Methyl Nicotinate-Induced Vasodilation in Generalized Social Phobia

Abstract

Elevated vasodilatory response (blushing) to social situations is characteristic of social phobia (SP). A relatively unexplored basis for this phenomenon is alteration in underlying vasodilatory mechanisms. To investigate this possibility, we evaluated the vasodilatory response induced by methyl nicotinate (niacin ester derivative) in 31 generalized SP patients and 41 matched healthy volunteers (HV). A patch impregnated with 0, 0.1, 0.5, 1, and 10 mM methyl nicotinate was applied to the forearm or face of subjects for 1 min, followed by 20-min laser Doppler spectroscopy blood flow monitoring. Blood flow stimulation with 1 and 10 mM methyl nicotinate was significantly reduced in SP patients by 35 and 17%, respectively. Induced blood flow was negatively correlated with patients' Leibowitz Social Phobia Scale (LSAS) at 1 and 10 mM doses. Furthermore, the maximal rate of change of vasodilatory reaction was correlated with symptom scores at 1 and 10 mM doses. Induced increases in the arm and face blood flow measurements correlated, supporting the external validity of the former location. Generalized SP patients vasodilate less to topical methyl nicotinate challenges, with effect amplification in severely ill patients. Although the mechanism for this is unclear, we propose desensitization of the prostaglandin-mediated vasodilating system as an explanation.

Anticellulite efficacy of Trichilia catigua and Ptychopetalum olacoides Bentham extracts

“…Initially, the positive control comprised of methyl nicotinate caused an increase in the skin temperature, from 31.94 to 32.46 º C, 40 minutes following the application, unlike placebo and the test product. The observed increase in this parameter was expected as methyl nicotinate is rubefacient and vasodilator [19]. In the same period of time, the test product containing Trichilia da coxa e do abdômen receberam uma aplicação do produto teste.…”

“…Inicialmente, o controle positivo composto por nicotinato de metila causou aumento da temperatura da pele, de 31,94 a 32,46ºC, após 40 min de aplicação, ao contrário do placebo e do produto teste. O aumento observado neste parâmetro já era esperado, uma vez que o nicotinato de metila é rubofaciente e vasodilatador [19].…”

Establishing a Minimal Erythema Concentration of Methyl Nicotinate for Optimum Evaluation of Anti-Inflammatories

“…In addition, circadian rhythms are reported to infl uence the vasodilatory response to methyl nicotinate, with maximal onset responses occurring in early morning hours and minimal onset responses occurring at midday [23] . Finally, individuals with generalized social phobia present a varied response in vasodilation induced by methyl nicotinate compared with a normal population [7] . Taken together, these fi ndings establish that the vasodilatory response to methyl nicotinate can be readily infl uenced by numerous factors including skin hydration, emotional state and time of day.…”

“…NICU-inducing substances include benzoic acid, sorbic acid and nicotinic acid derivatives, such as methyl nicotinate [5] . Methyl nicotinate is a water-soluble derivative of nicotinic acid that has been shown to rapidly induce a transient localized infl ammatory response [6] through vasodilation of dermal capillaries when applied to skin [7,8] . Many in-…”

Stability of methylnicotinate in aqueous solution as utilized in the 'niacin patch test'

“…Methylnicotinate has found application as a rubefacient [ 4 ] and in the development and testing of anti-inflammatory drugs [ 5 ]. Topical application of methylnicotinate has also been used to investigate the inflammatory response in a variety of disorders including autism [ 6 ], Huntington's disease [ 7 ], social phobia [ 8 ], major depressive disorder [ 9 , 10 ] and schizophrenia [ 3 , 10 - 18 ]. In this latter application varying doses of methynicotinate are applied to the skin (normally the forearm) in the form of a patch (frequently, if inaccurately, referred to as a 'niacin patch').…”