scholarly journals STIMULATION OF FUNDULUS BY HYDROCHLORIC AND FATTY ACIDS IN FRESH WATER, AND BY FATTY ACIDS, MINERAL ACIDS, AND THE SODIUM SALTS OF MINERAL ACIDS IN SEA WATER

1934 ◽  
Vol 17 (6) ◽  
pp. 803-816 ◽  
Author(s):  
J. B. Allison ◽  
William H. Cole

1. Fundulus heteroclitus was found to be a reliable experimental animal for studies on chemical stimulation in either fresh or sea water. 2. The response of Fundulus to hydrochloric, acetic, propionic, butyric, valeric, and caproic acids was determined in fresh water, while the same acids plus sulfuric and nitric, as well as the sodium salts of the mineral acids, were tested in sea water. 3. Stimulation of Fundulus by hydrochloric acid in fresh water is correlated with the effective hydrogen ion concentration. Stimulation by the n-aliphatic acids in the same environment is correlated with two factors, the effective hydrogen ion concentration and the potential of the non-polar group in the molecule. However, as the number of CH2 groups increases the stimulating effect increases by smaller and smaller amounts, approaching a maximum value. 4. Stimulation of Fundulus by hydrochloric, sulfuric, and nitric acids in sea water is correlated with the forces of primary valence which in turn are correlated with the change in hydrogen ion concentration of the sea water. The n-aliphatic acids increase in stimulating efficiency in sea water as the length of the carbon chain increases, but a limiting value is not reached as soon as in fresh water. 5. Only a slight difference in stimulation by hydrochloric acid is found in sea water and in fresh water. However, there is a significant difference in stimulation by the fatty acids in fresh and in sea water, which is partly explained by the different buffering capacities of the two media. It is to be noted that in the same environment two different fish, Fundulus and Eupomotis, give different results, while the same fish (Fundulus) in two different environments responds similarly to mineral acids but differently to fatty acids. These results illustrate that stimulation is a function of the interaction between environment and receptors, and that each is important in determining the response. 6. Stimulation by sodium chloride, nitrate, and sulfate is correlated with equivalent concentrations of the salts added to sea water, or with the forces of primary valence. Although the threshold for stimulation by the salts is considerably higher than for the acids, the efficiency of stimulation by the salts is greater.

Nature ◽  
1923 ◽  
Vol 111 (2778) ◽  
pp. 132-133
Author(s):  
J. J.

Author(s):  
W. R. G. Atkins

The present paper is a continuation of the work already published under the above general title and should be considered in relation to the results previously recorded. The method of performing the measurements remained unchanged; xylenol blue was used to check the determinations made with cresol red in the more alkaline regions—namely, around pH 8.24. The water was tested immediately after being drawn, or within a few hours, unless otherwise stated in the tables.


1922 ◽  
Vol 4 (3) ◽  
pp. 305-317 ◽  
Author(s):  
Edwin B. Powers

1. The ability of marine fishes to absorb oxygen at low tension from the sea water is more or less dependent upon the hydrogen ion concentration of the water. 2. The ability of fishes to withstand wide variations in the range of hydrogen ion concentration of the sea water can be correlated with their habitats. The fishes that are most resistant to a wide variation in the hydrogen ion concentration are most cosmopolitan in their habitat. Those that are least resistant to a variation in the hydrogen ion concentration are the most restricted in their range of habitat. 3. There is a close correlation between the optimum condition of the sea water for the absorption of oxygen at low tension by the herring (Clupea pallasii), the condition of the sea water to which they react positive and that in which they are found most abundantly. 4. It is suggested that the variation in the ability to absorb oxygen at low tension at a given pH of individuals of a species is dependent upon the alkaline reserve of the blood of the individual fish.


Author(s):  
W. R. G. Atkins

In the first publication under the above general title the seasonal changes in sea water were studied, but as explained previously it was not possible to regard all the data as of an equal degree of accuracy. For this and other reasons the seasonal changes were further traced in the hydrographical cruises up to October, 1922, when the approach of the winter equilibrium made it profitless for some months to continue. Since, however, at times from April to September the changes are relatively rapid it may be advisable to follow up the matter during the period mentioned at shorter intervals.


1980 ◽  
Vol 239 (3) ◽  
pp. G210-G214 ◽  
Author(s):  
D. Hollander

Absorption of [3H]retinol into lymph and bile was studied in unanesthetized rats with cannulated thoracic and common bile ducts. Retinol in a micellar solution was infused into the duodenum. Absorption of retinol into lymph increased when the infusate's taurocholate concentration was increased to 10 mM, when the hydrogen ion concentration was increased, or when octanoic acid was added to the infusate. Absorption of retinol into lymph decreased when the taurocholate concentration was decreased to 5 mM or when long-chain unsaturated fatty acids or retinoic acid were added to the duodenal infusate. Retinol absorption into bile increased following additions of linoleic and arachidonic acids to the infusate, but absorption did not change following modifications of the infusate's taurocholate concentration or pH. These experiments, which demonstrate that intraluminal factors do modify the extrusion of retinol into bile and lymph, enhance our overall understanding of the process of absorption of this lipid nutrient.


Author(s):  
W. R. G. Atkins

1. Measurements of hydrogen ion concentration, of phosphate concentration, and of temperature all show at certain seasons a well-marked gradient from surface to bottom. The upper 10–20 metres is more alkaline, notably depleted of phosphates and warmer.2. Settled summer weather and deep water, free from irregularities of the bottom, favour the formation of such a gradient. Its breaking up is occasioned by wave action and the cooling of the surface water in autumn.3. Thermal stratification in the English Channel arises at each station, and is not due to the inflow of warm over colder water.


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