scholarly journals The mechanism of ciliary movement. —V. The effect ions the duration of beat

1926 ◽  
Vol 99 (698) ◽  
pp. 398-404 ◽  
Keyword(s):  
Sea Water ◽  
Direct Result ◽  
Active Movement ◽  
Healthy Animal ◽  
Marked Contrast ◽  
Ciliary Movement ◽  
Available Energy ◽  
Gill Filaments ◽  
Two Sides ◽  
Acid Substance

In a previous paper (Gray, 1924) it was shown that the whole series of events which accompany continuous ciliary movement is divisible into at least three phases: (i) A reaction which is sensitive to monovalent cations (particularly the hydrogen-ion); any interference with this mechanism involves a change in the rate of beat of the cilia, and ultimately leads to a corresponding change in the oxygen consumption of the cells, (ii) A mechanism which is brought into operation by the presence of an activating acid substance, (iii) A reaction of an oxidative nature which removes some factor which is the direct result of activity and which, if allowed to accumulate, will inhibit the activity of the whole ciliary apparatus. The present paper deals primarily with the first of these processes. For this purpose the lateral epithelium on the gills of Mytilusedulis form a convenient material, since under appropriate conditions the cilia of these cells can (for many hours after excision of the gill) either be maintained in an active state of movement or be kept quite motionless. If the gills of a healthy animal be excised and examined at once under the microscope, the lateral cilia are seen to be in active movement, and exhibit a very beautiful metachronial rhythm which passes up and down the two sides of the gill-filaments. If these gills are now thoroughly washed with sea-water the lateral cilia sooner or later come to rest; the period which elapses before quiescence varies considerably with different individuals. It is usually about 15 mins., but it may be considerably longer in the case of well-fed mussels. It is to be concluded that the amount of available energy in the lateral epithelium is usually sufficient to maintain activity in sea-water for a strictly limited period. This is in marked contrast to the frontal epithelium, which remains active in sea-water for very long periods; in this case it may be assumed that the supply of energy is still being maintained from the glycoprotein (Gray 1924).

scholarly journals The mechanism of ciliary movement.—IV. The relation of ciliary activity to oxygen consumption

1924 ◽  
Vol 96 (673) ◽  
pp. 95-114 ◽  
Keyword(s):  
Sea Water ◽  
Atmospheric Oxygen ◽  
Pure Oxygen ◽  
Active Movement ◽  
Ciliary Activity ◽  
Partial Recovery ◽  
Ciliary Movement ◽  
Hydrogen Recovery ◽  
Typical Experiment ◽  
Time Required

Engelmann (5) showed that the cells of the ciliated epithelium of the frog’s œsophagus remain active for as much as two hours after the tissue is exposed to an atmosphere of hydrogen. From this he concluded that the cells contained a considerable store of intramolecular oxygen, on which they could draw in the total absence of atmospheric oxygen. This experiment is, however, not conclusive. In the case of the cilia on the gills of Mytilus edulis , the absolute time required for cessation of movement in hydrogen depends very largely on the amount of water in contact with the tissue. Oxygen dissolved in an undisturbed drop of water is only slowly removed by a current of hydrogen; in a large drop of water there is, therefore, more oxygen available for the use of the tissue than is the case when the experiment is performed with tissue simply moistened with water. If a piece of gill, kept moist but not immersed in sea-water, is placed on a coverslip in an Engelmann gas chamber and exposed to an atmosphere of hydrogen, active movement persists for 30 to 45 minutes; the speed of the beat gradually falls, and after 60 to 75 minutes all movement ceases. If air be admitted when the movement has begun to slow down partial recovery takes place at once, and is soon complete. If, however, the cilia have become almost inactive in hydrogen, recovery in air is much slower, and may not be complete for about half an hour. In pure oxygen recovery is much more rapid. In order to determine to what extent the prolonged activity of the cells in an atmosphere of hydrogen is due to free oxygen in the water or tissue, the experiments were repeated with hæmoglobin in sea-water. A solution of hæmoglobin was used of such a strength as would enable a film of liquid in contact with the tissue to give a well-marked spectrum with a Zeiss microspectroscope. The following table gives the details of a typical experiment.

scholarly journals THE KINETICS OF PENETRATION

1937 ◽  
Vol 20 (5) ◽  
pp. 737-766 ◽  
Author(s):  
A. G. Jacques
Keyword(s):  
Sea Water ◽  
Surface Layers ◽  
Marked Contrast ◽  
External Concentration ◽  
Protoplasmic Surface ◽  
Kinetics Of ◽  
External Ph

When 0.1 M NaI is added to the sea water surrounding Valonia iodide appears in the sap, presumably entering as NaI, KI, and HI. As the rate of entrance is not affected by changes in the external pH we conclude that the rate of entrance of HI is negligible in comparison with that of NaI, whose concentration is about 107 times that of HI (the entrance of KI may be neglected for reasons stated). This is in marked contrast with the behavior of sulfide which enters chiefly as H2S. It would seem that permeability to H2S is enormously greater than to Na2S. Similar considerations apply to CO2. In this respect the situation differs greatly from that found with iodide. NaI enters because its activity is greater outside than inside so that no energy need be supplied by the cell. The rate of entrance (i.e. the amount of iodide entering the sap in a given time) is proportional to the external concentration of iodide, or to the external product [N+]o [I-lo, after a certain external concentration of iodide has been reached. At lower concentrations the rate is relatively rapid. The reasons for this are discussed. The rate of passage of NaI through protoplasm is about a million times slower than through water. As the protoplasm is mostly water we may suppose that the delay is due chiefly to the non-aqueous protoplasmic surface layers. It would seem that these must be more than one molecule thick to bring this about. There is no great difference between the rate of entrance in the dark and in the light.

A light microscopic study of the action of sodium orthovanadate on the gills of fresh-water and sea-water eels (Anguilla anguilla L.)

1979 ◽  
Vol 59 (4) ◽  
pp. 859-865 ◽  
Author(s):  
K. F. Kelly ◽  
B. J. S. Pirie ◽  
M. V. Bell ◽  
J. R. Sargent
Keyword(s):  
Light Microscopy ◽  
Fresh Water ◽  
Constant Pressure ◽  
Sea Water ◽  
Anguilla Anguilla ◽  
Chloride Cells ◽  
Sodium Orthovanadate ◽  
Central Venous ◽  
Water Fish ◽  
Gill Filaments

Gills of fresh-water and sea-water eels were perfused at a constant pressure with physiological Ringer containing 10−6 M sodium orthovanadate and examined by light microscopy. The secondary gill filaments were markedly vasoconstricted in both freshwater and sea-water fish although the peripheral blood route around the secondary filaments was unaffected. The central venous space in the primary filament was largely unaffected. Significant constriction of both afferent and efferent arteries on the primary filament occurred. We conclude that orthovanadate vasoconstricts eel gills mainly at the level of the secondary filaments. The study also emphasizes that chloride cells are located on both the primary and secondary filaments of fresh-water gills but solely on the primary filaments of sea-water gills.

scholarly journals Note on the Regeneration of the Gill of Mytilus edulis

1931 ◽  
Vol 17 (2) ◽  
pp. 551-566 ◽  
Author(s):  
D. Atkins
Keyword(s):  
Food Supply ◽  
General Circulation ◽  
Sea Water ◽  
The Other ◽  
Experimental Conditions ◽  
Cut Edge ◽  
Retarding Effect ◽  
Gill Filaments ◽  
Food Groove ◽  
Optimum Salinity

Experiments have shown that the gill of Mytilus is capable of regeneration, and that this may occur in less than eight months. It may be confined to the formation of a food grove at the cut edge of the gill, without appreciable regeneration in length of the gill filaments. Regeneration of a food groove appears always to occur at the cut edge, if the ends of the descending and ascending filaments are able to touch and so to fuse. On the other hand, regeneration of gill filaments does not seem to occur invariably, and when it does the rate is slow, at least under experimental conditions and in mussels of a length of about 7·0 to 8·0 cm., such as were used for the experiments: it is possible that regeneration would occur more surely and rapidly in young mussels, but owing to the thinness of the shell they would be more difficult to wedge open without fracturing. Coulthard (6, p. 136), however, says that “The rate of growth is independent of size in the mussel, being apparently influenced only by the environment.” Perhaps the lack of an abundant food supply under the conditions of the experiments should be taken into consideration, though it is well known that in general the amount of food available to an animal has little influence on regeneration (9, p. 27). The salinity of the water in general circulation is about 36–37°/oo, that is, higher than normal sea-water, which is about 35°/oo, and would be considerably higher than the optimum salinity for growth (see Flattely and Walton, 7, p. 81). This may also possibly have a retarding effect on the initiation of regeneration and the rate.

Acetylene Reduction in an Avicennia marina Community in Southern Australia

1984 ◽  
Vol 32 (2) ◽  
pp. 157 ◽  
Author(s):  
Der Valk AG Van ◽  
PM Attiwill
Keyword(s):  
Leaf Litter ◽  
N2 Fixation ◽  
Interstitial Water ◽  
Sea Water ◽  
Avicennia Marina ◽  
Direct Result ◽  
C2h2 Reduction ◽  
Nitrogen Concentrations ◽  
Mesh Bags ◽  
Fibrous Roots

Rates of C2H2 reduction associated with decomposing leaf litter of Avicennia marina (white mangrove) reached 469 nmol C2H4 g-1 h-1 in air after 21 days of decomposition. Maximum rates of C2H2 reduction measured in sea water were 328 nmol C2H4 g-1 h-1 for leaf litter confined in mesh bags and 352 nmol C2H4 g-1 h-1 for unconfined leaf litter; the rates in sea water were always, and often substantially, lower than rates in air. Rates of decomposition and C2H2 reduction were less in leaf litter confined in mesh bags than in unconfined litter. Decomposing dead fibrous roots and live roots showed average rates of C2H2 reduction in interstitial water of only 9.3 and 3.5 nmol C2H4 g-1 h-1, respectively. During decomposition of leaf litter, the concentration of nitrogen increased; 41-64% of this increase was estimated to be the direct result of N2 fixation. No change in nitrogen concentrations occurred in decomposing dead roots or in live roots. N2 fixation associated with decomposing leaf litter and dead roots, and with live roots and surficial sediments, is thought to supply about 40% of the nitrogen required annually by the Avicennia marina trees. This estimate is relatively low in comparison with data for other marine wetlands, and it follows from the low rates of C2H2 reduction associated with the root system and the sediments.

Fast pressure pulses and communication between fish

1991 ◽  
Vol 71 (1) ◽  
pp. 83-106 ◽  
Author(s):  
J. A. B. Gray ◽  
E. J. Denton
Keyword(s):  
Sea Water ◽  
Opposite Polarity ◽  
Clupea Harengus ◽  
Free Swimming ◽  
Pressure Fields ◽  
Pressure Pulses ◽  
Merlangius Merlangus ◽  
Electrical Stimuli ◽  
Two Sides ◽  
Fast Pulse

Experiments on herring (Clupea harengus L.), sprat (Sprattus sprattus (L.)) and whiting (Merlangius merlangus (L.)) showed that when these fish make rapid swimming movements, such movements are preceded by fast pressure pulses in the surrounding sea water. Thefirst (a) phases of these pulses had durations of from 1–5 to 3–5 ms. The pulses could be excited in free-swimming fish by both visual and auditory stimuli and the latencies to the latter ranged from 5 to 8–5 ms. Identical pulses could be elicited by giving electrical stimuli to anaesthetized fish; these pulses had latencies from 34 to 7 ms.The pressure fields around the fish were measured on suspended anaesthetized fish stimulated electrically. At any instant the fields of the fast pulses produced by whiting had the same polarity at all positions round the fish and pressure decayed inversely with the 1–5 powerof distance. The a phase of the fast pulse was usually a decompression.The fields around a stimulated herring were different. The pressures on both sides oppositethe centre of the fish were of one polarity while those around the head and the tail were of the opposite polarity, the pattern of pressure being symmetrical about the long axis of the fish.In our experiments the a phase opposite the centre of the fish was always a compression. The amplitudes of these pulses declined with distance by the power of 2–5. In all species in our experiments the fast pulses were followed by slower pulses associated with swimming movements; these slower pulses had opposite polarities at corresponding points on the two sides of the fish.

scholarly journals THE RELATIVE IMPORTANCE OF pH AND CARBON DIOXIDE TENSION IN DETERMINING THE CESSATION OF CILIARY MOVEMENT IN ACIDIFIED SEA WATER

1925 ◽  
Vol 7 (6) ◽  
pp. 693-697 ◽  
Author(s):  
Charlotte Haywood
Keyword(s):  
Carbon Dioxide ◽  
Sea Water ◽  
Carbon Dioxide Tension ◽  
Relative Importance ◽  
Ciliary Movement

The length of time that cilia from the gills of Mylilus continue to beat in acidified sea water depends to some extent on the pH of the solution but to a greater extent on its carbon dioxide tension.

Memoirs: On the Ciliary Mechanisms and Interrelationship of Lamellibranchs

1938 ◽  
Vol s2-80 (319) ◽  
pp. 331-344
Author(s):  
DAPHNE ATKINS
Keyword(s):  
General Type ◽  
Ciliated Cells ◽  
Marked Contrast ◽  
Gill Filaments ◽  
Orderly Arrangement

The pattern of the lateral ciliated cells of the gill filaments has been examined in a number of Lamellibranchs and figures given, In the Protobranchia the lateral ciliated cells, except for a row on the abfrontal side, have no definite shape or arrangement; in the higher Lamellibranchs there is an orderly arrangement of the approximately rhomboidal cells in rows. The arrangement of the cells in any species appears to be constant. In the group possessing micro-latero-frontal cilia the variation in the pattern of the lateral ciliated cells in the various families is in marked contrast with the constancy of the general type of pattern found in the majority of the Eulamellibranchs.

scholarly journals CHANGES OF APPARENT IONIC MOBILITIES IN PROTOPLASM

1937 ◽  
Vol 20 (5) ◽  
pp. 685-693 ◽  
Author(s):  
W. J. V. Osterhout
Keyword(s):  
Sea Water ◽  
Marked Contrast ◽  
Normal Value ◽  
Ionic Mobilities

The normal P.D. across the protoplasm of Valonia macrophysa is about 10 mv. negative (inwardly directed). On adding 0.01 M guaiacol to the sea water the P.D. becomes positive and then slowly returns approximately to the normal value. In many cases this behavior is not much affected by raising the pH and so increasing the concentration of the guaiacol ion but in other cases such an increase makes the P.D. somewhat more negative. But if we wait until the exposure to guaiacol has lasted 5 minutes (and the P.D. has returned to its normal value) before we raise the pH, the result is very different. The cell then behaves as though it had been sensitized to the action of the guaiacol ion which appears to be far more effective than undissociated guaiacol in making the P.D. more positive. This may be due in part to the high apparent mobility of the guaiacol ion and in part to alterations which it produces in the protoplasm (such alterations increase the P.D. across the protoplasm whereas ordinary injury would be expected to lower it and the cells live on after this treatment and show no signs of injury). This action of the guaiacol ion is in marked contrast to the behavior of other anions whose effect resembles that of Cl-.

Energetics of Ciliary Movement in Sabellaria and Mytilus

1969 ◽  
Vol 50 (3) ◽  
pp. 733-743
Author(s):  
M. A. SLEIGH ◽  
M. E. J. HOLWILL
Keyword(s):  
High Speed ◽  
Angular Frequency ◽  
Viscous Resistance ◽  
Ciliary Movement ◽  
Viscous Forces ◽  
Ciliary Motion ◽  
Elastic Forces ◽  
Gill Filaments ◽  
Recovery Stroke ◽  
Work Done

1. High-speed cinephotography has been used to study the movements performed by compound cilia from the segmental gills of Sabellaria and from the abfrontal face of the gill filaments of Mytilus. 2. The two types of cilium have distinctly different beat patterns. 3. Equations are derived which allow the calculation of the energy necessary to overcome viscous resistance during the effective and recovery strokes of a cilium in terms of its dimensions and angular frequency. 4. In Sabellaria cilia the energy needed to overcome viscous forces is greater for the effective stroke than for the recovery stroke, but the reverse is true for Mytilus abfrontal cilia. 5. Estimates of the work done to overcome elastic forces are probably too high, but it appears that the elastic work done in the recovery stroke is greater than that in the effective stroke for cilia of both types if the stiffness remains constant throughout the beat. 6. The energy released if each fibrillar arm causes the breakdown of one ATP molecule per beat cycle is greater than that required to overcome viscous resistance to ciliary motion.

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