X-Message-Number: 11996
Date: Wed, 23 Jun 1999 13:06:18 -0700 (PDT)
From: Doug Skrecky <>
Subject: no effect of GH on rodent lifespan

  Kalu DN.  Orhii PB.  Chen C.  Lee DY.  Hubbard GB.  Lee S.  Olatunji-Bello Y.
  Department of Physiology, The University of Texas Health Science Center at
  San Antonio, 78284-7756, USA. 
  Aged-rodent models of long-term growth hormone therapy: lack of deleterious
  effect on longevity.
  Journals of Gerontology.  Series A, Biological Sciences &  Medical Sciences. 
  53(6):B452-63, 1998 Nov.
  Studies were carried out to examine the effects of long-term recombinant
  human growth hormone (GH) therapy on longevity in rodents.
  In the first study, 150 18-month-old female F344 rats were
  divided into three groups of 50 rats per group: Group 1, solvent vehicle;
  Group 2, 10 microg GH/kg body weight three times per week; Group 3, 50 microg
  GH/kg body weight three times per week. GH and solvent vehicle therapies were
  started at 18 months of age and continued until all the animals died
  spontaneously. Serum insulin-like growth factor (IGF)-I was measured at 18
  and 29 months of age and on 3-month-old rats. Serum IGF-I level decreased
  between 3 and 29 months of age. GH therapy reversed the decrease in a
  dose-dependent manner, with the 50 microg GH dose returning the serum IGF-I
  level to that of 3-month-old animals. However, statistical analysis revealed
  no significant effect of GH therapy on median life span, 10th percentile life
  span, or maximum life span. Similar observations on
  longevity were made on aged F344 male rats
  and on aged Balb/c mice, even when the dose of GH was increased to 1.0 mg/kg
  body weight two times per week. The main pathologic lesions in control
  animals were nephropathy, cardiomyopathy, leukemia, and testicular
  interstitial cell tumor; the prevalence of these lesions was not
  significantly altered by GH therapy. We conclude that long-term low-dose GH
  therapy that includes doses in the range that is given to humans in clinical
  trials in GH deficiency and to revert age-related physiologic declines has no
  overt deleterious effects on longevity and pathology in aged

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