The locomotory function of the fins in the squid Loligo pealei

2005 ◽  
Vol 38 (3) ◽  
pp. 169-189 ◽  
Author(s):  
Erik Anderson ◽  
M. Edwin Demont
Keyword(s):  
Loligo Pealei

The Significance of the Bohr Effect in the Respiration and Asphyxiation of the Squid, Loligo Pealei

1929 ◽  
Vol 6 (4) ◽  
pp. 340-349 ◽  
Author(s):  
ALFRED C. REDFIELD ◽  
ROBERT GOODKIND
Keyword(s):  
Carbon Dioxide ◽  
Toxic Effect ◽  
Venous Blood ◽  
Bohr Effect ◽  
Reciprocal Effects ◽  
Cent Oxygen ◽  
Carbon Dioxide Content ◽  
Arterial Blood ◽  
Loligo Pealei

1. The oxygen and carbon-dioxide content of the arterial and venous blood of the squid, Loligo pealei, have been measured. 2. Using a nomographic method of analysis it is shown that the reciprocal effects of oxygen and carbon dioxide upon the respiratory properties of squid haemocyanin account for one-third of the respiratory exchange. 3. The venous blood is estimated to be 0.13 pH unit more acid than the arterial blood. 4. Death from asphyxiation occurs when the oxygen and carbon-dioxide pressures are such that the arterial blood can combine with only 0.5 to 1.5 volumes per cent, oxygen. Carbon dioxide exerts no toxic effect except through its influence on the oxygenation of the blood. 5. The haemocyanin of the blood is of vital necessity to the squid, because the amount of oxygen which can be physically dissolved in blood is less than the amount which is necessary for the maintenance of life.

Electric current generated by squid giant axon sodium pump: external K and internal ADP effects

1978 ◽  
Vol 235 (1) ◽  
pp. C63-C68 ◽  
Author(s):  
R. F. Abercrombie ◽  
P. de Weer
Keyword(s):  
Sodium Pump ◽  
Giant Axon ◽  
Pump Current ◽  
Membrane Resistance ◽  
Extracellular Potassium ◽  
Sodium Efflux ◽  
Steroid Sensitive ◽  
External Potassium ◽  
Loligo Pealei ◽  
External K

The operation of the sodium pump of giant axons of the squid, Loligo pealei, has been studied simultaneously in two independent ways: 1) by measuring sodium efflux with 22Na, and 2) by calculating the transmembrane current generated by the pump from measurements of membrane resistance and digitalis-sensitive membrane potential. In normal, untreated axons, the effect of increasing the external potassium concentration on both sodium efflux and pump current is similar, which suggests that Na:K pump stoichiometry remains relatively constant in the range of 0-20 mM external K. The data are compatible with a 3:2 Na:K ratio. In axons whose intracellular ADP level has been elevated by injection of L-arginine, a large, electrically silent, cardiotonic steroid-sensitive sodium efflux takes place in the absence of external potassium; this suggests that pump-mediated Na:Na exchange is 1:1 or electroneutral. Finally, elevation of external potassium levels causes the appearance, in high-ADP axons, of electrogenic pumping, with little effect on sodium efflux; hence, in contrast to what is seen in normal (low-ADP) axons, the charge translocated, per sodium ion extruded, increases sharply with increasing extracellular potassium levels.

Physical studies of hemocyanins. IV. Oxygen-linked disassociation of Loligo pealei hemocyanin

Biochemistry ◽  
1969 ◽  
Vol 8 (9) ◽  
pp. 3665-3672 ◽  
Author(s):  
Henry A. DePhillips ◽  
Kenneth W. Nickerson ◽  
Michael Johnson ◽  
Kensal E. Van Holde
Keyword(s):  
Loligo Pealei

scholarly journals The Effects of External Potassium and Long Duration Voltage Conditioning on the Amplitude of Sodium Currents in the Giant Axon of the Squid, Loligo pealei

1969 ◽  
Vol 54 (5) ◽  
pp. 589-606 ◽  
Author(s):  
William J. Adelman ◽  
Yoram Palti
Keyword(s):  
Steady State ◽  
Time Constant ◽  
State Level ◽  
Giant Axon ◽  
Sodium Concentration ◽  
Quasi Steady State ◽  
Steady State Level ◽  
Long Duration ◽  
Time Courses ◽  
Loligo Pealei

Giant axons were voltage-clamped in solutions of constant sodium concentration (230 mM) and variable potassium concentrations (from 0 to 210 mM). The values of the peak initial transient current, Ip, were measured as a function of conditioning prepulse duration over the range from less than 1 msec to over 3 min. Prepulse amplitudes were varied from Em = -20 mv to Em = -160 mv. The attenuation of the Ip values in high [Ko] was found to vary as a function of time when long duration conditioning potentials were applied. In both high and low [Ko], Ip values which had reached a quasi-steady—state level within a few milliseconds following a few milliseconds of hyperpolarization were found to increase following longer hyperpolarization. A second plateau was reached with a time constant of about 100–500 msec and a third with a time constant in the range of 30 to 200 sec. The intermediate quasi-steady—state level was absent in K-free ASW solutions. Sodium inactivation curves, normalized to Ipmax values obtained at either the first or second plateaus, were significantly different in different [Ko]. The inactivation curves, however, tended to superpose after about 1 min of hyperpolarizing conditioning. The time courses and magnitudes of the intermediate and very slow sodium conductance restorations induced by long hyperpolarizing pulses are in agreement with those predicted from the calculated rates and magnitudes of [K+] depletion in the space between the axolemma and the Schwann layer.

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