Hormonal and cardiovascular response to low-intensity exercise with atropine administration.

ABSTRACTThe hormonal and cardiovascular responses to atropine and low-intensity exercise were examined in 7 young men. Subjects completed 3 trials in a single blind crossover design. During the first trial (T1), subjects received 2.0 mg of atropine intramuscularly at rest. Subsequently in trial 2 (T2), subjects received a saline placebo before 90 minutes of intermittent exercise, and during trial 3 (T3), they received atropine before 90 min of intermittent exercise [3 × (25-minute cycle/5-minute rest) @ 40% VO2 peak]. Venous blood samples and physiological data were collected before, during, and post exercise. Growth hormone (GH) was significantly increased in T2 but unchanged in T1 and T3. Cortisol (CORT) was unchanged in T1 and T2, but in T3 significantly increased (p < 0.05) from 45 to 90 minutes compared to T2. Plasma luteinizing hormone (LH) was unaffected in all trials. Plasma prolactin (PRO) significantly increased in T3 from 45 to 90 minutes in comparison to T2. Norepinephrine (NE) was unaffected ...