Serotonergic receptors in the brain of in utero undernourished rats.
In this study, we report that 5-HT(1A) receptors are already present in fractions of axonal growth cones, from the normal rat fetal brain (E-17). Also, in utero undernourished (UN) rat pups at birth show a noteworthy enhancement in the B(max) of [3H]5-hydroxytryptamine (5-HT) and [3H]8-hydroxy-(2-N,N-dipropilamin)-tetralin (([3H])8-OH-DPAT), in the brainstem and cerebral cortex up to the second week after birth. Afterwards, there is a significant decrease in the binding of these ligands. [125I]Cyanopindolo binding in the cerebral cortex only showed a decrease in the same period. An elevation of brain serotonin in both regions was also present. These findings together, suggest that the mechanisms of regulation of serotonergic receptors' expression during the period studied, may not depend on the amount of neurotransmitter in the synaptic cleft, because in the early UN brain it would be expected only a lower receptor's density due to the chronic serotonin increase. On this basis, we propose that developmental activation of brain serotonin biosynthesis observed in early UN animals may disrupt the mechanism regulating the expression of 5-HT receptors during development.
Manjarrez
Gabriel
G
Laboratory of Neurochemistry, 20th Century National Medical Center, Mexican Institute of Social Security (IMSS), Mexico City, Mexico. willisga@dfl.telmex.net.mx
Manuel-A
Leticia
L
Mercado-C
Rosalio
R
Hernandez-R
Jorge
J
D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000196:embryology* / Q000254:growth & development / Q000378:metabolism*; D001923:Brain Chemistry; D001933:Brain Stem / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D003677:Deficiency Diseases / Q000378:metabolism; D005260:Female; D020439:Growth Cones / Q000378:metabolism; D008297:Male; D009747:Nutritional Physiological Phenomena; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000378:metabolism*; D044263:Receptors, Serotonin, 5-HT1; D012701:Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000378:metabolism; D017366:Serotonin Receptor Agonists / Q000378:metabolism
D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D012701:Serotonin