Objective To identify proteins that have expressed in human eyes from adults and two-month old infants by proteomics approach, so as to build a two-dimensional gel electrophoresis (two-DE) reference map for human retina. The difference of proteomics between the retinas of adults and two-month old infants are also studied. Methods Human retina tissues were collected from donor eyes (nine adults and two infants). Proteins were separated by two-DE. The gels were analyzed by image software. Protein spots were excised from the gels and detected by matrix assisted laser desorption ionization time off light mass spectrometry (MALDI-TOF-MS). Results A total of 1179 spots and 1295 spots were detected respectively on two-DE gels of Coomassie-stained adults and two-month old infants retina, of which 1039 spots were matched in the position. Five spots up-regulated were successfully identified. Human serum albumin and 4 guanylate kinase 1 (GUK1) were identified in adult retina. beta;2-tubulin, transaldolase1 and alpha A-crystallin were identified in infant retina. Conclusion The two-DE reference map for retina proteomics is successfully established. This study provides an evidence of changes in retinal protein levels between adults and infants and biochemical pathways for future studies of human retina development.
Objective To investigate the expression of hypoxia inducible factor 1(HIF1alpha;) in ratsprime; retinae during the embryonic and earlier postnatal period. Methods The retinal expression patterns of HIF-1alpha; protein and mRNA of embryonic day 12 (E12), E16, E20, and postnatal day 1(P1) and P5 rats were determined by immunohistochemical staining and reverse transcriptionpolymerase chain reaction (RT-PCR). Results HIF-1alpha; protein was detected in the neural epithelial layer and the pigment epithelial layer at all those 5 timepoints, with higher expression in the ganglion cell layer and the inner plexiform layer, and seems limited to the ganglion cell layer when re tina became more mature. Embryonic rat retina had higher expression of HIF-1alpha; protein and mRNA than postnatal retina, the difference was significant (P＜0.01）. Conclusion The expression of HIF1alpha; in ratsprime;retina e differs from embryonic to earlier postnatal stages.
Objective To observe the electrophysiological and morphological features of retinal ganglion cells (RGCs) in rats, and investigate its effect on the visual signal conduction. Methods Whole cell recordings were obtained from 112 RGCs of 30 rats at the age of 7-30 days. Resting membrane potential (RMP) was recorded, and input impedance was noted after given 2 mV hyperpolarizing current by voltage clamp. The action potential (AP) was induced by deplorizing current at different densities. The histological staining was actualized by injecting with biotin into the RGCs, and the diameter of the cells was measured. Results Three different discharge patterns of RGCs in response to maintained depolarizing currents were recorded: single spike (25 RGCs), transient firing (40 RGCs), and sustained firing (47 RGCs).The dia meter was 14-16μm in 57.14% transient firing RGCs, and 10-12 μm in 62.50% sustained firing RGCs. The maximum frequency of AP of sustained firing RGCs was significantly higher than that of transient firing RGCs (P＜0.05). Conclusion The single firing of RGCs was an immature electrophysiological feature. The electrophysiological features of transient firing and sustained firing RGCs may be important to make the visual information code in spatial and temporal pathway. The electrophysiological and morphological features of RGCs in rats may be correlated with each other. (Chin J Ocul Fundus Dis，2004，20：160-164)
Objective To investigate the damage to the retinal cells and apoptosis of retinal cells of rats after ischemia-reperfusion insult. Methods The retinal ischemia-reperfusion model was developed by increasing intraocular pressure to 109725 mm Hg in rat eyes. Morphological changes of the rat eyes were observed by means of routine histopathology with HE staining. Apoptosis of the retina was assayed by both DNA fragmentation gel-electrophoresis and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL). Results Compared with the normal control, no histopathological changes were revealed in the rat retinas 30 min after the ischemia and then reperfued for 24 h or 48 h. Retinal ganglion cell layer (RGL) and inner plaxiform layer (IPL) of the retina were observed, however, to become significantly thinner 60 min after the ischemia and then reperfued for 24 h or 48 h. Together with the pathological changes DNA ladder pattern was detected in the same group of the rats. Further, immunochemical stain of the eye demonstrated that TUNEL positive cells were localized in RGL and IPL of the retina. Conclusion Ischemia-reperfusion insult of the eye may remarkably damage the retina of the rat eye. The damage to the retinal cells is mainly localized within RGL and IPL and apoptosis is the important mechanism of the retinal disorder. (Chin J Ocul Fundus Dis, 2002, 18: 296-298)
Purpose To evaluate the correlation of retinal thickness between optical coherence tomography (OCT) images and histologic slides ． Methods Retinal thickness was measured in 16 rabbit retinal histologic slides．The same eyes were previously viewed by OCT for the comparison of results between two methods．Retinal thickness of each OCT image section was measured using both the manually assisted (requiring observer localization of reflectivity peaks) and the automated modes of the computer software． Results Retinal thickness as measured by OCT demonstrated a high degree of correlation with retinal histologic study．The automate d method (gamma;=0．66，P＜0.01) was less reliable than the manually assisted one (gamma;=0．84，P＜0．001)．The former had an error in 95% confidence interval，ranged in-0.71～11.09 mu;m，the latter had a less error，ranged in-2.99～5.13mu;ｍ． Conclusion Retinal thickness can be quantitatively measured by OCT examination．However，computer automatic identification of the reflective boundaries may result in errors in some cases．To measured the retinal thickness by manually assisted mode can increase the degree of accuracy． (Chin J Ocul Fundus Dis，2000，16：71-138)