title: Reciprocal effects of prolactin and thyroxine on the growth rate of rat pups from weaning to puberty.
abstract: Prolactin and thyroxine were added to the daily diet of rat pups from weaning to puberty (days 20--40). While prolactin significantly retarted the pups' growth, thyroxine stimulated growth and even compensated for the depression caused by prolactin. The significant retardation in the growth of the prolactin-treated pups around days 30--35 of age indicates that at that period they are extremely prolactin-dependent, thus confirming previous reports that exogenous prolactin inhibits its own endogenous secretion. On the other hand, the possible growth promotion caused by thyroxine is mild and does not initiate a feedback mechanism. This suggests that prolactin is indispensable for the normal development of the weaned, immature rat.
mesh_terms: D000818:Animals; D004338:Drug Combinations; D005260:Female; D006128:Growth / Q000187:drug effects*; D011388:Prolactin / Q000494:pharmacology*; D051381:Rats; D012741:Sexual Maturation; D013974:Thyroxine / Q000494:pharmacology*; D014886:Weaning
chemical_list: D004338:Drug Combinations; D011388:Prolactin; D013974:Thyroxine