Lactate dehydrogenase isoenzyme pattern in the eye muscles. Deviation in myopia.

Convergent strabismus fixus in high myopic patients

“…According to Lang's statistics [8], the Bielshowsky type occurs in 2 out of 1000 cases, while the myopathic type, which we have described here, is seen in 1 out of 2000. Lang is inclined, therefore, to consider the first form as a precursor of the second.…”

Lactate dyscrasia: a novel explanation for amyotrophic lateral sclerosis

“…Thus, lactate is a metabolic substrate that sustains extraocular muscle function and prevents muscle fatigue suggesting that these muscles have high lactate turnover (i.e., the molecular machinery to convert lactate to pyruvate). Supporting this, lactate dehydrogenase (LDH) activity is detected in oculomotor neurons (Hayashi, 1987) and in eye muscles (Kahan and Juhasz, 1976). Alternatively, it is possible that lactate is also removed from the nerves/muscles via a lactate shuttle (muscle-neuronal lactate shuttle; MNLS), like the recently proposed astrocyte-neuronal lactate shuttle (Erlichman et al, 2008;Mangia et al, 2009).…”

Elevated L-Lactate Drives Major Cellular Pathologies Associated With Neurodegeneration

“…Most of the research conducted in the 1900's was evaluating the role of lactic acid/lactate as a by-product of energy metabolism that occurs in exercising muscle (33,36,37). While this holds true, further advances in cellular and molecular techniques are opening up avenues of further investigation of lactate as a potentially significant energy substrate for the CNS.…”

“…shown that ocular muscles and nerves use lactate as an energy substrate, thus these tissues do not fatigue when exposed to lactic acid as is seen in skeletal musculature (4). Furthermore, it has been reported that LDH activity is detected in eye muscles (37) and oculomotor neurons (33). Taken together, these findings suggest that the eye muscles and associated neurons possess the cellular machinery to withstand abnormally high amounts of lactate without subsequent cellular degeneration.…”