BLOOD-PRESSURE, PLASMA NPY AND CATECHOLAMINES DURING PHYSICAL EXERCISE IN RELATION TO MENSTRUAL-CYCLE, OVARIECTOMY, AND ESTROGEN REPLACEMENT

Some evidences indicate that the female sex hormones protect against t he development of cardiovascular diseases. Modulation of sympathetic a ctivity may be one of the possibilities. We investigated the influence of treadmill stress on blood pressure (BP) and plasma neuropeptide Y (NPY), norepinephrine (NE) and epinephrine (E) concentrations in 11 no rmotensive, menstruating women in the follicular (HWf) and luteal (HWl ) phases and in eight ovariectomized women, before (OVX) and after est rogen supplementation (OVXe). Both at rest and during exercise there w ere no differences in BP between HWf and HWl and between OVX and OVXe. During stress BP was significantly lower in HWf and HWl than in OVX b ut not in OVXe. NPY did not differ significantly between the groups of women either at rest or during activity. We did not observe differenc es in resting and stimulated NE and E between HWf and HWl and between OVX and OVXe. Neither resting nor activated NE and E differed between the groups, except higher stimulated NE in OVX than in HWf. These resu lts suggest that the female sex hormones may modulate the BP response to dynamic exercise. Our data support evidence that this influence may be exerted by circulating catecholamines and not by NPY. (C) 1998 Els evier Science B.V. All rights reserved.