PMID: 2505465Aug 1, 1989Paper

Prolonged fasting or clonidine can restore the defective growth hormone secretion in old dogs

Acta Endocrinologica
S G CellaE E Müller

Abstract

Age-related changes in GH secretion were studied in dog. In preliminary experiments, administration of GH-releasing hormone (GHRH-40, 2 micrograms/kg, iv) or the alpha 2-adrenoceptor agonist clonidine (4 micrograms/kg, iv) elicited significantly higher plasma GH rises in 3 to 4 years old than in 10 to 14 years old beagle dogs. The pulsatile patterns of GH secretion in both young and old dogs under baseline conditions and after prolonged fasting or clonidine administration were studied. Samples were taken every 10 min from 09.00 to 15.00 h from five young and five old dogs of both sexes. Under baseline conditions, GH peak frequency, total peak area, and integrated GH secretion were significantly lower in old than in young dogs. In old dogs, 5-day complete fasting or 14-day clonidine administration (75 micrograms/dog, po, twice daily) increased the frequency and amplitude of spontaneous GH bursts, the total peak area, and the integrated GH secretion. After either stimulus, the GH secretory pattern was quantitatively and qualitatively indistinguishable from that of young dogs under baseline conditions. Similarly, the foregoing indices were significantly increased in young dogs by either stimulus, except for the inability of clonid...Continue Reading

Citations

Jan 1, 1993·European Journal of Applied Physiology and Occupational Physiology·J ArokoskiH J Helminen
Jul 1, 1994·Neurochemistry International·V De Gennaro ColonnaE E Müller
Oct 24, 2002·Neurobiology of Aging·Eugenio E MullerSilvano G Cella
May 1, 1994·Journal of the American Geriatrics Society·S E BorstD T Lowenthal
Jan 1, 1990·Nutrition Research Reviews·R J Ross, C R Buchanan
Jun 1, 1992·Aging : Clinical and Experimental Research·D Cocchi
Jan 1, 1997·Aging : Clinical and Experimental Research·E E MüllerD Cocchi
Oct 1, 1992·Journal of Endocrinological Investigation·E GhigoM F Boghen
Sep 1, 1999·Clinical Endocrinology·S Chappel

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