Food restriction modulates. beta. -adrenergic-sensitive adenylate cyclase in rat liver during aging
- Univ. of Texas Health Science Center, San Antonio (USA) Audie L. Murphy Memorial Veterans Hospital, San Antonio, TX (USA)
Adenylate cyclase activities were studied in rat liver during postmaturational aging of male Fischer 344 rats fed ad libitum or restricted to 60% of the ad libitum intake. Catecholamine-stimulated adenylate cyclase activity increased by 200-300% between 6 and 24-27 mo of age in ad libitum-fed rats, whereas in food-restricted rats catecholamine response increased by only 58-84% between 6 and 30 mo. In ad libitum-fed rats, glucagon-stimulated enzyme activity also increased by 40% between 6 and 12 mo and in restricted rats a similar age-related increase was delayed until 18 mo. {beta}-Adrenergic receptor density increased by 50% between 6 and 24 mo in livers from ad libitum-fed but not food-restricted rats and showed a highly significant correlation with maximal isoproterenol-stimulated adenylate cyclase activity over the postmaturational life span. Age-related increases in unstimulated (basal) adenylate cyclase activity and nonreceptor-mediated enzyme activation were retarded by food restriction. The results demonstrate that food restriction diminishes a marked age-related increase in {beta}-adrenergic-sensitive adenylate cyclase activity of rat liver. Alterations of adrenergic-responsive adenylate cyclase with age and the modulatory effects of food restriction appear to be mediated by changes in both receptor and nonreceptor components of adenylate cyclase.
- OSTI ID:
- 6993121
- Journal Information:
- American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 254:1; ISSN 0002-9513; ISSN AJPHA
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
AGE DEPENDENCE
AMINES
ANIMALS
AROMATICS
AZAARENES
AZOLES
BETA DECAY RADIOISOTOPES
BIOCHEMISTRY
BODY
CATECHOLAMINES
CHEMISTRY
CYCLASES
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
ELECTRON CAPTURE RADIOISOTOPES
ENZYME ACTIVITY
ENZYMES
FASTING
GLANDS
GLUCAGON
HETEROCYCLIC COMPOUNDS
HORMONES
HYDROXY COMPOUNDS
INDOLES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LIVER
LYASES
MAMMALS
NUCLEI
NUTRITIONAL DEFICIENCY
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PEPTIDE HORMONES
PEPTIDES
PHENOLS
POLYPEPTIDES
POLYPHENOLS
PROTEINS
PYRROLES
RADIOISOTOPES
RADIORECEPTOR ASSAY
RATS
RODENTS
TRACER TECHNIQUES
VERTEBRATES