Swimming training prevents fat deposition and decreases angiotensin II-induced coronary vasoconstriction in ovariectomized rats

Abstract

We investigated the effects of chronic swimming training (ST) on the deposition of abdominal fat and vasoconstriction in response to angiotensin II (ANG II) in the coronary arterial bed of estrogen deficient rats. Twenty-eight 3-month old Wistar female rats were divided into 4 groups: sedentary sham (SS), sedentary-ovariectomized (SO), swimming-trained sham (STS) and swimming-trained ovariectomized (STO). ST protocol consisted of a continuous 60-min session, with a 5% BW load attached to the tail, completed 5 days/week for 8-weeks. The retroperitoneal, parametrial, perirenal and inguinal fat pads were measured. The intrinsic heart rate (IHR), coronary perfusion pressure (CPP) and a concentration-response curve to ANG II in the coronary bed was constructed using the Langendorff preparation. Ovariectomy (OVX) significantly reduced 17-β-estradiol plasma levels in SO and STO groups (p<0.05). The STO group had a significantly reduced retroperitoneal and parametrial fat pad compared with the SO group (p<0.05). IHR values were similar in all groups; however, baseline CPP was significantly reduced in the SO, STS and STO groups compared with the SS group (p<0.05). ANG II caused vasoconstriction in the coronary bed in a concentration-dependent manner. The SO group had an increased response to ANG II when compared with all other experimental groups (p<0.05), which was prevented by 8-weeks of ST in the STO group (p<0.05). OVX increased ANG II-induced vasoconstriction in the coronary vascular bed and abdominal fat pad deposition. Eight weeks of swimming training improved these vasoconstrictor effects and decreased abdominal fat deposition in ovariectomized rats.

Keywords: ACE; ANG II; ANOVA; BW; CAD; CPP; CVD; Coronary dysfunction; Estrogen deficiency; HRT; IHR; ING; NO; OVX; PME; PR; Physical exercise; RAS; RET; ROS; Renin Angiotensin System; SO; SS; ST; STO; STS; UT; analysis of variance; angiotensin II; angiotensin-converting enzyme; body weight; cardiovascular diseases; coronary artery disease; coronary perfusion pressure; hormone replacement treatment; inguinal; intrinsic heart rate; nitric oxide; ovariectomy; parametrial; perirenal; reactive oxygen species; retroperitoneal abdominal adiposity; sedentary ovariectomized; sedentary sham; swimming training; swimming-trained ovariectomized; swimming-trained sham; uterus weight.