Developmental toxicity of trichloroethylene in zebrafish (Danio rerio)

2020 ◽  
Vol 22 (3) ◽  
pp. 728-739 ◽  
Author(s):  
Katharine A. Horzmann ◽  
Ana M. Portales ◽  
Kathryn G. Batcho ◽  
Jennifer L. Freeman

Embryonic exposure to ecologically relevant concentrations of TCE disrupts development, morphology, heart rate, and behavior in the zebrafish (Danio rerio) model system.

2015 ◽  
Vol 35 (5) ◽  
pp. 388
Author(s):  
M.M. Ernst ◽  
L.R. Hamm ◽  
M.L. Santiago ◽  
C.A. Shea Porr

2009 ◽  
Vol 297 (2) ◽  
pp. R412-R420 ◽  
Author(s):  
Shelby L. Steele ◽  
Kwok Hong Andy Lo ◽  
Vincent Wai Tsun Li ◽  
Shuk Han Cheng ◽  
Marc Ekker ◽  
...  

Fish exposed to hypoxia develop decreased heart rate, or bradycardia, the physiological significance of which remains unknown. The general muscarinic receptor antagonist atropine abolishes the development of this hypoxic bradycardia, suggesting the involvement of muscarinic receptors. In this study, we tested the hypothesis that the hypoxic bradycardia is mediated specifically by stimulation of the M2 muscarinic receptor, the most abundant subtype in the vertebrate heart. Zebrafish ( Danio rerio) were reared at two levels of hypoxia (30 and 40 Torr Po2) from the point of fertilization. In hypoxic fish, the heart rate was significantly lower than in normoxic controls from 2 to 10 days postfertilization (dpf). At the more severe level of hypoxia (30 Torr Po2), there were significant increases in the relative mRNA expression of M 2 and the cardiac type β-adrenergic receptors ( β1AR, β2aAR, and β2bAR) at 4 dpf. The hypoxic bradycardia was abolished (at 40 Torr Po2) or significantly attenuated (at 30 Torr Po2) in larvae experiencing M2 receptor knockdown (using morpholino antisense oligonucleotides). Sham-injected larvae exhibited typical hypoxic bradycardia in both hypoxic regimens. The expression of β1AR, β2aAR, β2bAR, and M 2 mRNA was altered at various stages between 1 and 4 dpf in larvae experiencing M2 receptor knockdown. Interestingly, M2 receptor knockdown revealed a cardioinhibitory role for the β2-adrenergic receptor. This is the first study to demonstrate a specific role of the M2 muscarinic receptor in the initiation of hypoxic bradycardia in fish.


2013 ◽  
Vol 136-137 ◽  
pp. 13-21 ◽  
Author(s):  
Katalin Bakos ◽  
Róbert Kovács ◽  
Ádám Staszny ◽  
Dóra Kánainé Sipos ◽  
Béla Urbányi ◽  
...  

2018 ◽  
Vol 26 (5) ◽  
pp. 4913-4923 ◽  
Author(s):  
Fangjie Cao ◽  
Christopher L. Souders ◽  
Pengfei Li ◽  
Sen Pang ◽  
Lihong Qiu ◽  
...  

2000 ◽  
Vol 279 (4) ◽  
pp. H1669-H1678 ◽  
Author(s):  
James E. Skinner ◽  
Brian A. Nester ◽  
William C. Dalsey

Indexes of heart rate variability (HRV) based on linear stochastic models are independent risk factors for arrhythmic death (AD). An index based on a nonlinear deterministic model, a reduction in the point correlation dimension (PD2 i), has been shown in both animal and human studies to have a higher sensitivity and specificity for predicting AD. Dimensional reduction subsequent to transient ischemia was examined previously in a simple model system, the intrinsic nervous system of the isolated rabbit heart. The present study presents a new model system in which the higher cerebral centers are blocked chemically (ketamine inhibition of N-methyl-d-aspartate receptors) and the system is perturbed over a longer 15-min interval by continuous hemorrhage. The hypothesis tested was that dimensional reduction would again be evoked, but in association with a more complex relationship between the system variables. The hypothesis was supported, and we interpret the greater response complexity to result from the larger autonomic superstructure attached to the heart. The complexities observed in the nonlinear heartbeat dynamics constitute a new genre of autonomic response, one clearly distinct from a hardwired reflex or a cerebrally determined defensive reaction.


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