Plasma concentrations of arginine vasopressin, oxytocin and angiotensin in patients with hymenoptera venom anaphylaxis

The plasma concentrations of arginine vasopressin, oxytocin, angiotensin I and II were studied in patients with hymenoptera venom anaphylaxis (n = 50) and healthy volunteers (n = 25). There was no difference in arginine vasopressin: 5.52 ± 0.45 fmol/ml vs. 3.99 ± 0.41 fmol/ml or oxytocin: 28.10 ± 1.13 fmol/ml vs. 26.24 ± 1.80 fmol/ml between patients and controls. No correlation between the severity of clinical symptoms and the plasma levels of arginine vasopressin and oxytocin was found in patients. However, patients with a history of hymenoptera venom anaphylaxis showed significantly reduced angiotensin I and angiotensin II plasma levels as compared to controls (ANG I: 9.51 ± 0.61 fmol/ml vs. 22.91 ± 1.73 fmol/ml; ANG II: 2.84 ± 0.16 fmol/ml vs. 6.95 ± 0.33 fmol/ml. A significant inverse correlation between the severity of clinical symptoms and the plasma levels of angiotensin I and angiotensin II was observed; the lower the concentrations the more severe the clinical symptoms. Oxytocin immunoreactivity eluted from the HPLC column as a single peak with the same retention time as synthetic oxytocin. The vasopressin immunoreactive material could be characterized on HPLC as arginine-vasopressin and two other peptides of unknown nature which crossreacted with the vasopressin antibody. These findings suggest a possible role of angiotensin I and angiotensin II in hymenoptera venom anaphylaxis while arginine vasopressin and oxytocin are most likely not involved.