Brain insulin growth factor-I induces diuresis increase through the inhibition of arginin-vasopressin release in aged rats.
Normal aging is associated with water homeostasis impairment, arginin-vasopressin (AVP) neuron dysfunction and cerebral insulin growth factor-I (IGF-I) expression deficit. Therefore, we aimed at investigating whether a cerebral chronic treatment of IGF-I in aged rats (26-mo) could restore diuretic function comparable with that observed in adults (3-mo). By using osmotic pumps, we have shown that in aged rats, IGF-I treatment in the third ventricle for four weeks increases water intake and restores diuresis and AVP plasma release similar with that observed in adults. The decrease in AVP plasma release induced by brain IGF-I treatment was also associated with the decrease in urinary osmolality. These results indicate that the age-dependent IGF-I deficit in the brain may be involved in the age-impaired fluid homeostasis in rats.
Laboratoire Psynugen, Université de Bordeaux 2, CNRS UMR5226, INRA UMR1286, IFR8, Bâtiment UFR des Sciences Pharmaceutiques, 146 rue Léo Saignat, Bordeaux, F-33076, France.
M L
ML
Moreau
J
J
Sauvant
F
F
Moos
K
K
Palin
D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D001127:Arginine Vasopressin / Q000097:blood / Q000378:metabolism*; D001921:Brain / Q000502:physiology*; D002404:Catheterization; D004231:Diuresis / Q000502:physiology*; D004327:Drinking Behavior / Q000502:physiology; D006706:Homeostasis / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D009994:Osmolar Concentration; D051381:Rats; D017208:Rats, Wistar; D014556:Urine / Q000737:chemistry; D014867:Water / Q000378:metabolism
D014867:Water; D001127:Arginine Vasopressin; D007334:Insulin-Like Growth Factor I