Spinal Cord Injury Blunted Effects of Endothelin-1 on Ca2+ Transients and Calcium Current in Isolated Rat Cardiomyocytes

Effects of BQ-788 on amitriptyline-induced cardiovascular toxicity

Objective:

We investigated both the effects of the endothelin type B (ETB) receptor antagonist, BQ-788, on amitriptyline-induced cardiotoxicity and the role of ETB receptors on amitriptyline-induced cardiovascular depression.

Methods:

Male Wistar rats were anaesthetized with urethane/chloralose. Mean arterial pressure (MAP), heart rate (HR) and QRS duration were recorded. Toxicity was induced by amitriptyline infusion (0.94 mg/kg per min) until the 50% inhibition of MAP. In the first protocol, 5% dextrose or BQ-788 bolus was administered to control or experimental group animals, respectively. In the second protocol, after incubation with BQ-788 or 5% dextrose, amitriptyline was infused.

Results:

Amitriptyline caused a significant decrease in MAP, prolonged QRS duration and decreased HR for both the groups. BQ-788 administration improved MAP (5, 10 and 15 min), shortened the prolonged QRS (5 and 10 minutes) and increased HR (5, 10 and 15 min) compared with dextrose group. While all the amitriptyline-infused rats survived in BQ-788 group, all the amitriptyline-infused rats died within 20 min in dextrose group. In the second protocol, BQ-788 incubation did not cause any statistically significant change in amitriptyline-induced cardiovascular depression.

Conclusion:

BQ-788 may have beneficial effects in amitriptyline-induced cardiovascular changes via a physiologic antagonism. ETB receptor antagonists may be the promising antidotes for the cardiovascular toxicity with hypotension and bradycardia.

Chondroitinase ABC Treatment and the Phenotype of Neural Progenitor Cells Isolated From Injured Rat Spinal Cord

The aim of the present study was to investigate whether enzyme chondroitinase ABC (ChABC) treatment influences the phenotype of neural progenitor cells (NPCs) derived from injured rat spinal cord. Adult as well as fetal spinal cords contain a pool of endogenous neural progenitors cells, which play a key role in the neuroregenerative processes following spinal cord injury (SCI) and hold particular promise for therapeutic approaches in CNS injury or neurodegenerative disorders. In our study we used in vitro model to demonstrate the differentiation potential of NPCs isolated from adult rat spinal cord after SCI, treated with ChABC. The intrathecal delivery of ChABC (10 U/ml) was performed at day 1 and 2 after SCI. The present findings indicate that the impact of SCI resulted in a decrease of all NPCs phenotypes and the ChABC treatment, on the contrary, caused an opposite effect.