An Inexpensive Method for Assessing Pituitary Response to Luteinizing Hormone Releasing Hormones: Analysis of Serum Gonadotropins in Pooled Samples

Summary Sixty-two children, aged 2-18 years, suspected of an endocrine disorder were given one of several IM injections of the LHRH and the blood was drawn prior to and at 30, 60, 90, 120, 240 minutes after the injection. An aliquot of .2 ml of serum was taken from each post-LHRH specimen and pooled. The gonadotropins were measured in all the individual and pooled samples. A high correlation (r=.974, LH; r=.981, FSH) between the peak and the pooled sample suggests that the analysis of gonadotropins in a pooled sample gives information comparable to that obtained by the gonadotropin analysis in multiple serum samples. A formula to calculate the peak LH and FSH from the pooled specimen taken from only four post-LHRH injections is: peak LH = 3.015 + 1.049 times the pooled LH; peak FSH = 3.153 + 1.072 times the pooled FSH value. The correlation coefficient between the observed and the calculated LH was .98; the same for the FSH was .987. I suggest that the pooled sample, due to it's integrated response, is a better reflection of the pituitary response to the LHRH.