Alteration of the GABAergic neuronal system of the retina and superior colliculus in streptozotocin-induced diabetic rat

Kobe J Med Sci. 1998 Feb;44(1):1-8.


Diabetes mellitus (DM) often causes neural dysfunctions, including visual disorders. To investigate the effect of hyperglycemia on the visual system, we studied the metabolism of gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter that has an important role in visual functions. We determined the GABA content and activities of glutamate decarboxylase (GAD) and GABA transaminase (GABA-T) in the retina and superior colliculus (SC) in streptozotocin (STZ)-induced DM rats. The GABA content and activities of GAD and GABA-T were decreased in the retinas of STZ-treated rats. The GABA content and GAD activity were reduced in the SC of STZ-treated rats, whereas GABA-T activity showed no marked change. This GABA reduction in the diabetes may be correlated with visual dysfunctions.

Publication types

  • Comparative Study

MeSH terms

  • 4-Aminobutyrate Transaminase / metabolism*
  • Animals
  • Diabetes Mellitus, Experimental / complications
  • Diabetes Mellitus, Experimental / metabolism*
  • Diabetic Retinopathy / etiology
  • Diabetic Retinopathy / metabolism
  • Disease Models, Animal
  • Glutamate Decarboxylase / metabolism*
  • Male
  • Rats
  • Rats, Wistar
  • Retina / metabolism*
  • Sensitivity and Specificity
  • Superior Colliculi / metabolism*
  • gamma-Aminobutyric Acid / metabolism*


  • gamma-Aminobutyric Acid
  • 4-Aminobutyrate Transaminase
  • Glutamate Decarboxylase