Biomechanical and morphometric intestinal remodelling during experimental diabetes in rats.
OBJECTIVE
Morphometric and passive biomechanical properties were studied in the duodenum, jejunum and ileum in 10 non-diabetic and 40 streptozotocin-induced diabetic rats.


METHODS
The diabetic rats were divided into groups living 4 days, 1, 2, and 4 weeks after diabetes was induced ( n=10 for each groups). The mechanical test was done as a ramp distension experiment. The intestinal diameter and length were obtained from digitised images of the intestinal segments at pre-selected pressures and at no-load and zero-stress states. Circumferential and longitudinal stresses (force per area) and strains (deformation) were computed from the length, diameter and pressure data and from the zero-stress state geometry.


RESULTS
The blood glucose concentration increased four- to fivefold in the diabetic rats. Streptozotocin-induced diabetes generated pronounced increase in the weight per centimetre length, wall thickness and wall cross-sectional area in all intestinal segments during diabetes ( p<0.05). Histological analysis showed that the thickness of the intestinal layers was increased in all segments during diabetes ( p<0.05). In the duodenum the opening angle did not change in the first 2 weeks and decreased after 4 weeks ( p<0.05). In the jejunum and ileum the opening angle increased after 1 week in the diabetic group. The residual strain showed the same pattern as the opening angle. Furthermore, it was found that the circumferential and longitudinal stiffness of the intestinal wall increased with the duration of diabetes ( p<0.05 and p<0.01).


CONCLUSIONS
Morphological and biomechanical remodelling of the small intestine occurred during the development of diabetes.
Centre of Sensory-Motor Interaction, Aalborg University, Denmark.
J
J
Zhao
J
J
Yang
H
H
Gregersen
D000818:Animals; D001696:Biomechanical Phenomena; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D004195:Disease Models, Animal; D004386:Duodenum; D005769:Gastrointestinal Motility / Q000502:physiology*; D007082:Ileum; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000503:physiopathology; D007421:Intestine, Small / Q000503:physiopathology*; D007583:Jejunum; D008297:Male; D008871:Microvilli / Q000648:ultrastructure; D008954:Models, Biological; D051381:Rats; D017208:Rats, Wistar; D013314:Stress, Mechanical
D001786:Blood Glucose