The Central Melanocortin System and the Integration of Short- and Long-term Regulators of Energy Homeostasis

The central melanocortin system plays a key role in the regulation of energy homeostasis. Neurons containing the peptide precursor proopiomelanocortin (POMC) are found at two sites in the brain, the arcuate nucleus of the hypothalamus (ARC) and the caudal region of the nucleus of the solitary tract (NTS). ARC POMC neurons, which also express cocaine- and amphetamine-regulated transcript (CART), are known to mediate part of the response to factors regulating energy homeostasis, such as leptin and ghrelin. In contrast, the physiological role(s) of the POMC neurons in the caudal brainstem are not well characterized. However, development of a transgenic mouse expressing green fluorescent protein under the control of the POMC promoter [POMC-enhanced green fluorescent protein (EGFP) mouse] has aided the study of these neurons. Indeed, recent studies have shown significant activation of NTS POMC-EGFP cells by the gut released satiety factor cholecystokinin (CCK). Here we show that peripheral leptin administration induces the expression of phospho-signal transducer and activator of transcription 3 immunoreactivity (pSTAT3-IR), a marker of leptin receptor signaling, in more than 50% of NTS POMC-EGFP neurons. Furthermore, these POMC-EGFP neurons comprise 30% of all pSTAT3-IR cells in the NTS. Additionally, we also show that in contrast to the ARC population, NTS POMC-EGFP neurons do not coexpress CART immunoreactivity. These data suggest that NTS POMC neurons may participate with ARC POMC cells in mediating some of the effects of leptin and thus comprise a novel cell group regulated by both long-term adipostatic signals and satiety factors such as CCK.

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Obesity, food intake and exercise: Relationship with ghrelin

Biomedical Human Kinetics ◽

10.1515/bhk-2015-0018 ◽

2015 ◽

Vol 7 (1) ◽

Cited By ~ 2

Author(s):

Gul Tiryaki-Sonmez ◽

Serife Vatansever ◽

Burcin Olcucu ◽

Brad Schoenfeld

Keyword(s):

Food Intake ◽

Energy Homeostasis ◽

Adult Population ◽

Peptide Hormone ◽

Adverse Health Outcomes ◽

General Adult Population ◽

Orexigenic Peptide ◽

Term Energy ◽

Short And Long Term

SummaryObesity, a disorder of body composition, is defined by a relative or absolute excess of body fat. In general adult population, obesity has been associated with a diverse array of adverse health outcomes, including major causes of death such as cancer, diabetes, cardiovascular disease, as well as functional impairment from problems such as osteoarthritis and sleep apnea. Ghrelin is a newly discovered peptide hormone which plays an important role in obesity. It is a powerful, endogenous orexigenic peptide and has a crucial function in appetite regulation, as well as short – and long-term energy homeostasis. In the presence of increased obesity, decreased physical activity, and high food consumption, the relationship between exercise, appetite, food intake and ghrelin levels has important implications. In this review, we discuss the effect of acute and chronic exercise performance on appetite, food intake and ghrelin and their relationships.

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Activation of the central melanocortin system chronically reduces body mass without the necessity of long-term caloric restriction

Canadian Journal of Physiology and Pharmacology ◽

10.1139/cjpp-2016-0290 ◽

2017 ◽

Vol 95 (2) ◽

pp. 206-214 ◽

Cited By ~ 2

Author(s):

I. Côté ◽

Y. Sakarya ◽

N. Kirichenko ◽

D. Morgan ◽

C.S. Carter ◽

...

Keyword(s):

Energy Balance ◽

Caloric Restriction ◽

Body Mass ◽

Energy Homeostasis ◽

Control Level ◽

Negative Energy ◽

Dependent Manner ◽

Melanocortin System ◽

Balance State

Melanotan II (MTII) is a potent appetite suppressor that rapidly reduces body mass. Given the rapid loss of anorexic response upon chronic MTII treatment, most investigations have focused on the initial physiological adaptations. However, other evidence supports MTII as a long-term modulator of energy balance that remains to be established. Therefore, we examined the chronic effects of MTII on energy homeostasis. MTII (high or low dose) or artificial cerebrospinal fluid (aCSF) was infused into the lateral ventricle of the brain of 6-month-old F344BN rats (6–7/group) over 40 days. MTII suppressed appetite in a dose-dependent manner (P < 0.05). Although food intake promptly rose back to control level, body mass was persistently reduced in both MTII groups (P < 0.01). At day 40, both MTII groups displayed lower adiposity than the aCSF animals (P < 0.01). These results show that MTII chronically reduces body mass without the requirement of long-term caloric restriction. Our study proposes that food restriction helps initiate mass loss; however, combined with a secondary pharmacological approach preserving a negative energy balance state over time may help combat obesity.

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Focus on the short- and long-term effects of ghrelin on energy homeostasis

Nutrition ◽

10.1016/j.nut.2009.09.013 ◽

2010 ◽

Vol 26 (6) ◽

pp. 579-584 ◽

Cited By ~ 32

Author(s):

Carine De Vriese ◽

Jason Perret ◽

Christine Delporte

Keyword(s):

Energy Homeostasis ◽

Long Term Effects ◽

Short And Long Term

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Hormonal Regulation of Food Intake

Physiological Reviews ◽

10.1152/physrev.00015.2004 ◽

2005 ◽

Vol 85 (4) ◽

pp. 1131-1158 ◽

Cited By ~ 233

Author(s):

Sarah Stanley ◽

Katie Wynne ◽

Barbara McGowan ◽

Stephen Bloom

Keyword(s):

Adipose Tissue ◽

Gastrointestinal Tract ◽

Food Intake ◽

Energy Expenditure ◽

Hormonal Regulation ◽

Energy Homeostasis ◽

Neuropeptide Release ◽

Short And Long Term ◽

Physiological Systems

Our knowledge of the physiological systems controlling energy homeostasis has increased dramatically over the last decade. The roles of peripheral signals from adipose tissue, pancreas, and the gastrointestinal tract reflecting short- and long-term nutritional status are now being described. Such signals influence central circuits in the hypothalamus, brain stem, and limbic system to modulate neuropeptide release and hence food intake and energy expenditure. This review discusses the peripheral hormones and central neuronal pathways that contribute to control of appetite.

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Experience with Short and Long Term Courses of Local Adrenal Steroid Therapy For Ulcerative Colitis

Gastroenterology ◽

10.1016/s0016-5085(62)80117-6 ◽

1962 ◽

Vol 42 (6) ◽

pp. 669-677 ◽

Cited By ~ 18

Author(s):

Jean A. Spencer ◽

Joseph B. Kirsner

Keyword(s):

Ulcerative Colitis ◽

Steroid Therapy ◽

Adrenal Steroid ◽

Short And Long Term

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Short- and Long-Term Results of Total vs Subtotal Thyroid- ectomies in the Surgical Treatment of Graves' Disease

Swiss Surgery ◽

10.1024/1023-9332.7.1.20 ◽

2001 ◽

Vol 7 (1) ◽

pp. 20-24 ◽

Cited By ~ 14

Author(s):

Robert ◽

Mariéthoz ◽

Pache ◽

Bertin ◽

Caulfield ◽

...

Keyword(s):

Recurrent Laryngeal Nerve ◽

Nerve Palsy ◽

Recurrent Laryngeal Nerve Palsy ◽

Laryngeal Nerve ◽

Long Term Results ◽

Graves Disease ◽

Laryngeal Nerve Palsy ◽

Short And Long Term

Objective: Approximately one out of five patients with Graves' disease (GD) undergoes a thyroidectomy after a mean period of 18 months of medical treatment. This retrospective and non-randomized study from a teaching hospital compares short- and long-term results of total (TT) and subtotal thyroidectomies (ST) for this disease. Methods: From 1987 to 1997, 94 patients were operated for GD. Thirty-three patients underwent a TT (mostly since 1993) and 61 a ST (keeping 4 to 8 grams of thyroid tissue - mean 6 g). All patients had received propylthiouracil and/or neo-mercazole and were in a euthyroid state at the time of surgery; they also took potassium iodide (lugol) for ten days before surgery. Results: There were no deaths. Transient hypocalcemia (< 3 months) occurred in 32 patients (15 TT and 17 ST) and persistent hypocalcemia in 8 having had TT. Two patients developed transient recurrent laryngeal nerve palsy after ST (< 3 months). After a median follow-up period of seven years (1-15) with five patients lost to follow-up, 41 patients having had a ST are in a hypothyroid state (73%), thirteen are euthyroid (23%), and two suffered recurrent hyperthyroidism, requiring completion of thyroidectomy. All 33 patients having had TT - with follow-ups averaging two years (0.5-8) - are receiving thyroxin substitution. Conclusions: There were no instances of persistent recurrent laryngeal nerve palsy in either group, but persistent hypoparathyroidism occurred more frequently after TT. Long after ST, hypothyroidism developed in nearly three of four cases, whereas euthyroidy was maintained in only one-fourth; recurrent hyperthyroidy was rare.

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