beta. -adrenergic receptor-mediated hepatic glycogenolysis is increased in aged male rats

Conference · Tue Mar 04 23:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6991762

Herring, P A; Graham, S M; Arinze, I J

The effect of age on catecholamine-stimulated glycogenolysis was studied in isolated hepatocytes prepared from 3, 12, and 24 month-old rats. Glucose release was stimulated by epinephrine and norepinephrine, this was inhibited by phentolamine and prazosin. Isoproterenol (ISO) stimulated glycogenolysis only in cells from 24 month-old rats, this was blocked by propranolol. In liver plasma membranes, binding of (/sup 3/H)yohimbine (100-130 fmol/mg protein) did not change with age, whereas (/sup 3/H)prazosin binding decreased from 870 fmol/mg at 3 months to 435 fmol/mg at 12 months, but subsequently rose to 656 fmol/mg at 24 months. (/sup 125/I)Cyanopindolol binding increased from 8 fmol/mg at 3 months to 19 fmol/mg at 24 months. The proportion of ..beta..-receptors in the high affinity state increased from 28% at 3 months to 42% at 24 months. ISO stimulated adenylate cyclase at 24 months but not at 3 months. Basal, fluoride-, GTP-, and Gpp(NH)p-stimulated activities were 1.4- to 2.4-fold greater at 24 months than at 3 months. These results suggest an age-related increase in the sensitivity of adenylate cyclase to ..beta..-receptor stimulation.

• Research Organization: Meharry Medical College, Nashville, TN
• OSTI ID: 6991762
• Report Number(s): CONF-8604222-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Vol. 45:4; ISSN FEPRA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AGE DEPENDENCE
ALDEHYDES
ANIMAL CELLS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CARBOHYDRATES
CYCLASES
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ENZYME ACTIVITY
ENZYMES
GLUCOSE
GLYCOGEN
HEXOSES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LIVER CELLS
LYASES
MALES
MAMMALS
MEMBRANE PROTEINS
METABOLISM
MONOSACCHARIDES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
POLYSACCHARIDES
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SACCHARIDES
SOMATIC CELLS
SYMPATHOMIMETICS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES