The effect of topical application of the androgen 5 alpha-dihydrotestosterone (DHT), both encapsulated in liposomes and solved in acetone, has been evaluated using the female hamster flank organ as a model system. Systemic absorption of DHT was significant from the acetone solution, but negligible from the liposome system. The topical biological effect is, however, proportionally diminished when the liposome system is used. Under the experimental conditions used, the lited using the female hamster flank organ as a model system. Systemic absorption of DHT was significant from the acetone solution, but negligible from the liposome system. The topical biological effect is, however, proportionally diminished when the liposome system is used. Under the experimental conditions used, the liposome system had no advantages over application in acetone in this model.

It is generally accepted that in psoriasis there is an alteration of epidermal cell proliferation. It has been reported that an increased rate of thymidine incorporation into keratinocytes is found in the upper part of the hair follicle in involved skin, but this is not the case in the lower part. Here we show that cells from psoriatic hair follicles could be brought in culture under the same conditions as those of normal hair follicles. Cells, whether originating from the upper or lower part of the hair follicle sheath either from involved or uninvolved psoriatic skin, show a faster rate of outgrowth in the first days of culture. Moreover, a large number of psoriatic cells have an increased motility in the early stages of culture, as compared to control cells. These properties can no longer be observed after several days in culture. The activity of glucose-6-phosphate dehydrogenase known to be increased in psoriatic plaques is normal in hair follicles isolated from these plaques. Protein gel electrophoretic investigations showed that there is no difference in gel patterns between normal and psoriatic hair follicles. In conclusion, the isolation of human hair follicles represents a simple method that allows psoriatic keratinocytes to be brought in culture and permits the study of certain aspects of the disease.

The skin epithelium and its organelles use glycogen as well as glucose as source of energy. Therefore the characterisation of glycogen metabolism and the enzymes involved is important in the study of mechanisms regulating the normal or abnormal differentiation of skin organelles such as sebaceous glands and hair follicles. The present paper describes fluorimetric methods for the determination of glycogen and for the measurements of phosphorylase and phosphorylase kinase activity in one and the same lysate of minute tissue samples. The methods were tested for their suitability on freshly isolated human hair follicles and cultured hair follicle cells. The possible use of these techniques for studies on the pathophysiology of acne and hirsutism is discussed.

Androgen dependent skin disorders are important in clinical practice. Effective topical antiandrogens would lead to a breakthrough in their treatment. Although many attempts have been performed to develop such compounds, major successes have not been forthcoming. In the present study three existing antiandrogenic molecules have been compared with regard to their effect on androgen metabolism, receptor competition and on histological parameters in the hamster flank organ test. It appears that the effect on the hamster pigmented spot can be predicted on the basis of molecular mechanism. However, the effects on histological parameters are apparently dependent on additional factors such as metabolism of the active substance before reaching the sebaceous structure or limited penetration through the skin surface. The results indicate that in the development of new antiandrogens pre-screening can be performed with the aid of metabolic and receptor studies, while the histological parameters in the hamster flank organ test provide an animal model with a good predictive value.

Two thousand people on the Isles of the Baleares were screened for glucose-6-phosphate dehydrogenase deficiency using a commercially available kit. Among the thousand males tested, five were found deficient; of the thousand women, one had low enzyme activity according to this test. Diagnosis of glucose-6-phosphate dehydrogenase deficiency could be verified using hair follicle analysis on mailed hair samples. The same technique also allowed heterozygotes to be identified unequivocally.