Skip to main content

Effects of spaceflight on postnatal development of arterial baroreceptor reflex in rats

The full text article is not available.

Abstract Aim: 

It has been reported that spaceflight attenuates the arterial baroreceptor reflex. As this reflex function changes dramatically during postnatal development, we hypothesized that space flight depresses the developmental changes of the reflex system. To test this hypothesis, we evaluated the baroreceptor reflex function in rats, which were exposed to a microgravity environment on a space shuttle 9–25 days after birth. Methods: 

Baroreceptor reflex sensitivity and the afferent sensitivity were evaluated by measuring heart rate (HR) and aortic nerve activity (ANA) changes in response to an increase in mean arterial pressure (MBP) derived by phenylephrine injection (20–50 g kg−1) under urethane-anaesthesia. Results: 

Baroreceptor reflex sensitivity (% change of HR/% change of MBP) was lower in the flight group (FLT: −0.19 ± 0.04, n = 4) than either the asynchronous ground control group (AGC: −0.47 ± 0.06, n = 6, P < 0.01) or the vivarium group (VIV: −0.41 ± 0.07, n = 6, P < 0.05). This was similar to the differences of the afferent sensitivity (% change of ANA/% change of MBP) between FLT (2.07 ± 0.30) and the control groups (AGC: 2.71 ± 0.22, n.s.; VIV: 3.00 ± 0.32, P < 0.05). At the end of 30 days of recovery under normal gravity conditions, however, there were no significant group differences in these parameters. Conclusion: 

These results suggest that the space environment attenuates the postnatal development of the arterial baroreceptor reflex function in rats, which may be partially because of a depression of the postnatal development of the baroreceptor afferents. These functional alterations, however, recover to their normal level on re-exposure to the Earth's gravity.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: Sprague–Dawley rat; aortic nerve; baroreflex; blood pressure; postnatal development; weightlessness

Document Type: Research Article

Affiliations: 1:  Department of Physiology, Fukushima Medical University School of Medicine, Fukushima, Japan 2:  Experimental Animal Center, Fukushima Medical University School of Medicine, Fukushima, Japan 3:  National Space Development Agency of Japan, Tsukuba, Ibaraki, Japan 4:  Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan 5:  Department of Anesthesiology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan

Publication date: 2005-05-01

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more