Read by QxMD icon Read


Chaitanya K Gavini, Steven L Britton, Lauren G Koch, Colleen M Novak
OBJECTIVE: Activity thermogenesis and energy expenditure (EE) are elevated in intrinsically lean rats (high-capacity runners [HCR]) and are also stimulated by melanocortin receptor activation in the ventromedial hypothalamus (VMH). This study determined whether HCR are more responsive to central modulation of activity EE compared with low-capacity runners (LCR). METHODS: HCR and LCR rats received intra-VMH microinjections of melanotan II (MTII), a mixed melanocortin receptor agonist...
March 22, 2018: Obesity
Alexandre A da Silva, J Nathan Freeman, John E Hall, Jussara M do Carmo
Although central melanocortin 4 receptor (MC4R) blockade abolishes the central nervous system (CNS)-mediated anorexogenic, antidiabetic, and cardiovascular actions of leptin, chronic MC4R stimulation fails to completely mimic the effects of leptin. Because neuropeptide Y (NPY) and MC4R exert opposite effects on cardiovascular and metabolic functions, we tested the role of NPY in offsetting the long-term actions of MC4R activation. Wild-type (WT) and NPY-deficient (NPY-/- ) mice were implanted with telemetry probes for measuring mean arterial pressure (MAP) and heart rate (HR) 24 h/day...
April 1, 2018: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
Isabelle Côté, Sara M Green, Drake Morgan, Christy S Carter, Nihal Tümer, Philip J Scarpace
Recent evidence indicate that melanotan II (MTII) reduces body mass independently of caloric reduction. Because MTII induces a transient hypophagia, caloric reduction is still considered a primary mechanism for MTII-mediated body mass loss. To examine the contribution of caloric reduction to long-term body mass loss in response to MTII, we centrally infused MTII or vehicle in ad libitum fed (MTII and Control) animals in comparison with a group of animals that were pair-fed (PF) to the MTII group. Food intake and body mass were recorded daily, and body composition was assessed biweekly...
March 2018: Canadian Journal of Physiology and Pharmacology
Rajesh Gupta, Yunbing Ma, Manqi Wang, Matthew D Whim
Fasting evokes a homeostatic response that maintains circulating levels of energy-rich metabolites and increases the drive to eat. Centrally, this reflex activates a small population of hypothalamic neurons that are characterized by the expression of AgRP, a neuropeptide with an extremely restricted distribution. Apart from the hypothalamus, the only other site with substantial expression is the adrenal gland, but there is disagreement about which cells synthesize AgRP. Using immunohistochemistry, flow cytometry, and reverse transcription-polymerase chain reaction, we show AgRP is present in the mouse adrenal medulla and is expressed by neuroendocrine chromaffin cells that also synthesize the catecholamines and neuropeptide Y...
August 1, 2017: Endocrinology
Louis Habbema, Anne Berthe Halk, Martino Neumann, Wilma Bergman
Recently, the unregulated use of untested synthetic alpha-melanocyte-stimulating hormone (α-MSH) analogues, commonly known as melanotan I and II, appears to have increased. These analogues are primarily used for their tan-stimulating effects. Dermatologists see many patients in their clinic who tan. This review provides an overview of the risks of the unregulated use of these substances. Other topics discussed here include the history and safety of afamelanotide, which is the only α-MSH analogue that is approved for use in a limited number of medical indications...
March 7, 2017: International Journal of Dermatology
I Côté, Y Sakarya, N Kirichenko, D Morgan, C S Carter, N Tümer, P J Scarpace
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...
February 2017: Canadian Journal of Physiology and Pharmacology
L Paiva, N Sabatier, G Leng, M Ludwig
Melanocortins stimulate the central oxytocin systems that are involved in regulating social behaviours. Alterations in central oxytocin have been linked to neurological disorders such as autism, and melanocortins have been proposed for therapeutic treatment. In the present study, we investigated how systemic administration of melanotan-II (MT-II), a melanocortin agonist, affects oxytocin neuronal activity and secretion in rats. The results obtained show that i.v., but not intranasal, administration of MT-II markedly induced Fos expression in magnocellular neurones of the supraoptic (SON) and paraventricular nuclei (PVN) of the hypothalamus, and this response was attenuated by prior i...
February 2017: Journal of Neuroendocrinology
Jing Cui, Yi Ding, Shu Chen, Xiaoqiang Zhu, Yichen Wu, Mingliang Zhang, Yaxin Zhao, Tong-Ruei R Li, Ling V Sun, Shimin Zhao, Yuan Zhuang, Weiping Jia, Lei Xue, Min Han, Tian Xu, Xiaohui Wu
A rise in the occurrence of obesity has driven exploration of its underlying genetic basis and potential targets for intervention. GWAS studies have identified obesity susceptibility pathways involving several neuropeptides that control energy homeostasis, suggesting that variations in the genes that regulate food intake and energy expenditure may contribute to obesity. In this study, we identified 5 additional obesity loci, including a neuronal orphan GPCR called Gpr45, in a forward genetic screen of mutant mice generated by piggyBac insertional mutagenesis...
September 1, 2016: Journal of Clinical Investigation
Chaitanya K Gavini, William C Jones, Colleen M Novak
KEY POINTS: The ventromedial hypothalamus (VMH) and the central melanocortin system both play vital roles in regulating energy balance by modulating energy intake and utilization. Recent evidence suggests that activation of the VMH alters skeletal muscle metabolism. We show that intra-VMH melanocortin receptor activation increases energy expenditure and physical activity, switches fuel utilization to fats, and lowers work efficiency such that excess calories are dissipated by skeletal muscle as heat...
September 15, 2016: Journal of Physiology
N M Bazhan, E V Kulikova, E N Makarova, T V Yakovleva, A Yu Kazantseva
Melanocortin (MC) system regulates food intake under the rest conditions. Stress inhibits food intake. It is not clear whether brain MC system is involved in stress-induced anorexia in mice. The aim of the work was to investigate the effect of pharmacological blockade and activation of brain MC receptors on food intake under stress. C57B1/6J male mice were subjected to ether stress (0.5 minute ether anesthesia) before the administration of saline solution or synthetic non-selective blocker (SHU9119) or agonist (Melanotan II) of MC receptors into the lateral brain ventricle...
December 2015: Rossiĭskii Fiziologicheskiĭ Zhurnal Imeni I.M. Sechenova
Rebekah Brennan, John S G Wells, Marie Claire Van Hout
Injecting use of image and performance-enhancing drugs (IPED) in the general population is a public health concern. A wide and varied range of IPED are now easily accessible to all through the online market. A comprehensive literature review was undertaken according to Critical Appraisal Skills Programme (CASP) guidelines for systematic review, to identify the relevant literature. No date restrictions were placed on the database search in the case of human growth hormone melanotan I and II, and oil and cosmetic injectables...
January 25, 2016: Health & Social Care in the Community
Kavaljit H Chhabra, Jessica M Adams, Brian Fagel, Daniel D Lam, Nathan Qi, Marcelo Rubinstein, Malcolm J Low
Hypothalamic proopiomelanocortin (POMC) is essential for the physiological regulation of energy balance; however, its role in glucose homeostasis remains less clear. We show that hypothalamic arcuate nucleus (Arc)POMC-deficient mice, which develop severe obesity and insulin resistance, unexpectedly exhibit improved glucose tolerance and remain protected from hyperglycemia. To explain these paradoxical phenotypes, we hypothesized that an insulin-independent pathway is responsible for the enhanced glucose tolerance...
March 2016: Diabetes
Bastiaan J Venhuis, Peter H J Keizers, Rüdiger Klausmann, Ingrid Hegger
Operation Pangea is an annual international week of action combating pharmaceutical crime. In this study, called Operation Resistance, we asked the national agencies in Europe to search for falsified antibiotics and biopharmaceutical injectables (peptides and proteins) amongst the medicines seized in Pangea 7 (2014). Reports were received from Belgium, Cyprus, Czech Republic, Denmark, France, the Netherlands, Portugal, Sweden, Spain, the United Kingdom, Norway, and Switzerland. The countries reported seizing about 21,000 dose units (e...
March 2016: Drug Testing and Analysis
Dirk W Luchtman, Melissa J S Chee, Barbora Doslikova, Daniel L Marks, Vickie E Baracos, William F Colmers
Some animals and humans fed a high-energy diet (HED) are diet-resistant (DR), remaining as lean as individuals who were naïve to HED. Other individuals become obese during HED exposure and subsequently defend the obese weight (Diet-Induced Obesity- Defenders, DIO-D) even when subsequently maintained on a low-energy diet. We hypothesized that the body weight setpoint of the DIO-D phenotype resides in the hypothalamic paraventricular nucleus (PVN), where anorexigenic melanocortins, including melanotan II (MTII), increase presynaptic GABA release, and the orexigenic neuropeptide Y (NPY) inhibits it...
2015: PloS One
Brent M Molden, Kimberly A Cooney, Kirk West, Lex H T Van Der Ploeg, Giulia Baldini
The melanocortin-4 receptor (MC4R) is a G protein-coupled receptor expressed in the brain, where it controls energy balance through pathways including α-melanocyte-stimulating hormone (α-MSH)-dependent signaling. We have reported that the MC4R can exist in an active conformation that signals constitutively by increasing cAMP levels in the absence of receptor desensitization. We asked whether synthetic MC4R agonists differ in their ability to increase intracellular cAMP over time in Neuro2A cells expressing endogenous MC4R and exogenous, epitope-tagged hemagglutinin-MC4R-green fluorescent protein...
November 2015: Molecular Endocrinology
Zhigang Shi, Baoxin Li, Virginia L Brooks
Leptin binds to receptors in multiple hypothalamic nuclei to increase sympathetic nerve activity; however, the neurocircuitry is unclear. Here, using anesthetized male Sprague-Dawley rats, we investigated the role of the paraventricular nucleus of the hypothalamus. Intracerebroventricular injection of leptin slowly increased lumbar sympathetic nerve activity (LSNA), heart rate, mean arterial pressure, and baroreflex control of LSNA and heart rate. Inhibition of the paraventricular nucleus with muscimol completely reversed leptin's effects...
November 2015: Hypertension
Eugenia Mc Allister, Gustavo Pacheco-Lopez, Stephen C Woods, Wolfgang Langhans
Insulin inhibits eating after its intracerebroventricular (ICV) administration in multiple species and under a variety of conditions. Nevertheless, the results across reports are inconsistent in that ICV insulin does not always reduce food intake. The reasons for this variability are largely unknown. Using mice as a model, we performed several crossover trials with insulin vs. vehicle when infused into the third cerebral ventricle (i3vt) to test the hypothesis that recent experience with the i3vt procedure contributes to the variability in the effect of ICV insulin on food intake...
November 1, 2015: Physiology & Behavior
C Bayerl
BACKGROUND: Homogenous pigmentation can be induced by α-melanocyte-stimulating hormone (MSH) homologues. Cosmetically inacceptable pigmentation is mostly located on the face. OBJECTIVES: Although afamelatonide is a prescription drug for the orphan disease erthropoetic protoporphyria, structurally related α-MSH derivatives are available via the internet. Preventive and therapeutical options are necessary for postinflammatory hyperpigmentation, melasma, and lentigines...
October 2015: Der Hautarzt; Zeitschrift Für Dermatologie, Venerologie, und Verwandte Gebiete
C E Barrett, S E Arambula, L J Young
Genes and social experiences interact to create variation in social behavior and vulnerability to develop disorders of the social domain. Socially monogamous prairie voles display remarkable diversity in neuropeptide receptor systems and social behavior. Here, we examine the interaction of early-life adversity and brain oxytocin receptor (OTR) density on adult social attachment in female prairie voles. First, pups were isolated for 3 h per day, or unmanipulated, from postnatal day 1-14. Adult subjects were tested on the partner preference (PP) test to assess social attachment and OTR density in the brain was quantified...
July 21, 2015: Translational Psychiatry
Montserrat Navarro, Francisca Carvajal, Jose Manuel Lerma-Cabrera, Inmaculada Cubero, Mitchell J Picker, Todd E Thiele
BACKGROUND: The nonselective opioid receptor antagonist, naltrexone (NAL), reduces alcohol (ethanol [EtOH]) consumption in animals and humans and is an approved medication for treating alcohol abuse disorders. Proopiomelanocortin (POMC)-derived melanocortin (MC) and opioid peptides are produced in the same neurons in the brain, and recent preclinical evidence shows that MC receptor (MCR) agonists reduce excessive EtOH drinking in animal models. Interestingly, there is a growing body of literature revealing interactions between the MC and the opioid systems in the modulation of pain, drug tolerance, and food intake...
August 2015: Alcoholism, Clinical and Experimental Research
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"