PLASMA PROENKEPHALIN PEPTIDE-F AND HUMAN B-CELL RESPONSES TO EXERCISESTRESS IN FIT AND UNFIT WOMEN

In vitro studies have connected immune cell function to Peptide F. The primary purpose of this investigation aias to examine the responses o f plasma Peptide F and epinephrine along with the changes in B cell an tibody production in vivo in physically fit and unfit women in respons e to physical exercise on a cycle ergometer at 60% and 80% of peak oxy gen consumption. Seven aerobically fit and eight untrained (i.e., unfi t) women between the ages of 18 and 30 volunteered to participate in t his investigation. Blood samples (analyzed for plasma Peptide F and ep inephrine along with the number of antibody-producing B cells) were ob tained 24 hours prior to the exercise session, pre-exercise, during ea ch exercise intensity, and five minutes post-exercise. The fit group h ad a significantly higher plasma Peptide F concentration after the 80% exercise intensity along with significantly higher numbers of antibod y producing B cells compared to the unfit group. The results of this i nvestigation show that physically fit women have an enhanced secondary response of B cells to a specific antigen under conditions where Pept ide F is increased. Such data demonstrate that physical fitness as pro moted by the Public Health Service (e.g., Healthy People 2300) influen ces the underlying hormonal and immune cell responses when challenged by physical exercise stress. (C) 1998 Elsevier Science Inc.