thus , although trh is probably not directly responsible for the dramatic increase in the number of thyrotrophin-producing cells which occurs in the pars distalis of 10.5- to 11.5-day-old embryos ( r. c. thommes , j. b. martens , w. e. hopkins , j. caliendo , m. j. sorrentino , and j. e. woods ( 1983 ) . gen. comp . endocrinol . 51 , 434-443 ) the marked change in the activity of the pituitary-thyroid unit at this time may well reflect the response of these newly differentiated thyrothrophs to low levels of plasma trh .
C0032002
pituitary
C0040162
trh