scholarly journals Glucocorticoids attenuate the central sympathoexcitatory actions of insulin

2014 ◽  
Vol 112 (10) ◽  
pp. 2597-2604 ◽  
Author(s):  
Jennifer L. Steiner ◽  
Megan E. Bardgett ◽  
Lawrence Wolfgang ◽  
Charles H. Lang ◽  
Sean D. Stocker
Keyword(s):  
Food Intake ◽  
Mammalian Target Of Rapamycin ◽  
Chronic Administration ◽  
Sprague Dawley ◽  
Sympathetic Function ◽  
Sprague Dawley Rats ◽  
Access To Water ◽  
The Central Nervous System ◽  
Regulate Food Intake ◽  
Few Data

Insulin acts within the central nervous system to regulate food intake and sympathetic nerve activity (SNA). Strong evidence indicates that glucocorticoids impair insulin-mediated glucose uptake and food intake. However, few data are available regarding whether glucocorticoids also modulate the sympathoexcitatory response to insulin. Therefore, the present study first confirmed that chronic administration of glucocorticoids attenuated insulin-induced increases in SNA and then investigated whether these effects were attributed to deficits in central insulin-mediated responses. Male Sprague-Dawley rats were given access to water or a drinking solution of the glucocorticoid agonist dexamethasone (0.3 μg/ml) for 7 days. A hyperinsulinemic-euglycemic clamp significantly increased lumbar SNA in control rats. This response was significantly attenuated in rats given access to dexamethasone for 7, but not 1, days. Similarly, injection of insulin into the lateral ventricle or locally within the arcuate nucleus (ARC) significantly increased lumbar SNA in control rats but this response was absent in rats given access to dexamethasone. The lack of a sympathetic response to insulin cannot be attributed to a generalized depression of sympathetic function or inactivation of ARC neurons as electrical activation of sciatic afferents or ARC injection of gabazine, respectively, produced similar increases in SNA between control and dexamethasone-treated rats. Western blot analysis indicates insulin produced similar activation of Akt Ser473 and rpS6 Ser240/244 in the ventral hypothalamus of control and dexamethasone-treated rats. Collectively, these findings suggest that dexamethasone attenuates the sympathoexcitatory actions of insulin through a disruption of ARC neuronal function downstream of Akt or mammalian target of rapamycin (mTOR) signaling.

Chronic administration of OB protein decreases food intake by selectively reducing meal size in male rats

1998 ◽  
Vol 275 (1) ◽  
pp. R180-R185 ◽  
Author(s):  
Andrea Kahler ◽  
Nori Geary ◽  
Lisa A. Eckel ◽  
L. Arthur Campfield ◽  
Françoise J. Smith ◽  
...  
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Body Weight Gain ◽  
Chronic Administration ◽  
Meal Size ◽  
Male Rats ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Ad Libitum ◽  
Ob Protein

The potent hypophagic effect of OB protein (OB) is well established, but the mechanism of this effect is largely unknown. We investigated the effects of chronic administration of a novel modified recombinant human OB (Mod-OB) with a prolonged half-life (>48 h) on ad libitum food intake, spontaneous meal patterns, and body weight in 24 adult, male Sprague-Dawley rats (body weight at study onset: 292 g). Single daily subcutaneous injections of Mod-OB (4 mg/kg daily) for 8 consecutive days significantly reduced ad libitum food intake compared with vehicle injections from injection day 3through postinjection day 3. Mod-OB-injected rats ate between 4.5 and 7.1 g (or 13–20%) per day less than controls, with the reduction primarily occurring during the dark period. Body weight gain was significantly decreased in response to Mod-OB from injection day 8until postinjection day 4, with a maximum difference of 24 g on postinjection day 3. The reduction of food intake by Mod-OB was mainly due to a 21–34% decrease in nocturnal spontaneous meal size. There was no significant effect of Mod-OB on nocturnal meal frequency or duration. Mod-OB also did not reliably affect the size, duration, or frequency of diurnal meals. Mod-OB-injected rats displayed no compensatory hyperphagia after the injection period. These results indicate that chronically administered OB selectively affects the mechanisms controlling meal size in male rats.

Central KATP channels modulate glucose effectiveness in humans and rodents

2020 ◽  
Author(s):  
Ada Admin ◽  
Michelle Carey ◽  
Eric Lontchi-Yimagou ◽  
William Mitchell ◽  
Sarah Reda ◽  
...  
Keyword(s):  
Katp Channel ◽  
Glucose Production ◽  
Katp Channels ◽  
Endogenous Glucose Production ◽  
Elevated Plasma ◽  
Sprague Dawley ◽  
Glucose Effectiveness ◽  
Sprague Dawley Rats ◽  
The Central Nervous System

Hyperglycemia is a potent regulator of endogenous glucose production (EGP). Loss of this ‘glucose effectiveness’ is a major contributor to elevated plasma glucose concentrations in type 2 diabetes (T2D). ATP-sensitive potassium channels (K<sub>ATP</sub> channels) in the central nervous system (CNS) have been shown to regulate EGP in humans and rodents. We examined the contribution of central K<sub>ATP</sub> channels to glucose effectiveness. Under fixed hormonal conditions (‘pancreatic clamp’ studies), hyperglycemia suppressed EGP by ~50% in both non-diabetic humans and normal Sprague Dawley rats. By contrast, antagonism of K<sub>ATP</sub> channels with glyburide significantly reduced the EGP-lowering effect of hyperglycemia in both humans and rats. Furthermore, the effects of glyburide on EGP and gluconeogenic enzymes in rats were abolished by intracerebroventricular (ICV) administration of the KATP channel agonist diazoxide. These findings indicate that about half of EGP suppression by hyperglycemia is mediated by central K<sub>ATP</sub> channels. These central mechanisms may offer a novel therapeutic target for improving glycemic control in T2D.

scholarly journals CCK-8 and CCK-58 differ in their effects on nocturnal solid meal pattern in undisturbed rats

2012 ◽  
Vol 303 (8) ◽  
pp. R850-R860 ◽  
Author(s):  
Miriam Goebel-Stengel ◽  
Andreas Stengel ◽  
Lixin Wang ◽  
Gordon Ohning ◽  
Yvette Taché ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Food Intake ◽  
Molecular Forms ◽  
Reduce Food Intake ◽  
Dark Phase ◽  
Sprague Dawley ◽  
Solid Meal ◽  
Sprague Dawley Rats ◽  
And Behavior

Various molecular forms of CCK reduce food intake in rats. Although CCK-8 is the most studied form, we reported that CCK-58 is the only detectable endocrine peptide form in rats. We investigated the dark-phase rat chow intake pattern following injection of CCK-8 and CCK-58. Ad libitum-fed male Sprague-Dawley rats were intraperitoneally injected with CCK-8, CCK-58 (0.6, 1.8, and 5.2 nmol/kg), or vehicle. Food intake pattern was assessed during the dark phase using an automated weighing system that allowed continuous undisturbed monitoring of physiological eating behavior. Both CCK-8 and CCK-58 dose dependently reduced 1-h, dark-phase food intake, with an equimolar dose of 1.8 nmol being similarly effective (−49% and −44%). CCK-58 increased the latency to the first meal, whereas CCK-8 did not. The intermeal interval was reduced after CCK-8 (1.8 nmol/kg, −41%) but not after CCK-58. At this dose, CCK-8 increased the satiety ratio by 80% and CCK-58 by 160%, respectively, compared with vehicle. When behavior was assessed manually, CCK-8 reduced locomotor activity (−31%), whereas grooming behavior was increased (+59%). CCK-58 affected neither grooming nor locomotor activity. In conclusion, reduction of food intake by CCK-8 and CCK-58 is achieved by differential modulation of food intake microstructure and behavior. These data highlight the importance of studying the molecular forms of peptides that exist in vivo in tissue and circulation of the animal being studied.

Appetite suppressant activity in plasma of rats after intestinal bypass surgery

1982 ◽  
Vol 243 (1) ◽  
pp. R60-R64 ◽  
Author(s):  
R. L. Atkinson ◽  
E. L. Brent
Keyword(s):  
Food Intake ◽  
Polymorphonuclear Leukocytes ◽  
Bypass Surgery ◽  
Aversive Conditioning ◽  
Jejunoileal Bypass ◽  
Intestinal Bypass ◽  
Sprague Dawley ◽  
Appetite Suppressant ◽  
Sprague Dawley Rats ◽  
Subsequent Intake

Male Sprague-Dawley rats with a jejunoileal bypass ate 32% less in the 1st h of refeeding after an overnight fast than did sham-bypass rats. Fasted recipients injected intraperitoneally with 6-7 ml of bypass plasma also ate 32% less (P less than 0.001) during the 1st h of refeeding than did recipients of sham-bypass plasma, but subsequent intake was not significantly different. Rectal temperature, hematocrit, white blood cell count, and percent polymorphonuclear leukocytes were not different between bypass and sham-bypass rats. A test for aversive conditioning suggested that the effect of bypass plasma was not due to illness or discomfort. These data suggest that intestinal bypass produces a transferable humoral factor that suppresses food intake and that the effect is not due to illness or discomfort. If the decreased food intake in humans after intestinal bypass is due to a similar mechanism, the possibility exists that this humoral appetite-suppressant factor may be clinically useful in the treatment of morbid obesity.

scholarly journals Effect of fish paste products, fish balls ‘tsumire’, intake in Sprague–Dawley rats

2021 ◽  
Vol 10 ◽  
Author(s):  
Kazunari Kadokura ◽  
Tsuyoshi Tomita ◽  
Kohei Suruga
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Health Management ◽  
Scientific Evidence ◽  
Inorganic Phosphorus ◽  
Organ Weight ◽  
Sprague Dawley ◽  
Group I ◽  
Sprague Dawley Rats ◽  
Group Ii

Abstract The fish paste product, fish balls ‘tsumire’, is a traditional type of Japanese food made from minced fish as well as imitation crab, kamaboko and hanpen. Although tsumire is known as a high-protein and low-fat food, there is a lack of scientific evidence on its health benefits. Hence, we aimed to investigate the effects of tsumire intake on organ weight and biomarker levels in Sprague–Dawley rats for 84 d as a preliminary study. Six-week-old male Sprague–Dawley rats were divided into two groups: group I, fed normal diets, and group II, fed normal diets with 5 % dried tsumire. Throughout the administration period, we monitored their body weight and food intake; at the end of this period, we measured their organ weight and analysed their blood biochemistry. No significant differences were observed with respect to body weight, food intake, organ weight and many biochemical parameters between the two groups. It was found that inorganic phosphorus and glucose levels were higher in group II rats than in group I rats. On the other hand, sodium, calcium, amylase and cholinesterase levels were significantly lower in group II than in group I. Interestingly, we found that the levels of aspartate aminotransferase, alanine transaminase, lactate dehydrogenase and leucine aminopeptidase in group II were significantly lower than in group I, and that other liver function parameters of group II tended to be lower than in group I. In conclusion, we consider that the Japanese traditional food, ‘tsumire,’ may be effective as a functional food for human health management worldwide.

Whey protein, as exclusively nitrogen source, controls food intake and promotes glutathione antioxidant protection in Sprague-Dawley rats

2008 ◽  
Vol 1 (2) ◽  
pp. 109-116 ◽  
Author(s):  
Samir G. Sukkar ◽  
Franca Cella ◽  
Stefania Patriarca ◽  
Anna L. Furfaro ◽  
Francesca Abate ◽  
...  
Keyword(s):  
Food Intake ◽  
Nitrogen Source ◽  
Whey Protein ◽  
Antioxidant Protection ◽  
Sprague Dawley ◽  
Sprague Dawley Rats

Regional effect of naltrexone in the nucleus of the solitary tract in blockade of NPY-induced feeding

2000 ◽  
Vol 278 (2) ◽  
pp. R499-R503 ◽  
Author(s):  
C. M. Kotz ◽  
M. J. Glass ◽  
A. S. Levine ◽  
C. J. Billington
Keyword(s):  
Cerebrospinal Fluid ◽  
Food Intake ◽  
Paraventricular Nucleus ◽  
Opioid Receptors ◽  
The Other ◽  
Solitary Tract ◽  
Sprague Dawley ◽  
Regional Effect ◽  
Sprague Dawley Rats ◽  
Artificial Cerebrospinal Fluid

Naltrexone (NLTX) in the nucleus of the solitary tract (NTS) decreases feeding induced by neuropeptide Y (NPY) in the paraventricular nucleus (PVN). We sought to determine the NTS region most sensitive to NLTX blockade of PVN NPY-induced feeding. Male Sprague-Dawley rats were fitted with two cannulas; one in the PVN and one in a hindbrain region: caudal, medial, or rostral NTS or 1 mm outside the NTS. Animals received NLTX (0, 1, 3, 10, and 30 μg in 0.3 μl) into the hindbrain region just prior to PVN NPY (0.5 μg, 0.3 μl) or artificial cerebrospinal fluid (0.3 μl). Food intake was measured at 2 h following injection. PVN NPY stimulated feeding, and NLTX in the medial NTS significantly decreased NPY-induced feeding at 2 h, whereas administration of NLTX in the other hindbrain regions did not significantly influence PVN NPY induced feeding. These data suggest that opioid receptors in the medial NTS are most responsive to feeding signals originating in the PVN after NPY stimulation.

scholarly journals Investigation of hemotoxicologic potential of an ayurvedic preparation Kutajarista used in Sprue syndrome after chronic administration to male Sprague-Dawley rats

2020 ◽  
Vol 14 (8) ◽  
pp. 308-315
Author(s):  
Tohidul Amin Mohammad ◽  
Fatema Kaniz ◽  
karmakar Palash ◽  
Abdur Rahman Md. ◽  
Haque Tazmel ◽  
...  
Keyword(s):  
Chronic Administration ◽  
Sprague Dawley ◽  
Sprague Dawley Rats

Acute cyclosporine-induced renal vasoconstriction: lack of effect of theophylline

1990 ◽  
Vol 258 (1) ◽  
pp. F41-F45
Author(s):  
P. C. Churchill ◽  
N. F. Rossi ◽  
M. C. Churchill ◽  
A. K. Bidani ◽  
F. D. McDonald
Keyword(s):  
Renal Plasma Flow ◽  
Left Kidney ◽  
Chronic Administration ◽  
Sprague Dawley ◽  
Renal Vasoconstriction ◽  
Adenosine Receptor Antagonist ◽  
Arterial Blood ◽  
Sprague Dawley Rats ◽  
Group 1

Both acute and chronic administration of cyclosporine A (CSA) lead to renal vasoconstriction, but the mechanism is not fully understood. The present studies were designed to explore the possible role of adenosine in acute CSA-induced renal vasoconstriction in rats. Six groups of anesthetized Sprague-Dawley rats were studied using standard clearance techniques: group 1 rats were controls; groups 2, 4, and 6 received CSA intravenously at 20, 30, and 40 mg.h-1.kg body wt-1, respectively; groups 3 and 5 were identical to groups 2 and 4 except that a priming injection of theophylline was given (56 mumol/kg body wt) and theophylline was included in the intravenous infusate (0.56 mumol.min-1.kg body wt-1). CSA produced acute and concentration-dependent reductions in renal plasma flow (left kidney) and in the clearances of p-aminohippuric acid and inulin (both kidneys). Except in group 6, these changes were observed in the absence of a decrease in arterial blood pressure, demonstrating that CSA produced an acute and concentration-dependent increase in renovascular resistance. Theophylline not only failed to block CSA-induced renal vasoconstriction, if anything, it potentiated it. Because theophylline is an adenosine receptor antagonist, these findings contradict the hypothesis that adenosine mediates acute CSA-induced renal vasoconstriction.

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