Elevated hypothalamic orexin signaling, sensitivity to orexin A, and spontaneous physical activity in obesity-resistant rats

2006 ◽  
Vol 291 (4) ◽  
pp. R889-R899 ◽  
Author(s):  
J. A. Teske ◽  
A. S. Levine ◽  
M. Kuskowski ◽  
J. A. Levine ◽  
C. M. Kotz
Keyword(s):  
Gene Expression ◽  
Physical Activity ◽  
Caloric Intake ◽  
Sprague Dawley ◽  
Rt Pcr ◽  
Orexin A ◽  
Daily Caloric Intake ◽  
Behavioral Studies ◽  
Sprague Dawley Rats ◽  
Spontaneous Physical Activity

Selectively-bred obesity-resistant [diet resistant (DR)] rats weigh less than obesity-prone [diet-induced obese (DIO)] rats, despite comparable daily caloric intake, suggesting phenotypic energy expenditure differences. Human data suggest that obesity is maintained by reduced ambulatory or spontaneous physical activity (SPA). The neuropeptide orexin A robustly stimulates SPA. We hypothesized that DR rats have greater: 1) basal SPA, 2) orexin A-induced SPA, and 3) preproorexin, orexin 1 and 2 receptor (OX1R and OX2R) mRNA, compared with DIO rats. A group of age-matched out-bred Sprague-Dawley rats were used as additional controls for the behavioral studies. DIO, DR, and Sprague-Dawley rats with dorsal-rostral lateral hypothalamic (rLHa) cannulas were injected with orexin A (0, 31.25, 62.5, 125, 250, and 500 pmol/0.5 μl). SPA and food intake were measured for 2 h after injection. Preproorexin, OX1R and OX2R mRNA in the rLHa, and whole hypothalamus were measured by real-time RT-PCR. Orexin A significantly stimulated feeding in all rats. Orexin A-induced SPA was significantly greater in DR and Sprague-Dawley rats than in DIO rats. Two-mo-old DR rats had significantly greater rLHa OX1R and OX2R mRNA than DIO rats but comparable preproorexin levels. Eight-mo-old DR rats had elevated OX1R and OX2R mRNA compared with DIO rats, although this increase was significant for OX2R only at this age. Thus DR rats show elevated basal and orexin A-induced SPA associated with increased OX1R and OX2R gene expression, suggesting that differences in orexin A signaling through OX1R and OX2R may mediate DIO and DR phenotypes.

Effect of acute and chronic caloric restriction and metabolic glucoprivation on spontaneous physical activity in obesity-prone and obesity-resistant rats

2009 ◽  
Vol 297 (1) ◽  
pp. R176-R184 ◽  
Author(s):  
J. A. Teske ◽  
C. M. Kotz
Keyword(s):  
Physical Activity ◽  
Caloric Restriction ◽  
Phenotypic Traits ◽  
Time Interval ◽  
Sprague Dawley ◽  
Orexin A ◽  
Time Period ◽  
Sprague Dawley Rats ◽  
Spontaneous Physical Activity

Caloric restriction (CR) and metabolic glucoprivation affect spontaneous physical activity (SPA), but it's unknown whether these treatments similarly affect SPA in selectively bred obesity-prone (OP) and -resistant (OR) rats. OR rats have greater basal SPA and are more responsive to treatments that modulate SPA, such as orexin A administration. We hypothesized that OR rats would be more sensitive to other treatments modulating SPA. To test this, continuous 24-h SPA was measured before and during acute (24 h) and chronic (8 wk) CR in OR, OP, and Sprague-Dawley rats. Pharmacological glucoprivation was produced by injection of 2-deoxyglucose (2-DG), and SPA was measured 5 h postinjection. Acute CR increased SPA in all groups; however, the effect was dependent on the index of SPA and time interval during the 24-h time period. In contrast to OR rats, chronic CR increased distance traveled, ambulatory episodes, and time spent in ambulation and stereotypy during the time interval preceding anticipation of food in OP and Sprague-Dawley rats. Although the effects of 2-DG treatment on SPA were minimal, OR rats had significantly greater SPA than OP and Sprague-Dawley rats independent of treatment. That chronic CR failed to result in significant changes in SPA in OR rats suggests that these rats may be especially unresponsive to treatments modulating feeding. This insensitivity coupled with elevated basal SPA levels may in part mediate phenotypic traits of lean rats.

scholarly journals Behavioral responses to orexin, orexin receptor gene expression, and spontaneous physical activity contribute to individual sensitivity to obesity

2012 ◽  
Vol 303 (7) ◽  
pp. E865-E874 ◽  
Author(s):  
Claudio E. Perez-Leighton ◽  
Kelsey Boland ◽  
Jennifer A. Teske ◽  
Charles Billington ◽  
Catherine M. Kotz
Keyword(s):  
Physical Activity ◽  
Receptor Gene ◽  
Caloric Intake ◽  
Receptor Expression ◽  
Energetic Cost ◽  
Sprague Dawley ◽  
Orexin A ◽  
Orexin Receptors ◽  
Before And After ◽  
Spontaneous Physical Activity

There is significant variability in diet-induced obesity (DIO) among humans and rodents, which has been associated with differences in intrinsic spontaneous physical activity (SPA). The orexin neuropeptides positively modulate SPA through multiple brain sites, but the effects of DIO on orexin's activity are not well understood. In this study, we tested the hypothesis that DIO sensitivity is mediated by decreased SPA and changes in the function of the orexins. As a DIO model, we used male Sprague-Dawley rats fed a high-fat (HF; 45% kcal from fat) or a low-fat (LF; 10% kcal from fat) diet for 10 wk. We measured SPA before and after HF or LF feeding and expression of orexin receptors by real-time PCR after dietary treatments. We tested DIO effects on orexin signaling by measuring SPA after injection of orexin A in the rostral lateral hypothalamus (RLH) before and after 10 wk of HF feeding. Finally, we tested whether daily orexin A RLH injections prevent DIO caused by HF feeding. Our results show that resistance to DIO is associated with an increase in SPA, SPA after injection of orexin A in RLH, and orexin receptor expression in sites that mediate orexin's effect on SPA, including RLH. We show that daily injections of orexin peptide in RLH prevent DIO without altering food intake. We estimate that the energetic cost of SPA after orexin A RLH injection accounts for approximately 61% of the extra caloric intake associated with HF intake, suggesting additional effects of orexins. In summary, our results suggest that variability in DIO sensitivity is mediated through adaptations in the activity of the orexin peptides and their receptors.

scholarly journals Role of the locus coeruleus in enhanced orexin A-induced spontaneous physical activity in obesity-resistant rats

2013 ◽  
Vol 305 (11) ◽  
pp. R1337-R1345 ◽  
Author(s):  
Jennifer A. Teske ◽  
Claudio E. Perez-Leighton ◽  
Charles J. Billington ◽  
Catherine M. Kotz
Keyword(s):  
Physical Activity ◽  
Locus Coeruleus ◽  
Expression Pattern ◽  
Principal Component ◽  
Brain Regions ◽  
Sprague Dawley ◽  
Orexin A ◽  
Orexin Receptors ◽  
Sprague Dawley Rats ◽  
Spontaneous Physical Activity

Orexin/hypocretin terminals innervate noradrenergic locus coeruleus (LC) neurons that project to the prefrontral cortex, which may influence spontaneous physical activity (SPA) and energy balance. Obesity-resistant (OR) rats have higher orexin receptors (OXR) mRNA in the LC and other brain regions, as well as lower adiposity compared with obese rats. These findings led us to hypothesize that orexin activity in the LC is relevant for the OR phenotype. We compared OR rats to Sprague-Dawley rats. We predicted that: 1) brain OXR expression pattern is sufficient to differentiate OR from non-bred Sprague-Dawley rats; 2) nonresting energy expenditure (NREE) and orexin A (OXA)-stimulated SPA after injection in LC would be greater in OR rats; and 3) the effect of OXA on SPA would be greater than its effect on feeding. OXR mRNA from 11 brain sites and the SPA and feeding responses to OXA in the LC were determined. Body composition, basal SPA, and EE were determined. Principal component analysis of the OXR expression pattern differentiates OR and Sprague-Dawley rats and suggests the OXR mRNA in the LC is important in defining the OR phenotype. Compared with Sprague-Dawley rats, OR rats had greater SPA and NREE and lower resting EE and adiposity. SPA responsivity to OXA in the LC was greater in OR rats compared with Sprague-Dawley rats. OXA in the LC did not stimulate feeding in OR or Sprague-Dawley rats. These data suggest that the LC is a prominent site modulating OXA-stimulated SPA, which promotes lower adiposity and higher nonresting EE.

Local mechanisms for acupoint sensitization in gall bladder meridian of foot shaoyang-a gene chip study

2019 ◽  
Vol 44 (2) ◽  
pp. 77-87
Author(s):  
Koichi Ishida ◽  
Liyue Qin ◽  
Ting Wang ◽  
Ying Lei ◽  
Weiwei Hu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gall Bladder ◽  
Interleukin 1 ◽  
Gene Chip ◽  
Molecular Evidence ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Bladder Meridian ◽  
Integrin Linked Kinase ◽  
Necrosis Factor

Acupuncture manipulations are clinically important to traditional Chinese medicine, yet the biological mechanisms have not been fully understood. This study aimed to investigate continuous stimulation-induced gene expression changes at stimulated and non-stimulated adjacent acupoints in the same meridian. Catgut embedding into acupoint (CEP) was conducted at acupoint Yanglingquan (gall bladder meridian of foot-shaoyang 34, GB34) of Sprague Dawley rats once or continuously for eight weeks, and gene expression changes at GB34 were assessed by gene chip array analysis 72 h after the last CEP treatment. A total of 688 genes exhibited opposite changes in expression between the two treatments, and 1,336 genes were regulated only by the eight-week CEP treatment. Ingenuity Pathway Analysis revealed that among these differentially regulated genes by one-time and eight-week CEP treatment, insulin-like growth factor-1 pathway and integrin-linked kinase pathway, and Wnt/~ catenin signaling pathway match the observed gene changes to predicted up/down regulation patterns. Upstream analysis further predicted six molecules, namely, tumor necrosis factor, interleukin 1~, interleukin la, kallikrein-related peptidase 5, protein kinase Ca, and catenin ~1. On the other hand, continuous eight-week CEP stimulation at acupoint Xuanzhong (GB39) caused similar changes in the expression of 32 genes at acupoints GB34 and Fengshi (GB31) on the same meridian. Taken together, our results provide the first molecular evidence for the local acupoints' mechanisms for acupoint sensitization theory, and implicate the existence of signaling pathways, either direct or indirect, between acupoints within the meridian GB.

scholarly journals Differential Effects of Refeeding on Melanocortin-Responsive Neurons in the Hypothalamic Paraventricular Nucleus

Endocrinology ◽  
2008 ◽  
Vol 149 (9) ◽  
pp. 4329-4335 ◽  
Author(s):  
Edith Sánchez ◽  
Praful S. Singru ◽  
Runa Acharya ◽  
Monica Bodria ◽  
Csaba Fekete ◽  
...  
Keyword(s):  
Gene Expression ◽  
Paraventricular Nucleus ◽  
Hypothalamic Paraventricular Nucleus ◽  
Mrna Levels ◽  
Sprague Dawley ◽  
Early Action ◽  
Sprague Dawley Rats ◽  
Melanocortin Signaling ◽  
Agouti Related Protein ◽  
Serum Tsh

To explore the effect of refeeding on recovery of TRH gene expression in the hypothalamic paraventricular nucleus (PVN) and its correlation with the feeding-related neuropeptides in the arcuate nucleus (ARC), c-fos immunoreactivity (IR) in the PVN and ARC 2 h after refeeding and hypothalamic TRH, neuropeptide Y (NPY) and agouti-related protein (AGRP) mRNA levels 4, 12, and 24 h after refeeding were studied in Sprague-Dawley rats subjected to prolonged fasting. Despite rapid reactivation of proopiomelanocortin neurons by refeeding as demonstrated by c-fos IR in ARC α-MSH-IR neurons and ventral parvocellular subdivision PVN neurons, c-fos IR was present in only 9.7 ± 1.1% hypophysiotropic TRH neurons. Serum TSH levels remained suppressed 4 and 12 h after the start of refeeding, returning to fed levels after 24 h. Fasting reduced TRH mRNA compared with fed animals, and similar to TSH, remained suppressed at 4 and 12 h after refeeding, returning toward normal at 24 h. AGRP and NPY gene expression in the ARC were markedly elevated in fasting rats, AGRP mRNA returning to baseline levels 12 h after refeeding and NPY mRNA remaining persistently elevated even at 24 h. These data raise the possibility that refeeding-induced activation of melanocortin signaling exerts differential actions on its target neurons in the PVN, an early action directed at neurons that may be involved in satiety, and a later action on hypophysiotropic TRH neurons involved in energy expenditure, potentially mediated by sustained elevations in AGRP and NPY. This response may be an important homeostatic mechanism to allow replenishment of depleted energy stores associated with fasting.

scholarly journals Antiobesity Activity of Elateriospermum tapos Shell Extract in Obesity-Induced Sprague Dawley Rats

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 321
Author(s):  
Kokila Vani Perumal ◽  
Nor Liyana Ja’afar ◽  
Che Norma Mat Taib ◽  
Nurul Husna Shafie ◽  
Hasnah Bahari
Keyword(s):  
Body Weight ◽  
Corn Starch ◽  
Milk Powder ◽  
Caloric Intake ◽  
Lipid Lowering ◽  
Sprague Dawley ◽  
Triglyceride Accumulation ◽  
Sprague Dawley Rats ◽  
Effective Result ◽  
Lipid Lowering Effect

Obesity is one of the risk factors associated with cardiovascular diseases, hypertension, abnormal liver function, diabetes, and cancers. Orlistat is currently available to treat obesity, but it is associated with adverse side effects. Natural resources are widely used for obesity treatment. Hence, this study aimed to investigate the anti-obesity activity of Elateriospermum tapos (E. tapos) shell extract in obesity induced Sprague Dawley rats. The rats’ obesity was induced by a high-fat (HF) diet made up of 50% standard rat pellet, 20% milk powder, 6% corn starch, and 24% ghee and a cafeteria (CAF) diet such as chicken rolls, salty biscuits, cakes, and cheese snacks. A hot aqueous method for the extraction of E. tapos shells was applied by using 500 mL of distilled water for about 24 h. Various dosages of E. tapos shell extract (10 mg/kg, 100 mg/kg, and 200 mg/kg) were used. At the end of the study, body weight, caloric intake, organ weight, lipid profile, lipoprotein lipase (LPL) activity, and histopathology analysis were carried out. E. tapos shell extract treated groups showed a reduction in body weight, positive lipid-lowering effect, decrements in triglyceride accumulation and LPL activity, and positive improvement in histopathology analysis. A dose of 200 mg/kg showed the most effective result compared to 10 mg/kg and 100 mg/kg doses.

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