Insulin secretion decline in Walker-256 tumor-bearing rats is early, follows the course of cachexia, and is not improved by lixisenatide

The effect of cachexia on insulin secretion was examined in adult male rats. Isolated islets of Langerhans from Walker 256 tumor-bearing rats secreted less insulin by glucose stimuli as compared with the control group; this was accompanied by significant change in 45Ca2+ outflow rate. Reduced insulin secretion to glucose stimuli in tumor-bearing rats probably led to low insulinemia (one-third). These findings indicate that reduced insulin secretion is probably an important factor for the development of cachexia in Walker 256 tumor-bearing rats.

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Impairment of insulin secretion in pancreatic islets isolated from Walker 256 tumor-bearing rats

AJP Cell Physiology ◽

10.1152/ajpcell.1996.271.3.c804 ◽

1996 ◽

Vol 271 (3) ◽

pp. C804-C809 ◽

Cited By ~ 21

Author(s):

S. el Razi Neto ◽

T. M. Zorn ◽

R. Curi ◽

A. R. Carpinelli

Keyword(s):

Insulin Secretion ◽

Phosphoinositide Metabolism ◽

High Potassium ◽

Tumor Bearing ◽

Voltage Dependent ◽

Outflow Rate ◽

Voltage Dependent Calcium Channels ◽

Walker 256 ◽

And Control ◽

Walker 256 Tumor

Previous study has shown that insulin secretion in response to a glucose stimulus (16.7 mM) is reduced in islets isolated from Walker 256 tumor-bearing rats compared with controls. The ultrastructure, 45Ca2+ and 86Rb+ fractional outflow rate, phosphoinositide hydrolysis, and [U-14C]glucose decarboxylation were examined in islets isolated from tumor-bearing and control rats. The general morphological features of the islets from the control and experimental groups were very similar. The 86Rb+ fractional outflow rate was not changed, whereas the 45Ca2+ fractional outflow rate, [U-14C]glucose decarboxylation, and phosphoinositide metabolism were markedly reduced in islets from tumor-bearing rats. The changes in 45Ca2+ fractional outflow rate in islets from tumor-bearing rats were not due to impaired functioning of voltage-dependent calcium channels. By perifusing the islets in the presence of high potassium concentration, evidence was obtained that phospholipase C from islets from tumor-bearing rats reduced response to calcium. To further examine the mechanism involved in the impairment of insulin secretion by islets from tumor-bearing rats, islets isolated from normal rats were perifused after preincubation in the presence of serum from tumor-bearing rats. The results suggest that a thermolabile circulating factor is partially responsible for the changes described in islets isolated from Walker 256 tumor-bearing rats.

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Aerobic Exercise Training Attenuates Tumor Growth and Reduces Insulin Secretion in Walker 256 Tumor-Bearing Rats

Frontiers in Physiology ◽

10.3389/fphys.2018.00465 ◽

2018 ◽

Vol 9 ◽

Cited By ~ 5

Author(s):

Veridiana Mota Moreira ◽

Claudinéia Conationi da Silva Franco ◽

Kelly Valério Prates ◽

Rodrigo Mello Gomes ◽

Ana Maria Praxedes de Moraes ◽

...

Keyword(s):

Insulin Secretion ◽

Exercise Training ◽

Tumor Growth ◽

Aerobic Exercise ◽

Aerobic Exercise Training ◽

Tumor Bearing ◽

Walker 256 ◽

Walker 256 Tumor

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Nocturnal depletion of hypothalamic dynorphin in anorexic walker-256 tumor-bearing rats

Pharmacology Biochemistry and Behavior ◽

10.1016/0091-3057(88)90017-2 ◽

1988 ◽

Vol 29 (3) ◽

pp. 541-545 ◽

Cited By ~ 4

Author(s):

T.D. Steele ◽

H.U. Bryant ◽

P.V. Malven ◽

G.K.W. Yim

Keyword(s):

Tumor Bearing ◽

Walker 256 ◽

Walker 256 Tumor

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l-Glutamine supplementation promotes an improved energetic balance in Walker-256 tumor–bearing rats

Tumor Biology ◽

10.1177/1010428317695960 ◽

2017 ◽

Vol 39 (3) ◽

pp. 101042831769596 ◽

Cited By ~ 6

Author(s):

Heber Amilcar Martins ◽

Roberto Barbosa Bazotte ◽

Geraldo Emilio Vicentini ◽

Mariana Machado Lima ◽

Flavia Alessandra Guarnier ◽

...

Keyword(s):

Phosphoenolpyruvate Carboxykinase ◽

Experimental Period ◽

Plasma Corticosterone ◽

Glutamine Supplementation ◽

Tumor Bearing ◽

Male Wistar Rats ◽

Energetic Balance ◽

Walker 256 ◽

Immunohistochemical Techniques ◽

Walker 256 Tumor

We evaluated the effects of supplementation with oral l-glutamine in Walker-256 tumor–bearing rats. A total of 32 male Wistar rats aged 54 days were randomly divided into four groups: rats without Walker-256 tumor, that is, control rats (C group); control rats supplemented with l-glutamine (CG group); Walker-256 tumor rats without l-glutamine supplementation (WT group); and WT rats supplemented with l-glutamine (WTG group). l-Glutamine was incorporated into standard food at a proportion of 2 g/100 g (2%). After 10 days of the experimental period, the jejunum and duodenum were removed and processed. Protein expression levels of key enzymes of gluconeogenesis, that is, phosphoenolpyruvate carboxykinase and glucose-6-phosphatase, were analyzed by western blot and immunohistochemical techniques. In addition, plasma corticosterone, glucose, insulin, and urea levels were evaluated. The WTG group showed significantly increased plasma glucose and insulin levels ( p < 0.05); however, plasma corticosterone and urea remained unchanged. Moreover, the WTG group showed increased immunoreactive staining for jejunal phosphoenolpyruvate carboxykinase and increased expression of duodenal glucose-6-phosphatase. Furthermore, the WTG group presented with less intense cancer cachexia and slower tumor growth. These results could be attributed, at least partly, to increased intestinal gluconeogenesis and insulinemia, and better glycemia maintenance during fasting in Walker-256 tumor rats on a diet supplemented with l-glutamine.

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