Absence of oxytocin in the central nervous system of the snake Bothrops jararaca.

We used four complementary techniques to investigate the presence of oxytocin peptide in the hypophysis and brain of the snake Bothrops jararaca. A high-pressure liquid chromatographic analysis failed to show oxytocin in extracts of hypophysial and brain tissues but provided estimative values of the amounts of vasotocin (12 ng/mg hypophysis and 0.5 ng/mg brain) and mesotocin (500 pg/mg hypophysis and 8 pg/mg brain).