Abstract
To search for the mechanisms involved in coronary artery spasm, alcohol provocation tests were performed in patients with variant angina (VA) whose histories suggested a close relationship between anginal attacks and alcohol ingestion. Plasma levels of ethanol, serotonin, catecholamines, prostanoids, and cyclic nucleotides were monitored before and after ingestion of alcohol.
We studied 8 male patients and 8 male control subjects. Four hundred milliliters of rice wine containing 17% ethanol was given to each of them in the evening (7:00-9:00 p.m.). Blood samples were taken every 3 hours to determine plasma levels of ethanol (ETOH), serotonin (SHT), adrenaline (Ad), noradrenaline (NA), thromboxane B2 (TXB2), 6-keto PGF1α (6-Kp), cAMP and cGMP.
Four patients developed angina early in the morning of the next day(3:00-7:20 a.m.), when the plasma levels of ETON were null but increases in those of 5HT, TXB2, and 6-Kp were noted.
Before and just after alcohol ingestion, plasma levels of 6-Kp in VA were significantly less than those of controls (p<0.05). Before the tune of attacks (3:00 a.m.), the plasma levels of 6-Kp in VA as well. as those of 5HT, Ad, NA, and cAMP did not show significant differences from those in controls.
However, plasma levels of cGMP in VA exhibited gradual decreases after alcohol ingestion to the levels which were significantly lower than those before alcohol ingestion (p<0.01), and also lower than those in the controls (p<0.05).
In summary, plasma levels of 6-keto PGF1α in patients with variant angina were significantly lower than those of controls before alcohol ingestion. On the other hand, plasma levels of cGMP decreased after alcohol ingestion and showed significant differences between the patients and controls.
We concluded that decreased plasma levels of cGMP and 6-keto PGF1α may be involved in enhanced arterial tone, which may be associated with induction of coronary artery spasm.
