Neurohypophysial Hormones and Circadian Rhythm<sup>a</sup>

Forsling, Mary L.

doi:10.1111/j.1749-6632.1993.tb55562.x

Cited by 31 publications

(21 citation statements)

References 52 publications

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“…Neuroendocrine systems more directly implicated in maternal-infant attachment processes are also REM dependent. Oxytocin, for example, displays a sleep-sensitive pattern of release in humans, with peak levels occurring at about 4 o'clock in the morning when REM sleep begins to predominate over NREM (Forsling 1993). When injected centrally, oxytocin induces several of the behaviors associated with social bond formation in mammals including maternal-infant contact, nursing in infants, care-taking behaviors in the mother, and species-typical reproductive behaviors in adults (Argiolas and Gessa 1991;Insel 1992).…”

Section: Hormonal Effects: Oxytocin Vasopressin and Arginine Vasotocinmentioning

confidence: 99%

Rem sleep, early experience, and the development of reproductive strategies

McNamara

Dowdall

Auerbach

2002

Hum Nat

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We hypothesize that rapid eye movement or REM sleep evolved, in part, to mediate sexual/reproductive behaviors and strategies. Because development of sexual and mating strategies depends crucially on early attachment experiences, we further hypothesize that REM functions to mediate attachment processes early in life. Evidence for these hypotheses comes from (1) the correlation of REM variables with both attachment and sexual/reproductive variables; (2) attachment-related and sex-related hormonal release during REM; (3) selective activation during REM of brain sites implicated in attachment and sexual processes; (4) effects of maternal deprivation on REM; (5) effects of REM deprivation on sexual behaviors; and (6) the REM-associated sexual excitation. To explain why we find associations among REM sleep, attachment, and adult reproductive strategies, we rely on recent extensions of parent-offspring conflict theory. Using data from recent findings on genomic imprinting, Haig (2000) and others suggest that paternally expressed genes are selected to promote growth of the developing fetus/child at the expense of the mother, while maternally expressed genes counter these effects. Because developmental REM facilitates attachment-related outcomes in the child, developmental REM may be regulated by paternally expressed genes. In that case, REM

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Section: Hormonal Effects: Oxytocin Vasopressin and Arginine Vasotocinmentioning

confidence: 99%

Rem sleep, early experience, and the development of reproductive strategies

McNamara

Dowdall

Auerbach

2002

Hum Nat

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“…In fact, neurons in the supraoptic nucleus appear to be regulated in part by a projection from the SCN that has a strong GABAergic component (Cui et al 1997). This, in concert with the humoral input from the pineal, could account for the diurnal changes in neurohypophysial hormone secretion (Forsling, 1993).…”

Section: Gaba Efferentsmentioning

confidence: 99%

Morphological heterogeneity of the GABAergic network in the suprachiasmatic nucleus, the brain's circadian pacemaker

Castel

Morris

2000

Journal of Anatomy

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GABA (gamma-amino-butyric acid) is the predominant neurotransmitter in the mammalian suprachiasmatic nucleus (SCN), with a central role in circadian time-keeping. We therefore undertook an ultrastructural analysis of the GABA-containing innervation in the SCN of mice and rats using immunoperoxidase and immunogold procedures. GABA-immunoreactive (GABA-ir) neurons were identified by use of anti-GABA and anti-GAD (glutamic acid decarboxylase) antisera. The relationship between GABA-ir elements and the most prominent peptidergic neurons in the SCN, containing vasopressin-neurophysin (VP-NP) or vasoactive intestinal polypeptide (VIP), was also studied. Within any given field in the SCN, approximately 40-70 % of the neuronal profiles were GABA-ir. In GABA-ir somata, immunogold particles were prominent over mitochondria, sparse over cytoplasm, and scattered as aggregates over nucleoplasm. In axonal boutons, gold particles were concentrated over electron-lucent synaptic vesicles (diameter 40-60 nm) and mitochondria, and in some instances over dense-cored vesicles (DCVs, diameter 90-110 nm). GABA-ir boutons formed either symmetric or asymmetric synaptic contacts with somata, dendritic shafts and spines, and occasionally with other terminals (axo-axonic). Homologous or autaptic connections (GABA on GABA, or GAD on GAD) were common. Although GABA appeared to predominate in most neuronal profiles, colocalisation of GABA within neurons that were predominantly neuropeptide-containing was also evident. About 66 % of the VIP-containing boutons and 32 % of the vasopressinergic boutons contained GABA. The dense and complex GABAergic network that pervades the SCN is therefore comprised of multiple neuronal phenotypes containing GABA, including a wide variety of axonal boutons that impinge on heterologous and homologous postsynaptic sites.

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“…To determine how this defect affected endogenous vasopressin, we measured vasopressin levels in the plasma of IRAP Ϫ/Ϫ mice and compared them with the levels in IRAP ϩ/ϩ mice. Blood samples were taken between 5 and 7 PM, a time when vasopressin levels peak in rodents (10), and plasma vasopressin levels were determined with an RIA. We found that mean vasopressin levels were twofold higher in IRAP Ϫ/Ϫ compared with IRAP ϩ/ϩ mice.…”

Section: Irapmentioning

confidence: 99%

“…1), are not cleaved by any of the known aminopeptidases in vitro, except IRAP and P-LAP (19,20). Since the K m values of vasopressin and oxytocin for cleavage by purified IRAP and P-LAP are in the low-micromolar range (13), and the two peptide hormones are present only at picomolar concentrations in the circulation (10), it remained questionable whether vasopressin and oxytocin were in vivo substrates for IRAP. Angiotensins III and IV and met-enkephalin are also efficiently cleaved by aminopeptidase N in vitro (6,39).…”

mentioning

confidence: 99%

Vasopressin is a physiological substrate for the insulin-regulated aminopeptidase IRAP

Wallis

Lankford²,

Keller³

2007

American Journal of Physiology-Endocrinology and Metabolism

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Wallis MG, Lankford MF, Keller SR. Vasopressin is a physiological substrate for the insulin-regulated aminopeptidase IRAP. Am J Physiol Endocrinol Metab 293: E1092-E1102, 2007. First published August 7, 2007; doi:10.1152/ajpendo.00440.2007.-Insulin-regulated aminopeptidase (IRAP) is a membrane aminopeptidase and is homologous to the placental leucine aminopeptidase, P-LAP. IRAP has a wide distribution but has been best characterized in adipocytes and myocytes. In these cells, IRAP colocalizes with the glucose transporter GLUT4 to intracellular vesicles and, like GLUT4, translocates from these vesicles to the cell surface in response to insulin. Earlier studies demonstrated that purified IRAP cleaves several peptide hormones and that, concomitant with the appearance of IRAP at the surface of insulin-stimulated adipocytes, aminopeptidase activity toward extracellular substrates increases. In the present study, to identify in vivo substrates for IRAP, we tested potential substrates for cleavage by IRAP-deficient (IRAP Ϫ/Ϫ ) and control mice. We found that vasopressin and oxytocin were not processed from the NH2 terminus by isolated IRAP Ϫ/Ϫ adipocytes and skeletal muscles. Vasopressin was not cleaved from the NH2 terminus after injection into IRAP Ϫ/Ϫ mice and exhibited a threefold increased half-life in the circulation of IRAP Ϫ/Ϫ mice. Consistent with this finding, endogenous plasma vasopressin levels were elevated twofold in IRAP Ϫ/Ϫ mice, and vasopressin levels in IRAP Ϫ/Ϫ brains, where plasma vasopressin originates, showed a compensatory decrease. We further established that insulin increased the clearance of vasopressin from control but not from IRAP Ϫ/Ϫ mice. In conclusion, we have identified vasopressin as the first physiological substrate for IRAP. Changes in plasma and brain vasopressin levels in IRAP Ϫ/Ϫ mice suggest a significant role for IRAP in regulating vasopressin. We have also uncovered a novel IRAP-dependent insulin effect: to acutely modify vasopressin.peptide hormone cleavage; insulin-regulated aminopeptidase-deficient mice; insulin action THE INSULIN-REGULATED AMINOPEPTIDASE (IRAP) is a member of the family of zinc-dependent membrane aminopeptidases and is the homologue of the human placental leucine aminopeptidase (P-LAP) (16). IRAP has a wide tissue distribution (18, 34) but in each of the tissues is expressed only in specific cell types (28). In all cells so far examined, IRAP is found in an intracellular location and is recruited to the cell surface in response to different stimuli (reviewed in Ref. 16). The subcellular localization of IRAP and regulation thereof have been best characterized in adipocytes and muscle cells (reviewed in Ref. 16). In these cells, under basal conditions, IRAP is sequestered within intracellular vesicles that also harbor the insulin-responsive glucose transporter GLUT4. In response to insulin, IRAP, like GLUT4, translocates from the intracellular vesicles to the cell surface. In adipocytes, this results in a 6-to 8-and 10-to 20-fold increase of IRAP and GLUT4, ...

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Neurohypophysial Hormones and Circadian Rhythm^a

Cited by 31 publications

References 52 publications

Rem sleep, early experience, and the development of reproductive strategies

Rem sleep, early experience, and the development of reproductive strategies

Morphological heterogeneity of the GABAergic network in the suprachiasmatic nucleus, the brain's circadian pacemaker

Vasopressin is a physiological substrate for the insulin-regulated aminopeptidase IRAP

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Neurohypophysial Hormones and Circadian Rhythma

Cited by 31 publications

References 52 publications

Rem sleep, early experience, and the development of reproductive strategies

Rem sleep, early experience, and the development of reproductive strategies

Morphological heterogeneity of the GABAergic network in the suprachiasmatic nucleus, the brain's circadian pacemaker

Vasopressin is a physiological substrate for the insulin-regulated aminopeptidase IRAP

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Product

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Neurohypophysial Hormones and Circadian Rhythm^a