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The 24 h pattern of arterial pressure in mice is determined mainly by heart rate-driven variation in cardiac output.

Kurtz TW, Lujan HL, DiCarlo SE - Physiol Rep (2014)

Bottom Line: Understanding the hemodynamic mechanisms that determine the 24 h patterns of blood pressure may lead to a better understanding of how such patterns become disturbed in hypertension and influence risk for cardiovascular events.The higher arterial pressure during the nighttime period was mediated by higher cardiac output (+2.6 ± 0.3 mL/min, [26%], P < 0.05) in association with lower peripheral resistance (-1.5 ± 0.3 mmHg/mL/min, [-13%] P < 0.05).These findings suggest that the differences in blood pressure between nighttime and daytime are mainly driven by differences in heart rate which are strongly correlated with differences in locomotor activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Laboratory Medicine, University of California, San Francisco, San Francisco, California.

No MeSH data available.


Related in: MedlinePlus

The 12 h daytime and 12 h nighttime mean values for each variable determined over the 5 consecutive 24 h periods. Data are presented as means ± SEM. *P < 0.05, night versus day. The absolute and percent differences between the paired daytime and nighttime values are shown in Table 1.
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fig03: The 12 h daytime and 12 h nighttime mean values for each variable determined over the 5 consecutive 24 h periods. Data are presented as means ± SEM. *P < 0.05, night versus day. The absolute and percent differences between the paired daytime and nighttime values are shown in Table 1.

Mentions: All physiological recordings were sampled continuously at 2 kHz, beat to beat 24 h/day for 5 consecutive days and nights. Subsequently, 1 h averages for each variable were calculated over each 24 h period and are presented in Figure 2. In addition, the 12 h daytime and nighttime averages were obtained for each animal for each of the five 24 h sampling periods. The 12 h averages from these five 24 h periods were averaged for each animal to yield the study average daytime and nighttime values for each animal. The study average values from the individual animals were also averaged to give the group mean study values for the daytime period and for the nighttime period (Fig. 3). Paired t‐tests were used to compare the study average daytime versus nighttime values within the animals. To obtain nighttime–daytime differences for each variable, the difference between the 12 h nighttime average minus the 12 h daytime average was calculated for each animal for each of the five 24 h periods. These nighttime–daytime differences in each of the five 24 h periods were then averaged to obtain the study average nighttime–daytime difference for each animal. These study average nighttime–daytime differences from each animal were then averaged to give the group means for the nighttime–daytime differences. Data are expressed as means ± SE.


The 24 h pattern of arterial pressure in mice is determined mainly by heart rate-driven variation in cardiac output.

Kurtz TW, Lujan HL, DiCarlo SE - Physiol Rep (2014)

The 12 h daytime and 12 h nighttime mean values for each variable determined over the 5 consecutive 24 h periods. Data are presented as means ± SEM. *P < 0.05, night versus day. The absolute and percent differences between the paired daytime and nighttime values are shown in Table 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4255824&req=5

fig03: The 12 h daytime and 12 h nighttime mean values for each variable determined over the 5 consecutive 24 h periods. Data are presented as means ± SEM. *P < 0.05, night versus day. The absolute and percent differences between the paired daytime and nighttime values are shown in Table 1.
Mentions: All physiological recordings were sampled continuously at 2 kHz, beat to beat 24 h/day for 5 consecutive days and nights. Subsequently, 1 h averages for each variable were calculated over each 24 h period and are presented in Figure 2. In addition, the 12 h daytime and nighttime averages were obtained for each animal for each of the five 24 h sampling periods. The 12 h averages from these five 24 h periods were averaged for each animal to yield the study average daytime and nighttime values for each animal. The study average values from the individual animals were also averaged to give the group mean study values for the daytime period and for the nighttime period (Fig. 3). Paired t‐tests were used to compare the study average daytime versus nighttime values within the animals. To obtain nighttime–daytime differences for each variable, the difference between the 12 h nighttime average minus the 12 h daytime average was calculated for each animal for each of the five 24 h periods. These nighttime–daytime differences in each of the five 24 h periods were then averaged to obtain the study average nighttime–daytime difference for each animal. These study average nighttime–daytime differences from each animal were then averaged to give the group means for the nighttime–daytime differences. Data are expressed as means ± SE.

Bottom Line: Understanding the hemodynamic mechanisms that determine the 24 h patterns of blood pressure may lead to a better understanding of how such patterns become disturbed in hypertension and influence risk for cardiovascular events.The higher arterial pressure during the nighttime period was mediated by higher cardiac output (+2.6 ± 0.3 mL/min, [26%], P < 0.05) in association with lower peripheral resistance (-1.5 ± 0.3 mmHg/mL/min, [-13%] P < 0.05).These findings suggest that the differences in blood pressure between nighttime and daytime are mainly driven by differences in heart rate which are strongly correlated with differences in locomotor activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Laboratory Medicine, University of California, San Francisco, San Francisco, California.

No MeSH data available.


Related in: MedlinePlus