Development of pancreatic and plasma insulin in prenatal and suckling Zucker rats

Turkenkopf, I. J.; Johnson, Patricia R.; Greenwood, M. R. C.

doi:10.1152/ajpendo.1982.242.4.e220

Cited by 29 publications

(24 citation statements)

References 24 publications

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“…Similarly, rats in which the ventromedial hypothalamus has been destroyed secrete more insulin but this increase is reduced by vagotomy in conjunction with the development of obesity [179]. Finally, a study in obese Zucker rats has shown that hyperinsulinaemia evolves before the onset of obesi-ty [180]. A comparison which was carefully carried out has shown, however, that obese subjects do not have an exaggerated cephalic phase insulin secretion when calculated in per cent of baseline insulin secretion and the net cephalic phase insulin secretion is negatively correlated to body mass index [127].…”

Section: Islet Autonomic Nerves Insulin Resistance Diabetes and Obementioning

confidence: 99%

Autonomic regulation of islet hormone secretion - Implications for health and disease

2000

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Section: Islet Autonomic Nerves Insulin Resistance Diabetes and Obementioning

confidence: 99%

Autonomic regulation of islet hormone secretion - Implications for health and disease

2000

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“…21] To confirm and precise the relationship between UCP2 mRNA and insulin release in vivo, we infused Wistar rats with glucose to provoke hyperinsulinemia and the infusion rate was adjusted to reach plasma insulin levels similar to those of obese fa/fa Zucker rats. When glucose infusion and consequently hyperinsulinemia lasted 5 days, an increase in UCP2 mRNA was observed.…”

Section: Stz Ratsmentioning

confidence: 99%

“…TM Until recently, the contribution of this pathway to the regulation of energy expenditure and ATP synthesis was considered as restricted to neonate mammalians and rodents because BAT is present only in small amounts in non-rodent adult mammalians including humans. 21 The discovery of homologs of UCP i.e.,…”

Section: Introductionmentioning

confidence: 99%

Correlation Between Pancreatic Islet Uncoupling Protein‐2 (UCP2) mRNA Concentration And Insulin Status in Rats

Kassis

Bernard

Pusterla

et al. 2000

Journal of Diabetes Research

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Hypothesizing that UCP2 may influence insulin secretion by modifying the ATP/ADP ratio within pancreatic islets, we have investigated the expression of intraislet UCP2 gene in rats showing insulin oversecretion (non-diabetic Zucker fa/fa obese rats, glucose-infused Wistar rats) or insulin undersecretion (fasting and mildly diabetic rats). We found that in Zucker fa/fa obese rats, hyperinsulinemia (1222 4-98 pmol/1 vs. 128 4-22 pmol/1 in lean Zucker rats) was accompanied by a significant increase in UCP2 mRNA levels. In rat submitted to a 5 day infusion with glucose, hyperinsulinemia (1126 4-101 pmol/l vs. 215 4-25 pmol/1 in Wistar control rats), coincided with an enhanced intraislet UCP2 gene expression, whereas a 8h or a 2 day-infusion did not induce significant changes in UCP2 mRNA expression. In rats made hypoinsulinemic and mildly diabetic by the injection of a low dose of streptozotocin, and in 4-day-fasting rats (plasma insulin 28 4-5 pmol/1) UCP2 (Fig. 1). Plasma insulin was 10-fold higher in obese Zucker rats compared to lean Zucker rats (Fig. 1). Glucose-infused RatsSustained and steady hyperglycemia of about 20mmol/1 was produced in rats infused with glucose during 8h, or 2 days or 5 days. As a result, insulinemia was dramatically increased (Fig. 1). In both hyperglycemic-hyperinsulinemic groups, the glucose and insulin plateaus were reached after 4h of infusion with glucose (data not shown). STZ RatsTwo days after STZ injection, plasma glucose and insulin concentrations were, as compared to controls, significantly increased and decreased, respectively (Fig. 3).Fifteen days after STZ injection, STZ rats were hyperglycemic and hypoinsulinemic compared to control Wistar rats (Figs. 2 and 3). Moreover, glucose tolerance and glucose-induced insulin secretion were impaired as reflected in the AG and the AI/AG, respectively (Fig. 2) histochemistry (Fig. 4) (Fig. 1). Neither a 8h nor a 2-day infusion with glucose did not result in any significant change in UCP2 gene expression, whereas rats infused with glucose during 5 days showed higher UCP2 mRNA levels than controls (Fig. 1). In STZ rats studied 15 days after the injection of the drug, UCP2 mRNA levels were clearly decreased compared to Wistar non diabetic rats (Fig. 2). When the rats were studied 2 days after the injection no change in islet UCP2 gene expression could be observed. Islet UCP2 gene expression was also markedly lowered after a 4-day fast but a 3-day fast failed to alter this parameter (Fig. 2)

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“…Homozygotes (fdfu) display a dramatic obesity with up to 50% of adult body weight as fat. This obesity is characterized by hyperinsulinemia (33), increased fat deposition in all adipose depots, increased fat cell size and cell number (15). and a multitude of metabolic alterations (6,20,23).…”

Section: Introductionmentioning

confidence: 99%

Characteristics of the Obesity Syndrome in Zucker‐Brown Norway (ZBN) Hybrid Rats

et al. 1994

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The existence of a restriction fragment length polymorphism (RFLP) closely linked to the fatty locus between the Zucker (Z) and Brown Norway (BN) rat strains allows evaluation of early effects of the fatty (fa) gene using offspring of back-crosses (N2) between F1 females and Zucker obese males. We examined several metabolic characteristics of N2 animals to determine if these hybrid animals exhibited similar characteristics of the obese syndrome to those of Zucker rats. Females from crosses of obese male Zucker (fdfa) and lean female BN (+/+) rats were back-crossed to their sires, resulting in twelve N2 litters. At 9 weeks of age, liver, spleen, interscapular brown fat (IBAT), and gonadal, retroperitoneal (RP), and inguinal fat depots were removed and weighed. Samples of the RP depot were analyzed for cell size and number. Obese N2 rats were hyperphagic, with body weights in the range of those of obese Zucker rats. Obese N2 rats were also hyperinsulinemic [mean f SEM, pU/ml: females, 7.9 f 0.6 vs. 82.1 f 8.4 (lean vs. obese); males, 10.5 f 1.6 vs. 128.5 f 13.4 (lean vs. obese)] and mildly hyperglycemic [mean f SEM, mg/dl: females, 104.1 f 2.0 vs. 139.0 k 14.7 (lean vs. obese); males, 100.9 _+ 2.6 vs.132.0 f 2.8 (lean vs. obese) p I. 0.051. White fat depots in obese tats were 3 to 7 times heavier than those in lean rats; adipocyte numbers in RP depots were 50% greater in obese than in lean rats; and cell size was more than 3 times larger. IBAT, liver, and spleen were also heavier in obese vs. lean rats, while tail lengths were shorter. Percent lean carcass mass and % carcass protein were about 30% greater in lean vs. obese rats, while % carcass fat in obese rats was 5 times greater than that of lean rats. Thus,

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Development of pancreatic and plasma insulin in prenatal and suckling Zucker rats

Cited by 29 publications

References 24 publications

Autonomic regulation of islet hormone secretion - Implications for health and disease

Autonomic regulation of islet hormone secretion - Implications for health and disease

Correlation Between Pancreatic Islet Uncoupling Protein‐2 (UCP2) mRNA Concentration And Insulin Status in Rats

Characteristics of the Obesity Syndrome in Zucker‐Brown Norway (ZBN) Hybrid Rats

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