Fig 1.
Effects of various salt challenges on mean blood pressure and heart rate in C57BL/6N male mice.
Mice were monitored with telemetry and placed in a standard (A, C) or modified light/dark cycle (B, D). NS = normal salt diet (n = 12 and n = 17, for the standard and modified light cycle respectively), LS = low salt diet (n = 11 and n = 15, for the standard and modified light cycle respectively), HS = high Na+/normal K+ diet (n = 5 and n = 6, for the standard and modified light cycle respectively). One-way ANOVA per light phase followed by Tukey’s post-hoc test; *: p<0.05 compared to NS diet.
Table 1.
Sodium and potassium levels in urine and plasma in C57BL/6N.
Table 2.
Plasma ion, aldosterone and renin activity measurements in C57BL/6N and C57BL/6J male mice.
Fig 2.
Comparison between C57BL/6N and C57BL/6J for their mean blood pressure and heart rate responses to various salt challenges.
Mice were monitored with telemetry during the dark (A, B) and light (C) periods of a modified light/dark cycle. NS = normal salt diet (n = 17 and n = 17, for C57BL/6N and C57BL/6J respectively), LS = low salt diet (n = 15 and n = 17, for C57BL/6N and C57BL/6J respectively), HS = high Na+/normal K+ diet (n = 8 and n = 8, for C57BL/6N and C57BL/6J respectively) and HS/LK = high Na+/low K+ diet (n = 6 and n = 9, for C57BL/6N and C57BL/6J respectively). One-way ANOVA per light phase followed by Tukey’s post-hoc test; *: p<0.05 compared to NS diet; #: p<0.05 HS/LK compared to HS.
Fig 3.
Effects of high-salt/normal potassium and high-salt/low potassium on mean blood pressure and heart rate in C57BL/6N mice.
Mice were monitored with telemetry in the dark (A, B, C) and light (C) periods of a modified light/dark cycle. NS = normal salt diet (n = 17), LS = low salt diet (n = 15), HS = high Na+/normal K+ diet (n = 8) and HS/LK = high Na+/low K+ diet (n = 6). One-way ANOVA per light phase followed by Tukey’s post-hoc test; *: p<0.05 compared to NS diet; #: p<0.05 HS/LK compared to HS.
Fig 4.
Effect of high salt diets on the circadian blood pressure variations in C57BL/6N and C57BL/6J mice under a reverse light/dark cycle.
2.5 days continuous telemetric recordings of systolic blood pressure after 2 weeks of NS, HS or HS/LK diet challenge. A) n = 8 per group B) n = 6 per group C) n = 8 per group D) n = 9 per group. Two-way ANOVA followed by Sidak’s post-hoc test *: p<0.05 for interaction.
Fig 5.
Comparison between C57BL/6N and C57BL/6J for their systolic blood pressure and heart rate responses to various salt challenges measured by NIBP.
Measurements were made during the dark periods of a modified light/dark cycle. NS = normal salt diet (n = 20 and n = 20, for C57BL/6N and C57BL/6J respectively), LS = low salt diet (n = 20 and n = 20, for C57BL/6N and C57BL/6J respectively), HS = high Na+/normal K+ diet (n = 9 and n = 10, for C57BL/6N and C57BL/6J respectively) and HS/LK = high Na+/low K+ diet (n = 9 and n = 10, for C57BL/6N and C57BL/6J respectively). One-way ANOVA per light phase followed by Tukey Kramer’s post-hoc test; #: p<0.05 HS/LK compared to HS.