Endocrine Abstracts

Introduction: Intrauterine growth is a biological process regulated by maternal, placental, and foetal endocrine signals. Birth weight is an indicator of the health of the newborn. Alterations in foetal growth lead to perinatal health risks and favour metabolic diseases during adult life. Therefore, the study of endocrine factors determining birth weight, such as ghrelin is an important issue. Ghrelin may exist as two molecular forms, desacyl ghrelin (DAG) and acyl ghrelin (AG). Current evidence showed to DAG as an active hormone with effects on different tissues in diverse physiological and pathophysiological states. Although cord blood (CB) ghrelin levels have been correlated to birth weight, it is unknown which ghrelin’s molecular variants are involved and if expression and methylation of ghrelin receptor (GHSR1) has a key role in foetal development.

Methods: We performed a cross-sectional comparative study healthy mothers and their term newborns small for gestational age (SGA), adequate for gestational age (AGA), and large for gestational age (LGA) (n=20/group). Total ghrelin, AG, and DAG levels were measured in CB by ELISA. Placental GHSR1 expression was evaluated by western blot and GHSR1 promoter methylation by qPCR after bisulphite modification of DNA.

Results: Cord blood DAG levels were increased in SGA compared to AGA newborns (902.1±109.1 and 597.4±58.2 pg/ml, respectively, P=0.01) while LGA and AGA showed similar values (627.2±76.4 pg/ml for LGA, P=0.80). DAG levels negatively correlated with birth weight (r=−0.31, P=0.02) and placental weight (r=−0.33, P=0.02). No differences in AG or total ghrelin levels were found. Expression and methylation of GHSR1 in placenta was not differentially among SGA, AGA, and LGA.

Conclusions: Our results showed that expression and methylation of ghrelin receptor (GHSR1) has unrelated with birth weight. Suggesting that additional factors, such as DAG, are involved in the mechanism that determines birth weight.

Disclosure: This study was supported by University of Guanajuato (0095/13) and FOMIX CONACYT – Guanajuato State Government (GTO-2012-C03-195238). M I Gonzalez Dominguez was the recipient of CONACYT (CVU-217761).