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1.  Regeneration of Cryoinjury Induced Necrotic Heart Lesions in Zebrafish Is Associated with Epicardial Activation and Cardiomyocyte Proliferation 
PLoS ONE  2011;6(4):e18503.
In mammals, myocardial cell death due to infarction results in scar formation and little regenerative response. In contrast, zebrafish have a high capacity to regenerate the heart after surgical resection of myocardial tissue. However, whether zebrafish can also regenerate lesions caused by cell death has not been tested. Here, we present a simple method for induction of necrotic lesions in the adult zebrafish heart based on cryoinjury. Despite widespread tissue death and loss of cardiomyocytes caused by these lesions, zebrafish display a robust regenerative response, which results in substantial clearing of the necrotic tissue and little scar formation. The cellular mechanisms underlying regeneration appear to be similar to those activated in response to ventricular resection. In particular, the epicardium activates a developmental gene program, proliferates and covers the lesion. Concomitantly, mature uninjured cardiomyocytes become proliferative and invade the lesion. Our injury model will be a useful tool to study the molecular mechanisms of natural heart regeneration in response to necrotic cell death.
PMCID: PMC3075262  PMID: 21533269
2.  Effects of cromolyn sodium on isolated rat's trachea 
Allergy & Rhinology  2011;2(2):e46-e50.
Cromolyn sodium (cromolyn) effectively inhibits both antigen- and exercise-induced asthma when used as an aerosol. Intranasal cromolyn is also recommended for preventing and treating allergic rhinitis. By inhibiting the degranulation of sensitized mast cells, cromolyn reduces the release of mediators that trigger inflammation and the allergic response. The precise pharmacologic activity of cromolyn has not been fully elucidated. This study evaluated the effect of cromolyn on isolated rat's trachea. The following assessments of cromolyn were performed: (1) effect on tracheal resting tension, (2) effect on contraction caused by 10−6 M of methacholine as a parasympathetic mimetic, and (3) effect of the drug on electrically induced tracheal contractions. The results indicated cromolyn could inhibit electrical field stimulation-induced spike contraction when the preparation was increased to 10−4M. Adding cromolyn at doses of ≥10−8 M did not elicit a relaxation or contraction response to 10−6 M of methacholine-induced contraction. It alone had a minimal effect on the basal tension of the trachea as the concentration increased. This study indicates cromolyn had no cholinergic or anticholinergic effect and high concentrations of cromolyn might actually inhibit parasympathetic function of the trachea. Inhibiting parasympathetic function of the trachea through stabilizing the presynaptic nerve by cromolyn may be responsible for protecting patients against antigen- and exercise-induced asthma.
PMCID: PMC3390115  PMID: 22852116
Cromolyn; in vitro study smooth muscle; trachea

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