Survival of structure and function in postmortem rat and human retinas: rhodopsin regeneration, cGMP and the ERG.
Procedures for regenerating visual pigment and restoring phototransduction have been established with freshly isolated, bleached rat retinas. Phosphatidyl choline liposomes containing a 500 microM mixture of retinal isomers, including the 9-cis and 11-cis forms, were employed and the results compared with dark-adapted retinas, incubated similarly but without retinal. The following were recovered in a 60 min incubation, rhodopsin (plus isorhodopsin) to 91% of the original rhodopsin concentration, 87% of cGMP and 89% of PIII amplitude at saturation. PIII amplitude vs. log intensity curves gave values of n between 0.6 and 1/2.0 and sigma between 85 and 439 quanta/micron 2. Human retinas, ranging from 18 to 58 hours postmortem and treated as above, also produced photoresponses. Of the 7 retinas studied so far, rhodopsin has been regenerated to 0.1-0.35 nmol/mg protein, cGMP to 23.5-49.2 pmol/mg protein, and PIII to 20-50 microV: in some cases a b-wave was also seen. Values of n varied between 0.6 and 1.0, and sigma between 132 and 3700 quanta/micron 2. PIII responses were also seen after retinas, approximately 30 hours postmortem, were incubated for a further 24 hours in fortified medium. After incubation, retinal vacuolation was reduced.
Huang
J C
JC
Institute of Ophthalmology, University of London, UK.
Voaden
M J
MJ
Marshall
J
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D006152:Cyclic GMP / Q000096:biosynthesis*; D003623:Dark Adaptation; D004596:Electroretinography; D005260:Female; D006801:Humans; D008081:Liposomes; D010786:Photoreceptor Cells / Q000378:metabolism / Q000473:pathology; D011180:Postmortem Changes; D051381:Rats; D011919:Rats, Inbred Strains; D012038:Regeneration; D012160:Retina / Q000378:metabolism* / Q000648:ultrastructure; D012168:Retinal Pigments / Q000096:biosynthesis*; D012172:Retinaldehyde / Q000494:pharmacology; D012243:Rhodopsin / Q000096:biosynthesis*
D008081:Liposomes; D012168:Retinal Pigments; D012243:Rhodopsin; D006152:Cyclic GMP; D012172:Retinaldehyde