The Effects of the Sympathetic Nervous System on Accommodation
Autor: | Jacob Davidowitz, Newton B. Chin, Goodwin M. Breinin, Byron S. Hurwitz |
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Rok vydání: | 1972 |
Předmět: |
Atropine
medicine.medical_specialty Sympathetic nervous system Sympathetic Nervous System Time Factors Receptors Drug Adrenergic beta-Antagonists Stimulation Baroreflex Methoxamine Stereotaxic Techniques Norepinephrine Mesencephalon Internal medicine Animals Medicine Beta (finance) business.industry Isoproterenol Accommodation Ocular Haplorhini Electric Stimulation Stimulation Chemical Electrophysiology Ophthalmology Endocrinology medicine.anatomical_structure Depression Chemical Stereotaxic technique business Drug Antagonism medicine.drug |
Zdroj: | Archives of Ophthalmology. 87:668 |
ISSN: | 0003-9950 |
Popis: | The effects of beta sympathetic drugs on positive accommodation (accommodation for near vision) were studied in vervet monkeys. Isoproterenol, a beta sympathetic stimulator, depressed the positive accommodation function. It was not a complete antagonist since 3 to 4 diopters of accommodation remained. Only atropine, a parasympathetic blocker, could abolish these 3 to 4 D as well as the entire function. In many of the experimental animals, positive accommodation function was biphasic. The initial component had a flatter slope, lower amplitude, and lower threshold of stimulation than the second. The transition point of the components was between 2 and 4 D. Beta sympathetic stimulation appeared to abolish selectively the second component while parasympathetic inhibition abolished both components. It appeared that peripherally, parasympathetic inhibition was a more potent and thus more important mechanism in antagonizing positive accommodation than beta sympathetic stimulation. |
Databáze: | OpenAIRE |
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