Angiotensin extraction by trout tissues in vivo and metabolism by the perfused gill

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

OSTI ID:5681280

Olson, K R; Kullman, D; Narkates, A J; Oparil, S

Plasma clearance and tissue accumulation of 125I-angiotensin I, (Asp1, Ile5)ANG I, and (14C)sucrose, an inert volume reference, were measured after a bolus injection into the dorsal aorta of rainbow trout, Salmo gairdneri. Retention and metabolism of ANG I to angiotensin II (ANG II) and their constituent 1-4 peptide by the gill were examined using an isolated perfused arch preparation in which outflow from the respiratory and central filamental (venous) pathways was separated. Clearance of ANG I from plasma is multiexponential, reflecting dilution and tissue extraction. Liver, bile, gonads, corpuscles of Stannius, and white skeletal muscle accumulate more 125I than 14C; gill tissue accumulates less 125I than 14C. ANG I and II are retained by the perfused gill longer than the inert vascular marker sucrose, even though the distribution volumes of the former are less. The gill respiratory pathway converts ANG I to ANG II whereas the venous pathway metabolizes either ANG I or II to the 1-4 peptide and other metabolites. The gill respiratory pathway is in series with the systemic vasculature, has a large blood-cell contact area, and, like the mammalian lung, is ideally suited to activate ANG I. The gill venous pathway is in parallel with the systemic vasculature and removes ANG II from the circulation. During stress, elevated plasma catecholamines may reduce venous perfusion and thereby help maintain elevated circulating ANG II levels through reduced venous metabolism.

• Research Organization: Univ. of Notre Dame, IN
• OSTI ID: 5681280
• 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
ANGIOTENSIN
ANIMALS
AQUATIC ORGANISMS
BETA DECAY RADIOISOTOPES
BILE
BIOLOGICAL MATERIALS
BLOOD-PLASMA CLEARANCE
BODY
BODY FLUIDS
CARBON 14 COMPOUNDS
CARDIOVASCULAR AGENTS
CLEARANCE
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DISTRIBUTION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
FISHES
GILLS
GLANDS
GLOBULINS
GONADS
IN VITRO
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIVER
MATERIALS
METABOLISM
MUSCLES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
RESPIRATORY SYSTEM
TISSUE DISTRIBUTION
TRACER TECHNIQUES
TROUT
VASOCONSTRICTORS
VERTEBRATES