(Pro)Insulin Biosynthesis and Secretion of Islets Prepared from Human Pancreas Biopsies

Jahr, H; Lorenz, D; Besch, W; Zühlke, H; Schmidt, Sabine; Lippert, H.; Bibergeil, H

doi:10.1055/s-2007-996207

Cited by 4 publications

(4 citation statements)

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“…In vitro study. Islets of Langerhans for the in vitro experiments were prepared by a combined collagenase digestion/microdissection method (details see Jahr, 1981;Jahr et al, 1980;Jahr et al, 1983) from patients who had undergone a cholecystectomy and in whom pancreatic tissue had been taken for histological examination (for method see Mättig et al, 1983). The informed consent of all patients was obtained.…”

Section: Methodsmentioning

confidence: 99%

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Insulin Secretion in Type II Diabetics: In Vivo and in Vitro Investigation¹)

Hj¹,

Jahr²

2009

Exp Clin Endocrinol Diabetes

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Many cases of type II diabetes present an anomaly of insulin secretion which is characterized by a missing, reduced, or delayed glucose-stimulated insulin output from the beta cell. We aimed at finding out whether this characteristic disorder is a consequence of reduced beta cell mass or of a more functional disturbance. In the latter case it was to be clarified whether the disturbed beta cell "glucoreceptor" function represents a qualitative or rather a quantitative difference. By the evaluation of insulin secretion and of carbohydrate tolerance during oral and/or intravenous intake of glucose, and after intravenous application of tolbutamide or glucagon the defective insulin secretion in type II diabetics was found to represent a more functional disturbance which could not be explained by reduction of beta cell mass. Thus it was concluded that the anomaly of insulin secretion mentioned above might be a consequence of a qualitative defect of the glucoreceptor. To prove this, isolated human islets (insulin secretion under incubation with glucose, measurements of 3H-leucine incorporation and of the insulin content) were also studied. In contrast to the in vivo results, insulin release of the isolated islets of type II diabetics was normal. From this it must be concluded that the glucoreceptor of the beta cell, which in vivo reacts in a qualitatively different manner from that of subjects with intact metabolism, is not irreversibly disturbed.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Methodsmentioning

confidence: 99%

“…All patients were characterized by missing or reduced insulin secretion during an oral glucose load (lOOg). Insulin content, 3H-leucine incorporation into (pro)insulin, and insulin release from the isolated islets were examined (Jahr et al, 1980;Jahr et al, 1983;Lohmann et al, 1980). These data were compared with those under in vivo conditions.…”

Section: Methodsmentioning

confidence: 99%

Insulin Secretion in Type II Diabetics: In Vivo and in Vitro Investigation¹)

Hj¹,

Jahr²

2009

Exp Clin Endocrinol Diabetes

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“…Islets can be isolated from adult human pancreases by using the collagenase digestion technique [98,99,128,257,276,[370][371][372][373][374][375][376]. Isolated human islets can synthetize insulin and glucagon [98, 375,377] and can release insulin in response to in vitro challenge with glucose or other secretagogues [99,276,375,376]. Isolated humans islets have been maintained in tissue culture for several weeks and in vitro evidence of viability has been obtained [257, 372,375].…”

Section: A Preparation and Isolation Of Human Islet Tissuementioning

confidence: 99%

“…Isolated human islets can synthetize insulin and glucagon [98, 375,377] and can release insulin in response to in vitro challenge with glucose or other secretagogues [99,276,375,376]. Isolated humans islets have been maintained in tissue culture for several weeks and in vitro evidence of viability has been obtained [257, 372,375]. Unfortunately, the size, architecture, and compact, fibrous nature of the human pancreas has made the islets separation procedure more difficult than it is in animals and the yields have been low.…”

Section: A Preparation and Isolation Of Human Islet Tissuementioning

confidence: 99%

Pancreas and islet transplantation

Sutherland

1981

Diabetologia

153

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Clinical islet allotransplantation has been a safe, but largely unsuccessful enterprise. It has been difficult to apply techniques that might overcome the islet yield and allograft rejection problems encountered in animal experiments. Over the past decade only 4 of 74 attempts at islet transplantation have been followed by long term withdrawal of exogenous insulin therapy, and there are problems with intrepretation of the outcome in each of theses cases, as discussed in the preceding section. In the islet allograft situation, the failures may have been for technical or for immunological reasons. In the autograft situation, rejection could not occur and the failures were clearly technical. The success rate with islet autografts gives some indication as to what might be achieved with islet allotransplantation if rejection could be prevented in the latter situation. The islet autotransplant experience is not entirely predictative, however, for two reasons: 1) the uncertainty over the contribution of the pancreatic remnant to carbohydrate metabolism when less than the total pancreatectomy is done; 2) the increased difficulty with liberating islets from diseased, fibrotic pancreases. For both islet allo- and autotransplantation, the success rate will probably remain low until more effective techniques are developed for preparation of islets from adult pancreases. For the allograft situation, additional advances will be needed in immunosuppression or in techniques to alter islet graft immunogenicity in order to overcome the rejection phenomenon.

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