Glucagon mediated Ca/sup 2 +/-mobilization in the isolated perfused rat liver is dependent on cellular oxidation-reduction state

Conference · Fri May 01 04:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6079275

Rashed, H M; Patel, T B

Alterations in the efflux of /sup 45/Ca/sup 2 +/ from non-recirculating isolated perfused rat livers during glucagon (G) or phenylephrine (Ph) infusion was employed as a monitor of Ca/sup 2 +/-mobilization in the intact organ. The effect of altering cellular redox state with infusion of either pyruvate (P) alone, or lactate (L) alone, or a mixture of P and L on Ca/sup 2 +/-mobilization by G was investigated. As a control in all experiments, the ability of Ph (1 x 10/sup -5/M) to alter /sup 45/Ca/sup 2 +/ efflux was also monitored. Under all experimental conditions Ph infusion in liver resulted in a stimulation of /sup 45/Ca/sup 2 +/ efflux. In livers of 24h-fasted rats perfused in the absence of any substrate, or in the presence of P alone, or L alone, infusion of 1 x 10/sup -8/M G resulted in a small increase in the rate of /sup 45/Ca/sup 2 +/ efflux while 1 x 10/sup -9/M G was ineffective. However, when livers derived from 24h-fasted rats were perfused with a mixture of L and P such that the concentration of L + P was fixed at 2.0 mM and the ratio of L/P was either 4 or 8, infusion of 1 x 10/sup -9/M G resulted in a substantial increase in the rate of /sup 45/Ca/sup 2 +/ efflux. These data indicate that cellular redox potential may facilitate or potentiate the ability of G to mobilize Ca/sup 2 +/ in the isolated perfused liver.

• Research Organization: Univ. of Tennessee, Memphis
• OSTI ID: 6079275
• Report Number(s): CONF-870644-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 46:6
• Country of Publication: United States
• Language: English

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550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CALCIUM 45
CALCIUM COMPOUNDS
CALCIUM ISOTOPES
CARBOXYLIC ACIDS
CATIONS
CHARGED PARTICLES
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
EVEN-ODD NUCLEI
GLANDS
HORMONES
HYDROXY ACIDS
INFUSION
INTAKE
INTERMEDIATE MASS NUCLEI
IONS
ISOTOPE APPLICATIONS
ISOTOPES
KETO ACIDS
KINETICS
LACTIC ACID
LIVER
MAMMALS
MEMBRANE TRANSPORT
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PERFUSED ORGANS
PYRUVIC ACID
RADIOISOTOPES
RATS
REACTION KINETICS
REDOX POTENTIAL
RODENTS
TRACER TECHNIQUES
VERTEBRATES