Marsupial hypothalamo-neurohypophyseal hormones. The brush-tailed possum (Trichosurus vulpecula) active peptides.
The hypothalamo-neurohypophyseal hormones of the brush-tailed possum (Trichosurus vulpecula) have been purified through molecular sieving and paper chromatoelectrophoresis. Two peptides have been isolated, one with pressor property, the other with uterotonic activity. The pressor hormone has been identified as arginine vasopressin by amino acid composition and amino acid sequence. The oxytocin-like hormone has been characterized as mesotocin by amino acid composition. The amounts per dried neuro-intermediate gland (1.0-1.5 mg) are approximately 12 and 5 nmol, respectively. Up to now, mesotocin has only been found in non-mammalian tetrapods, particularly in reptiles. Its preservation in Australian marsupials (Macropodidae and Phalangeridae), and the replacement of vasotocin by a vasopressin-like peptide, suggests that they are transition species between reptiles and Eutheria. However, the presence of mesotocin raises the question of its role in marsupial lactation.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001127:Arginine Vasopressin / Q000302:isolation & purification*; D001681:Biological Assay; D005075:Biological Evolution; D002850:Chromatography, Gel; D007030:Hypothalamo-Hypophyseal System / Q000032:analysis*; D009893:Opossums / Q000502:physiology*; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000302:isolation & purification; D010902:Pituitary Gland / Q000502:physiology; D051381:Rats
D000596:Amino Acids; D001127:Arginine Vasopressin; C001713:mesotocin; D010121:Oxytocin