Elevation of cGMP with normal expression and activity of rod cGMP-PDE in photoreceptor degenerate labrador retrievers

Ophthalmic Res. 1996;28(1):19-28. doi: 10.1159/000267869.


Cyclic guanosine 3',5'-monophosphate (cGMP) levels were determined in retinas from a strain of Labrador Retrievers with inherited retinal dystrophy manifesting at early stages of retinal differentiation. The cGMP contents of dystrophic retinas of dogs from 1 to 4 months of age (n = 7) were significantly higher (p = 0.001) than in age-matched controls of the same breed (n = 11). Ultrastructure along the vertical retinal meridian was studied in developing retinas and findings were related to those of age-matched wild-type controls of the same breed. Slow central to peripheral progression of degeneration was observed in affected dogs. No differences were found in total cGMP-phosphodiesterase (PDE) activity, in PDE subunit composition as determined by Western blotting of 2-month-old homozygote affected retinas, or in the amino acid sequence deduced from the nucleotide sequence of the PDE beta-subunit as compared to controls. This model of photoreceptor degeneration thus is the first case of an apparent abnormality of cGMP metabolism that is not associated with a defect in the PDE catalytic subunits, and it is also the first reported model not associated with severe developmental abnormalities and rapid degeneration.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 3',5'-Cyclic-GMP Phosphodiesterases / metabolism*
  • Animals
  • Blotting, Western
  • Cyclic GMP / metabolism*
  • Disease Models, Animal*
  • Dog Diseases / enzymology*
  • Dog Diseases / pathology*
  • Dog Diseases / physiopathology
  • Dogs
  • Electroretinography
  • Enzyme Activation
  • Microscopy, Electron
  • Nerve Degeneration
  • Photoreceptor Cells / pathology
  • Reference Values
  • Retina / metabolism
  • Retina / ultrastructure
  • Retinal Rod Photoreceptor Cells / enzymology*
  • Retinitis Pigmentosa / enzymology
  • Retinitis Pigmentosa / pathology
  • Retinitis Pigmentosa / veterinary*
  • Trypsin / pharmacology


  • 3',5'-Cyclic-GMP Phosphodiesterases
  • Trypsin
  • Cyclic GMP

Associated data

  • GENBANK/Z75134
  • GENBANK/Z75156