Effects of Anti-Thyrotropin-Releasing Hormone Anti-Serum Treatment during the Neonatal Period on the Development of Rat Thyroid Function

Summary

Effects of anti-thyrotropin-releasing hormone (TRH) antiserum treatment during the neonatal period on the development of rat thyroid function were studied. On postnatal days 2 and 4, rats were administered anti-TRH anti-serum ip, and they were serially decapitated at the 4th, 8th and 12th week after birth. TRH, thyrotropin (TSH), thyroxine (T₄) and 3,3′,5-triiodothyronine (T₃) were measured by radioimmunoassay.

Immunoreactive TRH (ir-TRH) in the hypothalamus did not change significantly after anti-TRH anti-serum treatment, and plasma ir-TRH tended to decrease. The plasma ir-TRH and TSH responses to cold were significantly inhibited. The plasma TSH response to TRH was also significantly inhibited. The plasma basal TSH levels were significantly lower than incontrols.The plasma T₄ and T₃ levels were found to be lower than those in the controls.

Findings suggested that treatment with anti-TRH antiserum during the neonatal period disturbed the development of rat thyroid function, inhibiting TRH release and altering thyrotroph sensitivity to TRH.

Key-Words:

Thyrotropin-Releasing Hormone - Thyrotropin - Anti-TRH Anti-serum - Development of Thyroid Function