Calcium metabolism and cardiovascular function after spaceflight

Daniel C. Hatton, Qi Yue, Jacqueline Dierickx, Chantal Roullet, Keiichi Otsuka, Mitsuaki Watanabe, Sarah Coste, Jean Baptiste Roullet, Thongchan Phanouvang, Eric Orwoll, Shiela Orwoll, David A. McCarron

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17 Scopus citations

Abstract

To determine the influence of dietary calcium on spaceflight-induced alterations in calcium metabolism and blood pressure (BP), 9-wk-old spontaneously hypertensive rats, fed either high- (2%) or low-calcium (0.02%) diets, were flown on an 18-day shuttle flight. On landing, flight animals had increased ionized calcium (P < 0.001), elevated parathyroid hormone levels (P < 0.001), reduced calcitonin levels (P < 0.05), unchanged 1,25(OH)2D3 levels, and elevated skull (P < 0.01) and reduced femur bone mineral density. Basal and thrombin-stimulated platelet free calcium (intracellular calcium concentration) were also reduced (P < 0.05). There was a tendency for indirect systolic BP to be reduced in conscious flight animals (P = 0.057). However, mean arterial pressure was elevated (P < 0.001) after anesthesia. Dietary calcium altered all aspects of calcium metabolism (P < 0.001), as well as BP (P < 0.001), but the only interaction with flight was a relatively greater increase in ionized calcium in flight animals fed low- compared with high-calcium diets (P < 0.05). The results indicate that 1) flight-induced disruptions of calcium metabolism are relatively impervious to dietary calcium in the short term, 2) increased ionized calcium did not normalize low-calcium-induced elevations of BP, and 3) parathyroid hormone was paradoxically increased in the high-calcium-fed flight animals after landing.

Original languageEnglish (US)
Pages (from-to)3-12
Number of pages10
JournalJournal of Applied Physiology
Volume92
Issue number1
StatePublished - Jul 3 2002

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Keywords

  • Dietary calcium
  • Microgravity
  • Parathyroid hormone
  • Platelet intracellular calcium
  • Spontaneously hypertensive rat

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this

Hatton, D. C., Yue, Q., Dierickx, J., Roullet, C., Otsuka, K., Watanabe, M., Coste, S., Roullet, J. B., Phanouvang, T., Orwoll, E., Orwoll, S., & McCarron, D. A. (2002). Calcium metabolism and cardiovascular function after spaceflight. Journal of Applied Physiology, 92(1), 3-12.