Developmental studies on the uptake of tyrosine by synaptosomes and plasma membrane vesicles derived from rat brain. Effect of thyroid hormones.
The uptake of L-tyrosine at various stages of development was examined in synaptosomes and in plasma membrane vesicles derived from rat brain. The total uptake has two components, Na+-dependent and Na+-independent, respectively. The Na+-dependent component of the transport system appears around the 5th postnatal day and increases with age. The affinity of the transport system for tyrosine does not vary substantially during development. The Vmax increases more than six-fold between day 15 and adulthood. Plasma membrane vesicles derived from T3-treated rats accumulate more tyrosine than those obtained from the control animals. The results support the view that thyroid hormones during development promote the establishment of the systems implicated in neurotransmission in the developing nervous system.
Herrero
E
E
Departamento de Bioquimica y Biologia Molecular, Facultad de Ciencias, Universidad Autónoma, Madrid, Spain.
Diez-Guerra
J
J
Aragon
M C
MC
Valdivieso
F
F
Gimenez
C
C
D000375:Aging / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000494:pharmacology; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*; D014284:Triiodothyronine / Q000494:pharmacology*; D014443:Tyrosine / Q000493:pharmacokinetics*
D014284:Triiodothyronine; D014443:Tyrosine; D012964:Sodium