Cyclic GMP in the retinas of normal mice and those heterozygous for early-onset photoreceptor dystrophy.
Cyclic GMP metabolism has been investigated in the retinas of mice that are heterozygous for a 'photoreceptor dystrophy' gene and have a lowered concentration of cGMP in their photoreceptor cells. The concentration of rhodopsin, retinal morphology and guanylate cyclase kinetics were normal. Cyclic GMP phosphodiesterase had a lowered affinity for cGMP. In accord with previous observations, chelation of exogenous calcium had no effect on cGMP levels in light-adapted retinas but increased them in dark-adapted tissue. The difference between cGMP concentrations in heterozygous and normal retinas in the dark was then eliminated. It was concluded that a modulator of cGMP phosphodiesterase activity is most likely to be causing the lowered steady-state level of cGMP in heterozygous retinas and that calcium is not involved.
Doshi
M
M
Voaden
M J
MJ
Arden
G B
GB
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism*; D003623:Dark Adaptation; D006162:Guanylate Cyclase / Q000378:metabolism; D006579:Heterozygote; D051379:Mice; D008810:Mice, Inbred C57BL; D012160:Retina / Q000201:enzymology / Q000378:metabolism*; D012162:Retinal Degeneration / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D012243:Rhodopsin / Q000378:metabolism
D012243:Rhodopsin; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D002118:Calcium