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We studied by the Sebutape technique variations in the sebum excretion and in the number of active sebaceous glands during 3 consecutive menstrual cycles. In seborrheic women we found cyclic changes with a maximum sebum excretion during the week before menstruation. In women with a low sebum production, no changes were found.
We have evaluated the normal variations in the sebum excretion rate from follicle to follicle on the forehead by using the noninvasive techniques of the Lipometre and Sebutape. For a given overall amount of sebum excreted to the surface of the skin during a limited period of time, both the number of active sebaceous follicles and the amount of lipids excreted by them may vary. Significant intraindividual and interindividual differences may be found for these parameters. Such a noninvasive approach to the biology of sebaceous glands represents a new tool allowing a precise evaluation of diseases of the sebum excretion and of their treatments.
Altogether 30 patients (19 females and 11 males), mean age 19 years, were divided randomly into two groups. All patients had chronic papulopustular acne of the face. A total of 15 patients were treated topically with Silicol gel for 20 min twice daily for 6 weeks and the remaining 15 patients were treated with a placebo gel in a similar fashion. A clinical evaluation was carried out at baseline, and after 2, 4 and 6 weeks of treatment. The clinical variables evaluated were as follows: number of comedones, papules, pustules and cysts on a standard area of the left cheek (area 5 x 5 cm) and measurement of sebum production on the same area by the use of Sebumeter SM 810 PC (Courage and Khazaka, Ltd, Germany). No concomitant treatment was allowed during the study period. One patient using Silicol gel withdrew after 2 weeks of treatment because of severe irritation of the facial skin, leaving 29 patients who could be evaluated. In the active group, the number of comedones decreased from a mean of 48.5 to 15.1 after 6 weeks of treatment. The corresponding figures for papules were 10.7 and 1.0, for pustules 6.8 and 0, and for cysts 0.6 and 0. In the placebo group no improvement could be observed. There was a highly significant difference in efficacy between the two groups (P < 0.001) in favour of the actively treated group. The mean sebum index was 193 at baseline and 88 after 6 weeks. Correspondingly in the placebo group the mean sebum index at baseline was 187 and after 6 weeks 179. This difference between the two groups was also statistically significant (P < 0.001). After a short follow-up period (3 months) no deterioration was observed in the 14 'active' patients, showing either complete cure or improvement.
Newborn Sprague-Dawley rats of both sexes were treated with 28 micrograms thyroxine (T4) daily for the first week of life. At the age of 80 days, the secretion rate of sebum was measured from the amount of skin-surface lipids extractable by acetone and which had been produced during 2 days. Treatment with such excess amounts of T4 during the early postnatal period significantly reduced the production of sebum in both male and female rats when compared with control rats and with rats deprived of food early in life. The thyroid, the pituitary gland, the testes and the seminal vesicles were significantly smaller but the weights of the ovaries and uteri remained relatively unaffected. There was a similar ratio of sex difference in the rate of sebum secretion irrespective of treatment. It is suggested that a reduction of sebaceous response in rats made thyrotoxic with large doses of T4 early in life was probably due to a decreased secretion of thyroid hormone which is required to maintain normal activity of the sebaceous glands.
Newborn Sprague-Dawley rats were castrated within 24 h of birth and control animals were sham-operated. Intact female rats were also included for comparison. One-half of the rats in each group was treated with 28 micrograms thyroxine (t4) daily for the first week of life. The secretion rate of sebum was measured at the age of 80 days from the amount of skin-surface lipids that could be extracted with acetone and which had been produced during 2 days. Castration of rats at birth decreased the rate of sebum secretion and neonatal castration plus neonatal thyrotoxicosis produced an even lower level of sebum which more nearly approached that seen in female rats with neonatal T4 treatment. It was concluded that a reduction in the response of the sebaceous glands in adult rats made thyrotoxic with high doses of T4 in the early stage of life is not due to a decreased secretion of gonadal steroids.
The distribution of terbinafine in stratum corneum dermis-epidermis (without stratum corneum), sebum, hair, nails and plasma was studied in human male volunteers during and after 250 mg orally once daily for 28 days. The highest concentration was seen in sebum, 56.07 micrograms/g, after 14 days of therapy. The concentration was still 1.0 microgram/g 44 days after stop of medication. In stratum corneum the highest concentration, 14.4 micrograms/g, was seen 1 day after the last day of therapy, and it was 2.1 micrograms/g 44 days after stop of medication. The concentrations in hair and nails were lower with a maximum of 2.36 and 0.39 micrograms/g respectively, 1 day after stop of therapy, and still 0.21 microgram/g in hair and 0.09 microgram/g in nails 55 days after the last day of medication. With the exception of nails, all other tissue levels were at all times above the plasma concentrations. For nails, tissue levels exceeded that of plasma as early as 1 day after stop of medication, and this difference continued to increase until the last day of tissue sampling, 55 days after the last tablet. These results indicate that terbinafine is delivered to the stratum corneum through sebum and to a minor extent by direct diffusion through dermis-epidermis. Probably short-term therapy with terbinafine may be effective in the treatment of several dermatomycoses, due to the strong binding of terbinafine to stratum corneum for a long time after stop of medication.(ABSTRACT TRUNCATED AT 250 WORDS)
Concentrations of fluconazole in sebum and plasma were determined in 2 parallel groups, each consisting of 8 healthy subjects. Group 1 received a 150 mg fluconazole capsule once weekly over a period of 4 weeks, Group 2 was administered 2 capsules/week, corresponding to 300 mg fluconazole/week for 4 weeks. Sampling was performed immediately before and 5 hours after dosing, and at intervals up to 2 weeks after the last dose. Fluconazole concentrations were determined by a specific and highly sensitive gas chromatographic method. Both treatments were well tolerated. Maximum fluconazole concentrations (mean +/- SD) in plasma were 3.5 +/- 1.0 microg/ml (Group 1) and 5.5 +/- 1.0 microg/ml (Group 2); maximum sebum concentrations were 11.0 +/- 8.4 microg/g (Group 1) and 48.4 +/- 37.0 microg/g (Group 2). Significant accumulation of fluconazole in sebum relative to plasma was observed. Sebum/plasma ratios ranged from 1.6 to 6.5 (Group 1) and from 4.3 to 27.9 (Group 2), with median ratios of 2.4 and 9.1, respectively. The overall accumulation factor was 7. The findings may be of particular relevance for the treatment of dermal mycoses involving the sebaceous glands, especially those associated with hair, such as tinea capitis.
The aims of this study were to investigate the effect of UVA and UVB on comedones and sebum secretion in acne patients. Thirteen acne patients were irradiated by UVA (starting from 20J/cm2 and increasing 10% every day) and UVB (starting from 2/3 MED and increasing 10% every day). IL-1alpha, IL-6, IL-1 receptor antagonist (IL-1ra), IL-10 and GM-CSF were measured by ELISA. Measurement of sebum level was also performed. Sebum level was increased in the first three days by UVA (18.4 --> 37.6 microg/cm2) and UVB (19.1 --> 40.0 microg/cm2), but subsequently returned to normal values. Production of IL-1alpha, IL-1ra, IL-6, and IL-10 was generally higher on day 5 than on day 10. GM-CSF was not detected from all comedones. After UV irradiation, clinically stationary acne patients showed a higher increase in cytokine production compared with improved acne patients. It is suggested that IL-10 & IL-1ra have key roles in this cytokine network as the anti-inflammatory comedonal cytokines. They may play important roles in the immuno-regulation, which may be disturbed in stationary acne patients.
To allow cleaning of sebum ducts for acne prophylaxis the authors suggest use of triethanolamine buffered with anionic polymers of acrylic and methacrylic acid. In these preliminary researches addition of Eudragit L-100, Eudragit L-100-55 or Eudragit S-100 implicates decrease of pH of 1.49% triethahnolamine solution from 10.06 even to 7.20. Triethanolamine penetrates into the artificial skin sebum, gains hydrophylic properties, and reacted sebum increase in volume allowing mechanical remove of lipid bed. The highest triethanolamine penetration and the highest volume increase were observed after application of Eudragit S-100 complexes. Eudragit L-100 and L-100-55 proved milder action. These complexes may be applied for further examinations on acne prevention.
In an investigation into the effect of short-term exposure to different temperatures and humidities on the sebaceous glands of Ayrshire calves it was concluded that temperature had no appreciable effect on sebum output or its fatty acid composition. At a low humidity, however, the cutaneous outputs of palmitic and myristic acids were higher. On prolonged exposure to a warm environment, a higher output of sebum occurred together with an increase in the percentage of linoleic acid in the sebum.
We determined terbinafine levels in serum, stratum corneum, dermis-epidermis (without stratum corneum), hair, sebum and eccrine sweat before, during and after 250 mg doses orally to volunteers once daily. Terbinafine is concentrated rapidly in stratum corneum (up to 9.1 micrograms/g of tissue) primarily by diffusion from the vascular system through the dermisepidermis. It also reaches high concentration in sebum (up to 45.1 micrograms/ml) after several days and continue to concentrate in sebum for up to two days after discontinuation of drug. Hair concentration reach levels of 2.6 micrograms/g of tissue indicating high drug levels in and around the hair follicle. It is not found in sweat. Plasma levels range between 0.1 and 1.0 micrograms/ml. There is a tenfold accumulation of drug in stratum corneum by day 2. Elimination of drug from tissue occurs with a half-life of 4 to 5 days and with the potential for drug levels above fungicidal concentrations for dermatophytes for more than 3 weeks. The tissue pharmacokinetic profile of terbinafine is similar to that of another lipophilic drug, itraconazole, but is very different from ketoconazole and griseofulvin. Higher levels of terbinafine are achieved than of either of the imidazoles and remain longer than griseofulvin.
Sebum production is under hormonal control. We had shown that male sex is associated with more severe disease in Behçet's syndrome and the acneiform skin lesion of this disorder is not different from ordinary acne, an androgen-dependent lesion. Sebum excretion rate was higher in patients with Behçet's syndrome than in healthy controls, children and patients with ankylosing spondylitis. On the other hand, patients with rheumatoid arthritis had high levels of sebum excretion rate comparable to those found in patients with acne vulgaris. These suggest the presence of a sebotrophic hormone and/or other hormonal effects in Behçet's syndrome and rheumatoid arthritis.
In accordance with a randomized double-blind experimental design, capsules of zinc sulfate, 440 mg total daily dose, and lactose placebo were administered orally to 10 normal Caucasian males for 3 weeks. Sebum secretion rates and serum zinc levels were determined prior to and following treatment. There was a statistically significant change in the before and after mean sebum secretion rates of the zinc group when compared with those of the placebo group (p less than 0.028). The results of this preliminary study indicate that supplemental zinc sulfate may reduce the quantity of skin-surface sebum. Further investigation is warranted.
The present study was designed to assess whether 5% aluminium chloride hexahydrate in absolute alcohol exerted any effect on sebaceous gland excretory activity. Eleven acne patients controlled with long-term antibiotics applied active and placebo solutions in a double-blind trial. The sebum excretion rate was measured on two control visits and thereafter at fortnightly intervals for a further 6 weeks. Patients preferred the 'active' solution, many claiming increased dryness of their skin. However, neither the 'active' nor 'placebo' solution had a significant demonstrable effect on sebum excretion rate. The beneficial effect of topical aluminium chloride hexahydrate is therefore assumed to be due to factors other than an alteration in sebum excretion.
As neonates have a high sebum production compared with 6-month-old babies, we wished to investigate the relationship of sebum production in mother and neonate. The sebum excretion rate (SER) was therefore measured in 10 mothers prenatally, and in each mother and baby as soon after birth as possible, and again 5-12 weeks postnatally. There was a significant correlation between the maternal and neonatal SER perinatally. The perinatal SER in the babies was markedly higher than the postnatal sample. These observations suggest an important role for the maternal hormonal environment on the infant sebaceous glands. There is animal evidence which suggests that the endocrine environment of the neonate influences the sebaceous gland development in puberty, but it is not known whether babies with a high SER are more prone to seborrhoea and acne in later life.
Topical corticosteroids are widely used in cutaneous diseases. Although their mode of action on different skin compartments has been documented, little is known about their effects on the human sebaceous gland. We investigated the effects of two corticosteroids of differing potency on the excretion of sebum by means of two validated techniques: the Sebutape and the Lipometre. This study was conducted on the forehead skin of normal healthy subjects. The results obtained with both techniques correlated well. The application of both corticosteroids during a 4-week period led to a significant decrease in sebum excretion. This decrease was more pronounced with the more potent corticosteroid (Dermovate). In the light of these findings, it is likely that topical corticosteroids exert an anti-proliferative action upon the sebaceous cells in a similar manner to their effect in other skin compartments.
Utilizing a solvent extraction system and colorimetric analysis, surface lipid levels were determined on the forehead. To understand the mechanisms involved in the sebaceous gland apparatus, repeated sampling at varying timed intervals were made. The data suggest that frequent surface samplings produce higher rates of lipid replacement. The increasing lipid replacement rates seen with sampling intervals of greater frequency do not follow a linear pattern. Also, lipid replacement rates show a gradual decline with time. This data suggest the existence of a multifunctional sebaceous apparatus involved in sebum production (a rate function), sebum storage (a volume function) and surface delivery (a rate function).
We determined the capacity of steroid hormone receptors in the sebaceous glands of intact nontreated, castrated, with testosterone substituted castrated male, intact female, and intact with testosterone substituted female animals using the animal ear model of the Syrian hamster. The steroid hormone binding capacity was compared with the sebaceous gland areas and sebogenesis. Intact male animals showed large sebaceous follicles, a high sebogenesis rate, and high capacity for sexual hormone binding proteins. In castrated males, the sebaceous gland areas and sebogenesis were both diminished, and androgen and estrogen receptors were decreased. When the castrated males were substituted with testosterone propionate, the sebaceous glands showed large volumes, high sebum production, and androgen binding activity again. In female animals having small sebaceous follicles and a low rate of sebogenesis, testosterone propionate enlarged the sebaceous glands and increased sebogenesis and the capacity of androgen binding. One can conclude from these data that testosterone is not only the main hormone for sebum production but also induces the synthesis of its own receptor.