title: Diminished axonal transport of glycoproteins in the senescent rat brain.
abstract: At various time intervals (10, 15, 20, 25, 30 min) after injection of 3H-fucose into the medial septal nucleus of young adult (3 months old) and senescent (25 months old) Fischer-344 rats, the specific activities of trichloroacetic acid-phosphotungstic acid (TCA-PTA) soluble and insoluble fractions were determined in the medial area of the septum and in three successive rostro-caudal sections of the hippocampal formation containing mainly the dentate gyrus, but also its hilus with fields CA4 and CA3c of the hippocampus. The rate of 3H-fucose incorporation into glycoproteins of the septum did not differ in young adult and senescent rats. Part of the TCA-PTA soluble and insoluble radioactive material was transported through the septo-hippocampal pathway to the dentate gyrus. This transport was inhibited by the injection of colchicine into the septum prior to 3H-fucose injection and was completely blocked by electrolytic lesion of the medial septal nucleus. The arrival time and the amount of the TCA-PTA soluble radioactive material transported to the dentate gyrus did not differ in young adult and senescent rats. However, the TCA-PTA insoluble labelled glycoprotein was transported to the dentate gyrus in a significantly smaller amount and during a longer period of time in the senescent animals. This age-related change may reflect a reduction in amount and/or in rate of axonal transport of glycoproteins in the septo-hippocampal pathway of senescent rats.
mesh_terms: D000375:Aging; D000818:Animals; D001369:Axons / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D001921:Brain / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism; D003078:Colchicine / Q000494:pharmacology; D005643:Fucose / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism; D008297:Male; D010772:Phosphotungstic Acid / Q000378:metabolism; D051381:Rats; D012688:Septum Pellucidum / Q000378:metabolism; D014238:Trichloroacetic Acid / Q000378:metabolism
chemical_list: D006023:Glycoproteins; D010772:Phosphotungstic Acid; D005643:Fucose; D014238:Trichloroacetic Acid; D003078:Colchicine