The effects of antithyroid drugs on chick embryos

Physiology of Turkey Embryos During Pipping and Hatching. III. Thyroid Function ,

“…The data from the present study with turkeys indicate temporal patterns in thyroid function exist in poult embryos during hatching that are similar to those noted previously in chick embryos (Grossowicz, 1946;Bull, 1949 Adams andBuss, 1952;Romijn et al, 1952 Romanoff andLaufer, 1956;Sinha<?+a/., 1959 Balaban andHill, 1971;Davison, 1976;Thommes et al, 1977;Decuypere et al, 1979a,b). The present study also suggests T 3 and T 4 may increase and decrease at different stages of hatching, but the distinctive roles played by T 3 and T4 as well as the relative importance of each remain to be demonstrated.…”

“…Grossowicz (1946) injected thiourea into chick embryo yolk sacs between the 7th and 17th days of incubation and observed a delay of 10 days in pipping. Injections of eidier thiourea or thiouracil at various stages of incubation have corroborated these initial observations (Adams and Bull;1949;Adams and Buss, 1952;Romijn et al, 1952;Romanoff and Laufer, 1956;Sinha et al, 1959;Balaban and Hill, 1971). Balaban and Hill (1971) observed that thyroid function blocked by thiourea caused coincidental reduced loss of yolk sac material and delayed puncture of the chorioallantoic membrane, whereas exogenous injections of thyroxine (T 4 ) reinitiated both processes and led to successful hatching.…”

The Effect of Injected Thiouracil on Body Weight and Hatchability of the Chick Embryo

“…At any given time after treatment, the average body weights of embryos from eggs that had been injected with thiouracil were less than the average body weights of embryos from eggs receiving an injection of Ringer's solution alone or from eggs receiving no injection at all. These findings are in agreement with those of a number of other investigators who used other goitrogenic compounds (Andrews and Schnetzler, 1945;Adams and Bull, 1949;Romanoff and Laufer, 1956). In general, from the 7th through the 11th days of incubation, no consistent significant differences were found between body weights of embryos from eggs receiving the different levels of thiouracil; however, all groups receiving thiouracil were significantly smaller than either the group receiving Ringer's solution alone or the group receiving no inj'ection at all.…”

The Development of Thyroid-Stimulating Hormone-Releasing Factor Activity in the Neonatal Rabbit

“…Though the chick thyroid can produce monoiodotyrosine and di-iodotyrosine before colloid formation, thyroxine does not appear until the first colloid droplets are present (Trunnell & Wade, 1955). At 14 days the thyroid gland of the chick embryo reacts to treatment with exogenous TSH or antithyroid drugs and little change occurs until hatching except for follicular growth and enlarge¬ ment (Woodside, 1937;Adams & Bull, 1949).…”