Dopaminergic receptors in the human skin.

Dopamine is a neurotransmitter which plays an important role in many human organs including the skin. In this study we will examine the presence and the distribution of D1 and D2 dopamine receptors in a particular zone of the human skin. Samples of the human plantar skin were harvested during autopsies after the consent of relatives of the dead donors. In this study the following experimental procedures were performed: 1) drawing of the human plantar skin; 2) cutting of tissues; 3) staining of tissues; 4) staining of the nerve fibres; 5) radio-binding methods for labelling D1 and D2 dopamine receptors; 6) light microscope autoradiography; 7) quantitative analysis of images and 8) statistical analysis of data. The dopamine receptors D1 are distributed particularly in the dermis layer of the human plantar skin. They are numerous in lower epidermal layers (with exclusion of the corneal layer) and few in subcutaneous tissue. On the contrary D2 dopamine receptors are prominent in the subcutaneous tissue near the vessels. Quantitative analysis of images and statistical analysis of the data confirm all our results. The specific distribution of D1 and D2 dopamine receptors in the human plantar skin is in close relation with the functions of a particular zone of the human skin that supports the weight of all the body. Moreover the character of dopamine receptors distribution is very important for further understanding the role of these receptors in the human skin.