Vol. 94, Issue 2, 518-524, February 2003
Exercise increases prolactin-receptor expression on human
lymphocytes
Keiichiro
Dohi1,
William J.
Kraemer2, and
Andrea M.
Mastro3
Departments of 1 Kinesiology and
3 Biochemistry and Molecular Biology, The
Pennsylvania State University, University Park, Pennsylvania 16802; and
2 Human Performance Laboratory, Department of
Kinesiology, and Department of Physiology and Neurobiology,
University of Connecticut, Storrs, Connecticut 06269-1110
Plasma prolactin has been shown to
increase during stress; the immune system is responsive to prolactin
and affected by stress. Therefore, this study was undertaken to
investigate the effects of acute graded, maximal treadmill exercise on
prolactin-receptor expression by lymphocytes. Eight healthy men
underwent one exercise and one nonexercise session. Blood was sampled
immediately before and after the exercise. On the day of the
nonexercise session, two resting blood samples were obtained at the
same times as the exercise session samples to act as baseline data.
Plasma prolactin concentrations were significantly elevated in response
to exercise and correlated positively with total prolactin-receptor
expression per B lymphocyte. An increase in total prolactin-receptor
expression per B lymphocyte in response to exercise also was observed.
In addition, exercise significantly increased the total number of circulating B lymphocytes expressing prolactin receptor as well as the
total number of circulating B lymphocytes. These data support the idea
that exercise may enhance the interaction between immune target cells
and prolactin, a stress hormone capable of enhancing immune function.
stress hormones; B lymphocytes; immune-neuroendocrine interactions; treadmill exercise
