Ghrelin, Obestatin and Their Receptors As Well As Metabotropic Glutamate Receptor Assessment in Chronic Functional Constipation in Children.

OBJECTIVES: The aim of this study was to examine the role of ghrelin, obestatin, and glutamate and their receptors in the pathogenesis of children functional constipation. METHODS: Children ages 4-17 were the subject of the study: 121 children with constipation (55 boys and 66 girls), 36 patients of the same age (26 boys and 10 girls) were the controls. Expression of ghrelin, obestatin, and glutamate receptors on gastric and colon specimens taken by endoscopy were assessed. The concentration of the above agents was estimated in serum by the enzyme-linked immunosorbent assay test. RESULTS: The lower median serum concentrations of ghrelin, in the constipated children than in controls were confirmed (1.9 ng/mL vs 2.6 ng/mL, P < 0.05). The expression of the metabotropic receptor 7 for glutamate (mGlu7) RNA was higher in the stomach (32.49 vs 31.47, P < 0.05), and was lower in the rectum in constipated patients compared to the control group (31.76 vs 32.62, P < 0.05). A negative correlation between the concentration of ghrelin in serum and colonic transient time (P = 0.01, rho = -0.23) was shown in the study group.Higher median expression of obestatin receptor G protein-coupled receptor39 in rectal mucosae was found in a constipated group than in the controls (29.9 vs 26.9, P < 0.05). CONCLUSION: Ghrelin, and receptors for ghrelin, obestatin, and glutamate in gastrointestinal mucosa play a role in the pathogenesis of functional constipation in children.

Dyssynergic Defecation and Anal Sphincter Disorders in Children in High-Resolution Anorectal Manometry Investigation.

OBJECTIVES: Dyssynergic defecation is a common disorder in children with functional constipation (FC) because of relaxation disorders of the sphincter apparatus and intra-rectal pressure during defecation. The aim of the study was to determine frequency and type of dyssynergic defecation and to assess pressure in the anal canal poles during simulated evacuation and function of puborectalis muscle in defecation in children with FC. METHODS: Three-dimensional (3D) high-resolution anorectal manometries (3D HRAM) were performed in 131 children with FC. In the manometric test, resting pressure measurements were assessed in 4 measuring poles of the anal canal. RESULTS: One hundred thirty-one children ages 5 to 17 years (mean age 10.2; SD ±â€Š3.8; median 10) were involved in the study (69 girls and 62 boys). Dyssynergic defecation was shown in 106/131 (80.9%) examined children. A statistically significant difference between the age of examined children (P < 0.02) and intrarectal pressures at the anal canal measuring points (left P < 0.009, right P < 0.005, anterior P < 0.01) was found. Correlation between the residual pressure values in lateral anal canal measurement poles and intrarectal pressure was demonstrated in all types of dyssynergy (left: r = 0.69, P < 0.0005; right: r = 0.74, P < 0.0005). In a group of 53/131 (40.5%) children, 3D HRAM showed a rectal pressure increase during simulated defecation, because of the dysfunction of the puborectalis muscle. CONCLUSION: The increase in sphincter pressure in lateral and posterior poles in I and II types of dyssynergia and in lateral poles in other types of dyssynergia may depend on relaxation disorders of the puborectalis muscle during defecation.