1,2-diacylglycerol content and its arachidonyl-containing molecular species are reduced in sciatic nerve from streptozotocin-induced diabetic rats

J Neurochem. 1990 Sep;55(3):1087-90. doi: 10.1111/j.1471-4159.1990.tb04604.x.

Abstract

The content of 1,2-diacylglycerol (DAG) was determined in sciatic nerves from normal and streptozotocin-induced diabetic rats. In nerves frozen in situ, DAG content was reduced 22% in the proximal region and 77% in the distal region of diabetic nerve, principally because of the loss of associated fat. DAG levels in freshly dissected and desheathed diabetic nerve were decreased from 23 to 30% as compared with normal nerve. Determination of DAG molecular species distribution in desheathed normal nerve indicated that 18:0/20:4 accounted for 34%, 16:0/18:1 for 17%, and several other polyunsaturated fatty acid-containing species for 17% of the total. In diabetic nerve, the quantity of the 18:0/20:4 DAG, species was reduced by 37%, and this drop was 62% of the reduction in all molecular species. The content of the minor species, 16:0/20:4 DAG, was decreased by 48%. Our results suggest that nerve DAG arises in large part from phosphoinositide degradation. Moreover, these results provide support for the hypothesis that reduced Na+,K(+)-ATPase activity in diabetic nerve is a consequence of decreased phosphoinositide turnover, which thereby generates insufficient DAG to maintain a protein kinase C-mediated step necessary for activation of Na+,K(+)-ATPase.

Publication types

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

MeSH terms

  • Animals
  • Arachidonic Acid
  • Arachidonic Acids / metabolism*
  • Diabetes Mellitus, Experimental / metabolism*
  • Diglycerides / metabolism*
  • Glycerides / metabolism*
  • Male
  • Phospholipids / metabolism
  • Rats
  • Rats, Inbred Strains
  • Sciatic Nerve / metabolism*
  • Tissue Distribution

Substances

  • 1,2-diacylglycerol
  • Arachidonic Acids
  • Diglycerides
  • Glycerides
  • Phospholipids
  • Arachidonic Acid