Because of its unique microvascular anatomy, the intestine is particularly vulnerable to microcirculatory disturbances. During inflammation, pathological changes in blood flow, vessel integrity and capillary density result in impaired tissue oxygenation. In severe cases, these changes can progress to multiorgan failure and possibly death. Microcirculation may be evaluated in superficial tissues in patients using video microscopy devices, but these techniques do not allow the assessment of intestinal microcirculation. The gold standard for the experimental evaluation of intestinal microcirculation is intravital microscopy, a technique that allows for the in vivo examination of many pathophysiological processes including leukocyte-endothelial interactions and capillary blood flow. This review provides an overview of changes in the intestinal microcirculation in various acute and chronic inflammatory conditions. Acute conditions discussed include local infections, severe acute pancreatitis, necrotizing enterocolitis and sepsis. Inflammatory bowel disease and irritable bowel syndrome are included as examples of chronic conditions of the intestine.

Embryos of the crustacean Artemia franciscana may arrest as gastrulae, forming cysts that enter diapause, which is a state of reduced metabolism and enhanced stress tolerance. Diapausing cysts survive physiological stresses for years due, in part, to molecular chaperones. p26, a small heat-shock protein, is an abundant diapause-specific molecular chaperone in cysts, and it affects embryo development and stress tolerance. p26 is therefore thought to influence many proteins in cysts, and this study was undertaken to determine how the loss of p26 by RNA interference (RNAi) affects the diapause proteome of A. franciscana. The proteome was analyzed by shot-gun proteomics coupled to differential isotopic labeling and tandem mass spectrometry. Proteins in the diapause proteome included metabolic enzymes, antioxidants, binding proteins, structural proteins, transporters, translation factors, receptors, and signal transducers. Proteins within the diapause proteome either disappeared or were reduced in amount when p26 was knocked down, or conversely, proteins appeared or increased in amount. Those proteins that disappeared may be p26 substrates, whereas the synthesis of those proteins that appeared or increased may be regulated by p26. This study provides the first global characterization of the diapause proteome of A. franciscana and demonstrates that the sHsp p26 influences proteome composition.