March 1999
Volume 40, Issue 3
Free
Articles  |   March 1999
Latrunculin-A causes mydriasis and cycloplegia in the cynomolgus monkey.
Author Affiliations
  • J A Peterson
    Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, USA.
  • B Tian
    Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, USA.
  • B Geiger
    Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, USA.
  • P L Kaufman
    Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, USA.
Investigative Ophthalmology & Visual Science March 1999, Vol.40, 631-638. doi:
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      J A Peterson, B Tian, B Geiger, P L Kaufman; Latrunculin-A causes mydriasis and cycloplegia in the cynomolgus monkey.. Invest. Ophthalmol. Vis. Sci. 1999;40(3):631-638.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

PURPOSE: To determine the effect of latrunculin (LAT)-A, which binds to G-actin and disassembles actin filaments, on the pupil, accommodation, and isolated ciliary muscle (CM) contraction in monkeys. METHODS: Pupil diameter (vernier calipers) and refraction (coincidence refractometry) were measured every 15 minutes from 0.75 to 3.5 hours after topical LAT-A 42 microg (approximately 10 microM in the anterior chamber [AC]). Refraction was measured every 5 minutes from 0.5 to 1.5 hours after intracameral injection of 10 microl of 50 microM LAT-A (approximately 5 microM in AC), with intramuscular infusion of 1.5 mg/kg pilocarpine HCl (PILO) during the first 15 minutes of measurements. Pupil diameter was measured at 1 and 2 hours, and refraction was measured every 5 minutes from 1 to 2 hours, after intravitreal injection of 20 microl of 1.25 mM LAT-A (approximately 10 microM in vitreous), with intramuscular infusion of 1.5 mg/kg PILO during the first 15 minutes of measurements (all after topical 2.5% phenylephrine), and contractile response of isolated CM strips, obtained <1 hour postmortem and mounted in a perfusion apparatus, to 10 microM PILO +/- LAT-A was measured at various concentrations. RESULTS: Topical LAT-A of 42 microg dilated the pupil without affecting refraction. Intracameral LAT-A of 5 microM inhibited miotic and accommodative responses to intramuscular PILO. Intravitreal LAT-A of 10 microM had no effect on accommodative or miotic responses to intramuscular PILO. LAT-A dose-dependently relaxed the PILO-contracted CM by up to 50% at 3 microM in both the longitudinal and circular vectors. CONCLUSIONS: In monkeys, LAT-A causes mydriasis and cycloplegia, perhaps related to its known ability to disrupt the actin microfilament network and consequently to affect cell contractility and adhesion. Effects of LAT-A on the iris and CM may have significant physiological and clinical implications.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×