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Effects of lactate ions on the cardiorespiratory system in rainbow trout ( Oncorhynchus mykiss ).
- Source :
-
American journal of physiology. Regulatory, integrative and comparative physiology [Am J Physiol Regul Integr Comp Physiol] 2019 May 01; Vol. 316 (5), pp. R607-R620. Date of Electronic Publication: 2019 Feb 27. - Publication Year :
- 2019
-
Abstract
- Lactate ions are involved in several physiological processes, including a direct stimulation of the carotid body, causing increased ventilation in mammals. A similar mechanism eliciting ventilatory stimulation in other vertebrate classes has been demonstrated, but it remains to be thoroughly investigated. Here, we investigated the effects of lactate ions on the cardiorespiratory system in swimming rainbow trout by manipulating the blood lactate concentration. Lactate elicited a vigorous, dose-dependent elevation of ventilation and bradycardia at physiologically relevant concentrations at constant pH. After this initial confirmation, we examined the chiral specificity of the response and found that only l-lactate induced these effects. By removal of the afferent inputs from the first gill arch, the response was greatly attenuated, and a comparison of the responses to injections up- and downstream of the gills collectively demonstrated that the lactate response was initiated by branchial cells. Injection of specific receptor antagonists revealed that a blockade of serotonergic receptors, which are involved in the hypoxic ventilatory response, significantly reduced the lactate response. Finally, we identified two putative lactate receptors based on sequence homology and found that both were expressed at substantially higher levels in the gills. We propose that lactate ions modulate ventilation by stimulating branchial oxygen-sensing cells, thus eliciting a cardiorespiratory response through receptors likely to have originated early in vertebrate evolution.
- Subjects :
- Animals
Biomarkers blood
Chemoreceptor Cells metabolism
Dose-Response Relationship, Drug
Fish Proteins genetics
Gills metabolism
Hydrogen-Ion Concentration
Injections, Intra-Arterial
Lactic Acid blood
Oncorhynchus mykiss blood
Oncorhynchus mykiss genetics
Receptors, Odorant agonists
Receptors, Odorant genetics
Receptors, Odorant metabolism
Swimming
Time Factors
Chemoreceptor Cells drug effects
Fish Proteins metabolism
Gills drug effects
Heart Rate drug effects
Lactic Acid administration & dosage
Oncorhynchus mykiss metabolism
Pulmonary Ventilation drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 1522-1490
- Volume :
- 316
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- American journal of physiology. Regulatory, integrative and comparative physiology
- Publication Type :
- Academic Journal
- Accession number :
- 30811217
- Full Text :
- https://doi.org/10.1152/ajpregu.00395.2018