Background: GnRHa (gonadotropin releasing hormone analogue) inhibits growth spurt during treatment of precocious puberty. So they have limitation of final height gain.
Objective and hypotheses: It is need to study about what factor associated with growth decrement and ideal suppression level of sex steroid during GnRHa treatment.
Method: Female SpragueDawley rats of 3 weeks of age (Total 15) were divided into three groups; (1) normal control (n=5), (2) GnRHa (25), (3) GnRHa (100). Each group were injected normal saline, 25 and 100 mcg of GnRHa intramusculary at day 1 respectively. Study measure was as follows.
Day 1: Measurement of head to tail length, leg length and body weight. Day 13: Brdu injection. D 14: repeated measurment of body size as same of day 1. Then rats were decapitated and harvested growth plate of tibia. Growth plate was stained by H-E method. Brdu, VEGF, IGF-1 receptor and GnRH receptor were calculated by Immunocytochemistry.
Results: Mean body weight were 175.9±4.5 g, 176.6±7.5 cm and 194.1±5.9 cm. Mean total length were 36±0.1, 35.6±0.7, 34.9±0.3 cm. Growth plate thickness were 8.86±1.2, 8.18±1.4 and 9.6±1.5 mm in normal, GnRHa (25) and GnRHa (100) respectively. Expression of IGF-1 receptor, Brdu and VEGF were decreased at the treated group. Small scattered GnRHa receptors expressed at the growth plate.
Conclusion: In this pilot study, sex hormone inhibited rats showed body weight gain and short leg length than control. To investigate the effect of GnRHa about growth plate, it is needed more sophisticated experiments.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology