Thyroid metabolism in the recessive sex-linked dwarf female chicken. 3. The influence of exogenous thyroid hormones in glycogen metabolism.

The influence of exogenous thyroid hormones on glycogen-body and liver glycogen was studied in fasted and full-fed 3 wk. old dwarf and non-dwarf White Leghorn chickens. The results indicated that in contrast to normals, the glycogen-body of the dwarf was still physiologically active at age 3 wks. and they also exhibited a relatively higher liver glycogen concentration. The liver glycogen concentration was significantly higher in T3-treated, full-fed dwarf chickens when compared with other groups. The data were interpreted to suggest that the differential response observed in both dwarf and non-dwarf chickens of increasing liver glycogen levels with T3 and T4 injections indicated that the proper ratios of serum T3:T4 were probably more vital to the normal metabolic functions than changes in the individual concentrations of either T3 or T4.