Extraction and metabolism of circulating catecholamines by the trout gill

Journal Article · Sat Mar 01 04:00:00 EST 1986 · Am. J. Physiol.; (United States)

OSTI ID:5620314

Nekvasil, N P; Olson, K R

Extraction and metabolism of (3H)-norepinephrine (NE) and (3H)epinephrine (E) by the respiratory (efferent branchial) and filamental (venous) vasculature of the trout gill were examined using an isolated perfused arch technique in which outflow from the two circulations was separated. Deaminated and O-methylated metabolites in the effluent were identified by ion-exchange chromatography. Metabolism by tissue homogenates was also measured. Gill homogenates deaminate catecholamines (CAs) faster than homogenates of liver, kidney, and skeletal muscle; branchial O-methylation was comparable to that of liver and kidney. The perfused gill extracted 60% of a NE pulse and 47% of an E pulse. During continuous CA perfusion the gill removed greater than 30% of the NE from the circulation through extraction and metabolism; only 7% of the E was removed. The gill venous system extracts and metabolizes more CAs than the efferent. NE is the preferred substrate for extraction and metabolism. A mechanism is proposed whereby high circulating CA levels, common during stress, are maintained through CA-induced reduction in venous blood flow. After the stress is alleviated, CA levels begin to fall, flow to the venous pathway increases, and the rate of inactivation of circulating CAs increases.

• Research Organization: Univ. of Notre Dame, IN
• OSTI ID: 5620314
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States); ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
ADRENALINE
AMINES
ANIMALS
AQUATIC ORGANISMS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
CARDIOTONICS
CARDIOVASCULAR AGENTS
CATECHOLAMINES
DRUGS
FISHES
GILLS
HORMONES
HYDROXY COMPOUNDS
IN VITRO
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
METABOLISM
NEUROREGULATORS
NORADRENALINE
ORGANIC COMPOUNDS
PHENOLS
POLYPHENOLS
RESPIRATORY SYSTEM
STEROID HORMONES
SYMPATHOMIMETICS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
TROUT
VERTEBRATES