mydriasis/tyrosine

1. The effect of intravenous administration of dexamphetamine [+)-Amp) on rat pupil diameter was investigated. In all experiments, the vagosympathetic trunks were sectioned bilaterally at the cervical level. 2. In rats anaesthetized with urethane, (+)-Amp (0.1-0.3 mg kg-1, i.v.) produced a

Intravenous injection of xylazine (0.01-1 mg/kg) produced a dose-dependent mydriasis associated with a depression of tonic ciliary nerve activity in anesthetized cats. Xylazine-induced mydriasis was apparent in the sympathectomized iris but was absent in the parasympathectomized,

Intravenous administration of clonidine hydrochloride (3-100 micrograms/kg) produced a dose-dependent pupillary dilation in anaesthetized rats. All experiments were carried out in rats in which vagosympathetic nerve trunks were sectioned bilaterally at the cervical level. Clonidine-induced mydriasis

This study was undertaken in order to determine the relative extent to which amphetamine-induced mydriasis is of central nervous system (CNS) or of peripheral origin. Anesthetized cats were administered cumulative dosages of amphetamine given either intravenously (0.05-3.2 mg/kg) or directly into

Pupillary and cardiac responses to the insecticide/acaricide amitraz (0.03 to 1.0 mg/kg, iv) and chlordimeform (0.03 to 10.0 mg/kg, iv), as well as the alpha 2-adrenergic agonists clonidine (1 to 30 micrograms/kg, iv) and xylazine (10 to 300 micrograms/kg, iv), were investigated in rats anesthetized

Intravenous administration of clonidine (1--100 micrograms/kg) produces a dose-dependent mydriasis in cats by inhibition of parasympathetic tone to the iris. The magnitude of CNS-induced pupillary dilation was similar in both normal anaesthetized cats and in anaesthetized preparations pretreated

Inhibition of parasympathetic neural tone to the iris was produced by electrical stimulation of the afferent sciatic nerve, medullary reticular formation, and posterior hypothalamus in anesthetized cats in which only the parasympathetic nerves to the eye were intact. Stimulation of all 3 sites of

Amantadine, injected into mice, produces dose-dependent mydriasis. The pupillary dilation caused by amantadine is not abolished by pretreatment with reserpine, or by combined pretreatment with reserpine and alpha-methyl-p-tyrosine, although the mydriasis is reduced by approximately 25%. Thus,

Single administration of the new drug modafinil was followed by an increase in locomotor activity in mice and in nocturnal activity in monkeys. Stereotyped behaviour in mice and rats, and potentiation of amphetamine-induced stereotyped behaviour were not observed; however, at the highest dose used,