Elsevier

Life Sciences

Volume 36, Issue 21, 27 May 1985, Pages 2025-2032
Life Sciences

Improving cold tolerance in elderly rats by aminophylline

https://doi.org/10.1016/0024-3205(85)90452-7Get rights and content

Abstract

During severe cold exposure, old rats (23–26 months) were less capable in maintaining normal body temperature as compared to young rats (6–9 months) due to lower rate of heat production (HP). Single injection of optimal doses of aminophylline (AMPY; 10 and 18.7 mg/kg, i.p.), a phosphodiesterase inhibitor which enhances the intracellular cyclic AMP concentration, significantly increased the rate of HP in old rats to levels beyond the control values observed in young rats. Consequently, cold tolerance of the old rats was significantly improved. This AMPY-improved cold tolerance is apparently not due to increased non-shivering thermogenesis (NST) since AMPY failed to enhance norepinephrine-stimulated NST in the old rats. It is likely that AMPY increased substrate mobilization and/or conversion, thereby circumventing the limiting role of substrate availability for shivering thermogenesis. Thus, the age-dependent decrease in cold tolerance may be due to a reduced capacity for substrate mobilization when challenged by cold.

References (31)

  • B. Cox et al.

    Life Sci.

    (1981)
  • A.J. Watts

    Environ. Res.

    (1972)
  • L.C.H. Wang

    Life Sci.

    (1981)
  • T. Balmagiya et al.

    Exptl. Geront.

    (1983)
  • L.C.H. Wang

    Life Sci.

    (1978)
  • P. Schoeffter et al.

    Eur. J. Pharmac.

    (1983)
  • J. Forn et al.

    Biochim. Biophys. Acta.

    (1970)
  • R.W. Butcher et al.

    J. Biol. Chem.

    (1962)
  • B.P. Yu et al.

    Metabolism

    (1980)
  • B. Grad et al.

    J. Geront.

    (1957)
  • K.J. Collins et al.

    J. Am. Geriat. Soc.

    (1983)
  • N.W. Shock

    The Biology of Aging

  • R.H. Fox et al.

    Br. Med. J.

    (1973)
  • L.C.H. Wang et al.

    J. Appl. Physiol.

    (1982)
  • L.C.H. Wang

    Int. J. Biometeor.

    (1984)
  • Cited by (0)

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