Fig. 5

Effects of autonomic blockers on cardiovascular parameters during exposure to low ambient temperature (LT-exposure): baseline: before LT-exposure (n = 9); control: during LT-exposure without an autonomic blocker (n = 9); atenolol: during LT-exposure after intraperitoneal (i.p.) injection of atenolol (1 mg/kg, n = 5 or 10 mg/kg, n = 5); phentolamine: during LT-exposure after i.p. injection of phentolamine (10 mg/kg, n = 5). HR, SBP and SBPV data are presented as in Fig. 3. Averaged 30-min data were used as baseline data, and 90-min data throughout the exposure period were used for the LT-exposure groups. *p < 0.05, **p < 0.01 and ***p < 0.001 compared with baseline and control (paired t test); †p < 0.05, ††p < 0.01 and †††p < 0.001 compared among LT-exposure groups [one-way analysis of variance (ANOVA) and Holm’s post hoc test]