Studies on detection and synthesis of prostaglandins in tail skin of the rat

Abstract

Studies are reported on the detection and in vitro biosynthesis of prostaglandins of the E type in the tail skin of male Sprague-Dawley rats. It was found that strips of skin were preferred to other techniques of skin preparations, such as mincing or homogenization for the assay of endogenous prostaglandins. Each strip of tail skin could be used at least twice, each time in fresh buffer to obtain additional release of endogenous prostaglandins. The skin was stripped from a longitudinal incision in the tail in one piece and cut into four parallel strips lengthwise. Each strip of skin was incubated singly and the prostaglandins were extracted with ethyl acetate. The detection and analysis of prostaglandins of the E type were carried out by standard procedures on the residue of this extract dissolved in 95% ethanol. By means of this technique, endogenous prostaglandins were detected in the tail skin of rats. Little or no prostaglandins were extracted by organic solvents directly from the tissue, and the yields were low when the tissue was minced. The results indicate the possibility that endogenous prostaglandins may be synthesized during incubation in buffer or may be released from binding with other cellular components. The major prostaglandin of this tissue was PGE₂; prostaglandin E₁ (PGE₁) was also detected. Using the same procedure, the presence of a prostaglandin synthetase system in the tail skin was demonstrated by the conversion of exogenous arachidonic acid to prostaglandin E₂ (PGE₂).