A randomized trial of the effect of a GnRH analogue injection on ghrelin levels in girls

Introduction: Ghrelin concentrations decline during puberty by an unclear mechanism. Acylated ghrelin (AG) is unstable in sampling tubes, but no standardized sampling protocol exists. We hypothesized that ghrelin levels decrease as a consequence of increased gonadotropin releasing hormone (GnRH) signalling and that the addition of a protease inhibitor to sampling tubes preserves the AG levels. Methods: In this randomized, placebo-controlled, cross-over study, 13 girls with suspected central precocious puberty were included. They performed an adjusted GnRH stimulation test twice and were given Relefact LHRH ® (100 g/m2) or saline in a randomized order. Blood was sampled repeatedly for 150 min for the analysis of hormone concentrations. Oestradiol levels were only measured at baseline. The protease inhibitor 4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride (AEBSF) was added to the sampling tu bes. Specific ELISA kits were used for the analysis of AG and desacylated ghrelin (DAG) levels. Results: Neither AG nor DAG levels changed after GnRH analogue injection in comparison to saline. The addition of AEBSF preserved AG levels (650.1  257.1 vs. 247.6  123.4 pg/ml, p
Source: Hormone Research in Paediatrics - Category: Endocrinology Source Type: research