Adiponectin affects the mechanical responses in strips from the mouse gastric fundus

AIM To investigate whether the adipocytes derived hormone adiponectin(ADPN) affects the mechanical responses in strips from the mouse gastric fundus. METHODS For functional experiments, gastric strips from the fundal region were cut in the direction of the longitudinal muscle layer and placed in organ baths containing KrebsHenseleit solution. Mechanical responses were recorded via force-displacement transducers, which were coupled to a polygraph for continuous recording of isometric tension. Electrical field stimulation(EFS) was applied via two platinum wire rings through which the preparation was threaded. The effects of ADPN were investigated on the neurally-induced contractile and relaxant responses elicited by EFS. The expression of ADPN receptors, Adipo-R1 and Adipo-R2, was also evaluated by touchdown-PCR analysis. RESULTS In the functional experiments, EFS(4-16 Hz) elicited tetrodotoxin(TTX)-sensitive contractile responses. Addition of ADPN to the bath medium caused a reduction in amplitude of the neurally-induced contractile responses(P < 0.05). The effects of ADPN were no longer observed in the presence of the nitric oxide(NO) synthesis inhibitor L-NG-nitro arginine(L-NNA)(P > 0.05). The direct smooth muscle response to methacholine was not influenced by ADPN(P > 0.05). In carbachol precontracted strips and in the presence of guanethidine, EFS induced relaxant responses. Addition of ADPN to the bath medium, other than causing a slight and progressive decay of the basal tension, increased the amplitude of the neurally-induced relaxant responses(P < 0.05). Touchdown-PCR analysis revealed the expression of both Adipo-R1 and Adipo-R2 in the gastric fundus.CONCLUSION The results indicate for the first time that ADPN is able to influence the mechanical responses in strips from the mouse gastric fundus.

Association between resting energy expenditure, psychopathology and HPA-axis in eating disorders

AIM: To investigate the complex relationships between resting energy expenditure(REE), eating psychopathology, and Hypothalamus Pituitary Adrenal axis functioning in patients with eating disorders. METHODS: The study was designed as a crosssectional survey, and it was planned by the Clinic for Eating Disorders of the University of Florence(Italy). The protocol was approved by the Ethics Committee of the Institution. Twenty two anorexia nervosa and twenty one Bulimia Nervosa patients were assessed by means of a clinical interview and the structured clini-cal interview for diagnostic and statistical manual of mental disorders, fourth edition. Eating attitudes and behaviour were specifically investigated by means of the eating disorder examination questionnaire(EDE-Q). Patients were also evaluated by means of the symptom checklist(SCL 90-R), REE was measured by means of indirect calorimetry, and blood cortisol morning levels were evaluated. RESULTS: Both anorexia nervosa and bulimia nervosa patients showed a reduced REE as compared with predicted REE. Body mass index(BMI) was positively associated with resting energy expenditure in Bulimics, whereas a strong, negative association between BMI and REE was observed in Anorectics. The pattern of associations between variables supported a mediation model, where shape concern accounted for variations in REE and cortisol levels(mediator), and variations in the mediator significantly accounted for variations in REE. When these associations where taken into account together, the relationship between shape concern and REE was no longer significant, whereas the association between cortisol levels and REE retained its significance, showing strong evidence for a single, dominant mediator. Anorectics and Bulimics showed an opposite pattern of association between BMI and REE. In Anorectics only, a higher REE was associated with a more severe eating disorder specific psychopathology, and cortisol levels represent a possible mediating factor for this relationship. CONCLUSION: The data supported a mediation model where cortisol levels mediated the relationship between eating psychopathology(concern about body shape) and REE.