Development Of RIA For Melatonin And Preliminary Application

An indirect RIA was developed in order to measure melatomn level in animal blood. Melatonin was abstracted from animal blood with chloroform. The minimum detectable concentration of melatonin with the RLA was 4OpgIml. The minimum melatonin concentration detected in blood was I Spg/ml. The intra-variation was 9.46%. Recovery rate is 85.37% and cross-reactivity of the antiserum with 6-OH-MLT is 1 .27%.Blood samples from Hu and Corridale ewes were measured. Serum MLT concentration in the Corridale measured by the RIA was similar to foreign reports. The nadir of melatonin levels in Corridale ewes was approximately 2OpgIml which lasted about 15 h in day, the duration of elevated levels of 36OpgIml was 9 h. The nadir and peak levels of Flu ewes were 100 and I 200pg/ml, respectively, and the duration of elevated levels was I 7h. The results showed that Hu sheep had higher melatonin level and longer elevated duration than Corridale.