Dietary Sucrose Enhances Insulin Secretion of Aging Fischer 344 Rats

Hara, Sally L.; Ruhe, Rodney C.; Curry, Donald L.; McDonald, Roger B.

doi:10.1093/jn/122.11.2196

Cited by 18 publications

(5 citation statements)

References 26 publications

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“…This hypothesis has been supported by observations of age-related increases in peripheral insulin resistance (30, 3 l), decreased glucose tolerance (7,32), and insulin secretion (33,34). However, the data reported here as well as that of some recent investigations have raised questions concerning the validity of this hypothesis (1, 20,21,[35][36][37][38]. For example, we found no significant dlfferences in the IBAT and skeletal muscle glucose utilization in old versus young male and female rats (cold-exposed or non-coldexposed).…”

Section: Ibatsupporting

confidence: 73%

“…That is, although we (19) as well as others (1 1-14) have observed lower plasma insulin levels during cold exposure, skeletal muscle GUI reported here was either unchanged or slightly increased. Furthermore, recent investigations have observed no significant differences in glucose tolerance (20,21) or in skeletal muscle insulin resistance (21,22) of senescent rats. Thus, if a reduction in cold-exposed skeletal muscle thermogenesis does occur in the aging male rat as a result of lower carbohydrate oxidation, it more likely reflects changes in rate or amount of glycogenolysis.…”

Section: Discussionmentioning

confidence: 93%

See 1 more Smart Citation

Age and Gender Effects on Glucose Utilization in Skeletal Muscle and Brown Adipose Tissue of Cold-Exposed Rats

McDonald

Murtagh

Horwitz

1994

Experimental Biology and Medicine

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We hypothesized that glucose utilization by skeletal muscle is less in cold-exposed older male versus female Fischer 344 (F344) rats and that this reduction may contribute to the poorer cold-exposed thermoregulatory ability of the older males. To test this hypothesis, the rates of in vivo glucose utilization of skeletal muscle in 6-, 12-, and 26-month-old male and female F344 rats were estimated during cold exposure by measuring the cellular incorporation of [14C]-2-deoxyglucose ([14C]-2DG) after its conversion to [14C]-2DG-6-phosphate ([14C]-2DGP). Comparable measurements were also made in the interscapular brown fat depot (IBAT). Four-hour fasted rats, that had been fitted with femoral arterial and venous cannulae 24 hr earlier, were exposed to either 26 degrees or 6 degrees C for 2 hr and then received a bolus infusion of [14C]-2DG (125 microCi/kg body wt). Arterial plasma glucose and [14C]-2DG concentrations were measured periodically for an additional 45 min. Rats were sacrificed, and various skeletal muscles and IBAT were removed and immediately frozen in liquid N2 for subsequent analysis of [14C]-2DGP content. Cold-exposed male rats had significantly lower rectal temperatures than comparably treated females (26-month-old male, 34.8 degrees +/- 0.3 degrees; female, 36.1 degrees +/- 0.2 degrees C). There was no main effect of age, gender, or cold exposure on skeletal muscle glucose utilization when the data were expressed as nmol/min/g. In contrast, when data were expressed relative to total tissue weight (nmol/min), skeletal muscle glucose utilization was significantly higher in male than in female rats. Although estimated glucose utilization in IBAT (nmol/min/g) isolated from cold-exposed rats was significantly greater than that in brown fat isolated from non-cold-exposed animals, there was no main effect of age or gender. However, glucose utilization per IBAT depot (nmol/min) was significantly less in older male than in female rats, and reflected the fact that IBAT weight of older males was more than 50% lower than that of comparably aged females. Thus, our hypothesis that reduced skeletal muscle glucose utilization contributes to the blunted thermoregulatory ability of older male versus female F344 rats is negated.(ABSTRACT TRUNCATED AT 400 WORDS)

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Section: Ibatsupporting

confidence: 73%

Section: Discussionmentioning

confidence: 93%

Age and Gender Effects on Glucose Utilization in Skeletal Muscle and Brown Adipose Tissue of Cold-Exposed Rats

McDonald

Murtagh

Horwitz

1994

Experimental Biology and Medicine

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“…However, similar to results from in vivo assessment of insulin secretion in humans, results from in vitro methods have been inconsistent. Some have found decreased (3, 1&22), increased (23,24), or unchanged (25)(26)(27)(28)(29) insulin secretion with age. The various results among in vitro studies of insulin secretion most likely reflect differences in age groups used as comparison for aging rats as well as differences in the definition of senescence in rodents.…”

Section: In Vitro Assessment Of Insulin Secretionmentioning

confidence: 99%

Aging and Insulin Secretion

Coordt¹,

Ruhe²,

McDonald³

1995

Experimental Biology and Medicine

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Aging in mammals has often been associated with decreased insulin secretion and a subsequent deterioration in the ability to maintain glucose homeostasis. However, recent studies have demonstrated that factors such as disease, obesity, and physical activity more closely reflect diminished insulin secretion rather than aging per se. Thus, the purpose of this article is to review recent studies of how biological aging, i.e. the process independent of disease states such as type II diabetes, may affect insulin secretion. To this end, this review will address the impact of aging on insulin secretion in terms of in vivo and in vitro assessment, as well as possible age-related alterations in the hormonal and neural regulation of insulin secretion. Finally, this review describes some evidence that alterations in the functional heterogeneity of the beta-cell population may represent a means by which the endocrine pancreas is able to maintain appropriate insulin secretion during senescence.

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“…In addition, it is currently unclear if age can modify the ability of dietary nutrients to influence insulin action. High-sucrose diet-induced increases in glucosestimulated pancreatic insulin secretion appear to be greater in older (Ͼ12 mo) compared with younger (Ͻ4 mo) rats (11). Chevalier et al (4) demonstrated that a high-sucrose diet (70% by weight) increased serum triglycerides in older (body wt 500 g at start of dietary period) compared with weanling rats.…”

mentioning

confidence: 99%

Developmental stage modifies diet-induced peripheral insulin resistance in rats

Pagliassotti

Gayles²,

Podolin³

et al. 2000

American Journal of Physiology-Regulatory, Integrative and Comp

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In the present study, the effects of age and diet on glucose disappearance and tissue-specific glucose uptake (R'g) were examined under basal or hyperinsulinemic, euglycemic conditions in male Sprague-Dawley rats. Rats were equicalorically fed either a high-starch diet (68% of kcal), high-fat diet (HFD; 45% of kcal), or high-sucrose diet (68% of kcal), beginning at either 5 (W; weanling), 10 (Y; young), 18 (M; mature), or 58 wk (O; older) of age for 5 wks (n = 6-9. group(-1) x diet(-1)). Body weight gain was not significantly different among dietary groups within a given age. Significant (P< 0.05) age effects were observed on basal and clamp free fatty acid concentrations. Significant diet effects were observed on basal and clamp triglyceride concentrations. There were significant diet and age effects on basal skeletal muscle R'g. This interaction was primarily due to an age-associated increase in basal R'g microg x g(-1). min(-1)) in HFD (gastrocnemius R'g: 0.9+/-0.2 in W, 1.1+/-0.2 in Y, 1.8+/-0.2 in M, 2.5+/-0.2 in O). Both age and diet significantly decreased insulin-stimulated muscle R'g. However, whereas age-associated reductions in both glucose-6-phosphate concentration and glycogen synthase activity were observed, significant diet effects were observed on glucose-6-phosphate concentrations only. Age significantly reduced basal and clamp adipose tissue R'g when expressed per gram of tissue but significantly increased R'g when expressed per total fat pad mass. These data suggest that diet-induced changes in peripheral glucose metabolism are modulated by age.

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Dietary Sucrose Enhances Insulin Secretion of Aging Fischer 344 Rats

Cited by 18 publications

References 26 publications

Age and Gender Effects on Glucose Utilization in Skeletal Muscle and Brown Adipose Tissue of Cold-Exposed Rats

Age and Gender Effects on Glucose Utilization in Skeletal Muscle and Brown Adipose Tissue of Cold-Exposed Rats

Aging and Insulin Secretion

Developmental stage modifies diet-induced peripheral insulin resistance in rats

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