Research output: Contribution to Journal/Magazine › Journal article
Research output: Contribution to Journal/Magazine › Journal article
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TY - JOUR
T1 - The effects of the adrenoceptor agonists phenylephrine and isoproterenol on the intracellular ion concentrations of branchial epithelial-cells of brown trout (Salmo trutta L.).
AU - Morgan, I. J.
AU - Potts, W. T. W.
PY - 1995/12
Y1 - 1995/12
N2 - Brown trout were fitted with indwelling, intraperitoneal catheters and injected with 4–6 mol · kg-1 of the -receptor agonist phenylephrine or the -receptor agonist isoproterenol. The intracellular concentrations of sodium, chlorine, potassium and phosphorus in the pavement epithelial cells and the mitochondria-rich cells of the branchial epithelium were measured by X-ray microanalysis 1 h after the injection of the adrenoreceptor agonists. Injection with phenylephrine resulted in a significant increase in intracellular chlorine and potassium in mitochondria-rich cells and a significant but relatively smaller increase in chlorine in pavement epithelial cells. Injection with isoproterenol resulted in a significant increase in sodium and chlorine concentration in pavement epithelial cells and a significant decrease in potassium concentration. The only significant effect of isoproterenol injection on mitochondria-rich cells was a decrease in intracellular chlorine concentration. The results suggest that these adrenoreceptor agonists have a direct effect on the influx of Na+ and Cl- across the branchial epithelium. These effects may be a mechanism for acid-base regulation during the severe stress conditions that elicit catecholamine release in vivo. These results corroborate previous studies using X-ray microanalysis which suggested that pavement epithelial cells are the sites of Na+ uptake in freshwater fish whilst Cl- uptake occurs via mitochondria-rich cells.
AB - Brown trout were fitted with indwelling, intraperitoneal catheters and injected with 4–6 mol · kg-1 of the -receptor agonist phenylephrine or the -receptor agonist isoproterenol. The intracellular concentrations of sodium, chlorine, potassium and phosphorus in the pavement epithelial cells and the mitochondria-rich cells of the branchial epithelium were measured by X-ray microanalysis 1 h after the injection of the adrenoreceptor agonists. Injection with phenylephrine resulted in a significant increase in intracellular chlorine and potassium in mitochondria-rich cells and a significant but relatively smaller increase in chlorine in pavement epithelial cells. Injection with isoproterenol resulted in a significant increase in sodium and chlorine concentration in pavement epithelial cells and a significant decrease in potassium concentration. The only significant effect of isoproterenol injection on mitochondria-rich cells was a decrease in intracellular chlorine concentration. The results suggest that these adrenoreceptor agonists have a direct effect on the influx of Na+ and Cl- across the branchial epithelium. These effects may be a mechanism for acid-base regulation during the severe stress conditions that elicit catecholamine release in vivo. These results corroborate previous studies using X-ray microanalysis which suggested that pavement epithelial cells are the sites of Na+ uptake in freshwater fish whilst Cl- uptake occurs via mitochondria-rich cells.
KW - Gills - X-ray microanalysis - Phenylephrine - Isoproterenol - Trout
KW - Salmo trutta
U2 - 10.1007/BF00261300
DO - 10.1007/BF00261300
M3 - Journal article
VL - 165
SP - 458
EP - 463
JO - Journal of Comparative Physiology B
JF - Journal of Comparative Physiology B
SN - 0174-1578
IS - 6
ER -