Plasma levels of opioid peptides after sunbed exposures

Influence of ultraviolet A1 exposures on mood states: a randomized controlled study

We investigated the effects of daily ultraviolet A1 (UV-A1, 340-400 nm) exposures on mood states (#R19055, approval on 21 October 2020). Based on our earlier findings of the influence of diurnal preference on mood, we investigated further whether diurnal preference plays a role in the influence of UV-A1 on mood states. Forty-one healthy participants aged 19-55 years were randomized to receive either UV-A1 (n = 21) or control (n = 20) exposures (violet light, 390-440 nm). The irradiations were administered on three consecutive mornings on the skin of the buttocks and middle back. Diurnal preference was assessed with the modified 6-item Morningness-Eveningness Questionnaire (mMEQ). Changes in mood were assessed with Total Mood Disturbance (TMD) score of the 40-item Profile of Mood States (POMS) before the first irradiation, immediately after each irradiation and one week after the last irradiation. Mood improved among those subjected to UV-A1 exposures compared with the controls (p = 0.031). Individuals with more pronounced morningness had mood improvement (p = 0.011), whereas those with more pronounced eveningness did not (p = 0.41). At follow-up of one week after the last irradiation the mood improvement had disappeared.

β-Endorphin mediates radiation therapy fatigue

Fatigue is a common adverse effect of external beam radiation therapy in cancer patients. Mechanisms causing radiation fatigue remain unclear, although linkage to skin irradiation has been suggested. β-Endorphin, an endogenous opioid, is synthesized in skin following genotoxic ultraviolet irradiation and acts systemically, producing addiction. Exogenous opiates with the same receptor activity as β-endorphin can cause fatigue. Using rodent models of radiation therapy, exposing tails and sparing vital organs, we tested whether skin-derived β-endorphin contributes to radiation-induced fatigue. Over a 6-week radiation regimen, plasma β-endorphin increased in rats, paralleled by opiate phenotypes (elevated pain thresholds, Straub tail) and fatigue-like behavior, which was reversed in animals treated by the opiate antagonist naloxone. Mechanistically, all these phenotypes were blocked by opiate antagonist treatment and were undetected in either β-endorphin knockout mice or mice lacking keratinocyte p53 expression. These findings implicate skin-derived β-endorphin in systemic effects of radiation therapy. Opioid antagonism may warrant testing in humans as treatment or prevention of radiation-induced fatigue.

The effect of narrow-band ultraviolet B radiation on sleep, happiness, and appetite: A prospective cohort study

BACKGROUND

The health benefits of sunlight are well documented, including the effects on happiness and sleep. However, only a few studies have investigated the benefits of artificial narrow-band ultraviolet B (NB-UVB) radiation.

OBJECTIVES

To investigate the effect of NB-UVB on sleep quality, happiness, and appetite.

METHODS

Patients from a single phototherapy unit were selected, and their epidemiological characteristics were documented. Subjects were asked to complete questionnaires including the Pittsburg Sleep Quality Index (PSQI), Subjective Happiness Scale (SHS), and the Simplified Nutritional Appetite Questionnaire (SNAQ) 4 weeks before and after the initiation of the NB-UVB therapy. The sample consisted of 52 patients.

RESULTS

Four weeks after the initiation of NB-UVB sessions, sleep quality was significantly improved (the PSQI decreased from 6.5 to 5.23 (t = -3.52, P < .01). In contrast, subjective happiness did not improve (the SHS decreased from baseline 5.5 to 5.2, P > .05). Similarly, appetite did not change (the SNAQ score increased from baseline 14.75 to 15.05, P > .05) and body mass index was not affected by phototherapy. In general, men were found to have better sleep quality before and after UV light therapy.

CONCLUSION

Our data suggest that NB-UVB exposure over 4 weeks improves sleep quality; however, it does not influence happiness or appetite.

Neuropeptides and neurohormones in immune, inflammatory and cellular responses to ultraviolet radiation

Humans are exposed to varying amounts of ultraviolet radiation (UVR) through sunlight. UVR penetrates into human skin leading to release of neuropeptides, neurotransmitters and neuroendocrine hormones. These messengers released from local sensory nerves, keratinocytes, Langerhans cells (LCs), mast cells, melanocytes and endothelial cells (ECs) modulate local and systemic immune responses, mediate inflammation and promote differing cell biologic effects. In this review, we will focus on both animal and human studies that elucidate the roles of calcitonin gene-related peptide (CGRP), substance P (SP), nerve growth factor (NGF), nitric oxide and proopiomelanocortin (POMC) derivatives in mediating immune and inflammatory effects of exposure to UVR as well as other cell biologic effects of UVR exposure.

The Effect of Ultraviolet B Irradiation Compared with Oral Vitamin D Supplementation on the Well-being of Nursing Home Residents with Dementia: A Randomized Controlled Trial

There are indications that ultraviolet B (UVB) exposure has beneficial effects on well-being through mechanisms other than vitamin D synthesis alone. We conducted a randomized controlled multicenter trial to compare the effects of UVB light and vitamin D supplementation (VD) in terms of the well-being of nursing home residents with dementia. Participants were randomly assigned to the intervention group (UVB group, n = 41; half-body UVB irradiation, twice weekly over 6 months, with 1 standard erythema dose (SED)) or to the control group (VD group, n = 37; 5600 International units (IU) cholecalciferol supplementation once a week). The main outcome was well-being, measured by the Cohen-Mansfield Agitation Inventory (CMAI) and the Cornell scale for depression in dementia at 0, 3, and 6 months. Secondary outcomes were QUALIDEM quality of life domains and biochemical parameters of bone homeostasis. Intention-to-treat analysis with linear mixed modeling showed no significant between-group differences on agitation (p = 0.431) or depressive symptoms (p = 0.982). At six months, the UVB group showed less restless/tense behavior compared to the VD group (mean difference of the mean change scores 2.2, 95% CI 0.8 to 3.6; p = 0.003 for group x time interaction) and lower serum 25(OH)D3 concentration (estimated mean difference - 21.9, 95% CI −32.6 to −11.2; p = 0.003 for group difference). The exposure of nursing home residents with dementia to UVB light showed no positive benefits in terms of wellbeing. UVB treatment may have a positive effect on the restless/tense behavior characteristic of advanced dementia but more research is needed to confirm this finding.

Blue light (λ=453 nm) nitric oxide dependently induces β-endorphin production of human skin keratinocytes in-vitro and increases systemic β-endorphin levels in humans in-vivo

β-Endorphin exerts a broad spectrum of physiological activity on mood, immune functions, pain management, reward effects, and behavioral stability. β-Endorphin is produced in certain neurons within the central and peripheral nervous system but also in the skin, especially in response to ultraviolet radiation. In the present study we have investigated the impact of visible blue light at λ = 453 nm (BL) on β-endorphin production of primary human skin keratinocytes (hKC) in-vitro as well as on systemic β-endorphin formation of whole-body exposed subjects in-vivo. We found that BL irradiation significantly enhanced both keratinocytic β-endorphin production of hKC cultures as well as systemic β-endorphin concentrations in light exposed healthy subjects. Interestingly, in hKC cultures elevated β-endorphin formation was paralleled by significantly increased levels of non-enzymatically generated nitric oxide (NO), whereas elevated systemic β-endorphin values of BL-exposed subjects were accompanied by enhanced systemic concentration of bioactive NO-derivates. These findings point to a pivotal role of NO in the molecular mechanism of the observed BL-induced effects, and indeed, exogenously applied NO was able to significantly enhance β-endorphin production in hKC cultures. Thus, our finding of BL-induced increases in systemic β-endorphin concentration in-vivo can be plausibly explained by an event sequence comprising 1.) BL-driven non-enzymatic formation of NO in the exposed skin tissue, 2.) systemic distribution of cutaneously produced NO in the form of bioactive nitroso compounds, 3.) a subsequent NO-dependent induction of β-endorphin synthesis in epidermal keratinocytes, and 4.) probably also a NO-dependent modulation of β-endorphin synthesis in specialized neurons within the central and peripheral nervous system.

Tanning dependence and seasonal affective disorder are frequent among sunbathers but are not associated

Ultraviolet radiation (UVR) is a known risk factor for skin cancers. Those who are tanning dependent seek out UVR exposure. Many tanners have expressed symptoms of seasonal affective disorder (SAD), but conclusive evidence of a connection with tanning dependence is lacking. We evaluated the frequency of tanning dependence or abuse and symptoms of SAD among Finnish sunbathers and analysed whether phenomena are associated which could indicate a common biological mechanism. Sunbathing related tanning dependence/abuse among Finnish sunbathers were assessed using the Structured Interview for Tanning Abuse and Dependence measure (SITAD), and symptoms of SAD were assessed with the Seasonal Pattern Assessment Questionnaire (SPAQ). Of 229 sunbathers, 8% (n = 18) were classified as tanning-dependent, and 26% (n = 59) were classified as tanning abusers. Additionally, 16% (n = 37) met the criteria for SAD, and 26% (n = 60) met the criteria for subsyndromal seasonal affective disorder (S-SAD), but there was no significant association between tanning dependence or abuse and SAD or S-SAD. Sunbathing dependence or abuse and SAD/S-SAD were frequent among sunbathers, and they may promote sun-seeking risk behaviour. However, within this sample, tanning dependence and SAD/S-SAD were not associated.

Serum endocannabinoids and N-acyl ethanolamines and the influence of simulated solar UVR exposure in humans in vivo

Solar ultraviolet radiation (UVR) exposure of human skin has beneficial and harmful effects on health, including impact on immune function, inflammation and reportedly mood, but these are not fully elucidated. Since the endocannabinoid system is implicated in many activities including mood alteration, our objective was to (i) determine and quantify circulating levels of a wide range of endocannabinoid and N-acyl ethanolamine (NAE) species (ii) evaluate whether these are modulated by cutaneous UVR exposures, as attained through repeated low level summer sunlight exposure. Wearing goggles to prevent eye exposure, 16 healthy volunteers (23-59 y; 10 light skin, phototype II, and 6 dark skin, phototype V) received the same UVR exposures (1.3 SED, 95% UVA/5% UVB) thrice weekly for 6 weeks, whilst casually dressed to expose ∼35% skin surface area. Blood samples were taken at baseline, days 1, 3 and 5 of week one, then at weekly intervals, and analysed by LC-MS/MS. Eleven endocannabinoids and NAEs were detected and quantified at baseline, with N-palmitoyl ethanolamine the most abundant (30% of total). Levels did not vary according to phototype (p > 0.05), except for the NAE docosapentaenoyl ethanolamide, which was higher in phototype II than V (p = 0.0002). Level of the endocannabinoid, 2-AG, was elevated during the UVR exposure course (p < 0.05 vs. baseline for all subjects; p < 0.01 for each phototype group), with maximum levels reached by week 2-3, while NAE species did not significantly alter. These findings suggest differential involvement of the cutaneous endocannabinoid system in low dose solar UVR responses in humans.

Tanning as a substance abuse

While few people would deny the appeal of a day in the sun there are some who seem to take it too far. In recent years the concept of ‘tanning addiction’ has become popular and several studies have supported the notion of viewing exposure to UV radiation as a form of substance abuse. In this article we will review some of the literature on sun seeking behavior.

Skin β-endorphin mediates addiction to UV light

UV light is an established carcinogen, yet evidence suggests that UV-seeking behavior has addictive features. Following UV exposure, epidermal keratinocytes synthesize proopiomelanocortin (POMC) that is processed to melanocyte-stimulating hormone, inducing tanning. We show that, in rodents, another POMC-derived peptide, β-endorphin, is coordinately synthesized in skin, elevating plasma levels after low-dose UV. Increases in pain-related thresholds are observed and reversed by pharmacologic opioid antagonism. Opioid blockade also elicits withdrawal signs after chronic UV exposure. This effect was sufficient to guide operant behavioral choices to avoidance of opioid withdrawal (conditioned place aversion). These UV-induced nociceptive and behavioral effects were absent in β-endorphin knockout mice and in mice lacking p53-mediated POMC induction in epidermal keratinocytes. Although primordial UV addiction, mediated by the hedonic action of β-endorphin and anhedonic effects of withdrawal, may theoretically have enhanced evolutionary vitamin D biosynthesis, it now may contribute to the relentless rise in skin cancer incidence in humans.

Phenomenology and psychopathology of excessive indoor tanning

Excessive indoor tanning, defined by the presence of an impulse towards and repetition of tanning that leads to personal distress, has only recently been recognized as a psychiatric disorder. This finding is based on the observations of many dermatologists who report the presence of addictive relationships with tanning salons among their patients despite being given diagnoses of malignant melanoma. This article synthesizes the existing literature on excessive indoor tanning and addiction to investigate possible associations. This review focuses on the prevalence, clinical features, etiology, and treatment of this disorder. A literature review was conducted, using PubMed, Google Scholar, EMBASE and PsycINFO, to identify articles published in English from 1974 to 2013. Excessive indoor tanning may be related to addiction, obsessive-compulsive disorder, impulse control disorder, seasonal affective disorder, anorexia, body dysmorphic disorder, or depression. Excessive indoor tanning can be included in the spectrum of addictive behavior because it has clinical characteristics in common with those of classic addictive disorders. It is frequently associated with anxiety, eating disorders, and tobacco dependence. Further controlled studies are required, especially in clinical psychopathology and neurobiology, to improve our understanding of excessive indoor tanning.

Teens and indoor tanning: a cancer prevention opportunity for pediatricians

In October 2011, California became the first US state to ban indoor tanning for minors under age 18 years. Vermont followed in May 2012. Increasingly, scientific evidence shows that artificial tanning raises the risk of skin cancer, including melanoma, a common cancer in adolescents and young adults and the type most likely to result in death. The World Health Organization, the American Academy of Pediatrics, the American Academy of Dermatology, the American Medical Association, and other organizations strongly recommend legislation to ban minors under age 18 from indoor tanning. Several nations have banned teen tanning. Yet, tanning in salons is still a prevalent practice in the United States, especially among teen girls, where rates for the oldest teens approach 40%. There is no federal legislation to restrict minors from salon tanning. More than 60% of states have some kind of legislation regarding minors' use of tanning salons, but only California and Vermont have passed complete bans of indoor tanning for minors. The Indoor Tanning Association, an industry advocacy group, has vigorously opposed legislative efforts. Pediatricians can play key roles in counseling families and with legislative efforts. In this update, we review the prevalence of salon tanning, association with skin cancer risk, tanning addiction, the roles of the federal and state governments in regulation and legislation, and responses to arguments created by industry to oppose legislation. Preventing exposure to artificial tanning may save lives, including young lives, and is a key cancer prevention opportunity for pediatricians.

Beneficial effects of UV radiation other than via vitamin D production

Most of the positive effects of solar radiation are mediated via ultraviolet-B (UVB) induced production of vitamin D in skin. However, several other pathways may exist for the action of ultraviolet (UV) radiation on humans as focused on in this review. One is induction of cosmetic tanning (immediate pigment darkening, persistent pigment darkening and delayed tanning). UVB-induced, delayed tanning (increases melanin in skin after several days), acts as a sunscreen. Several human skin diseases, like psoriasis, vitiligo, atopic dermatitis and localized scleroderma, can be treated with solar radiation (heliotherapy) or artificial UV radiation (phototherapy). UV exposure can suppress the clinical symptoms of multiple sclerosis independently of vitamin D synthesis. Furthermore, UV generates nitric oxide (NO), which may reduce blood pressure and generally improve cardiovascular health. UVA-induced NO may also have antimicrobial effects and furthermore, act as a neurotransmitter. Finally, UV exposure may improve mood through the release of endorphins.

Cutaneous hypothalamic-pituitary-adrenal axis homolog: regulation by ultraviolet radiation

The hypothalamic-pituitary-adrenal (HPA) axis maintains basal and stress-related homeostasis in vertebrates. Skin expresses all elements of the HPA axis including corticotropin-releasing hormone (CRH), proopiomelanocortin (POMC), ACTH, β-endorphin (β-END) with corresponding receptors, the glucocorticoidogenic pathway, and the glucocorticoid receptor (GR). To test the hypothesis that cutaneous responses to environmental stressors follow the organizational structure of the central response to stress, the activity of the "cutaneous HPA" axis homolog was investigated after exposure to ultraviolet radiation (UVR) wavelengths of UVA (320-400 nm), UVB (280-320 nm), and UVC (100-280 nm) in human skin organ culture and in co-cultured keratinocytes/melanocytes. The level of stimulation of CRH, POMC, MC1R, MC2R, CYP11A1, and CYP11B1 genes was dependent on UV wavelengths and doses, with the highest effects observed for highly energetic UVC and UVB. ELISA and Western assays showed significant production of CRH, POMC, ACTH, and CYP11A1 proteins and of cortisol, with a decrease in GR expression only after UVB and UVC. However, β-END expression was also stimulated by UVA. Immunocytochemistry localized the deposition of the aforesaid antigens predominantly to the epidermis with additional accumulation of CRH, β-END, and ACTH in the dermis. UVR-stimulated CYP11A1 expression was seen in the basal layer of the epidermis and cells of adjacent dermis. Thus, the capacity to activate or change the spatial distribution of the cutaneous HPA axis elements is dependent on highly energetic wavelengths (UVC and UVB), implying a dependence of a local stress response on their noxious activity with overlapping or alternative mechanisms activated by UVA.

Indoor tanning, mental health, and substance use among college students: the significance of gender

This study examined relations among indoor tanning frequency, symptoms of depression, anxiety, and obsessive-compulsive disorder, and substance use. A total of 421 college students (68% female) completed self-report measures on one occasion. Among men, indoor tanning was positively associated with symptoms of anxiety and obsessive-compulsive disorder, whereas indoor tanning was unrelated to these symptoms among women. Among women, indoor tanning was positively associated with the use of alcohol, tobacco, and other substances. Further research is needed to explore contextual and coping processes that may underlie these gender differences.

Ultraviolet tanning addiction

Behavioral studies of ultraviolet light exposure behavior have provided insight into motivations for tanning, which include not only the desire for a tanned appearance but also the physiologic response to ultraviolet light. Many frequent tanners continue to tan despite knowledge or personal experience of adverse consequences. Efforts to reduce tanning behavior need to account for the interplay between physiologic effects of tanning and psychosocial drives behind tanning behavior.

The benefits and risks of ultraviolet tanning and its alternatives: the role of prudent sun exposure

Sunlight- and indoor ultraviolet (UV)-induced tanning is a common behavior, especially among adolescents, young adults, and individuals who have lighter skin. Excessive sun exposure is associated with several health risks, including the acceleration of skin aging and the promotion of skin cancers. Several health benefits of UV exposure include vitamin D production and improved mood. This article analyzes these health risks and benefits and discusses pertinent issues surrounding indoor tanning, the role of sunless tanning products, and prudent sun exposure.

The benefits and risks of ultraviolet tanning and its alternatives: the role of prudent sun exposure

Sunlight- and indoor ultraviolet (UV)-induced tanning is a common behavior, especially among adolescents, young adults, and individuals who have lighter skin. Excessive sun exposure is associated with several health risks, including the acceleration of skin aging and the promotion of skin cancers. Several health benefits of UV exposure include vitamin D production and improved mood. This article analyzes these health risks and benefits and discusses pertinent issues surrounding indoor tanning, the role of sunless tanning products, and prudent sun exposure.

A preliminary investigation of the predictors of tanning dependence

OBJECTIVES

To investigate possible predictors of tanning dependence including demographic variables, exposure and protective behaviors, and other health-related behaviors.

METHODS

This study consisted of an online survey of 400 students and other volunteers from a university community.

RESULTS

Twenty-seven percent of the sample was classified as tanning dependent. Tanning dependence was predicted by ethnicity and skin type, indoor and outdoor tanning and burning, and lower skin protective behaviors, as well as smoking and body mass index.

CONCLUSIONS

Young adults are at risk for tanning dependence, which can be predicted by specific demographic and behavioral variables.

Artificial and natural ultraviolet radiation exposure: beliefs and behaviour of 7200 French adults

BACKGROUND

Despite the increasing use of indoor tanning facilities, little is known regarding the behaviour of adults with respect to artificial and natural ultraviolet (UV) radiation exposure and the relationship between the two forms of exposure.

OBJECTIVES

To describe the beliefs and behaviour of French middle-aged volunteers regarding artificial and natural UV exposure.

METHODS

Cross-sectional study of a French national cohort using a self-completed questionnaire.

RESULTS

Participants were identified as 'indoor UV tanners' (n= 1076) and as 'non-users' (n= 6124). Predictor factors associated with indoor tanning were gender, age, smoking, phototype, region of residence, sun exposure during hobbies, voluntary sun exposure in particular during the hottest hours of the day, nudism practice, facial sunscreen habits, sunglass use, importance for lying in the sun and the claim 'ever heard of melanoma'.

LIMITATIONS

The quality of information may be limited by the data collection method.

CONCLUSION

Whereas indoor tanning should be discouraged, it seems that indoor tanners are also regular sunbathers unconcerned about the risk of photoageing and skin cancer occurrence. Moreover, indoor tanners seem to have more behavioural risk factors for cancer, such as smoking.

The effect of physical therapy on beta-endorphin levels

Beta-endorphin (betaE) is an important reliever of pain. Various stressors and certain modalities of physiotherapy are potent inducers of the release of endogenous betaE to the blood stream. Most forms of exercise also increase blood betaE level, especially when exercise intensity involves reaching the anaerobic threshold and is associated with the elevation of serum lactate level. Age, gender, and mental activity during exercise also may influence betaE levels. Publications on the potential stimulating effect of manual therapy and massage on betaE release are controversial. Sauna, mud bath, and thermal water increase betaE levels through conveying heat to the tissues. The majority of the techniques for electrical stimulation have a similar effect, which is exerted both centrally and--to a lesser extent--peripherally. However, the parameters of electrotherapy have not yet been standardised. The efficacy of analgesia and the improvement of general well-being do not necessarily correlate with betaE level. Although in addition to blood, increased brain and cerebrospinal fluid betaE levels are also associated with pain, the majority of studies have concerned blood betaE levels. In general, various modalities of physical therapy might influence endorphin levels in the serum or in the cerebrospinal fluid--this is usually manifested by elevation with potential mitigation of pain. However, a causal relationship between the elevation of blood, cerebrospinal fluid or brain betaE levels and the onset of the analgesic action cannot be demonstrated with certainty.

Central role of p53 in the suntan response and pathologic hyperpigmentation

UV-induced pigmentation (suntanning) requires induction of alpha-melanocyte-stimulating hormone (alpha-MSH) secretion by keratinocytes. alpha-MSH and other bioactive peptides are cleavage products of pro-opiomelanocortin (POMC). Here we provide biochemical and genetic evidence demonstrating that UV induction of POMC/MSH in skin is directly controlled by p53. Whereas p53 potently stimulates the POMC promoter in response to UV, the absence of p53, as in knockout mice, is associated with absence of the UV-tanning response. The same pathway produces beta-endorphin, another POMC derivative, which potentially contributes to sun-seeking behaviors. Furthermore, several instances of UV-independent pathologic pigmentation are shown to involve p53 "mimicking" the tanning response. p53 thus functions as a sensor/effector for UV pigmentation, which is a nearly constant environmental exposure. Moreover, this pathway is activated in numerous conditions of pathologic pigmentation and thus mimics the tanning response.

Do adolescent indoor tanners exhibit dependency?

BACKGROUND

Indoor tanning is a common adolescent risk behavior that has been hypothesized to be motivated and maintained by the mood-altering effects of ultraviolet light.

OBJECTIVE

Our purpose was to explore heretofore anecdotal reports that indoor tanning leads to dependency.

METHODS

A telephone interview was conducted among 1275 adolescents, ages 14 to 17 years. Self-reported difficulty in quitting indoor tanning was assessed among 267 adolescents (20.9% of total) who tanned indoors more than once in the previous year in relation to age of initiation, frequency of use, and positive or negative consequences of the practice.

RESULTS

Difficulty in quitting was more likely with younger age at initiation (age 13 years or younger vs ages 16 to 17; odds ratio = 4.3, 95% confidence interval 1.3-14.7) and higher frequency of use (P = .009), even after accounting for positive or negative consequences of indoor tanning and other demographic characteristics.

LIMITATIONS

This was a cross-sectional study design with a limited outcome measure.

CONCLUSION

Although preliminary, our findings for age at initiation and frequency of use in relation to difficulty in quitting indoor tanning are consistent with other potentially addictive behaviors taken up during adolescence.

Ultraviolet exposure is a reinforcing stimulus in frequent indoor tanners

BACKGROUND

Investigations into tanners' reasons for tanning have focused primarily on the perception of improved appearance. Reported relaxing effects of tanning suggest the possibility of a physiologic effect of UV that drives tanning behavior.

OBJECTIVE

We sought to determine if there is a physiologic reinforcing effect of UV exposure, separate from appearance motivation, that may contribute to tanning behavior.

METHODS

We determined the reinforcing effect of UV light in a series of controlled, blinded, repeated-choice trials of UV carefully designed to separate as cleanly as possible reinforcing effects of UV exposure from other factors including perceived benefits of having a tan. A total of 14 young adults who used tanning beds regularly were exposed to otherwise identical UV and non-UV tanning bed stimuli on Mondays and Wednesdays for 6 weeks. On Fridays, participants had concurrent access to the two beds. The primary dependent variable was the percentage of choice sessions during which more UV than non-UV tanning was chosen.

RESULTS

In all, 12 participants chose additional tanning exposure on Fridays and, of these, 11 consistently used the UV bed for that exposure. Of the total 41 occasions when participants chose to tan on Friday, 39 sessions (95%) were for the UV bed and only two for the non-UV bed. A more relaxed and less tense mood was reported after UV exposure compared with after non-UV exposure (P=.008 and P=.002, respectively).

DISCUSSION

When exposed to UV and non-UV under blinded conditions, frequent tanners can distinguish the two conditions and undertake further UV exposure, indicating that UV is a reinforcing stimulus. The relaxing and reinforcing effects of UV exposure contribute to tanning behavior in frequent tanners and should be explored in greater detail.

No significant change of plasma beta-endorphin levels of psoriasis patients after synchronous balneophototherapy

BACKGROUND/PURPOSE

Previous studies suggested that beta-endorphin has a pathogenic role in psoriasis: its increased plasma concentration may play a role in the neuroimmunological processes in the pathomechanism of the disease, and plasma beta-endorphin levels should reflect the changes in the patients' skin status. The purpose of this study was to investigate the changes of peripheral blood beta-endorphin levels in psoriatic patients in conjunction with changes in their skin symptoms after synchronous balneophototherapy.

METHODS

With synchronous balneophototherapy, 12 patients with extended skin symptoms of psoriasis were treated. The therapy followed the Regensburg protocol, consisting of a basic course of 35 sessions. Patients' skin status was characterized by evaluating the Psoriasis Area and Severity Index score before and after the therapy course. Blood samples were taken before treatment, and 1 day after the last session, with symptom-free skin. Plasma beta-endorphin levels were measured by a specific radioimmunoassay developed by the authors.

RESULTS

There was no significant change in plasma levels of beta-endorphin after clinical clearance of psoriatic skin symptoms.

CONCLUSION

In this non-randomized, uncontrolled study no significant difference could be detected between plasma beta-endorphin levels before and after a basic course of synchronous balneophototherapy in patients with psoriasis. Although beta-endorphin has many neuroimmunological effects, the changes of its plasma level do not consistently reflect the skin status. Inflammation in psoriatic skin lesions is probably not mediated directly by circulating beta-endorphin.

Solar-Simulated Ultraviolet Radiation-Induced Upregulation of the Melanocortin-1 Receptor, Proopiomelanocortin, and α-Melanocyte-Stimulating Hormone in Human Epidermis In Vivo

Ultraviolet light is one of the most crucial environmental factors with regard to its capacity to induce skin cancer, premature aging of the skin, and immunosuppression. Although ultraviolet directly affects the function of epidermal cells, many of these effects are mediated by induction of cytokines, growth factors, and neuropeptides, such as alpha-melanocyte-stimulating hormone. Recently, in addition to its well-known pigmentation inducing activity, a strong anti-inflammatory as well as an immunomodulatory potential of alpha-melanocyte-stimulating hormone has been recognized. The aim of this study was to determine, whether ultraviolet irradiation affects the expression of both alpha-melanocyte-stimulating hormone and the melanocortin-1 receptor in human epidermis in vivo. The volar aspects of the forearms were exposed to twice the minimal erythema dose of solar-simulating radiation. Three, 6, and 24 h after irradiation, the proopiomelanocortin and interleukin-10 mRNA levels in suction blister induced epidermal sheets were considerably upregulated as detected by semiquantitative reverse transcription-polymerase chain reaction. Furthermore, alpha-melanocyte-stimulating hormone and interleukin-10 protein levels in blister fluids were significantly increased 24 h after ultraviolet irradiation, an effect that could be abolished by application of the broad-spectrum sunscreen Anthélios XL prior to ultraviolet (solar-simulating radiation) exposure. In addition, enhanced melanocortin-1 receptor mRNA and receptor protein expression upon solar-simulating radiation was ascertained by reverse transcription-polymerase chain reaction and immunohistochemistry of the epidermal sheets, respectively. Proopiomelanocortin-derived neuropeptides, such as alpha-melanocyte-stimulating hormone may therefore play an important part in modulating ultraviolet-induced inflammation.