A sensitive and specific radioimmunoassay for leukotriene C4

Abstract
A sensitive and specific radioimmunoassay suitable for direct measurement of leukotrine C4 was developed. Acetylated leukotriene C4 was coupled to polyamino bovine serum albumin using 1‐ethyl‐3‐(3‐dimethylamino‐propyl) carbodiimide hydrochloride as coupling agent. The conjugate in complete or incomplete Freund's adjutant was injected into New Zealand white rabbits. At a final antiplasma dilution of 1 : 1050 the lowest detection limit of leukotriene C4 was 0.046 pmol. The antiplasma cross‐reacted 4, E4 and F4, while high relative cross‐reaction (86–100%) was obtained with leukotrienes C3, C5 and 11‐trans leukotriene C4. In experiments where known amounts of leukotriene C4 were added to leukocytes suspensions, 67–100% of the added amount was recovered by the method. The radioimmunoassay was used to study leukotriene C4 formation after stimulation of leukocyte suspensions with the ionophore A23187.