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In 12 healthy volunteers, the effects of a single oral dose of nimodipine (40 mg) on pupil size and on the mydriasis induced by conjunctival instillation of tyramine and phenylephrine were studied by using a TV monocular infrared pupillometer. Nimodipine alone was unable to modify the pupil area. When compared with placebo, the Ca2+ entry blocker reduced the pupil dilation caused by tyramine, whereas it did not affect the phenylephrine-induced mydriasis. Since tyramine provokes mydriasis by releasing neuronal norepinephrine, a full adrenoceptor agonist, whereas phenylephrine acts only on alpha 1-adrenoceptors insensitive of extracellular Ca2+, the hypothesis may be advanced that a heterogeneous population of alpha-adrenoceptors, located in the human iris dilator muscle and differently sensitive to Ca2+ entry blockade, is responsible for the reduction of the tyramine-induced mydriasis. Apart from this putative mechanism, the results suggest that nimodipine reduces the pupillary response to adrenergic activation in the human eye.
M Alessandri, and
U Pietrini, and
E B Bandini, and
S Beatrice, and
M Fanciullacci
May 1961,
Archives of ophthalmology (Chicago, Ill. : 1960),
M Alessandri, and
U Pietrini, and
E B Bandini, and
S Beatrice, and
M Fanciullacci
May 1962,
Archives internationales de pharmacodynamie et de therapie,
M Alessandri, and
U Pietrini, and
E B Bandini, and
S Beatrice, and
M Fanciullacci
June 1970,
The Journal of pharmacy and pharmacology,
M Alessandri, and
U Pietrini, and
E B Bandini, and
S Beatrice, and
M Fanciullacci
December 1995,
Clinical pharmacology and therapeutics,
M Alessandri, and
U Pietrini, and
E B Bandini, and
S Beatrice, and
M Fanciullacci
October 1945,
The Journal of pharmacology and experimental therapeutics,
M Alessandri, and
U Pietrini, and
E B Bandini, and
S Beatrice, and
M Fanciullacci
June 1956,
Archives internationales de pharmacodynamie et de therapie,
M Alessandri, and
U Pietrini, and
E B Bandini, and
S Beatrice, and
M Fanciullacci
March 1988,
Stroke,
M Alessandri, and
U Pietrini, and
E B Bandini, and
S Beatrice, and
M Fanciullacci
January 1992,
Eksperimental'naia i klinicheskaia farmakologiia,
M Alessandri, and
U Pietrini, and
E B Bandini, and
S Beatrice, and
M Fanciullacci
December 1965,
Sheng li xue bao : [Acta physiologica Sinica],
M Alessandri, and
U Pietrini, and
E B Bandini, and
S Beatrice, and
M Fanciullacci
June 1971,
Japanese journal of pharmacology,
