Effects of endotoxic shock on neuronal NOS and calcium transients in rat cardiac myocytes

Laura Comini, Antonella Boraso, Tiziana Bachetti, Palmira Bernocchi, Evasio Pasini, Daniela Bastianon, Salvatore Curello, Cesare Maria Terracciano, Claudio Ceconi, Roberto Ferrari

Research output: Contribution to journalArticlepeer-review

Abstract

Objective: The effects of endotoxic shock on transcriptional and translational pattern of nitric oxide synthase isoforms (NOSs) and cytoplasmic calcium were investigated. Methods: Male SD rats injected with lipopolysaccharides or saline were sacrificed after 6 and 20 h. Cardiac myocytes were enzimatically isolated from the excised hearts and evaluated for: (1) expression of constitutive (e and n) and inducible (i) NOSs by RT-PCR; (2) NOSs protein levels by Western blot, enzymatic activities by a radioimmunometric assay and nitric oxide metabolites by spectrophotometry; (3) calcium transients by Indo-1 fluorescence. Results: Increase in iNOS mRNA, and decrease in e and nNOS mRNAs were observed in cardiac myocytes isolated 6 h after LPS injection with recovery to basal levels at 20 h. Significant down-regulation of e and nNOS protein levels (p <0.01) and calcium-dependent activity (p <0.05) were detected at 20 h. Serum TNF-α increased after 6 and 20 h (p <0.05), whereas NO metabolites rose only after 20 h (p <0.0001). The diastolic calcium increased 6 h from LPS injection (p <0.0001) and remained significantly higher after 20 h. Calcium transients amplitude was not affected by LPS injection. Conclusions: Endotoxic shock stimulates iNOS and down-regulates expression of nNOS in purified cardiac myocytes, but endogenous NO production does not likely affect calcium transients.

Original languageEnglish
Pages (from-to)409-417
Number of pages9
JournalPharmacological Research
Volume51
Issue number5
DOIs
Publication statusPublished - May 2005

Keywords

  • Cell isolation
  • Cellular calcium
  • Nitric oxide
  • Rat cardiac myocytes
  • Septic shock

ASJC Scopus subject areas

  • Pharmacology

Fingerprint

Dive into the research topics of 'Effects of endotoxic shock on neuronal NOS and calcium transients in rat cardiac myocytes'. Together they form a unique fingerprint.

Cite this