[Studies of retinal dopamine transporter in experimental myopia].
OBJECTIVE
To investigate the distribution of dopamine transporter (DAT) in the chicken eye and to explore the role of DAT in the occurrence of experimental myopia.


METHODS
Thirty 2-day-old chickens were divided into four groups. Chicken eyes were fitted with lenses of -10 D (Group 1), -20 D (Group 2) and translucent goggles (Group 3) unilaterally. Chickens without any treatments were used as the control (Group 4). The refraction and the axial eye length of all chickens were measured after 3 weeks, then, all chickens were given an intramuscular injection of (125)I-beta-CIT [2beta-carbomethoxy-3beta-(4-iodophenyl) tropane] and sacrificed two hours after injection. Retinal pigment epithelium (RPE) and neural retina were dissected from the eye as a whole layer in Groups 1 and 4; and dissected separately in Groups 2 and 3. Radioactive DAT from each specimen was assayed by gamma-counter.


RESULTS
In Groups 2 and 3, the radioactive DAT value in the RPE from the experimental eyes was significantly greater than that in the neural retina and also greater than those in the RPE from the control eyes (P < 0.01). In Groups 1, 2, and 3, the radioactive DAT value in the whole retina or RPE from the experimental eyes was significantly greater than those from the control eyes (P < 0.01).


CONCLUSIONS
Retinal DAT is located mainly in the RPE and may be involved in the occurrence of both lens-induced myopia and form-deprivation myopia. These methods may provide a new approach for further studying the role of dopamine system in the occurrence of experimental myopia.
Xi
Xiao-qing
XQ
Department of Ophthalmology, Zhongshan Hospital of Fudan University, Shanghai 200032, China.
Chu
Ren-yuan
RY
Zhou
Xing-tao
XT
Lu
Yi
Y
Liu
Xing-dang
XD
D000818:Animals; D002645:Chickens; D004195:Disease Models, Animal; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000378:metabolism*; D009216:Myopia / Q000473:pathology*; D009419:Nerve Tissue Proteins; D012160:Retina / Q000378:metabolism*
D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins