Journal Article
Título | AVT and IT regulate ion transport across the opercular epithelium of killifish (Fundulus heteroclitus) and gilthead sea bream (Sparus aurata). |
Publication Type | Journal Article |
Authors | Martos-Sitcha, JAntonio, MartínezRodríguez, G, Mancera, JMiguel, Fuentes, J |
Year of Publication | 2015 |
Journal | Comp Biochem Physiol A Mol Integr Physiol |
Volume | 182 |
Date Published | 2015 Apr |
Pagination | 93-101 |
ISSN | 1531-4332 |
Palavras-chave | Animals, Benzazepines, Bumetanide, Chlorides, Dose-Response Relationship, Drug, Epithelium, Fish Proteins, Fundulidae, Indoles, Ion Transport, Oxytocin, Pyrrolidines, Receptors, Vasopressin, Sea Bream, Vasotocin |
Abstract | The regulatory role of arginine vasotocin (AVT) and isotocin (IT) in Cl(-) secretion was investigated with the short circuit current (Isc) technique in opercular epithelia of killifish (Fundulus heteroclitus) and gilthead sea bream (Sparus aurata). Sea bream operculum showed ~4-fold lower number of Na/K-ATPase immunoreactive cells and ~12-fold lower secretory current than the killifish. In sea bream opercular membranes, the basolateral addition of AVT (10(-6) M) significantly stimulated Cl(-) secretion, while IT (10(-6) M) was without effect. In killifish, IT produced an immediate dose-dependent stimulation of Cl(-) secretion with significant effect at doses ≥10(-7) M and stimulation maxima (∆Isc ~25 μA⋅cm(-2)) at 10(-6) M. The basolateral addition of bumetanide (200 μM) abolished >75% of the effect of IT on Cl(-) secretion. In turn, AVT had a dual effect on killifish opercular Isc: an immediate response (~3min) with Isc reduction in an inverted bell-shaped dose-response manner with higher current decrease (-22 μA⋅cm(-2)) at 10(-8) M AVT, and a sustained dose-dependent stimulation of Cl(-) secretion (stable up to 1h), with a threshold significant effect at 10(-8) M and maximal stimulation (~20 μA⋅cm(-2)) at 10(-6)M. Both effects of AVT appear receptor type specific. The V1-receptor antagonist SR 49059 abolished Isc reduction in response to AVT, while the specific V2-receptor antagonist (Tolvaptan, 1 μM) abolished the stimulatory action of AVT on Cl(-) secretion. According to these results, we propose a modulatory role for AVT and IT in Cl(-) (NaCl) secretion across the opercular epithelium of marine teleost. |
DOI | 10.1016/j.cbpa.2014.12.027 |
Sapientia | |
Alternate Journal | Comp. Biochem. Physiol., Part A Mol. Integr. Physiol. |
PubMed ID | 25536332 |