Effect of exogenous melatonin and flaxseed oil on the expression state of MT1 receptors in rat skin under light deprivation

Abstract

Most of the skin cells have their own autonomous functional circadian system, which is able to control physiological and biochemical processes in the general integument. A special role in these processes is assigned to the “clock” hormone of the pineal gland, melatonin, which acts on target cells through specific receptors (MT1, MT2, MT3 and RORα). Any disturbance of circadian rhythms can lead to rearrangements (disturbances) in the receptor apparatus of the cells of the general cover, which require a certain correction. Consequently, there is a need to search for effective and reliable drugs that will prevent the negative consequences caused by chronodestruction. In the present work, we studied the effectiveness of the effect of exogenous melatonin and flaxseed oil on the expression of MT1 receptors in the general coat of rats under light deprivation. An experimental study was carried out on 130 white outbred male rats (170-220 g), which were randomly divided into 5 groups: intact, light deprivation animals, light deprivation animals, which were injected intragastrically with flaxseed oil and melatonin. On days 7, 14 and 21, histological material was taken (fragments of the skin of the interscapular region of the back). For immunohistochemical studies, serial sections were stained using MTNR1A polyclonal antibodies. For morphometric data analysis, the Image Scope Color and ImageJ computer programs were used. All statistical data processing was performed using the Statistica 10.0 software. Differences were considered significant at a significance level of less than 0.01 (p <0.01). In the course of the experiment, it was found that light deprivation contributes to a change in the activity of expression of the MT1 melatonin receptors in the epidermis, sebaceous glands and hair follicles. Studies have shown that the administration of flaxseed oil, melatonin, and their combination to rats with desynchronosis is accompanied by the leveling of the adverse effect of desynchronosis on the studied parameters of MT1 receptors. The most pronounced corrective effect on the expression of MT1 receptors is observed with the introduction of exogenous melatonin on the 21st day of the experiment.

Expression of 5-HT1A receptors in skin of rats under dark deprivation

“…Это подтверждается ранее высказанным предположением о локализации 5-HTR1A-рецепторов в эпидермисе [16,18,19]. Аналогичное распределение в активно дифференцирующихся клетках иммуногистохимической позитивности наблюдалось и при исследовании рецепторов к мелатонину МТ1 [2,17]. Это может служить подтверждением того, что пролиферативная активность кератиноцитов эпидермиса, а также его барьерно-защитные свойства находятся в непосредственной зависимости от уровней гормонов мелатонина и серотонина.…”

“…Учитывая тот факт, что максимальная выработка данного гормона наблюдается в дневное время, можно предположить, что в ответ на круглосуточное пребывание при свете происходит увеличение уровня серотонина. Подтверждением этого могут выступать полученные авторами ранее данные по изменению экспрессии рецепторов мелатонина МТ1 при темновой депривации [2,17]. Так, при аналогичных условиях эксперимента отмечалось компенсаторное возрастание экспрессии МТ1-рецепторов на поверхности кератиноцитов и себоцитов в ответ на снижение количества высвобождаемого мелатонина.…”