Atrial natriuretic Peptide in young and elderly children with mild gastroenteritis

Atrial Natriuretic Peptide (ANP) has natriuretic and diuretic effects, synthesized and stored in the atrial cells, released in response to stretch of the atrial muscle during increase venous return. Acute gastroenteritis (AGE) causes dehydration. We intend to determine whether the decrease in venous return due to dehydration would lead to a decrease in ANP levels.

This is a prospective observational controlled study. Blood collected from 30 children with AGE and ANP's levels were compared with 25 controls. ANP levels were determined by radioimmunoassay.

The study group was in mild dehydration. As a significant difference was found in ANP levels between children in the 3mo-3y group and older children 3y-14y. We analyzed the results according to age. No difference was found between children with AGE and control, in the 3mo-3y, ANP was 12.1 +/- 11 pg/ml versus 13.4 +/- 12 pg/ml respectively, and 3 +/- 2 versus 3.8 +/- 3 pg/ml in the 3y-14y groups, respectively.

Dehydration due to AGE does not change the ANP's plasma levels. A weak positive correlation between sodium levels and ANP was found r = 0.29. The significant finding of our study is the difference in ANP levels related to age, in the control as well as the GE group.