Mark A. Yorek, PhD

Contact Information

Office: 204 40 VAMC 
Faculty Profile


Brief description of current research:

Dr. Yorek’s research focuses primarily on vascular and neural disease related to obesity and diabetes. They are interested in determining the etiology of peripheral neuropathy associated with these conditions. An overall goal of their studies is to determine the role of vascular dysfunction in obesity- and diabetic-neuropathy and the mechanism responsible for vascular dysfunction. Briefly, they have developed the methodology to examine the effect of diabetes on vasodilation of blood vessels that provide circulation to the sciatic nerve and the retina. Combined with the examination of motor and sensory nerve conduction velocity, neuronal blood flow in the sciatic nerve, and sensory nerve perception they are investigating the etiology of diabetic neuropathy with emphasis on vascular disease. In addition, they have also been conducting studies examining impairment of innervation of the cornea as a marker for obesity- and diabetic-neuropathy. Using animal models of obesity and diabetes they have demonstrated that loss of corneal nerves especially those innervating the cornea epithelium occurs early in disease. They have also shown that in the sub-epithelial layer of the cornea early detection of nerve loss can be achieved by examining the region of the whorl. These results have translational importance for the early detection of obesity- and diabetic-neuropathy that could be used for examining the progression and repair of neuropathy in patients. In this regard they have been conducting studies in the use of menhaden oil (fish oil), a natural source for n-3 fatty acids, for the treatment of obesity- and diabetic-neuropathy. They have demonstrated that treating rodent models of pre-diabetes and type 2 diabetes with menhaden oil improves insulin resistance and vascular and neural complications. They believe that the mechanism(s) responsible for the beneficial effects of menhaden oil is the reduction in the n-6 to n-3 fatty acid ratio and production of resolvins and neuroprotectin, metabolites of n-3 fatty acids that have anti-inflammatory and neuroprotection properties. Studies are ongoing to investigate the mechanism(s) responsible for the beneficial effects of fish oils in obesity and diabetes. In addition clinical studies are being designed to test the benefits of fish oil treatment in subjects with diabetes.

 

3 most influential diabetes/obesity/metabolism publications:

  • Changes in corneal innervation and sensitivity and acetylcholine-mediated vascular relaxation of the posterior ciliary artery in a type 2 diabetic rat. Davidson EP, Coppey LJ, Holmes A, Yorek MA. Invest Ophthalmol Vis Sci, 53:1182-7, 2012. PMID:22273725
  • Effect of inhibition of angiotensin converting enzyme and/or neutral endopeptidase on vascular and neural complications in high fat fed/low dose streptozotocin-diabetic rats. Davidson EP, Coppey LJ, Holmes A, Yorek MA. Eur J Pharmacol, 677:180-7, 2012. PMID:22198047
  • Effect of inhibition of angiotensin converting enzyme and/or neutral endopeptidase on neuropathy in high fat fed C57Bl/6J Mice. Coppey L, Lu B, Gerard C, Yorek MA. Journal of Obesity, 2012;2012:326806. PMID:23056927
  • Partial replacement with menhaden oil improves peripheral neuropathy in high fat fed low dose streptozotocin type 2 diabetic rat. Coppey LJ, Holmes A, Davidson EP, Yorek MA. Journal of Nutrition and Metabolism, 2012;2012:950517 PMID:22988492