PT-141 is a cyclic heptapeptide melanocortin analog which has been documented as being an intranasal treatment for erectile dysfunction . In addition, PT-141 is a seven amino acid analogue of the peptide known as alpha-melanocyte-stimulating hormone (a-MSH) . PT-141 has been heralded as a promising therapeutic agent for the treatment of erectile dysfunction .
PT-141 (Figure 1), also known as Bremelanotide, was initially synthesized from the Melanotan-2 peptide; in effect, it works by activating melanocortin receptors in the brain, increasing one’s sexual drive. It has a molar mass of 1,025.2 g/mol and an elimination half-life of 120 minutes in the body.
How it works
PT-141 is a melanocortinergic compound which acts on the melanocortinergic (MC) system . PT-141 function as a synthetic a-melanocyte stimulating hormone . Briefly, the melanocortinergic system is responsible for a range of physiological effects such as, skin pigmentation, salt and food intake regulation, sexual behaviour and penile erection . Moreover, PT-141, as a synthetic heptapeptide, binds to MC receptors 1, 3 and 4 – PT-141 shows high affinity for MC4R compared to MC3R . In addition, PT-141 is considered an active metabolite of melanotan II . The MC3R and MC4R receptors are primarily expressed in the central nervous system (CNS). Specifically, the MCR3 receptor is expressed in the brain, placenta, gut, heart and testis; the MCR4 receptor shows expression in the brain and adipose tissue .