Studies on the purification of the antigonadotropic melatonin-free pineal extract

Partial purification of a melatonin-free extract obtained from bovine pineal and showing an antigonadotropic activity was studied. The following methods were utilized: Sephadex gel filtration, ultrafiltration, precipitation by alcohol, ammonium sulphate and trichloracetic acid. The fractions obtained by all these procedures as well as the dialysed extract were biologically tested through the mouse uterine test. The protein contents in all the substances studied were assayed by Lowry's method. The results showed that in the extract studied, the antigonadotropic activity was present both in the fraction under 10,000 and in the fraction above 10,000, the latter containing 72% of the proteins from the total extract.