Effect of antiorthostatic hypokinesia and its combination with +Gz runs on the otolith regulation of cardiac rhythm in primates
Badakva, A.M.; Miller, N.V.; Riazanskiĭ, S.N.
Aviakosmicheskaia i Ekologicheskaia Meditsina 35(1): 32-37
2001
ISSN/ISBN: 0233-528X PMID: 11385980 Document Number: 6612
Amplitude of cardiac rhythm response to the otolith stimulus (AR-R), i.e. rapid reduction of the EKG R-R interval was determined in 24 Macacas mulatta before and after 28-d head-down (-6 degrees) immobilization (HDI). In two experimental series the animals were divided into 2 groups (control and CF) with 6 primates in each. In the HDI series-1, the CF animals were rotated on a centrifuge with a 3.62-m arm at 1.2 up to 1.6 +Gz for 30-40 minutes 4-5 times a week. In HDI series-2, the CF animals were rotated 30 min at 1.2 +Gz 2-3 times a week. In a day after HDI, AR-R was significantly reduced in both CF groups, which, when compared with EKG R-R intervals, suggests attenuation of equally parasympathetic and sympathetic influences on the heart. In 7 days since HDI, AR-R was close to baseline values in control primates on both series and CF primates in series-2, whereas in the CF group in series-2 AR-R exceeded baseline values. Significant differences in mean AR-R values in the control and CF groups in series-1 following 7 days after HDI point to the prophylactic effect of small but regular g-loads manifested in more rapid recovery of initial level of the cardiac rhythm regulation.
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