Dose-dependent ultrastructural changes in rat cornea after oral methylphenidate administration.
OBJECTIVE
To investigate dose-dependent ultrastructural changes in rat cornea after oral methylphenidate Ritalin administration.


METHODS
This study was conducted in the Department of Anatomy, Gazi University Faculty of Medicine, Ankara, Turkey between March and May 2005, with a total of 27 female prepubertal Wistar albino rats, divided into 3 different dose groups 5mg/kg, 10 mg/kg, 20 mg/kg, and their control groups. They were treated orally with methylphenidate, and eye tissue was removed to process for electron microscopic studies.


RESULTS
We observed that all cells, and prominently basal cells of the corneal epithelium show dose-dependent degenerative changes such as apoptotic bodies, chromatin condensation, and ondulation in their nuclei and crystolysis of the mitochondrion. In the stroma, the most evident finding was the increase of the collagen fiber. In addition to dose-dependent changes related to the apoptotic process, which is chromatin condensation in their nuclei, electron dense material accumulation, and pericellular edema in the cytoplasm were also seen. In the endothelial cell lines, disruption of the junctional complexes, vacuolization in the cell cytoplasms, and crystolysis of the mitochondrion's with rough endoplasmic reticulum cisternae activity were observed.


CONCLUSIONS
Ritalin is inducing an evident degeneration, especially in epithelium cells with increasing doses. Ultrastructural cell organelle composition degeneration with stromal fibrosis has a negative effect on cornea dehydration. In light of these findings, we believe that the Ritalin treatment doses need to be kept to a minimum to maintain healthy cornea ultrastructure and related physiology.
Gozil
Rabet
R
Department of Anatomy, Gazi University School of Medicine, Ankara, Turkey.
Take
Gulnur
G
Bahcelioglu
Meltem
M
Tunc
Erdinc
E
Oktem
Hale
H
Caglar
Guleser
G
Calguner
Engin
E
Erdogan
Deniz
D
D000818:Animals; D003315:Cornea / Q000187:drug effects* / Q000648:ultrastructure*; D004305:Dose-Response Relationship, Drug; D005260:Female; D008774:Methylphenidate / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar
D008774:Methylphenidate