical measurements showed that the treatments with efonidipine and lisinopril caused structural alteration of the vasculature, resulting in significantly greater efferent arteriolar diameters than in untreated SHR. In addition, lisinopril-treated rats had wider afferent lumina. The renoprotective effect of efonidipine and lisinopril might be partly due to the structurally larger efferent arteriolar lumen.
Nakamura
Masuhisa
M
Division of Pharmacology, Osaka University of Pharmaceutical Sciences, Nasahara, Takatsuki, Japan. mt-nakamura@jttk.zaq.ne.jp
Notoya
Mitsuru
M
Kohda
Yuka
Y
Yamashita
Junji
J
Takashita
Yuko
Y
Gemba
Munekazu
M
D000818:Animals; D001160:Arterioles / Q000187:drug effects / Q000648:ultrastructure; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D016319:Corrosion Casting; D004095:Dihydropyridines / Q000494:pharmacology*; D006977:Hypertension, Renal / Q000188:drug therapy*; D007678:Kidney Glomerulus / Q000098:blood supply; D008297:Male; D009596:Nitrophenols / Q000494:pharmacology*; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR; D012079:Renal Circulation / Q000187:drug effects*
D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D009596:Nitrophenols; D009943:Organophosphorus Compounds; C066425:efonidipine