Changes of the serum TSH, T_3 and T_4 concentrations observed during the first four hours after birth in the present study are in agreement with data reported previously(Eren burg et al., 1974;Sack et al., 1976).
The precise mechanism of neonatal TSH ...
Changes of the serum TSH, T_3 and T_4 concentrations observed during the first four hours after birth in the present study are in agreement with data reported previously(Eren burg et al., 1974;Sack et al., 1976).
The precise mechanism of neonatal TSH surge is not entirely clear, but it seems likely that it is mediated by increased TRH secretion. But exogenous TRH usually provokes both TSH and PRL release in human adult(Foley et al., 1972).
Our results indicate that there is, indeed, a significant PRL surge associated with TSH surge during the first 30 minutes after birth.
The mean serum GH concentration did not change significantly during the four hours after birth.
Our data are consistent with the hypothesis that there is a TRH surge during the early minutes after birth which provokes release of both TSH and PRL.
The fact that GH levels tent to decrease is against the view that the TSH and PRL increments represent stress responses.
It also is unlikely that the transient reduction stress responses.
It also in unlikely that the transient reduction in serum GH levels is mediated by somatostatin, since this releasing factor is known to inhibie the TSH response to TRH(Weeke et al., 1975).
Our data show the possibility that release of both thyrotropin and prolactin is provoked by the same mechanism during the early hours after birth.