Research Techniques Made Simple: Parabiosis to Elucidate Humoral Factors in Skin Biology.

Circulating factors in the blood and lymph support critical functions of living tissues. Parabiosis refers to the condition in which two entire living animals are conjoined and share a single circulatory system. This surgically created animal model was inspired by naturally occurring pairs of conjoined twins. Parabiosis experiments testing whether humoral factors from one animal affect the other have been performed for more than 150 years and have led to advances in endocrinology, neurology, musculoskeletal biology, and dermatology. The development of high-throughput genomics and proteomics approaches permitted the identification of potential circulating factors and rekindled scientific interest in parabiosis studies. For example, this technique may be used to assess how circulating factors may affect skin homeostasis, skin differentiation, skin aging, wound healing, and, potentially, skin cancer.