Effects of epinephrine on branchial and renal calcium handling in the rainbow trout
| Autor: | Steve F. Perry, M. G. Vermette, P. M. Verbost, Gert Flik |
|---|---|
| Rok vydání: | 1988 |
| Předmět: |
Gills
Male medicine.medical_specialty Epinephrine Trout chemistry.chemical_element Acid–base homeostasis Calcium In Vitro Techniques Kidney Urine flow rate Catecholamines Internal medicine Calcium flux medicine Animals biology Biological Transport General Medicine Hydrogen-Ion Concentration biology.organism_classification medicine.anatomical_structure Endocrinology chemistry Catecholamine Animal Science and Zoology Female Salmonidae medicine.drug |
| Zdroj: | The Journal of experimental zoology. 246(1) |
| ISSN: | 0022-104X |
| Popis: | Acute exposure of rainbow trout (Salmo gairdneri) to low external calcium (25 microM) caused an immediate but transient increase in plasma epinephrine concentration that may have been related to a concomitant depression of blood pH. Intra-arterial infusion of epinephrine at normal ambient calcium levels (0.35 mM) for 4 h caused circulating levels of epinephrine to rise from 2.9 X 10(-9) to 8.0 X 10(-8) M but did not affect norepinephrine levels, or branchial unidirectional calcium fluxes. Active (ATP-dependent) calcium transport across basolateral plasma membranes prepared from gill epithelial cells was not affected by pretreatment of fish with epinephrine or by direct application of epinephrine or cAMP, in vitro. Epinephrine infusion elevated urine flow rate, decreased urine pH, and increased urine phosphate levels significantly. Net renal calcium efflux increased significantly as a result of the increased urine flow rate. It is concluded that epinephrine does not stimulate branchial calcium uptake or renal conservation of calcium in rainbow trout at normal external calcium levels and therefore we cautiously suggest that epinephrine is unlikely to be involved in calcium balance during periods of exposure to low external calcium. Instead, epinephrine may play a role in compensating the acid-base disturbances and the increased branchial water influx that are associated with exposure to low ambient calcium. |
| Databáze: | OpenAIRE |
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