REGULATION AND DISTRIBUTION OF PLASMA CALCIUM AND INORGANIC PHOSPHATE IN THE EUROPEAN EEL (ANGUILLA ANGUILLA L.)

SUMMARY The amounts of ionized, complexed and protein-bound calcium and total inorganic phosphate were measured in the plasma of the eel. Groups comprised freshwater, seawater and distilled water eels; treatment with corticotrophin (ACTH), cortisol, aldosterone or oestrogen; adrenalectomized and hypophysectomized eels and those with the corpuscles of Stannius removed. In the intact animal, the amounts of ultrafiltrable and ionic calcium and inorganic phosphate in the plasma were very constant despite wide variation in the electrolyte composition of the external medium. In the freshwater eel, 1 week after removal of the corpuscles of Stannius, there was a rise in the level of ultrafiltrable calcium and a decline in that of inorganic phosphate. At 3 weeks after operation, although total calcium concentration remained elevated, ultrafiltrable and ionic calcium concentrations returned to control values. Adrenalectomy and hypophysectomy of the freshwater eel resulted in a decline in total calcium concentration with change in the levels of ultrafiltrable calcium or inorganic phosphate. In the seawater eel, adrenalectomy or removal of the corpuscles of Stannius resulted in an increase in total and ultrafiltrable calcium concentrations. Injection of ACTH, cortisol or aldosterone did not affect calcium concentrations but gave a slight decline in inorganic phosphate levels. Injection of oestrogen increased total calcium concentration without affecting ultrafiltrable or ionic calcium concentrations. The relationship of the amounts of ultrafiltrable calcium and inorganic phosphate to the solubility product [ultrafiltrable calcium] × [phosphate] is discussed and attention drawn to the importance of protein-binding in calcium homeostasis.

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Ionic and total calcium levels in the blood of the European eel (Anguilla anguilla): effects of stanniectomy and hypocalcin replacement therapy

Journal of Experimental Biology ◽

10.1242/jeb.141.1.177 ◽

1989 ◽

Vol 141 (1) ◽

pp. 177-186 ◽

Cited By ~ 2

Author(s):

R. G. Hanssen ◽

F. P. Lafeber ◽

G. Flik ◽

S. E. Wendelaar Bonga

Keyword(s):

Replacement Therapy ◽

Calcium Concentration ◽

Anguilla Anguilla ◽

European Eel ◽

Total Calcium ◽

Corpuscles Of Stannius ◽

Ionic Calcium

Removal of the corpuscles of Stannius (STX) in the freshwater European eel causes a marked increase in the concentrations of blood ionic calcium and protein-bound calcium. The hypercalcaemia peaks 20 days after STX and lasts at least another 20 days. In stanniectomized eels hypocalcin decreased both blood ionic and total calcium concentrations. The reduction of plasma total calcium concentration by hypocalcin is attributed to a reduction in blood ionic calcium concentration. We conclude that hypocalcin regulates blood ionic calcium levels in fish.

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Influence of Ambient Calcium Levels on Tanniocalcin Secretion in the European EEL (Anguilla Anguilla)

Journal of Experimental Biology ◽

10.1242/jeb.162.1.197 ◽

1992 ◽

Vol 162 (1) ◽

pp. 197-208 ◽

Cited By ~ 2

Author(s):

R.G.J. M. HANSSEN ◽

N. MAYER-GOSTAN ◽

G. FLIK ◽

S.E. WENDELAAR BONGA

Keyword(s):

Sea Water ◽

Secretory Granules ◽

Anguilla Anguilla ◽

Secretory Activity ◽

European Eel ◽

Apparent Effect ◽

Rapid Reduction ◽

Corpuscles Of Stannius ◽

Rapid Accumulation ◽

Ionic Calcium

The cells of the corpuscles of Stannius appeared to be more active in eels acclimated to sea water than in eels acclimated to fresh water. In acclimated eels, however, total and ionic plasma calcium concentrations and stanniocalcin titers did not differ. This suggests that levels of stanniocalcin in freshwater-acclimated eels are sufficient to maintain normocalcemia in sea water. When freshwateracclimated eels were transferred directly to sea water, total and ionic calcium concentrations in the plasma increased significantly within 24 h but there was no apparent effect on the corpuscles of Stannius within the same time. This suggests that changes in secretory activity of the corpuscles of Stannius do not occur rapidly when they are presented with a hypercalcemic challenge. Conversely, when seawater-acclimated eels were transferred to fresh or distilled water there appeared to be a very rapid reduction in secretory activity in the corpuscles of Stannius, as indicated by the rapid accumulation of secretory granules. These data suggest that stanniocalcin turnover is more rapid in seawater-acclimated eels and that the secretory activity of the corpuscles of Stannius is rapidly reduced when a hypercalcic challenge is removed.

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Relationships of Otolith Dimension with Body Length of European Eel Anguilla anguilla (Linnaeus, 1758) from Adriatic catchment of Montenegro

Acta Adriatica ◽

10.32582/aa.59.1.7 ◽

2018 ◽

Vol 59 (1) ◽

pp. 91-96 ◽

Cited By ~ 4

Author(s):

Tamara Kanjuh ◽

Danilo Mrdak

Keyword(s):

Linear Function ◽

Body Length ◽

Somatic Growth ◽

Anguilla Anguilla ◽

Body Growth ◽

The Body ◽

European Eel ◽

Fish Size ◽

Sagittal Otolith ◽

The Relationship

This study examined the relationship between the sagittal otolith morphometric variables (length, height and weight) and body growth of the European eel. Eels that were studied ranged in total length from 11.2 to 79.5 cm. The relationships between the sagittal otolith variables and fish somatic growth were described with a non-linear function. The resulting coefficients of determination \((r^2)\) ranged from 0.782 to 0.914. The variable most strongly related to fish size was found to be the sagittal otolith length (OL) with 91.4 % of the variability. The results of this study provide the first comprehensive data regarding the relationship between the sagittal otolith morphometric variables with the body length of Anguilla anguilla.

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RENAL FUNCTION IN THE EUROPEAN EEL (ANGUILLA ANGUILLA L.): CHANGES IN BLOOD PRESSURE AND RENAL FUNCTION OF THE FRESHWATER EEL TRANSFERRED TO SEA-WATER

Journal of Endocrinology ◽

10.1677/joe.0.0430009 ◽

1969 ◽

Vol 43 (1) ◽

pp. 9-19 ◽

Cited By ~ 49

Author(s):

I. CHESTER JONES ◽

D. K. O. CHAN ◽

J. C. RANKIN

Keyword(s):

Blood Pressure ◽

Renal Function ◽

Fresh Water ◽

Inorganic Phosphate ◽

Sea Water ◽

Anguilla Anguilla ◽

Urine Flow ◽

Inulin Clearance ◽

European Eel ◽

Clearance Rates

SUMMARY A method for the study of renal function and measurement of mean ventral and dorsal aortic blood pressure for the freshwater and seawater-adapted eel, and during transfer of the animal from fresh water to sea-water, is described. Freshwater eels have higher resting blood pressure, p-aminohippuric acid (PAH) and inulin clearance rates and urine flow than seawater eels. Urine from freshwater animals has low Na, K, Ca, Mg and Cl concentrations, while the clearance rate of inorganic phosphate exceeded that of inulin. Urine from seawater animals has high Na, Ca, Mg and Cl concentrations while that of inorganic phosphate was low. Clearance rates for Ca and Mg greatly exceeded those of inulin. During transfer from fresh water to sea-water there was an initial fluctuation in blood pressure, urine flow and PAH and inulin clearance rates which lasted about 2 hr. Thereafter these gradually declined to values observed for the seawater-adapted animal. The significance of PAH and inulin clearance rates in the study of renal function in the eel and in teleosts in general is discussed.

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Hypocalcaemic Activity of Trout Hypocalcin and Bovine Parathyroid Hormone in Stanniectomized Eels

Journal of Experimental Biology ◽

10.1242/jeb.140.1.199 ◽

1988 ◽

Vol 140 (1) ◽

pp. 199-208

Author(s):

FLORIS P.J. G. LAFEBER ◽

R.G.J. M. HANSSEN ◽

S. E. WENDELAAR BONGA

Keyword(s):

Parathyroid Hormone ◽

Calcium Level ◽

Calcium Concentration ◽

Three Dimensional ◽

Dimensional Structure ◽

Striking Similarity ◽

Total Calcium ◽

Molar Basis ◽

Ionic Calcium ◽

Bovine Parathyroid Hormone

Hypocalcin isolated from trout corpuscles of Stannius (CS) and bovine parathyroid hormone (bPTH) induce hypocalcaemia when injected intra-arterially in hypercalcaemic, stanniectomized (STX) eels. On a molar basis, both hormones have almost the same potency. Upon injection of hypocalcin we observed a decrease in blood ionic calcium level which fully accounts for the decrease in total calcium. Injections of bPTH also resulted in a decrease of total and ionic calcium concentrations in the blood. The decrease in ionic calcium level upon injection of bPTH, however, did not fully account for the decrease in total calcium concentration of the blood. Nevertheless, hypocalcin and bPTH showed striking similarity in bioactivity in stanniectomized eels. Some similarity in three-dimensional structure of both hormones may underlie this phenomenon.

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