Colchicine causes excessive ocular growth and myopia in chicks.
Colchicine has been reported to destroy ganglion cells (GCs) in the retina of hatchling chicks. We tested whether colchicine influences normal ocular growth and form-deprivation myopia, and whether it affects cells other than GCs. Colchicine greatly increased axial length, equatorial diameter, eye weight, and myopic refractive error, while reducing corneal curvature. Colchicine caused DNA fragmentation in many GCs and some amacrine cells and photoreceptors, ultimately leading to the destruction of most GCs and particular sub-sets of amacrine cells. Colchicine-induced ocular growth may result from the destruction of amacrine cells that normally suppress ocular growth, and corneal flattening may result from the destruction of GCs whose central pathway normally plays a role in shaping the cornea.
Fischer
A J
AJ
Department of Anatomy, University of Calgary, Faculty of Medicine, Alberta, Canada. ajfische@acs.ucalgary.ca
Morgan
I G
IG
Stell
W K
WK
D000818:Animals; D015415:Biomarkers / Q000032:analysis; D064032:Calbindin 2; D016923:Cell Death; D002645:Chickens; D002795:Choline O-Acetyltransferase / Q000032:analysis; D003078:Colchicine / Q000494:pharmacology*; D003315:Cornea / Q000473:pathology; D004249:DNA Damage; D004745:Enkephalins / Q000032:analysis; D005123:Eye / Q000737:chemistry / Q000187:drug effects* / Q000473:pathology; D005556:Form Perception; D005934:Glucagon / Q000032:analysis; D007150:Immunohistochemistry; D007536:Isomerism; D008297:Male; D009216:Myopia / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D016900:Neurofilament Proteins / Q000032:analysis; D012160:Retina / Q000187:drug effects; D012165:Retinal Ganglion Cells / Q000187:drug effects; D064030:S100 Calcium Binding Protein G / Q000032:analysis; D016212:Transforming Growth Factor beta / Q000032:analysis; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis; D014660:Vasoactive Intestinal Peptide / Q000032:analysis
D015415:Biomarkers; D064032:Calbindin 2; D004745:Enkephalins; D016900:Neurofilament Proteins; D064030:S100 Calcium Binding Protein G; D016212:Transforming Growth Factor beta; D014660:Vasoactive Intestinal Peptide; D005934:Glucagon; D014446:Tyrosine 3-Monooxygenase; D002795:Choline O-Acetyltransferase; D003078:Colchicine