In Vitro Placental Perfusion

Abstract

The placenta is a relatively short-lived tissue that is of absolute importance to the generation of future humans and indeed to the survival of all species of mammals. During its existence, it is responsible for a number of complex functions, which are normal features of separate organs and tissues within the body. Such functions include gas exchange, solute exchange, detoxification, primary endocrine functions, secondary endocrine functions and hormone degradation. In order to study the detailed biochemistry and physiology of full term placentae, in-vitro perfusion systems for this tissue were reported as long ago as 1922 (Schmitt), although the simplification of the procedure to incorporate the use of single placental lobules was not reported until much later (Panigel, 1962). The technique has been further refined since those early reports and has since been used to answer a wide range questions about normal and abnormal placental metabolism. In addition the technique has been applied to fields as diverse as toxicology, endocrinology and pharmacology, in order to determine the transfer kinetics of a range of xenobiotics. In-vitro placental perfusion using full-term human placentae has now been performed by our group in a number of locations for a period of years. As a result of a number of enquiries from other groups interested in establishing the procedure, it seemed timely to report our recent “success rate” with the procedure and to review the major factors which require attention to ensure reasonable performance of this demanding procedure. We report here an analysis of the outcomes of ninety such perfusions attempted over the last two-year period (mid 1996-mid 1998). We also proffer a technique, which may be found valuable in attempts to normalise results for such parameters as oxygen consumption between perfusions as well as affording the prospect of earlier prediction of perfusion instability.