Alterations in nitric oxide-cGMP pathway in ventricular myocytes from obese leptin-deficient mice

2003 ◽  
Vol 285 (5) ◽  
pp. H2111-H2117 ◽  
Author(s):  
Jun Su ◽  
Shengjun Zhang ◽  
James Tse ◽  
Peter M. Scholz ◽  
Harvey R. Weiss
Keyword(s):  
Nitric Oxide ◽  
Guanylyl Cyclase ◽  
Ventricular Myocytes ◽  
Contractile Function ◽  
Cyclase Activity ◽  
No Production ◽  
Obese Mice ◽  
Cell Contractility ◽  
Dependent Protein ◽  
Guanylyl Cyclase Activity

Leptin is a regulator of body weight and affects nitric oxide (NO) production. This study was designed to determine whether the myocardial NO-cGMP signal transduction system was altered in leptin-deficient obese mice. Contractile function, guanylyl cyclase activity, and cGMP-dependent protein phosphorylation were assessed in ventricular myocytes isolated from genetically obese (B6.V-Lepob) and age-matched lean (C57BL/6J) mice. There were no differences in baseline contraction between the lean and obese groups. After stimulation with the NO donor S-nitroso- N-acetyl-penicillamine (SNAP, 10–6and 10–5M) or a membrane-permeable cGMP analog 8-bromo-cGMP (8-Br-cGMP, 10–6and 10–5M), cell contractility was depressed. However, 8-Br-cGMP had significantly greater effects in obese mice than in lean controls with percent shortening reduced by 47 vs. 39% and maximal rate of shortening decreased by 46 vs. 36%. The negative effects of SNAP were similar between the two groups. Soluble guanylyl cyclase activity was not attenuated. This suggests that the activity of the cGMP-independent NO pathway may be enhanced in obesity. The phosphorylated protein profile of cGMP-dependent protein kinase showed that four proteins were more intensively phosphorylated in obese mice, which suggests an explanation for the enhanced effect of cGMP. These results indicate that the NO-cGMP signaling pathway was significantly altered in ventricular myocytes from the leptin-deficient obese mouse model.

Functional effects of C-type natriuretic peptide and nitric oxide are attenuated in hypertrophic myocytes from pressure-overloaded mouse hearts

2005 ◽  
Vol 288 (3) ◽  
pp. H1367-H1373 ◽  
Author(s):  
Jun Su ◽  
Qihang Zhang ◽  
Jacob Moalem ◽  
James Tse ◽  
Peter M. Scholz ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Natriuretic Peptide ◽  
Guanylyl Cyclase ◽  
Contractile Function ◽  
Calcium Transients ◽  
Cyclase Activity ◽  
No Donor ◽  
Inotropic Effects ◽  
Dependent Protein ◽  
Guanylyl Cyclase Activity

Increases in the myocardial level of cGMP usually exert negative inotropic effects in the mammalian hearts. We tested the hypothesis that the negative functional effects caused by nitric oxide (NO) or C-type natriuretic peptide (CNP) through cGMP would be blunted in hypertrophied cardiac myocytes. Contractile function, guanylyl cyclase activity, cGMP-dependent protein phosphorylation, and calcium transients were assessed in ventricular myocytes from aortic stenosis-induced hypertrophic and age-matched control mice. Basal percentage shortening was similar in control and hypertrophic myocytes. S-nitroso- N-acetyl-penicillamine (SNAP, an NO donor, 10−6 and 10−5 M) or CNP (10−8 and 10−7 M) reduced percentage shortening in both groups, but their effects were blunted in hypertrophic myocytes. Maximal rates of shortening and relaxation were depressed at the basal level, and both reagents had attenuated effects in hypertrophy. Similar results were also found after treatment with guanylin and carbon monoxide, other stimulators of particulate, and soluble guanylyl cyclase, respectively. Guanylyl cyclase activity was not significantly changed in hypertrophy. Addition of Rp-8-[(4-chlorophenyl)thio]-cGMPS triethylamine (an inhibitor of cGMP-dependent protein kinase, 5 × 10−6 M) blocked SNAP or the effect of CNP in control mice but not in hypertrophy, indicating the cGMP-dependent kinase (PKG) may not mediate the actions of cGMP induced by NO or CNP in the hypertrophic state. Calcium transients after SNAP or CNP were not significantly changed in hypertrophy. These results suggest that in hypertrophied mice, diminished effects of NO or CNP on ventricular myocyte contraction are not due to changes in guanylyl cyclase activity. The data also indicated that PKG-mediated pathways were diminished in hypertrophied myocardium, contributing to blunted effects.

Selective sequestration of nitric oxide by subcellular components of vascular smooth muscle and platelets: relationship to nitric oxide stimulation of the soluble guanylyl cyclase

1993 ◽  
Vol 71 (12) ◽  
pp. 938-945 ◽  
Author(s):  
Zhenguo Liu ◽  
Kanji Nakatsu ◽  
James F. Brien ◽  
E. Danielle Beaton ◽  
Gerald S. Marks ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Catalytic Activity ◽  
Guanylyl Cyclase ◽  
Soluble Guanylyl Cyclase ◽  
Subcellular Fractions ◽  
Cyclase Activity ◽  
Cytosolic Fraction ◽  
Headspace Gas ◽  
Guanylyl Cyclase Activity

Sequestration of nitric oxide (NO) by subcellular fractions isolated from bovine pulmonary arterial medial layer (BPA) and rabbit platelets (RP) was studied utilizing a novel chemiluminescence – headspace gas technique. Sequestration in all fractions was similarly rapid (5 min) and remained constant for at least 30 min. When incubated with 108 pmol of NO, the BPA mitochondrial, microsomal, and nuclear fractions sequestered 22.8 ± 1.9, 20.5 ± 2.2 and 15.2 ± 3.6% of the NO, respectively (n = 14). However, significantly more of the 108 pmol of NO, 36.8 ± 2.8 and 32.9 ± 3.6%, respectively, was sequestered by the BPA homogenate (about 2 mg protein/mL) and BPA cytosolic fraction (about 1 mg protein/mL) (n = 19). Also, RP cytosolic fraction (about 3 mg protein/mL) sequestered a greater amount of NO than any BPA fraction when incubated with 108 pmol of NO (83.0 ± 1.0%; n = 3). Analysis of the binding data obtained for the BPA homogenate and cytosolic fraction was consistent with the existence of two binding sites, one site with a Kd of approximately 100 nM and another with a Kd of approximately 1 μM. Both the BPA homogenate fraction and the cytosolic fraction as well as the RP cytosolic fraction were shown to have soluble guanylyl cyclase activity. The nitrovasodilator sodium nitroprusside (SNP) caused a concentration-dependent increase in the activity of this enzyme in all these fractions. Maximum stimulations caused by 1 mM SNP in BPA homogenate fraction, BPA cytosolic fraction, and RP cytosolic fraction were equivalent to 2-, 4- and 3-fold increases in catalytic activity, respectively. No effect of SNP was observed in BPA mitochondrial, microsomal, or nuclear fraction. Prior incubation of BPA and RP cytosolic fractions with authentic NO significantly stimulated the soluble guanyiyl cyclase activity. In both the BPA and RP cytosolic fractions, maximal stimulation brought about by prior incubation with authentic NO was equivalent to approximately 60% of that caused by 100 μM SNP. Thus, incubation of subcellular fractions from two nitrovasodilator-sensitive tissues with authentic NO resulted in significant sequestration of the free radical in these fractions and a concentration-dependent activation of the soluble guanylyl cyclase. In conclusion, the chemiluminescence – headspace gas technique is a suitable method for the study of NO sequestration in subcellular fractions of various tissues. Also, this study demonstrates that NO is sequestered preferentially by subcellular fractions of BPA and RP that contain soluble guanylyl cyclase activity, and that the sequestration of NO in these fractions stimulates the catalytic activity of this enzyme.Key words: nitric oxide, vascular smooth muscle, platelets, soluble guanylyl cyclase.

Nitric Oxide Synthase and Adenylyl and Guanylyl Cyclase Activity in Porcine Interposition Vein Grafts

1997 ◽  
Vol 63 (2) ◽  
pp. 470-476 ◽  
Author(s):  
Jamie Y Jeremy, PhD ◽  
Michael R Dashwood, PhD ◽  
Maureen Timm, BSc ◽  
Mohammad Bashar Izzat, FRCS ◽  
Dheeraj Mehta, FRCS ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Guanylyl Cyclase ◽  
Cyclase Activity ◽  
Vein Grafts ◽  
Oxide Synthase ◽  
Guanylyl Cyclase Activity

Nitric Oxide-Sensitive Guanylyl Cyclase Activity Inhibition Through Cyclic GMP-Dependent Dephosphorylation

2002 ◽  
Vol 75 (5) ◽  
pp. 2029-2039 ◽  
Author(s):  
Rut Ferrero ◽  
Fernando Rodríguez-Pascual ◽  
M. Teresa Miras-Portugal ◽  
Magdalena Torres
Keyword(s):  
Nitric Oxide ◽  
Cyclic Gmp ◽  
Guanylyl Cyclase ◽  
Cyclase Activity ◽  
Activity Inhibition ◽  
Guanylyl Cyclase Activity

Halothane, Enflurane, and Isoflurane Do Not Affect the Basal or Agonist-stimulated Activity of Partially Isolated Soluble and Particulate Guanylyl Cyclases of Rat Brain

1995 ◽  
Vol 83 (2) ◽  
pp. 395-404. ◽  
Author(s):  
Zhiyi Zuo ◽  
Roger A. Johns
Keyword(s):  
Nitric Oxide ◽  
Rat Brain ◽  
Signaling Pathway ◽  
Guanylyl Cyclase ◽  
Guanosine Monophosphate ◽  
Cyclase Activity ◽  
Experimental Conditions ◽  
Guanylyl Cyclases ◽  
Inhalational Anesthetics ◽  
Guanylyl Cyclase Activity

Background Evidence suggests that inhalational anesthetics interact with the nitric oxide-guanylyl cyclase signaling pathway in the central nervous system and that the inhibitation of this pathway in brain may result in an anesthetic, analgesic, or sedative effect. The mechanism of the effects inhalational anesthetics on this signaling pathway is not clear. This study attempted to determine whether inhalational anesthetics directly affect soluble or particulate guanylyl cyclase activity in a partially isolated enzyme system. Methods The effects of halothane (0.44-4.4%), enflurane (1.34-6.7%), and isoflurane (0.6-5.0%) on basal or stimulated soluble or particulate guanylyl cyclase activity were examined. Soluble guanylyl cyclase was isolated from whole rat brain and was stimulated by sodium nitroprusside or nitric oxide. Particulate guanylyl cyclase was isolated from rat olfactory bulb and was stimulated by rat atrial natriuretic peptide(1-28). Cyclic guanosine monophosphate content was measured by radiommunoassay. The concentrations of anesthetics in the incubation solution were confirmed by gas chromatography methods. Results None of the three anesthetics affected the activity of basal or stimulated soluble or particulate guanylyl cyclase at the concentrations examined in the current experimental conditions. Conclusions These results suggest that halothane, enflurane, and isoflurane do not directly interact with soluble or particulate guanylyl cyclases of rat brain.

scholarly journals Modulation of nitric oxide-stimulated soluble guanylyl cyclase activity by cytoskeleton-associated proteins in vascular smooth muscle

2018 ◽  
Vol 156 ◽  
pp. 168-176 ◽  
Author(s):  
Alexander Kollau ◽  
Bernd Gesslbauer ◽  
Michael Russwurm ◽  
Doris Koesling ◽  
Antonius C.F. Gorren ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Guanylyl Cyclase ◽  
Soluble Guanylyl Cyclase ◽  
Cyclase Activity ◽  
Associated Proteins ◽  
Guanylyl Cyclase Activity

Sulfhydryl involvement in nitric oxide sequestration and nitric oxide induced guanylyl cyclase activation in vascular smooth muscle

1995 ◽  
Vol 73 (8) ◽  
pp. 1144-1148 ◽  
Author(s):  
Zhen-Guo Liu ◽  
Brian E. McLaughlin ◽  
Gerald S. Marks ◽  
James F. Brien ◽  
Kanji Nakatsu
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Guanylyl Cyclase ◽  
Soluble Fraction ◽  
Cyclase Activity ◽  
Total Thiol ◽  
Cyclase Activation ◽  
Thiol Content ◽  
Guanylyl Cyclase Activity

In the present study, the role of vascular smooth muscle sulhydryl groups was investigated with respect to sequestration of nitric oxide (NO) and activation of soluble guanylyl cyclase by NO. Vascular smooth muscle 100 000 × g supernatant (soluble) fraction was prepared in phosphate buffer, using the medial layer of bovine pulmonary artery. The soluble fraction was incubated with 100 pmol NO for 5 min in a sealed flask at 37 °C under anerobic conditions in the presence or absence of the sulfhydryl reagent, N-ethylmaleimide (NEM, 5 mM). NO sequestration by the soluble fraction was measured as an indicator of NO binding. Total thiol content was measured in the soluble fraction with and without exposure to NEM. Guanylyl cyclase activity was measured in the soluble fraction with and without exposure to NO and a combination of NO and NEM. NEM decreased total thiol content in the soluble fraction from 103.59 nmol/mL to undetectable levels, and decreased guanylyl cyclase activity to below basal levels. The percentage of NO sequestered by the soluble fraction was inhibited by NEM by approximately 25% from a control value of 26.52 ± 9.39 to 18.72 ± 8.52, n = 13, p < 0.05. The data indicate that sulfhydryl groups are essential for guanylyl cyclase activation by NO, and are also involved in the sequestration of NO by the vascular smooth muscle soluble fraction.Key words: nitric oxide, binding site, sulfhydryl, vascular smooth muscle, guanylyl cyclase, chemiluminescence – headspace gas analysis.

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