These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Baroreflex control of muscle sympathetic nerve activity after 120 days of 6 degrees head-down bed rest.
    Author: Kamiya A, Iwase S, Kitazawa H, Mano T, Vinogradova OL, Kharchenko IB.
    Journal: Am J Physiol Regul Integr Comp Physiol; 2000 Feb; 278(2):R445-52. PubMed ID: 10666146.
    Abstract:
    To examine how long-lasting microgravity simulated by 6 degrees head-down bed rest (HDBR) induces changes in the baroreflex control of muscle sympathetic nerve activity (MSNA) at rest and changes in responses of MSNA to orthostasis, six healthy male volunteers (range 26-42 yr) participated in Valsalva maneuver and head-up tilt (HUT) tests before and after 120 days of HDBR. MSNA was measured directly using a microneurographic technique. After long-term HDBR, resting supine MSNA and heart rate were augmented. The baroreflex slopes for MSNA during Valsalva maneuver (in supine position) and during 60 degrees HUT test, determined by least-squares linear regression analysis, were significantly steeper after than before HDBR, whereas the baroreflex slopes for R-R interval were significantly flatter after HDBR. The increase in MSNA from supine to 60 degrees HUT was not different between before and after HDBR, but mean blood pressure decreased in 60 degrees HUT after HDBR. In conclusion, the baroreflex control of MSNA was augmented, whereas the same reflex control of R-R interval was attenuated after 120 days of HDBR.
    [Abstract] [Full Text] [Related] [New Search]