title: Stress-strain analysis of contractility in the ileum in response to flow and ramp distension in streptozotocin-induced diabetic rats--association with advanced glycation end product formation.
abstract: This study compared the ileal contractility and analyzed the association between contractility with advanced glycation end product (AGE) formation in normal and streptozotocin (STZ)-induced diabetic rats. Nine STZ-induced diabetic rats (Diabetes group) and 9 normal rats (Normal group) were used. The motility experiments were carried out on ileums in organ baths containing physiological Krebs solution. Ileal pressure and diameter changes were obtained from basic, flow-induced and ramp distension-induced contractions. The frequency and amplitude of contractions were analyzed from pressure-diameter curves. Distension-induced contraction thresholds and maximum contraction amplitude of basic and flow-induced contractions were calculated in terms of stress and strain. AGE and its receptor (RAGE) in the layers were detected by immunohistochemistry staining. The maximum stress of flow-induced contractions was lowest in the Diabetes Group (P<0.05). During ramp distension, the pressure and stress thresholds and Young's modulus to induce phasic contraction were lowest in the Diabetes Group (P<0.05 and P<0.01). AGE and RAGE expressions in the different ileum layers were highest in the Diabetes group. The contraction pressure and stress thresholds were significantly associated with AGE expression in the muscle layer and RAGE expression in mucosa epithelium and neurons. The diabetic intestine was hypersensitive to distension for contraction induction. However, the contraction force produced by smooth muscle was lowest in diabetic rats. Increased AGE/RAGE expression was associated with the contractility changes in diabetic rats.
authors: Institute of Clinical medicine, Aarhus University, Brendstrupgaardsvej 100, Aarhus N 8200, Denmark; GIOME Center, College of Bioengineering, Chongqing University, Chongqing 400045, China.
authors: Jingbo
authors: J
authors: Zhao
authors: Department of Molecular Biology, Institute of Clinical Medicine, China-Japan Friendship Hospital, Beijing 100029, China.
authors: Pengmin
authors: P
authors: Chen
authors: GIOME Center, College of Bioengineering, Chongqing University, Chongqing 400045, China. Electronic address: hag@giome.org.
authors: Hans
authors: H
authors: Gregersen
mesh_terms: D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology*; D004195:Disease Models, Animal; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D007082:Ileum / Q000378:metabolism / Q000503:physiopathology*; D007413:Intestinal Mucosa / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D009130:Muscle, Smooth / Q000378:metabolism / Q000503:physiopathology*; D009474:Neurons / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D000067759:Receptor for Advanced Glycation End Products / Q000378:metabolism; D013311:Streptozocin / Q000009:adverse effects; D013314:Stress, Mechanical
chemical_list: D017127:Glycation End Products, Advanced; D000067759:Receptor for Advanced Glycation End Products; D013311:Streptozocin
keywords: AGE; Contraction; Diabetes; Ileum; RAGE; Stress–strain