GABA Disturbance Contributes to Blindness 02/27/2009
Posted by nrcinc in GABA.Tags: blindness, diabetic retinopathy, eyesight, retina, retinopathy
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Diabetic retinopathy is very likely a consequence of peripheral GABA disorder. Visual function has been shown to depend on the integrity of GABAergic circuitry. Retinal GABA content and activity of the enzymes involved in GABA metabolism (Glutamic Acid Decarboxylase and GABA-Transaminase) are both diminished in diabetic neuropathy. This disturbed GABA activity correlates with visual dysfunctions.
The retina is one of the tissues with a high degree of GABA activity. Changes in GABA metabolism are thought to be responsible for disturbed retinal oscillatory potentials in diabetes. Diabetics also show increased GABA immunoreactivity.
As previously mentioned reports from the National Institutes of Health have confirmed that diabetic retinopathy occurs in pre-diabetes, indicating that some other causative factor is responsible. Our hypothesis is that the disturbance in GABA metabolism in beta cell is that other causative factor.
copyright © 2009 NRC®
Diabetes Is Not Just An Insulin Deficiency 02/15/2009
Posted by nrcinc in Insulin.Tags: diabetic retinopathy, retina, retinopathy
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Insulin is secreted from the beta cells in pancreatic tissue called the Islets of Langerhans. The classic characteristic of beta cell insufficiency is too little insulin being secreted. There is, however, another important compound made in the beta cells. When deficient, this “other” compound may also contribute to the multiple complications suffered by diabetics. In fact, this other compound appears to initiate diabetic complications before insulin secretion ceases and high blood sugar (hyperglycemia) manifests.
On June 28, 2005, the National Institutes of Health issued a press release confirming that diabetic retinopathy occurs in pre-diabetes, far sooner than previously thought. “These lesions are clearly the same ones we see in Type 2 diabetes,” said Richard Hamman, MD, DrPH, vice-chair of the Diabetes Prevention Program (DPP). “This confirms that diabetic retinopathy occurs in pre-diabetes.”
The American Diabetes Association (ADA) chief scientific and medical officer, Richard Kahn, PhD, pointed out that “the complications of diabetes may begin years before diagnosis and much earlier than we thought.”
Despite these observations, the scientific community seems to have overlooked their significance. These findings clearly indicate that complications that set in years before patients are ‘diabetic’ cannot be caused by high blood sugar.
According to a study published in 1992, complications are present in Type 2 diabetics four to seven years before these patients are diagnosed as diabetic. These data provide evidence indicating something other than high blood sugar is responsible for these degenerative changes. For example, if retinopathy develops years before the patient’s blood sugar rises, a factor other than insulin (or blood sugar) must be responsible for that retinopathy.
copyright © 2009 NRC®
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