scholarly journals Cannabinoid receptor 1 expression is higher in muscle of old vs. young males, and increases upon resistance exercise in older adults

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sebastiaan Dalle ◽  
Katrien Koppo

AbstractAged skeletal muscle undergoes metabolic and structural alterations eventually resulting in a loss of muscle strength and mass, i.e. age-related sarcopenia. Therefore, novel targets for muscle growth purposes in elderly are needed. Here, we explored the role of the cannabinoid system in muscle plasticity through the expression of muscle cannabinoid receptors (CBs) in young and old humans. The CB1 expression was higher (+ 25%; p = 0.04) in muscle of old (≥ 65 years) vs. young adults (20–27 years), whereas CB2 was not differently expressed. Furthermore, resistance exercise tended to increase the CB1 (+ 11%; p = 0.055) and CB2 (+ 37%; p = 0.066) expression in muscle of older adults. Interestingly, increases in the expression of CB2 following resistance exercise positively correlated with changes in key mechanisms of muscle homeostasis, such as catabolism (FOXO3a) and regenerative capacity (Pax7, MyoD). This study for the first time shows that CB1 is differentially expressed with aging and that changes in CB2 expression upon resistance exercise training correlate with changes in mediators that play a central role in muscle plasticity. These data confirm earlier work in cells and mice showing that the cannabinoid system might orchestrate muscle growth, which is an incentive to further explore CB-based strategies that might counteract sarcopenia.

2015 ◽  
Vol 112 (28) ◽  
pp. 8774-8779 ◽  
Author(s):  
Reem Smoum ◽  
Saja Baraghithy ◽  
Mukesh Chourasia ◽  
Aviva Breuer ◽  
Naama Mussai ◽  
...  

Activation of the CB2 receptor is apparently an endogenous protective mechanism. Thus, it restrains inflammation and protects the skeleton against age-related bone loss. However, the endogenous cannabinoids, as well as Δ9-tetrahydrocannabinol, the main plant psychoactive constituent, activate both cannabinoid receptors, CB1 and CB2. HU-308 was among the first synthetic, selective CB2 agonists. HU-308 is antiosteoporotic and antiinflammatory. Here we show that the HU-308 enantiomer, designated HU-433, is 3–4 orders of magnitude more potent in osteoblast proliferation and osteoclast differentiation culture systems, as well as in mouse models, for the rescue of ovariectomy-induced bone loss and ear inflammation. HU-433 retains the HU-308 specificity for CB2, as shown by its failure to bind to the CB1 cannabinoid receptor, and has no activity in CB2-deficient cells and animals. Surprisingly, the CB2 binding affinity of HU-433 in terms of [3H]CP55,940 displacement and its effect on [35S]GTPγS accumulation is substantially lower compared with HU-308. A molecular-modeling analysis suggests that HU-433 and -308 have two different binding conformations within CB2, with one of them possibly responsible for the affinity difference, involving [35S]GTPγS and cAMP synthesis. Hence, different ligands may have different orientations relative to the same binding site. This situation questions the usefulness of universal radioligands for comparative binding studies. Moreover, orientation-targeted ligands have promising potential for the pharmacological activation of distinct processes.


2017 ◽  
Vol 99 ◽  
pp. 98-109 ◽  
Author(s):  
Michael J. Stec ◽  
Anna Thalacker-Mercer ◽  
David L. Mayhew ◽  
Neil A. Kelly ◽  
S. Craig Tuggle ◽  
...  

2018 ◽  
Vol 43 (12) ◽  
pp. 1215-1223 ◽  
Author(s):  
Camila L.P. Oliveira ◽  
Isabelle J. Dionne ◽  
Carla M. Prado

Aging is characterized by physiological and morphological changes that affect body composition, strength, and function, ultimately leading to sarcopenia. This condition results in physical disability, falls, fractures, poor quality of life, and increased health care costs. Evidence suggests that increased consumption of dietary protein and physical activity levels, especially resistance exercise, can counteract the trajectory of sarcopenia. Canadian guidelines for protein intake and physical activity were last updated in 2005 and 2011, respectively, and new evidence on sarcopenia diagnosis, prevention, and treatment is rapidly evolving. Protein recommendations are set as “one-size-fits-all” for both young and older adults. Recent evidence demonstrates that current recommendations are insufficient to meet the minimum protein requirement to counteract muscle loss and to stimulate hypertrophy in healthy older adults. Beyond quantity, protein quality is also essential to benefit muscle anabolism in older adults. In terms of physical activity, resistance exercise training is a potential strategy to counteract age-related effects, as it can elicit muscle hypertrophic response in addition to increases in muscle strength and function in older adults. Canadian physical activity guidelines lack details on how this modality of training should be performed. Current guidelines for protein intake and physical activity do not reflect recent knowledge on sarcopenia prevention. The gap between guidelines and the latest evidence on the maintenance and promotion of older adult’s health highlight the need for updated protein and physical activity recommendations.


Author(s):  
Zeinab Momeni ◽  
Jessica E. Logan ◽  
Ronald J. Sigal ◽  
Jane E. Yardley

Due to improvements in diabetes care, people with type 1 diabetes (T1D) are living longer. Studies show that post-menopausal T1D women have a substantially elevated cardiovascular risk compared to those without T1D. As T1D may also accelerate age-related bone and muscle loss, the risk of frailty may be considerable for T1D women. Exercise and physical activity may be optimal preventative therapies to maintain health and prevent complications in this population: They are associated with improvements in, or maintenance of, cardiovascular health, bone mineral density, and muscle mass in older adults. Resistance exercise, in particular, may provide important protection against age-related frailty, due to its specific effects on bone and muscle. Fear of hypoglycemia can be a barrier to exercise in those with T1D, and resistance exercise may cause less hypoglycemia than aerobic exercise. There are currently no exercise studies involving older, post-menopausal women with T1D. As such, it is unknown whether current guidelines for insulin adjustment/carbohydrate intake for activity are appropriate for this population. This review focuses on existing knowledge about exercise in older adults and considers potential future directions around resistance exercise as a therapeutic intervention for post-menopausal T1D women.


2019 ◽  
Vol 70 (2) ◽  
pp. 627-629
Author(s):  
Mary Nicoleta Lupu ◽  
Magdalena Miulescu ◽  
Madalina Nina Sandu ◽  
Iulia Filip ◽  
Laura Rebegea ◽  
...  

In the human body there is an endocannabinoid system consisting of cannabinoid receptors and endogenous transmitters - the endocannabinoids (anandamides).This cannabinoid system works by certain principles: the presynaptic neuron releases the neurotransmitter that reaches the postsynaptic neuron, activating it; at this level endocannabinoids are synthesized, whichhave retrograde transmission through the synaptic gap, reaching the cannabinoid receptors where they can inhibit the anterograde release of neurotransmitters. At the same level, certain exogenous substances, derived from plants and called phytocannabinoids may also work, the most known one being tetrahydrocannabinol. 9-D-Tetrahydrocannabinol is a component extracted from hemp plant with intense psychotic action but also with some medical applications. The result of the cannabinoid system activity is to obtain certain psychoactive effects, euphoria, relaxation, intense sensory experiences, pain relief but also changes in perception, attention deficit, etc. Synthetic cannabinoids are obtained to mimic the effects of marijuana, are major cannabinoid receptor agonists and are at increased risk of toxicity. Chronic consumption of such substances can cause memory disorders, pulmonary disorders and, most importantly, addiction.


1992 ◽  
Vol 35 (4) ◽  
pp. 892-902 ◽  
Author(s):  
Robert Allen Fox ◽  
Lida G. Wall ◽  
Jeanne Gokcen

This study examined age-related differences in the use of dynamic acoustic information (in the form of formant transitions) to identify vowel quality in CVCs. Two versions of 61 naturally produced, commonly occurring, monosyllabic English words were created: a control version (the unmodified whole word) and a silent-center version (in which approximately 62% of the medial vowel was replaced by silence). A group of normal-hearing young adults (19–25 years old) and older adults (61–75 years old) identified these tokens. The older subjects were found to be significantly worse than the younger subjects at identifying the medial vowel and the initial and final consonants in the silent-center condition. These results support the hypothesis of an age-related decrement in the ability to process dynamic perceptual cues in the perception of vowel quality.


Author(s):  
Yvonne Rogalski ◽  
Muriel Quintana

The population of older adults is rapidly increasing, as is the number and type of products and interventions proposed to prevent or reduce the risk of age-related cognitive decline. Advocacy and prevention are part of the American Speech-Language-Hearing Association’s (ASHA’s) scope of practice documents, and speech-language pathologists must have basic awareness of the evidence contributing to healthy cognitive aging. In this article, we provide a brief overview outlining the evidence on activity engagement and its effects on cognition in older adults. We explore the current evidence around the activities of eating and drinking with a discussion on the potential benefits of omega-3 fatty acids, polyphenols, alcohol, and coffee. We investigate the evidence on the hypothesized neuroprotective effects of social activity, the evidence on computerized cognitive training, and the emerging behavioral and neuroimaging evidence on physical activity. We conclude that actively aging using a combination of several strategies may be our best line of defense against cognitive decline.


2014 ◽  
Vol 28 (3) ◽  
pp. 148-161 ◽  
Author(s):  
David Friedman ◽  
Ray Johnson

A cardinal feature of aging is a decline in episodic memory (EM). Nevertheless, there is evidence that some older adults may be able to “compensate” for failures in recollection-based processing by recruiting brain regions and cognitive processes not normally recruited by the young. We review the evidence suggesting that age-related declines in EM performance and recollection-related brain activity (left-parietal EM effect; LPEM) are due to altered processing at encoding. We describe results from our laboratory on differences in encoding- and retrieval-related activity between young and older adults. We then show that, relative to the young, in older adults brain activity at encoding is reduced over a brain region believed to be crucial for successful semantic elaboration in a 400–1,400-ms interval (left inferior prefrontal cortex, LIPFC; Johnson, Nessler, & Friedman, 2013 ; Nessler, Friedman, Johnson, & Bersick, 2007 ; Nessler, Johnson, Bersick, & Friedman, 2006 ). This reduced brain activity is associated with diminished subsequent recognition-memory performance and the LPEM at retrieval. We provide evidence for this premise by demonstrating that disrupting encoding-related processes during this 400–1,400-ms interval in young adults affords causal support for the hypothesis that the reduction over LIPFC during encoding produces the hallmarks of an age-related EM deficit: normal semantic retrieval at encoding, reduced subsequent episodic recognition accuracy, free recall, and the LPEM. Finally, we show that the reduced LPEM in young adults is associated with “additional” brain activity over similar brain areas as those activated when older adults show deficient retrieval. Hence, rather than supporting the compensation hypothesis, these data are more consistent with the scaffolding hypothesis, in which the recruitment of additional cognitive processes is an adaptive response across the life span in the face of momentary increases in task demand due to poorly-encoded episodic memories.


Author(s):  
Rachel L. C. Mitchell ◽  
Rachel A. Kingston

It is now accepted that older adults have difficulty recognizing prosodic emotion cues, but it is not clear at what processing stage this ability breaks down. We manipulated the acoustic characteristics of tones in pitch, amplitude, and duration discrimination tasks to assess whether impaired basic auditory perception coexisted with our previously demonstrated age-related prosodic emotion perception impairment. It was found that pitch perception was particularly impaired in older adults, and that it displayed the strongest correlation with prosodic emotion discrimination. We conclude that an important cause of age-related impairment in prosodic emotion comprehension exists at the fundamental sensory level of processing.


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