Accession Number : ADA119239

Title :   Acute Effects of Anticholinesterase Agents on Pupillary Function.

Descriptive Note : Interim rept. 15 Jun 81-15 Jun 82,


Personal Author(s) : Giacobini,E

PDF Url : ADA119239

Report Date : Jan 1982

Pagination or Media Count : 14

Abstract : The analysis of acetylcholine (ACh) levels, metabolism and release, as well as the uptake of choline, were performed on segments of rat iris to investigate the mechanisms involved in the response of the iris to acute and chronic cholinesterase inhibition. At various times after the topical administration of 0.1 % DFP in sesame oil to the corneal surface, the rats were decapitated and the irises were removed. Pupil size was measured and ACh levels and cholinesterase activity were determined in each iris following extraction of remaining free DFP with chloroform. No changes were detected 1 min. after the DFP, but by 5 min., pupil diameter was reduced by 50%, esterase activity was reduced by 90%, and ACh was increased by 60%. There were no further changes 30 min. after the DFP, but by 60 min., ACh had returned to control levels even though esterase activity was still inhibited by 90% and pupil diameter was still reduced by over 50%. Based on these results, a mechanism of action of DFP involving multiple effects on ACh metabolism is proposed.

Descriptors :   *Cholinesterase inhibitors, *Acetylcholine, *Iris, Physiological effects, Rats, Metabolism, Sizes(Dimensions), Diameters, Biochemistry, Pharmacology, Biological absorption

Subject Categories : Pharmacology

Distribution Statement : APPROVED FOR PUBLIC RELEASE