Limits...
Characterisation and comparison of temporal release profiles of nitric oxide generating donors.

Bradley SA, Steinert JR - J. Neurosci. Methods (2015)

Bottom Line: We found that donors such as NOC-5 and PAPA-NONOate decayed substantially within days, whereas SNP and GSNO showed greater stability releasing consistent levels of NO over days.In all donors tested, the amount of released NO differs between frozen and unfrozen stocks.Fluorescent and amperometric approaches to measure NO concentrations yield a wide range of levels.

View Article: PubMed Central - PubMed

Affiliation: MRC Toxicology Unit, Hodgkin Building, University of Leicester, Leicester LE1 9HN, UK.

No MeSH data available.


Related in: MedlinePlus

Temporal release of NO from PAPA NONOate. (A) Average NO release profiles from fresh PAPA NONOate at 5, 10 and 20 μM over a 30 min recording period. (B) Average release profile of NO yield from two day old stock at 5, 10 and 20 μM over 30 min. (C) Average profiles of NO release over 30 min from three day old stock at 5, 10 and 20 μM. (D) Average NO release profiles of 4 week old frozen stock at 5, 10 and 20 μM over a 30 min recording period. (E) Box and whisker plots depicting the plateau concentration range of NO recorded on day one, two and three and from frozen stock. (F) Box and whisker plots showing the range of the area under the curve using the same stock over 3 consecutive days and frozen stock.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4401449&req=5

fig0015: Temporal release of NO from PAPA NONOate. (A) Average NO release profiles from fresh PAPA NONOate at 5, 10 and 20 μM over a 30 min recording period. (B) Average release profile of NO yield from two day old stock at 5, 10 and 20 μM over 30 min. (C) Average profiles of NO release over 30 min from three day old stock at 5, 10 and 20 μM. (D) Average NO release profiles of 4 week old frozen stock at 5, 10 and 20 μM over a 30 min recording period. (E) Box and whisker plots depicting the plateau concentration range of NO recorded on day one, two and three and from frozen stock. (F) Box and whisker plots showing the range of the area under the curve using the same stock over 3 consecutive days and frozen stock.

Mentions: PAPA NONOate is a diazeniumdiolate compound that spontaneously decomposes in solution with first order kinetics, yielding two moles of NO per mole of PAPA NONOate (Feelisch, 1998; Scatena et al., 2010). NO release from this donor is unaffected by biological reactants but is dependent on pH, temperature and acid catalysed reactions. Owing to these characteristics this donor is a popular choice for reliable generation of NO. Here we characterise NO concentrations released from a stock solution of PAPA NONOate in PBS over a period of three consecutive days. On day one NO release from the donor is rapid with a steep rise in NO concentration upon application and reaching a plateau at ∼17 min at 5 μM and ∼11 min at both 10 and 20 μM (Fig. 3A). NO release on day two slows and reduces with NO release plateauing at ∼25 min at 5 μM and 10 μM and ∼23 min at 20 μM (Fig. 3B). Day three results in a further decrease in NO release at all concentrations, with a much slower release profile plateauing at ∼26 min (Fig. 3C). Frozen stock for four weeks showed a reduced release response to around 70% of the NO released from fresh stock at equivalent donor concentrations (Fig. 3A and D). Plateau concentrations of NO from day one are 292 ± 41 nM at 5 μM, 403 ± 51 nM at 10 μM and 562 ± 91 nM at 20 μM. Day two shows over a 50% fall in released NO (5 μM: 74 ± 18 nM, 10 μM: 123 ± 24 nM and 20 μM: 201 ± 31 nM) and day three release is down to less than 20% of day one (5 μM: 30 ± 7 nM, 10 μM: 51 ± 13 nM and 20 μM: 93 ± 24 nM). Frozen stock liberates plateau concentrations at 5 μM: 55 ± 5 nM, 10 μM: 89 ± 6 nM and 20 μM: 158 ± 16 nM (Fig. 3E, Table 1). Total amounts of NO released over the recording period are shown using AUC and it is demonstrated that total NO release is decreased at days 2, 3 as well as in the frozen stock at 4 weeks (Fig. 3F).


Characterisation and comparison of temporal release profiles of nitric oxide generating donors.

Bradley SA, Steinert JR - J. Neurosci. Methods (2015)

Temporal release of NO from PAPA NONOate. (A) Average NO release profiles from fresh PAPA NONOate at 5, 10 and 20 μM over a 30 min recording period. (B) Average release profile of NO yield from two day old stock at 5, 10 and 20 μM over 30 min. (C) Average profiles of NO release over 30 min from three day old stock at 5, 10 and 20 μM. (D) Average NO release profiles of 4 week old frozen stock at 5, 10 and 20 μM over a 30 min recording period. (E) Box and whisker plots depicting the plateau concentration range of NO recorded on day one, two and three and from frozen stock. (F) Box and whisker plots showing the range of the area under the curve using the same stock over 3 consecutive days and frozen stock.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401449&req=5

fig0015: Temporal release of NO from PAPA NONOate. (A) Average NO release profiles from fresh PAPA NONOate at 5, 10 and 20 μM over a 30 min recording period. (B) Average release profile of NO yield from two day old stock at 5, 10 and 20 μM over 30 min. (C) Average profiles of NO release over 30 min from three day old stock at 5, 10 and 20 μM. (D) Average NO release profiles of 4 week old frozen stock at 5, 10 and 20 μM over a 30 min recording period. (E) Box and whisker plots depicting the plateau concentration range of NO recorded on day one, two and three and from frozen stock. (F) Box and whisker plots showing the range of the area under the curve using the same stock over 3 consecutive days and frozen stock.
Mentions: PAPA NONOate is a diazeniumdiolate compound that spontaneously decomposes in solution with first order kinetics, yielding two moles of NO per mole of PAPA NONOate (Feelisch, 1998; Scatena et al., 2010). NO release from this donor is unaffected by biological reactants but is dependent on pH, temperature and acid catalysed reactions. Owing to these characteristics this donor is a popular choice for reliable generation of NO. Here we characterise NO concentrations released from a stock solution of PAPA NONOate in PBS over a period of three consecutive days. On day one NO release from the donor is rapid with a steep rise in NO concentration upon application and reaching a plateau at ∼17 min at 5 μM and ∼11 min at both 10 and 20 μM (Fig. 3A). NO release on day two slows and reduces with NO release plateauing at ∼25 min at 5 μM and 10 μM and ∼23 min at 20 μM (Fig. 3B). Day three results in a further decrease in NO release at all concentrations, with a much slower release profile plateauing at ∼26 min (Fig. 3C). Frozen stock for four weeks showed a reduced release response to around 70% of the NO released from fresh stock at equivalent donor concentrations (Fig. 3A and D). Plateau concentrations of NO from day one are 292 ± 41 nM at 5 μM, 403 ± 51 nM at 10 μM and 562 ± 91 nM at 20 μM. Day two shows over a 50% fall in released NO (5 μM: 74 ± 18 nM, 10 μM: 123 ± 24 nM and 20 μM: 201 ± 31 nM) and day three release is down to less than 20% of day one (5 μM: 30 ± 7 nM, 10 μM: 51 ± 13 nM and 20 μM: 93 ± 24 nM). Frozen stock liberates plateau concentrations at 5 μM: 55 ± 5 nM, 10 μM: 89 ± 6 nM and 20 μM: 158 ± 16 nM (Fig. 3E, Table 1). Total amounts of NO released over the recording period are shown using AUC and it is demonstrated that total NO release is decreased at days 2, 3 as well as in the frozen stock at 4 weeks (Fig. 3F).

Bottom Line: We found that donors such as NOC-5 and PAPA-NONOate decayed substantially within days, whereas SNP and GSNO showed greater stability releasing consistent levels of NO over days.In all donors tested, the amount of released NO differs between frozen and unfrozen stocks.Fluorescent and amperometric approaches to measure NO concentrations yield a wide range of levels.

View Article: PubMed Central - PubMed

Affiliation: MRC Toxicology Unit, Hodgkin Building, University of Leicester, Leicester LE1 9HN, UK.

No MeSH data available.


Related in: MedlinePlus