title: Effect of protein concentration on rate of closure of ameroid constrictors in vitro.
abstract: OBJECTIVE
  To evaluate the effect of protein concentration on rate of closure of ameroid constrictors in vitro.
  
  
  METHODS
  Twenty-four 3.5-mm ameroid constrictors.
  
  
  METHODS
  Ameroid constrictors were equally allocated into 4 treatment groups; constrictors were placed in saline (0.9% NaCl) solution (control) or plasma diluted with saline solution to obtain protein concentrations of 1.5, 3, or 6 g/dL. Ameroid constrictors were incubated for 27 days. A digital camera was used to image ameroid constrictors in culture at 1, 6, 11, 16, 21, and 27 days, and the lumen diameter of each constrictor was measured.
  
  
  RESULTS
  None of the rings were completely closed at 27 days. Mean final lumen diameter was 0.205 +/- 0.22 mm. Mean final lumen diameter of constrictors in the control group was significantly larger than that of constrictors in the 1.5, 3, and 6 g/dL groups. Constrictors in the 1.5 g/dL group closed to a larger diameter than that of constrictors in the 6 g/dL group. Constrictors in the control group had the smallest overall change in lumen diameter, compared with constrictors in the 3 and 6 g/dL groups. Constrictors in the 1.5 g/dL group had a significant decrease in overall lumen diameter, compared with constrictors in the 3 and 6 g/dL groups. The diameter of the ameroid lumen was a function of time and protein concentration.
  
  
  CONCLUSIONS
  High plasma protein concentrations resulted in rapid closure of the ameroid constrictor lumen. Complete closure of ameroid constrictors may not be attributable to imbibition of casein.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Monnet
authors.forename: Adam
authors.initials: A
authors.lastname: Rosenberg
mesh_terms: D001672:Biocompatible Materials; D001798:Blood Proteins; D002364:Caseins; D003250:Constriction; D013505:Digestive System Surgical Procedures / Q000295:instrumentation* / Q000662:veterinary; D020100:Hydrogels
chemical_list: D001672:Biocompatible Materials; D001798:Blood Proteins; D002364:Caseins; D020100:Hydrogels; C009719:ameroid