[Effects of nilvadipine on retinal microcirculation and systemic circulation].
OBJECTIVE
The effects of nilvadipine on retinal blood flow and systemic circulation were studied by the hydrogen clearance method.


METHODS
The subjects were 10 male beagles. Under general anesthesia, nilvadipine (32 micrograms/ml/kg), dissolved in polyethylene glycols was injected into the stomach of 5 beagles, and only polyethylene glycols was injected into the stomach of the other 5 beagles as controls. Retinal tissue blood flow, heart rate, arterial blood pressure, pulmonary arterial pressure, central vein pressure, cardiac output, and systemic vessel resistance were measured over time and compared between the two groups.


RESULTS
Retinal tissue blood flow showed significant increase only in the Nilvadipine group (max 29.2%). No marked changes were observed in the systemic circulation in either group. The time to maximum blood concentration of Nilvadipine was 120 min, and the maximum blood concentration was 1.27 ng/ml.


CONCLUSIONS
Nilvadipine may directly and selectively increase retinal tissue blood flow, while having only minimal effect on systemic circulation including arterial blood pressure.
Ogata
Y
Y
Department of Ophthalmology, St. Marianna University School of Medicine, Kawasaki, Japan.
Kaneko
T
T
Kayama
N
N
Ueno
S
S
D000818:Animals; D001775:Blood Circulation / Q000187:drug effects*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D008297:Male; D008833:Microcirculation / Q000187:drug effects*; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D012171:Retinal Vessels / Q000187:drug effects*
D002121:Calcium Channel Blockers; C035100:nilvadipine; D009543:Nifedipine