The Physiology of the Antennal Gland of Carcinus Maenas (L.)

1969 ◽  
Vol 51 (1) ◽  
pp. 1-10
Author(s):  
R. BINNS

1. U/B ratios for inulin and sorbitol have been measured in 100%, 75% and 50% sea water. 2. When Carcinus is in 100% sea water, a U/B ratio of 1 for both sorbitol and inulin is reached and maintained after 40 and 115 hr. respectively. A reason for this difference is suggested. 3. In dilute media the rate of increase of U/B ratio for both molecules is more rapid than in 100% sea water. For instance, in 50% sea water the inulin U/B ratio is 1 after 50-60 hr. Sorbitol ratios are generally less than 1 in dilute sea water and a possible explanation of this is given. 4. In any particular concentration of sea water blood and urine concentrations of injected solutes fall at approximately the same rate once the maximum urine concentration has been reached. 5. It is concluded that primary urine production in Carcinus is by a filtration mechanism and that reabsorption of water from the urine does not normally occur.

1969 ◽  
Vol 51 (1) ◽  
pp. 29-39
Author(s):  
R. BINNS

1. Amino acids are actively reabsorbed by the antennal gland of Carcinus in all concentrations of sea water, but there is never complete recovery of these molecules from the urine; even in animals in 100% sea water amino acids are eliminated in the urine. 2. The urine concentration of amino acids is related to (i) the blood amino acid concentration and (ii) the rate of urine production. An increase in either or both of these factors, for example, when animals are in dilute sea water, raises the U/B ratio of amino acids. 3. The rate of reabsorption of amino acids increases as the amino acid load on the antennal gland is raised. When reabsorption is maximal, the rate of transport is about seven times greater than at normal concentrations of amino acids in blood and urine when the animal is in 100% sea water. 4. Increases in blood amino acid concentrations when crabs are placed directly into dilute sea water are taken to be the result of changes in free amino acids of muscle which occur under these conditions. This intracellular regulation in dilute media is initiated when the blood sodium concentration is approximately 400 mM/l.


1969 ◽  
Vol 51 (1) ◽  
pp. 11-16
Author(s):  
R. BINNS

1. The space measured by inulin distribution, the ‘inulin volume’, has been determined, and represents approximately 20% of the body weight in crabs ranging in size from 20.0 to 57.2 g. 2. After the injection of labelled inulin into crabs, the increase in activity of the medium is equal to the fall in blood inulin in all dilutions of sea water. Clearance of inulin from the blood is due only to urine production, and therefore the molecule can be used for quantitative investigations of antennal gland function. 3. Urine production in various concentrations of sea water has been determined by measuring the clearance of inulin from the blood and the rates at which the tracer appeared in the external media. By these methods the mean rate of urine production in 100% sea water was estimated to be 4.4% body weight per day. In dilute sea water the rate of urine production increases; for example, in 50% sea water the urine flow is four times greater than in normal sea water.


1969 ◽  
Vol 51 (1) ◽  
pp. 17-27
Author(s):  
R. BINNS

1. Glucose is actively reabsorbed by the antennal gland. 2. In 100% sea water there is a blood threshold concentration of approximately 150 mg.%. This does not indicate the maximum rate of glucose reabsorption. 3. Below the threshold, reabsorption is not always complete, but may be if carbohydrate sources are limited or absent. 4. The threshold level depends on the rate at which fluid passes through the antennal gland, an increase in urine production rate being correlated with a reduction in the glucose threshold. 5. Phloridzin inhibits reabsorption and glucose U/B ratios approach unity, indicating that glucose is filtered passively into the antennal gland.


1978 ◽  
Vol 74 (1) ◽  
pp. 123-132
Author(s):  
J.R. W. NORFOLK

In Carcinus, in dilute media, internal volume and pressure were found to be regulated by the intermittent release of urine which maintained internal pressure at a mean value of 15 cm water, compared to a mean value of 10 cm for crabs in sea water. Following transfer of crabs from 100% to 50% sea water, urine production (measured by a continuous collection method) was observed to increase within 5 min of dilution of the medium, by which time the estimated increase in internal pressure would have been only 1.3 cm water. Such a pressure increase is considered inadequate to stimulate a rise in urine production, since artificially raising internal pressure of crabs in sea water did not result in an increase in urine flow, until the pressure was in excess of 20 cm water. The results support the hypothesis that the stimulus to increase urine production by crabs in dilute media is not raised internal pressure due to osmotic influx of water. An alternative hypothesis, namely that of changes in urine production being in response to direct monitoring of the external environment, is suggested.


1961 ◽  
Vol 38 (1) ◽  
pp. 135-152
Author(s):  
J. SHAW

1. The mechanism of sodium balance in Carcinus maenas has been investigated. 2. Measurements of sodium outflux showed no evidence of a decrease in surface permeability to sodium in dilute sea water. 3. The rate of urine production in normal sea water was 3.6% body weight per day and the sodium loss through the urine was insignificant compared with the total sodium loss. In 40% sea water the urine rate was increased to 30% body weight per day and the loss in the urine accounted for 20% of the total loss. 4. Measurements of sodium influx and calculation of the active component showed that the active uptake mechanism was fully saturated at all external concentrations in which the animals could survive. 5. Regulation of the blood sodium concentration is effected largely by the activation of the sodium uptake mechanism. This prevents the blood concentration falling below a critical level as long as the external concentration itself is not too low.


2016 ◽  
Vol 1 (1) ◽  
pp. 45-52
Author(s):  
Palupi Puspitorini

The aim of this study was to select the best sources of auxin of which it can stimulate the growth of shoots Pineapple plant cuttings. This research is compiled in a completely randomized design (CRD) with 4 treatments and 6 replications. The Data were statistically Analyzed by the DMRT. Level of treatment given proves that no treatment 0%, cow urine concentration of 25%, young coconut water concentration of 25% and Rootone F 100 mg / cuttings. The results showed that cow urine concentrations of 25% and Rootone F 100 mg give the best results in stimulating the growth of shoots pineapple stem cuttings. Experimental results concluded that the effect of this natural hormone were better than the shoots without given hormone.           


1974 ◽  
Vol 60 (1) ◽  
pp. 167-181
Author(s):  
J. A. RIEGEL ◽  
A. P. M. LOCKWOOD ◽  
J. R. W. NORFOLK ◽  
N. C. BULLEID ◽  
P. A. TAYLOR

1. Measurements have been made to determine the blood volume, bladder volume, clearance of 131I-sodium diatrizoate and U/H for diatrizoate in the crabs Carcinus maenas and Macropipus (Portunus) depurator. 2. Observed values of clearance blood volume and bladder volume in the two species at 18 °C were: Clearance (as % blood volume per day), Macropipus 56.1±14.5; Carcinus 27.1±5.8; Blood volume (as % body weight), Macropipus 21.0±4.0; Carcinus 19.2±3.0; Bladder volume (as % blood volume), Macropipus 12.1 ±5.0; Carcinus 11.0±8.0. 3. It is shown that the measured U/H differs from that to be expected if no reabsorption of water or secretion of diatrizoate occurs. 4. 14C-inulin and 51Cr-EDTA are excreted in an essentially similar manner to 131I-diatrizoate by Carcinus, implying that any active secretion of diatrizoate must be small in magnitude. 5. Injections of ethacrynic acid decrease the U/H ratio for diatrizoate relative to that in control Carcinus injected with sea water. In some Carcinus the concentration of diatrizoate in the urine comes to exceed that initially present in the blood. Both these points are taken, with 3, as support for the conclusion that water can be withdrawn from the primary urine of Carcinus.


1968 ◽  
Vol 48 (2) ◽  
pp. 339-358
Author(s):  
D. W. SUTCLIFFE ◽  
J. SHAW

1. A quantitative study of sodium influx and loss was made on populations of Gammarus duebeni obtained from four freshwater localities in Ireland. 2. Characteristic features of sodium regulation in animals from the four localities were as follows, (a) The sodium influx increases gradually with increasing external sodium concentrations, but a maximum (saturation) level is abruptly reached at an external concentration of 1-2 mM/l. and the transporting system is half saturated at about 0.5 mM/l. sodium, (b) Over the range of sodium concentrations found in fresh waters a low rate of sodium uptake is sufficient to balance sodium losses at concentrations down to between 0.5 and 0.25 mM/l. At lower concentrations the influx is increased and the loss rate is reduced. (c) Calculations suggest that hypotonic urine containing approximately 40 mM/l sodium is produced at external concentrations ranging from fresh water to 40 % sea water. At external concentrations below 0.25 mM/l. sodium the urine concentration is probably reduced to well below 40 mM/l. sodium. 3. A detailed comparison is made of sodium regulation at external concentrations ranging between 0.07 and 1 mM/l. sodium in G. duebeni from fresh water in Ireland and from fresh water and brackish water in Britain. It is suggested that G. duebeni in Ireland constitutes a distinct physiological race adapted for living in fresh waters with relatively low sodium concentrations.


Author(s):  
G. W. Bryan ◽  
L. G. Hummerstone ◽  
Eileen Ward

Zinc is one of the most important of the essential trace metals and more than 90 zinc-containing enymes and proteins have been discovered: furthermore, zinc increases the activity of many other enzymes (Vallee, 1978). It is not surprising, therefore, that in some groups of animals the body concentration is regulated against fluctuations in intake. Decapod crustaceans comprise one such group, although the ways in which regulation is achieved vary from species to species. In the freshwater crayfish, Austropotamobius pallipes, excretion in the faeces is a major pathway for removing zinc (Bryan, 1967a) whereas in the shore crab Carcinus maenas losses over the body surface also assume considerable importance (Bryan, 1966). On the other hand, preliminary work on the lobster Homarus gammarus (formerly H. vulgaris) suggests that in this species urinary excretion plays a major role in regulation (Bryan, 1964). The present work continues the study of zinc regulation in lobsters and its main aims are: (1) to measure rates of absorption from sea water over a wide range of concentrations and study the uptake mechanism; (2) to examine absorption from the stomach under different conditions; (3) to determine the relative importance of different pathways for the removal of zinc in response to various levels of intake.


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