Does long-term experimental antiorthostasis lead to cardiovascular deconditioning in the rat?

Title:

Does long-term experimental antiorthostasis lead to cardiovascular deconditioning in the rat?

Creator:

Raffai, Gábor, Csekő,C., Kocsis, L., Dézsi, L., and Monos, E.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:d4eda90f-a86f-4846-85fb-d74498422692
uuid:d4eda90f-a86f-4846-85fb-d74498422692

Subject:

Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, antiorthostasis, baroreflex sensitivity, cardiovascular deconditioning, microgravity, 14, and 612

Type:

article, články, model:article, and TEXT

Format:

print

Description:

Microgravity or simulated microgravity induces acute and chronic cardiovascular responses, whose mechanism is pivotal for understanding of physiological adaptation and pathophysiological consequences. We investigated hemodynamic responses of conscious Wistar rats to 45º head-down tilt (HDT) for 7 days. Arterial blood pressure (BP) was recorded by telemetry. Heart rate (HR), spectral properties and the spontaneous baroreflex sensitivity (sBRS) were calculated. Head-up tilt (HUT) was applied for 2 h before and after HDT to assess the degree of any possible cardiovascular deconditio ning. Horizontal control BP and HR were 112.5±2.8 mmHg and 344.7±10 bpm, respectively. HDT elicited an elevation in BP and HR by 8.3 % and 8.8 %, respectively, in less than 1 h. These elevations in BP and HR were maintained for 2 and 3 days, respectively, and then normalized. Heart rate variability was unchanged, while sBRS was permanently reduced from the beginning of HDT (1.01±0.08 vs. 0.74±0.05 ms/mmHg). HUT tests before and after HDT resulted in BP elevations (6.9 vs. 11.6 %) and sBRS reduction (0.44 vs. 0.37 ms/mmHg), respectively. The pressor response during the post-HDT HUT test was accompanied by tachycardia (13.7 %). In conclusion, chronic HDT does not lead to symptoms of cardiovascular deconditioning. However the depressed sBRS and tachycardic response seen during the post-HDT HUT test may indicate disturbances in cardiovascular control., G. Raffai ... [et al.]., and Obsahuje seznam literatury

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 2009 Volume:58 | Number:1

Harvested from:

CDK

Metadata only:

false