The role of prolactin in blocking thyroxine-induced differentiation of tail tissue in larval and neotenic Ambystoma tigrinum

摘要: Abstract Previous work ( J. E. Platt and M. A. Christopher, 1977 , Gen. Comp. Endocrinol. 31 243–248) had shown that a single injection of ovine prolactin (PRL) given to larval or neotenic tiger salamanders retarded tail fin regression induced in these animals with thyroxine (T 4 ). This antagonism T -induced was correlated PRL-induced changes the water sodium content tissue. The present study presents evidence which demonstrates alternation levels occurs well within normal lag period precedes morphological manifestations regression. Additional experiments using simple vitro incubation system show skin pieces maintained this increase their when incubated for 22 hr PRL. Incubation taken from recently metamorphosed under identical conditions does not reveal response Further, untreated maintains significantly higher than same time . These results are discussed regard mechanism whereby PRL acts block tissue differentiation amphibians.