Late endocrine effects of L-dopa, 5-HTP, and 6-OH-dopa administered to neonatal rats.
Neonatal rats were injected with L-dopa, 5-hydroxytryptophan (5-HTP) or 6-hydroxy-dopa (6-OH-dopa) and allowed to mature. Eye opening, vaginal opening, endocrine organ weights and pituitary hormone concentration in the serum were measured. Treatment with either the dopamine (DA) precursor or the serotonin (5-HT) precursor caused an acceleration in eye opening, a significant decrease in serum TSH (males) an elevation of serum prolactin (Prl; males), and a lowering of serum growth hormone (females). After chemical sympathectomy (6-OH-dopa) vaginal opening was delayed, thyroid weights were increased and serum TSH decreased (males). It is concluded that during the critical neonatal period overloading either of 2 of the principal monaminergic systems results in similar and persistent alterations in pituitary function. Chemical sympathectomy produced a different pattern of abnormalities.
D006916:5-Hydroxytryptophan / Q000494:pharmacology*; D000311:Adrenal Glands / Q000187:drug effects; D000818:Animals; D000831:Animals, Newborn; D004971:Estrus / Q000187:drug effects; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006128:Growth / Q000187:drug effects; D006892:Hydroxydopamines / Q000494:pharmacology*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects*; D007980:Levodopa / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D009929:Organ Size; D010053:Ovary / Q000187:drug effects; D010902:Pituitary Gland / Q000032:analysis; D011247:Pregnancy; D051381:Rats; D012737:Sex Factors; D012741:Sexual Maturation / Q000187:drug effects; D013737:Testis / Q000187:drug effects; D013972:Thyrotropin / Q000032:analysis; D014599:Uterus / Q000187:drug effects
D006892:Hydroxydopamines; D007980:Levodopa; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin; D006916:5-Hydroxytryptophan