The distribution of proteins that bind neurohypophysial hormones

Abstract

SUMMARY1. Protein fractions were prepared from serum and various organs of pigs following the methods used to extract and purify neurophysin from posterior pituitaries.2. Protein fractions extracted from porcine kidney, uterus, mammary gland or serum, which contain antigen reacting with anti-neurophysin serum, form non-dialysable complexes with oxytocin and/or lysine vasopressin.3. Protein from uterus or mammary gland bound oxytocin but not lysine vasopressin, while protein extracted from kidney bound lysine vasopressin but not oxytocin: protein from serum bound both hormones.4. Protein fractions prepared in the same way from porcine liver, spleen, skeletal muscle and brain, which do not contain antigen reacting with antineurophysin serum, did not form complexes with neurohypophysial hormone.5. The formation of complexes between the renal or uterine protein fractions and lysine vasopressin or oxytocin is inhibited by the addition of 1.0 x 10-6 M-CaCl2.6. I-Desamino 8-arginine vasopressin is not bound by neurophysin prepared from porcine posterior pituitaries or the protein from porcine kidneys, while 8-arginine vasopressin does form non-dialysable complexes with proteins from both sources. 7. A protein fraction extracted from guinea-pig kidney by similar preparative methods also bound lysine vasopressin and the binding was inhibited by addition of CaCl2.

Vasopressin: a possible link between hypoxia and hypertension

“…The prevailing number of the MNC neurons send axons to the posterior pituitary, however some of the axons end in the median eminence (ME) of the hypothalamus. Axons of the MCN neurons form close contacts with capillaries either in the posterior pituitary or in the ME, where AVP is released into the blood [23][24][25]. The PNC innervate the neighboring hypothalamic neurons.…”

“…The PNC innervate the neighboring hypothalamic neurons. They send also multiple projections to several regions of the central nervous system (CNS), namely to the bed nucleus of the stria terminalis (BNST), the medial amygdaloid nucleus, the dorsomedial hypothalamic nucleus, the locus coeruleus (LC), the vertical diagonal band of Broca and the olfactory bulb, as well as to the nucleus ambiguous, nucleus of the solitary tract (NTS), the lateral habenular nucleus, the basal nucleus of Meynert, the substantia nigra, the ventral hippocampus, the central gray, the rostral ventrolateral medulla (RVLM) and the spinal cord [23,24,[26][27][28][29][30][31][32][33].…”

“…Regulatory functions of vasopressin are mediated by V1a receptors (V1aRs), V1bRs and V2Rs, which are present in multiple regions of the CNS and in several peripheral organs (Figure 1) [22,24,[67][68][69][70][71][72][73][74][75]. Vasopressin can also interact with oxytocin receptors [21,76].…”