Islands of Langerhans

Pancreatic B cells are sensitive to reactive oxygen species and this may play an important role in type 1 diabetes and during transplantation. B cells 

The relationship between NO, endothehns, and prostaglandins have been explored in isolated pancreatic tissue from streptozocin-diabetic rats (Gon-zAlez et al. 1999). The addition of nitric oxide synthase inhibitors (1 mM h/°-nitro-L-arginine methyl ester or 600 pM h/°-monomethyl-L-arginine) in the incubating medium reduced and NO donors (300 iM SIN-1 or 100 iM spermine NONOate) increased endothehn levels in pancreatic slices from control and diabetic animals. 

The receptor tyrosine phosphatase-like protein islet cell autoantigen 512 binds the protein domain named for PSD-95, disc large and ZO-1 domains of P2-synthrophin and nNOS in pancreatic B cells (Ort et al. 2000). 

The neuropeptide pituitary adenylate cyclaseactivating polypeptide (1 x lO M) inhibited the reduction of PTC cell viability, NO production, expression of iNOS mRNA, and iNOS promoter activity caused by the combination of three proinflam-matory cytokines (Sekiya etal. 2000). Selective iNOS inhibitors also showed the cytoprotective effect in PTC cells. 

Reactive oxygen species induced within the pancreatic B cells by alloxan are involved in the pathogenesis of type I diabetes mellitus, while extracellular generation of reactive oxygen species by the xanthin-xanthin oxidase system only retarded insulin release from the B cells (Ebelt et al. 1999). Melatonin protected B cells from alloxan-induced lesion in vitro. 

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Blood sugar (blood glucose) in human beings is controlled by the secretion of (—>) insulin by the beta (B- or (3-) cells of the islands of Langerhans in the pancreas. Loss of insulin synthesis leads to (—>) diabetes. Type 1 diabetes (insulin dependent diabetes mellitus, EDDM) begins in juveniles as an organ-specific autoimmune reaction, the destructive insulitis. 

Oakberg, E. F. (1949). Quantitative studies of pancreas and islands of Langerhans in relation to age, sex and body weight in white Leghorn chicken. Am. J. Anat. 84,279. 

Zinc Insulin Crystals. Crystalline preparation of the active antidiabetic principle of the internal secretion of Langerhans islands of the pancreas. The crystals contain a small amount of zinc (not less than 0.45% nor more than 0.9%), which is chemically combined with the active principle. Each milligram nf the crystals is equivalent to not less than 22 units of insulin. The product is marketed in the form of cryst zinc-insulin injection. Study of the binding of zinc by insulin Tanford, Epstein, J. Am. Chem. Soc. 76, 2170 (1954) Cunningham, et al ibid. 77, 5703 (1955). Proposed crystallographic structure Marcker, Graae, Acm Chem. Sea rid. 16, 41 (1962). 

The intraperitoneal injection of streptozotocin to mouse, rat, monkey, and dog induces diabetes. However, when a large amount of nicotinamide is administered before the administration of streptozotocin, the streptozotocin-induced diabetes is inhibited. This is also effective when nicotinamide is administered within 2 hr after the streptozotocin administration (17,18). The NAD content in P-cells of Langerhans islands in the pancreas is reduced by the administration of streptozotocin. However, this decrease does not occur after prior administration of a large amount of nicotinamide (19,20). The decrease in NAD content by streptozo-... 

Insulin is produced in the islets of Langerhans in the pancreas. The name comes from the Latin insula meaning island. Its structure varies slightly between species porcine insulin is especially similar to the human version. Insulin is produced and stored in the body as ahexamer [a unit of six insulin molecules, connected by Zn ions (Figure 3.8), while the active form is the monomer. The hexamer is an inactive form with long-term stability, which serves as a way to keep the highly reactive insulin protected, yet readily available. 

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