STZ treatment induced apoptosis of retinal cells and effect of up-regulation of calcitonin gene related peptide in rats.
BACKGROUND
Evidence indicates an early neural injury of the retinal cells in diabetes. The aim of the current study was to investigate the apoptosis of the retinal cells and the relationship with CGRP.


METHODS
The diabetes was induced by treatment of STZ, using which the apoptosis of retinal cells, the caspase-3 activity and the expression of CGRP in the retina and the serum were examined. Capsaicin (20mg/kg) was given to the animals to induce up-regulation of the CGRP. Apoptosis and CGRP in the retina were also examined in an in vitro study.


CONCLUSIONS
The apoptosis of the retinal cells was confined to the GCL, in which CGRP was normally located. A significant increase in the apoptosis ratio (P<0.05) was observed in the STZ treated animals and high glucose incubated retina, with reductions of CGRP. The pre-treatment with capsaicin effectively up-regulated CGRP and its encoding mRNA and attenuated the cell apoptosis and caspase-3 activity in the retina. The increases of the cell apoptosis in the retina may be related to the down-regulation of endogenous CGRP in diabetes. Capsaicin may attenuate the apoptosis of the retina cells at early times of diabetes, via up-regulation of CGRP.
Department of Comprehensive Examination for Eye Diseases, Shanxi Eye Hospital. Electronic address: yjh187@yahoo.com.cn.
Ji-Hong
JH
Yang
Zheng
Z
Guo
Ting
T
Zhang
Xian Xian
XX
Meng
Tao
T
Sun
Juan
J
Wu
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015740:Calcitonin Gene-Related Peptide / Q000235:genetics* / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000235:genetics / Q000503:physiopathology; D003930:Diabetic Retinopathy / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D055351:Retinal Neurons / Q000187:drug effects / Q000378:metabolism; D013311:Streptozocin / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects / Q000941:ethics
D013311:Streptozocin; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin
Apoptosis; Calcitonin gene-related peptide CGRP; Capsaicin; Retina