On the possible involvement of plasma lipoproteins in choline transport to the brain
Ordóñez, L.A.; Arantza Bilbao, M.; Arreaza, C.
Acta Cientifica Venezolana 29(4): 245-250
1978
ISSN/ISBN: 0001-5504 PMID: 552756 Document Number: 136520
Adult female rats were injected i.p. with 20 .mu.Ci of methyl-14C-choline, and the incorporation of radioactivity was measured in total homogenates and in the chloroform and aqueous phases of Folch extracts prepared from plasma, liver, muscle and brain. Control brains showed a continuous increase in radioactivity in the total homogenate and in the organic phase of Folch extracts for up to 24 h. Following the administration of Triton WR-1339 (a blocker of plasma lipoprotein metabolism), total plasma radioactivity increased without a concomitant increase in brain, the latter tissue showing an incorporation of label similar to that of the controls. Colchicine, which blocks lipoprotein release by the liver, induced a reduction of the radioactivity both in total homogenates and in the organic phase of Folch extracts prepared from plasma. The lower values were paralleled by a similar decrease in brain radioactivity. Lipoproteins may play a role in the transport of lipid-bound choline to the brain.