Melanotan II: a possible cause of renal infarction: review of the literature and case report

An overview of benefits and risks of chronic melanocortin-1 receptor activation

The melanocortin-1 receptor (MC1R) is a G protein-coupled receptor that plays a pivotal role in human skin pigmentation, melanin synthesis, redox homeostasis and inflammation. Loss-of-function MC1R variants suppress G protein-coupled receptor coupling or cell surface expression leading to a decrease in adenyl cyclase activation and intracellular levels of cyclic adenosine monophosphate. Chronic activation of MC1R can occur in certain medical conditions such as Addison's disease and physiologic states such as pregnancy melasma. MC1R activation is more commonly caused by environmental exposure to ultraviolet (UV) radiation. Approved pharmacologic melanocortin agonists that activate MC1R signalling in a targeted manner or as a bystander effect have recently become available for erythropoietic protoporphyria, sexual desire disorders, monogenic obesity and syndromic obesity. Further, small peptide analogues of α-melanocortin-stimulating hormone, human MC1R selective agonists, are photoprotective, decreasing the adverse impact of UV radiation (a primary risk factor for skin cancer) and are being investigated as potential chemoprevention strategies. MC1R activation through induction of UV-protective skin pigmentation increased DNA repair, and control of aberrant cell growth may reduce the risk of melanoma but importantly does not prevent melanoma particularly in individuals with risk factors and regular skin examination remains critical in high-risk individuals.

Melanocortin agonism in a social context selectively activates nucleus accumbens in an oxytocin-dependent manner

Social deficits are debilitating features of many psychiatric disorders, including autism. While time-intensive behavioral therapy is moderately effective, there are no pharmacological interventions for social deficits in autism. Many studies have attempted to treat social deficits using the neuropeptide oxytocin for its powerful neuromodulatory abilities and influence on social behaviors and cognition. However, clinical trials utilizing supplementation paradigms in which exogenous oxytocin is chronically administered independent of context have failed. An alternative treatment paradigm suggests pharmacologically activating the endogenous oxytocin system during behavioral therapy to enhance the efficacy of therapy by facilitating social learning. To this end, melanocortin receptor agonists like Melanotan II (MTII), which induces central oxytocin release and accelerates formation of partner preference, a form of social learning, in prairie voles, are promising pharmacological tools. To model pharmacological activation of the endogenous oxytocin system during behavioral therapy, we administered MTII prior to social interactions between male and female voles. We assessed its effect on oxytocin-dependent activity in brain regions subserving social learning using Fos expression as a proxy for neuronal activation. In non-social contexts, MTII only activated hypothalamic paraventricular nucleus, a primary site of oxytocin synthesis. However, during social interactions, MTII selectively increased oxytocin-dependent activation of nucleus accumbens, a site critical for social learning. These results suggest a mechanism for the MTII-induced acceleration of partner preference formation observed in previous studies. Moreover, they are consistent with the hypothesis that pharmacologically activating the endogenous oxytocin system with a melanocortin agonist during behavioral therapy has potential to facilitate social learning.

A sentinel population: The public health benefits of monitoring enhanced body builders

There is heightened recognition of the public health implications of anabolic androgenic steroids (AAS) for the use of image and performance enhancement; with increasing evidence of their long-term negative health impacts, the hazards associated with their administration (often via injection), and the variability and unpredictability of their contents. In order to optimise the effects of these drugs, together with strict dietary and training regimes, AAS users typically supplement their use with an expansive and continually evolving range of ancillary drugs. The discovery and subsequent adoption of these drugs by the broader AAS user population is largely dependent upon a minority of social influencers within the bodybuilding community. Pioneering enhanced bodybuilders who self-experiment with a diverse range of image and performance enhancing drugs (IPEDs) and ancillary drugs have been the forerunners in the development of an underground user-led literature, online discussion forums, and were early adopters of internet-facilitated drug markets. Yet the impact of their self-experimentations extends well beyond the enhanced bodybuilding community, particularly in their use of ancillary drugs. Most significantly has been their role in the diffusion of various enhancement and psychoactive drugs to the wider population. Using the theoretical framework of the 'diffusion of innovation' we consider the role that pioneering enhanced bodybuilders have played in the diffusion of various enhancement and psychoactive drugs to the wider population through a focus on three substances: dinitrophenol (DNP), melanotan II and gamma-hydroxybtyrate (GHB). With an increasing range of drugs used by bodybuilders, coupled with an expansion in the use of online forums and online platforms to purchase pharmacological and new psychoactive drugs, we anticipate this trend of diffusion amongst the wider population will continue to flourish. Therefore, we highlight the need for policy makers to monitor emergent trends, not only in the general AAS population but particularly amongst enhanced bodybuilders.