Expression of monocarboxylate transporter mct1 by brain endothelium and glia in adult and suckling rats. Gerhart, David Z., Bradley E. Enerson, Olga Y. Zhdankina, Richard L. Leino, and Lester R. Drewes. Departments of Biochemistry and Molecular Biology and Anatomy and Cell Biology, University of Minnesota, Duluth, Minnesota 55812
APStracts 4:0077E, 1997.
A polyclonal affinity purified antibody to the carboxyl-terminal end of the rat monocarboxylate transporter MCT1 was generated in chickens and used in immunocytochemical studies of brain tissue sections from adult and suckling rats. The antibody identified a 48-kDa band on immunoblots and stained tissue sections of heart, cecum, kidney, and skeletal muscle, consistent with the reported molecular weight and cellular expression for this transporter. In tissue sections from adult brains, the antibody labeled brain microvessel endothelial cells, ependymocytes, glial limiting membranes, and neuropil. In brain sections from 3-14 day-old rats, microvessels were much more strongly labeled and neuropil was weakly labeled compared to sections from adults. Immunoelectron microscopy indicated that labeling was present on both luminal and abluminal endothelial cell plasma membranes. These results suggest that MCT1 may play an important role in the passage of lactate and other monocarboxylates across the blood-brain barrier and that suckling rats may be especially dependent on this transporter to supply energy substrates to the brain.

Received 16 December 1996; accepted in final form 18 March 1997.
APS Manuscript Number E616-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 15 April 1997