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 6h 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-alpha 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.
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 6h 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. SerumTNF-alpha 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.
Authors: Wei Tang; Huiying Li; Emma H Doud; Yunqiu Chen; Stephanie Choing; Carla Plaza; Neil L Kelleher; Thomas L Poulos; Richard B Silverman Journal: J Am Chem Soc Date: 2015-05-05 Impact factor: 15.419
Authors: Ion A Hobai; Emmanuel S Buys; Justin C Morse; Jessica Edgecomb; Eric H Weiss; Antonis A Armoundas; Xiuyun Hou; Alok R Khandelwal; Deborah A Siwik; Peter Brouckaert; Richard A Cohen; Wilson S Colucci Journal: Am J Physiol Heart Circ Physiol Date: 2013-08-09 Impact factor: 4.733
Authors: Soosung Kang; Wei Tang; Huiying Li; Georges Chreifi; Pavel Martásek; Linda J Roman; Thomas L Poulos; Richard B Silverman Journal: J Med Chem Date: 2014-05-07 Impact factor: 7.446
Authors: Mahtab Moayeri; Devorah Crown; David W Dorward; Don Gardner; Jerrold M Ward; Yan Li; Xizhong Cui; Peter Eichacker; Stephen H Leppla Journal: PLoS Pathog Date: 2009-05-29 Impact factor: 6.823