Structure changes in chicken retina caused by argon laser irradiation

ABSTRACT

Infrared spectroscopic study has been performed on chicken retina before and after argon laser irradiation. The infrared [IR] spectra obtained from intact retina are in agreement with the polarized [IR] studies on rhodopsin, which indicate that it has an alpha - helical structure with fixed orientation with the membrane normal. Retinae exposed to argon laser light of constant intensity [1mW/cm] and different durations [0.12 and 0.25 sec] at constant temperatures [10, 20 and 30 degree] show no detectable spectral changes, indicating that there is no change in the main helical structure of protein. However, distinct changes occur in the orientation angle of rhodopsin. It was found that the sensitivity of chicken retina for the recovery of the rhodopsin reorientation is more pronounced after laser irradiation of duration 0.12 sec. than that of 0.25 sec. Also the decrease in the chicken temperature by 10 degree could compensate the heating effect due to the increase in laser duration