Biphasic Release of Insulin from Islets of Langerhans After their Transplantation into the Liver of Rats

Hj, Brömme; Hj, Hahn; Blech, W

doi:10.1055/s-2007-1010777

Cited by 14 publications

(8 citation statements)

References 3 publications

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“…Although numerous laboratories have illustrated that intrahepatic portal-vein islet grafts secrete insulin in response to glucose (17)(18)(19)(20)(21)(22), and that insulin secretion is reduced at low islet numbers (23), this study is the first to demonstrate that AIRg is correlated with the transplanted islet mass. The findings of fasting normoglycemia in these animals are important because even with as few as 500 islets transplanted and an insulin secretion 12.8% that of controls, acute glucose toxicity in the fasting state was not a confounding factor in interpreting insulin secretion results (24)(25)(26).…”

Section: Discussionmentioning

confidence: 79%

Insulin Secretory Function in Relation to Transplanted Islet Mass in STZ-Induced Diabetic Rats

et al. 1993

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In vivo insulin secretion was quantified as the AIRg or AIRa in islet-transplanted rats. Male Wistar-Furth rats previously made diabetic by STZ administration (55 mg/kg) were transplanted with 500, 1000, 2000, or 3000 islets infused into the portal vein (n = 12-14 per group) and were compared with sham-treated controls (CN, n = 16). At 4-5 wk posttransplantation, no significant differences were noted in the FPG or fasting plasma insulin of the experimental groups (P > 0.05). Body weight, however, was 10% less (P < 0.05) in rats receiving 500 islets than in controls, indicating an effect of beta-cell deficiency on growth rates. To determine the relationship between islet mass and insulin secretion, we measured AIRg after a 0.3 g/kg glucose bolus in fasted conscious animals. A significant correlation was observed between the AIRg and islet number (r = 0.61, P = 0.0001), and both 500- and 1000-islet groups could be differentiated from controls by ANOVA (500: 8%; 1000: 12% of controls; P < 0.05). During a glycemic potentiation protocol, AIRa was measured at basal and elevated blood glucose (approximately 16 mM). At neither basal nor elevated blood glucose was AIRa correlated with islet number (basal r = 0.0622, P = 0.7834; elevated r = 0.3133, P = 0.1667). None of the groups could be differentiated by ANOVA (elevated 500: 37%; 1000, 68% of controls; P > 0.05). Although this study illustrates that AIRa may be better preserved in islet-transplanted rats, AIRg is the better correlate of islet number.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Discussionmentioning

confidence: 79%

Insulin Secretory Function in Relation to Transplanted Islet Mass in STZ-Induced Diabetic Rats

et al. 1993

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“…A first phase insulin response to intravenous glucose loading has previously been demonstrated by others for islet grafts to the liver [18,29,30], but was absent with grafts to the kidney [11] or spleen [18]. These studies used bolus injections and the subsequent very fast rise of the insulin levels interferes with visual discernment between the acute and secondary insulin response.…”

Section: Discussionmentioning

confidence: 94%

Insulin secretion by rat islet isografts of a defined endocrine volume after transplantation to three different sites

et al. 1992

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“…There are some previous studies concerning perfusion of graft-bearing livers (25)(26)(27). Those only concluded that a biphasic insulin release from intraportally transplanted islets does occur in response to glucose, but did not compare the response either to native islets or islets implanted to other organs.…”

Section: Discussionmentioning

confidence: 99%

Islets Transplanted Intraportally into the Liver are Stimulated to Insulin and Glucagon Release Exclusively through the Hepatic Artery

Lau¹,

Jansson²,

Carlsson

2006

American Journal of Transplantation

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Not much is known about the physiology of intraportally transplanted islets. One reason for this is that it is difficult to study such islets, since they are scattered throughout the liver. We employed a perfusion technique to characterize the functional properties of syngeneic intrahepatic 1-month-old islet grafts, and compared them to islets transplanted beneath the kidney capsule, as well as native islets. The cellular composition of the islet grafts was also examined. Glucose and arginine administered through the hepatic artery, but not through the portal vein, induced insulin release from the intraportally implanted islets. Moreover, arginine, only when administered through the hepatic artery, induced glucagon release from the same islets. The first phase of glucose-stimulated insulin release from both islets transplanted to the liver and kidney was delayed, and less prominent when compared to the pancreas. Intraportally transplanted islets contained fewer glucagon-positive cells than islets transplanted to the kidney and native islets. Our findings demonstrate that intraportally transplanted islets respond with insulin and glucagon to secretagogues, but only when stimulated through the hepatic artery. Whether intrahepatic islets may sense other substances than glucose or arginine occurring in high concentrations in the portal vein following intestinal uptake remains to be studied.

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Biphasic Release of Insulin from Islets of Langerhans After their Transplantation into the Liver of Rats

Cited by 14 publications

References 3 publications

Insulin Secretory Function in Relation to Transplanted Islet Mass in STZ-Induced Diabetic Rats

Insulin Secretory Function in Relation to Transplanted Islet Mass in STZ-Induced Diabetic Rats

Insulin secretion by rat islet isografts of a defined endocrine volume after transplantation to three different sites

Islets Transplanted Intraportally into the Liver are Stimulated to Insulin and Glucagon Release Exclusively through the Hepatic Artery

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