Title: BIOSYNTHESIS OF POSTERIOR PITUITARY HORMONES
Abstract: This chapter focuses on the biosynthesis of posterior pituitary hormones. Vasopressin (VP), oxytocin (OT), and their "carrier proteins" the neurophysins are synthesized in large neurons in the hypothalamic supraoptic and paraventricular nuclei. They are transported intraaxonally via the median eminence to nerve endings in the posterior pituitary. There they are stored and released into the systemic circulation. In 1977, a pulse-labeling paradign was used to identify separate precursors for the vasopressin associated neurophysin (Np-VP) and the oxytocin associated neurophysin (Np-OT). Both of these precursors were found to have molecular weights of approximately 20,000 daltons and both reacted with anti-rat neurophysin antibodies. They could be separated frcm one another by means of isoelectric focussing because they had different isoelectric points (PI): 5.4 and 6.1. Only the PI 5.4 precursor is synthesized in Brattleboro rats—animals with hereditary diabetes insipidus that make no vasopressin. Each of the precursors generated a 16-17,000 dalton intermediate that also reacted with the anti-neurophysin antibody.
Publication Year: 1981
Publication Date: 1981-01-01
Language: en
Type: book-chapter
Indexed In: ['crossref']
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Cited By Count: 11
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