| Abstrakt: |
In a previous work we demonstrated that in adults timing of GRH stimulation in relation to the pattern of spontaneous GH secretion could condition GH response. To investigate if there was a similar situation in children, a GRH test (GRF-29,Serono 1 mcg/kg, iv bolus) was performed in 17 SN (8M,9F,7-11 y) and 6 GHD (3M,3F,8-12 y) at 09.30 h after an overnight fast and 30' resting. From the analysis of plasma GH variations (-30'.0') prior to stimulation, 3 theoretical phases in HSR were established: A)Secretion Phase; B)Secreticn Plateau; C)Refractory Phase,(see fig.). GH peak after GRF-29 was evaluated according to the theoretical phase at testing. RESULTS (x±SEM).- A very high correlation (Spearman's test) was obtained between pre-GRF GH increments (+,- or 0) and GH peak in SN (r=0.81, p<0.0001). No differences were found in the distribution per phase between M and F SN. (GH=ng/ml).While it is clear that endogenous HSR conditions the response to GRF-29 in SN, it appears that sexual HSR dimorphism, previously reported by us, must begin after puberty, because both the sexual distribution per phase and GH peak were very similar. The fact that SN in phase C showed similar responses to those in GHD indicates that the functional status of HSR must be taken into account to minimize errors in diagnosis after GRH test and possibly also in GRH therapy.*p<0.005 vs.B and C. Partially supported by FISS 87/1359 |
