Na+-K+-activated adenosine triphosphatase and intestinal electrolyte transport. Effect of adrenal steroids

Sodium-potassium-activated adenosine triphosphatase (Na-K-ATPase) is associated with electrolyte transport in many tissues. To help delineate its role in intestinal transport, changes in rat intestinal electrolyte and water transport induced by injecting methylprednisolone acetate 3 mg/100 g or deoxycorticosterone acetate (DOCA) 0.5 mg/100 g per day for 3 days were correlated with changes in Na-K-ATPase activity. Methylprednisolone increased sodium and water absorption, potassium secretion, transmural potential difference, and Na-K-ATPase activity in the jejunum, ileum, and colon. Examination of isolated epithelial cells demonstrated that the jejunal and ileal increase in Na-K-ATPase occurred in both the villus tip and crypermeability, Mg-ATPase, and adenylate cyclase activities were unchanged by methylprednisolone. DOCA increased sodium and water absorption, potassium secretion, transmural potential difference, and Na-K-ATPase activity in the colon alone. Colonic Mg-ATPase and adenylate cyclase activities were unaffected. Jejunal and ileal enzyme activity, electrolyte transport, and permeability were unchanged by DOCA. Methylprednisolone and DOCA were not additive in their effect on colonic Na-K-ATPase activity. Methylprednisolone and DOCA increased electrolyte and water transport and Na-K-ATPase activity concomitantly in specific segments of small intestine and colon. These data are consistent with an important role for Na-K-ATPase in intestinal electrolyte and water transport.

Serum linoleic acid in multiple sclerosis

Total serum fatty acids were analyzed in 30 patients with multiple sclerosis and in 33 controls. No significant decrease in linoleic acid was found in the patients with multiple sclerosis. A disturbance in linoleic acid metabolism is not inevitably associated with this disease.

Gel filtration of myelin using 2,2,2-trichloroethanol as the solvent

The use of 2,2,2-trichloroethanol as a solvent for myelin from both the central and peripheral nervous systems is described. Concentrated, optically clear solutions of lyophilized myelin in this solvent are stable for weeks. The preparation of highly concentrated myelin proteins by gel filtration in trichloroethanol is described.

Amyotrophic lateral sclerosis: effect of serum on anterior horn cells in tissue culture

A high proportion of diluted serums of patients with amyotrophic lateral sclerosis were toxic to the anterior horn cells of the mouse in tissue culture. This is not a general cytotoxicity, since apparently only the neurons were killed. Serums from other degenerative neurological diseases were inactive.