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Wilkie, M.P., J. Couturier, and B.L. Tufts, 1998. Mechanisms of Acid-Base
Regulation in Migrant Sea Lampreys (Petromyzon marinus) Following
Exhaustive Exercise, Mount Allison University.
Reprinted from Journal of Experimental Biology (1998) 201(9): 1473-1482
Mechanisms of Acid-Base Regulation in Migrant Sea Lampreys (Petromyzon
marinus) Following Exhaustive Exercise
Summary
The life cycle of the sea lamprey (Petromyzon marinus) is characterized by a terminal upstream
spawning migration that may be associated with brief bursts of high-intensity swimming. Such activity
usually leads to pronounced blood acid-base disturbances in fishes, but lampreys rapidly correct
these perturbations within 1 h. In the present study, patterns of post-exercise H+ excretion
(J Hnet ) and ion movements were followed in sea lampreys to test the hypothesis that dynamic manipulation
of Na+ versus Cl- movements across the animal's body surface, presumably at the gills, accounted
for the rapid restoration of blood pH following exercise. The first hour of
post-exercise recovery in
sea lampreys was associated with marked stimulation of J Hnet
(equivalent to base uptake), which
approached -500 µmol kg-1 h-1. After 1h, J Hnet
patterns had returned to resting rates. Analyses of
net Na+ and Cl- movements (J Nanet , J Clnet
) suggested that elevated net Cl- losses, which greatly
exceeded net Na+ losses, accounted for most of the J Hnet. Subsequent experiments, using
radiotracers (22Na+, 36Cl-), indicated that differential increases in Cl- versus Na+ permeability
accounted for the greater post-exercise Cl- losses and the corresponding stimulation of net proton
excretion. Finally, metabolic acid budget analyses confirmed our hypothesis that rapid excretion of
metabolic protons was the primary means used by sea lampreys to correct post-exercise
extracellular acidosis.
Entire Paper
Contact: Michael Wilkie, Mount Allison University, Department of Biology,
Sackville, New Brunswick, CANADA E4L 1G7
Key Words: Sea_lamprey, Basic_biology
Product Type: Research, Basic_biology
User Type: General
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