Effects of a protective hydrolyzed casein diet upon the metabolic and secretory responses of pancreatic islets to IL-1 beta, cytokine production by mesenteric lymph node cells, mitogenic and biosynthetic activities in Peyer's patch cells, and mitogenic activity in pancreatic lymph node cells from control and diabetes-prone BB rats

The effects of substituting a plant-based control diabetogenic diet (NIH di et) by a protective hydrolyzed casein diet (HC diet) upon selected metaboli c and functional variables were recently investigated in Peyer's patch cell s, splenocytes, mesenteric lymph node cells, and pancreatic islets from eit her control (BBc) or diabetes-prone (EBdp) EB rats. In the present work, th e plasma D-glucose and insulin concentrations, the protein and insulin cont ent of pancreatic islets, the metabolism of D-glucose, and its insulinotrop ic action in islets first cultured for 24 h in the absence or presence of I L-1 beta, the production of IFN-gamma and IL-10 by mesenteric lymph node ce lls cultured for 48 h in the absence or presence of concanavalin A, the mit ogenic activity of Peyer's patch cells and pancreatic lymph node cells in t he absence or presence of the same lectin, and the biosynthetic activity of Peyer's patch cells were measured in the BBc and BBdp rats fed either the NIH or the HC diet. Two major novel findings emerged from this study. First , in immune cells, diet HC increased to a greater extent the responsiveness to concanavalin A of certain metabolic and functional variables in BBdp ra ts than in BBc rats. Secend, pancreatic islet cells of BBdp rats were less sensitive to IL-1 beta than those of BBc rats and this difference was furth er accentuated when the animals were fed the HC rather than the NIH diet. T hese findings afford further support to the view that, in BE rats, changes in the biological behavior of Peyer's patch cells, mesenteric and pancreati c lymph node cells, and pancreatic islet cells participate in the pathogene sis of insulin-dependent diabetes mellitus and its prevention by a suitable dietary manipulation. (C) 1999 Academic Press.