Abstract
The relationship between serum thyroxin and its central mechanism of stimulation was investigated in the juvenile and adult mouse. The dynamics of serum thyroxin was determined after administration of a single dose (100 ng/gr body weight) of thyrotropin releasing hormone (TRH). The response consists of two phases, in the adult and the juveniles on their 15th postnatal day. In the short term phase, a significant (10 up to 200% of control) and abrupt (within less than 4 hours) increase of serum thyroxin is observed. The following slower phase, evident at 30 hours after TRP administration, was found to be suppressed to 75% of its control level. In the 14 day old juvenile, no significant response of serum thyroxin to TRH administration was measured. The results are correlated with previously available data and the relative long term suppression is attributed to a rebound effect of either TRH or thyroxin upon TSH release.
| Original language | English |
|---|---|
| Pages (from-to) | 59-64 |
| Number of pages | 6 |
| Journal | Neuroendocrinology Letters |
| Volume | 12 |
| Issue number | 1 |
| State | Published - 1990 |