1. Hypomagnesemia Inhibits Nitric Oxide Release From Coronary Endothelium: Protective Role of Magnesium Infusion After Cardiac Operations1 
Paul J. Pearson, Paulo R.B. Evora, John F. Seccombe, Hartzell V. Schaff 
The Annals of Thoracic Surgery 
Volume 65, Issue 4, Pages (April 1998)
DOI: /S (98)

2. Fig. 1
Concentration-response curves for acetylcholine in canine coronary arteries. Segments were contracted with prostaglandin F2α (2 × 10−6 mol/L). Results are expressed as mean plus or minus standard error of the mean. Magnesium Free denotes experiments performed in the absence of magnesium sulfate (1.2 mmol/L). Maximum reversal of the prostaglandin contraction in control arteries with endothelium was 100%, whereas the magnesium-free group only relaxed to a maximum of 41.67% ± 7.91% (n = 10, each group; p < 0.05).
The Annals of Thoracic Surgery  , DOI: ( /S (98) )

3. Fig. 2
Effect of acetylcholine (ACh) and bradykinin (BK) on isometric tension of canine coronary arteries in the presence of NG-monomethyl-l-arginine (l-NMMA; 10−4 mol/L) (original trace). Segments of coronary artery, with (E+) and without (E−) endothelium, were suspended in organ chambers to measure isometric force. NG-monomethyl-l-arginine was added to the organ chamber at least 10 minutes before contraction with prostaglandin F2α (PGF2α) (2 × 10−6 mol/L). When the contraction induced by PGF2α was stable, the vessels were exposed to a single dose of ACh (10−4 mol/L) followed by BK (10−6 mol/L).
The Annals of Thoracic Surgery  , DOI: ( /S (98) )

4. Fig. 3
Concentration-response curves for adenosine diphosphate (ADP) in canine coronary arteries with and without endothelium. Segments were contracted with prostaglandin F2α (2 × 10−6 mol/L). Results are expressed as mean plus or minus standard error of the mean. Magnesium Free denotes experiments performed in the absence of magnesium sulfate (1.2 mmol/L). Values for 50% inhibition (−log mol/L) of contraction in control and magnesium-free experiments with endothelium are 6.61 ± 0.10 and 5.18 ± 0.22, respectively (n = 10, p < 0.05).
The Annals of Thoracic Surgery  , DOI: ( /S (98) )

5. Fig. 4
Concentration-response curves for the calcium ionophore A23187 in canine coronary arteries with and without endothelium. Segments were contracted with prostaglandin F2α (2 × 10−6 mol/L). Results are expressed as mean plus or minus standard error of the mean. Magnesium Free denotes experiments performed in the absence of magnesium sulfate (1.2 mmol/L). Values for 50% inhibition (−log mol/L) of contraction in control and magnesium-free experiments with endothelium are 7.39 ± 0.13 and 7.41 ± 0.07, respectively (n = 10, each group; p = not significant).
The Annals of Thoracic Surgery  , DOI: ( /S (98) )

6. Fig. 5
Concentration-response curves for sodium fluoride (NaF) in canine coronary arteries with and without endothelium. Segments were contracted with prostaglandin F2α (2 × 10−6 mol/L). Results are expressed as mean plus or minus standard error of the mean. Magnesium Free denotes experiments performed in the absence of magnesium sulfate (1.2 mM). Values for maximal relaxation to 9.5 mmol/L of NaF in control and magnesium-free experiments with endothelium were 50.7% ± 6.3% and 182.1% ± 22.3% of the initial prostaglandin F2α contraction, respectively (n = 10, each group; p < 0.05).
The Annals of Thoracic Surgery  , DOI: ( /S (98) )

7. Fig. 6
Effect of acetylcholine on isometric tension of canine coronary arteries (original trace). Segments of coronary artery, with (E+) and without (E−) endothelium, were suspended in organ chambers to measure isometric force and then contracted with prostaglandin F2α (PGF2α; 2 × 10−6 mol/L). When the contraction induced by PGF2α was stable, the vessels were exposed to increasing concentrations of acetylcholine. Magnesium Free denotes experiments performed in the absence of magnesium sulfate (1.2 mmol/L).
The Annals of Thoracic Surgery  , DOI: ( /S (98) )

8. Fig. 7
Possible mechanism of coronary vasospasm resulting from hypomagnesemia.
The Annals of Thoracic Surgery  , DOI: ( /S (98) )