EFFECTS OF CYPROHEPTADINE ON TXB(2) AND 6-KETO-PGF(1)ALPHA PLASMA-LEVELS IN RABBITS WITH HEMORRHAGIC-SHOCK

Profound hemorrhagic shock was produced in 26 rabbits by exsanguinatio n via carotid artery until blood pressure (BP) = 5.3 kPa (40 mmHg) for a period of 90 min. Rabbits were equally divided into a cyproheptadin e (Cyp) treated group and a control group. The blood samples before an d 90 min after shock and 30 min after liquid and blood infusion and ad ministering Cyp (10 mg . kg-1) were collected from the carotid artery. With radioimmunoassay, we measured the thromboxane B2(TXB2) and 6-ket oprostaglandin F1alpha (6-keto-PGF1alpha) contents in plasma. The resu lts indicated that the TXB2 and 6-keto-PGF1alpha levels during shock ( 1024 +/- 924, 30 +/- 32) and after liquid and blood infusion (990 +/- 943, 60 +/- 54) were higher than those (221 +/- 134, 6 +/- 4) in norma l rabbits (P < 0.01, P < 0.05). Cyp reduced obviously the TXA2 plasma level in rabbit with shock (304 +/- 299 vs 990 +/- 943, P < 0.05). We conclude that the decrease of TXB2 content is one of the possible mech anisms of cyproheptadine anti-shock effect.