scholarly journals Neural circuitry underlying the central hypertensive action of nesfatin-1: melanocortins, corticotropin-releasing hormone, and oxytocin

2014 ◽  
Vol 306 (10) ◽  
pp. R722-R727 ◽  
Author(s):  
Gina L. C. Yosten ◽  
Willis K. Samson
Keyword(s):  
Receptor Antagonist ◽  
Hormone Secretion ◽  
Neural Circuitry ◽  
Male Rats ◽  
Stress Hormone ◽  
Corticotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Melanocyte Stimulating Hormone ◽  
The Brain ◽  
Crh Receptors

Nesfatin-1 is produced in the periphery and in the brain where it has been demonstrated to regulate appetite, stress hormone secretion, and cardiovascular function. The anorexigenic action of central nesfatin-1 requires recruitment of neurons producing the melanocortins and centrally projecting oxytocin (OT) and corticotropin-releasing hormone (CRH) neurons. We previously have shown that two components of this pathway, the central melanocortin and oxytocin systems, contribute to the hypertensive action of nesfatin-1 as well. We hypothesized that the cardiovascular effect of nesfatin-1 also was dependent on activation of neurons expressing CRH receptors, and that the order of activation of the melanocortin-CRH-oxytocin circuit was preserved for both the anorexigenic and hypertensive actions of the peptide. Pretreatment of male rats with the CRH-2 receptor antagonist astressin2B abrogated nesfatin-1-induced increases in mean arterial pressure (MAP). Furthermore, the hypertensive action of CRH was blocked by pretreatment with an oxytocin receptor antagonist ornithine vasotocin (OVT), indicating that the hypertensive effect of nesfatin-1 may require activation of oxytocinergic (OTergic) neurons in addition to recruitment of CRH neurons. Interestingly, we found that the hypertensive effect of α-melanocyte stimulating hormone (α-MSH) itself was not blocked by either astressin2B or OVT. These data suggest that while α-MSH-producing neurons are part of a core melanocortin-CRH-oxytocin circuit regulating food intake, and a subpopulation of melanocortin neurons activated by nesfatin-1 do mediate the hypertensive action of the peptide, α-MSH can signal independently from this circuit to increase MAP.

scholarly journals A Possible Mechanism for the Action of Adrenomedullin in Brain to Stimulate Stress Hormone Secretion

Endocrinology ◽  
2004 ◽  
Vol 145 (11) ◽  
pp. 4890-4896 ◽  
Author(s):  
Meghan M. Taylor ◽  
Willis K. Samson
Keyword(s):  
Hpa Axis ◽  
Hormone Secretion ◽  
Plasma Corticosterone ◽  
Male Rats ◽  
Stress Hormone ◽  
Elevated Plasma ◽  
The Central Nervous System ◽  
Neuroendocrine Responses ◽  
The Brain

Abstract Adrenomedullin (AM) has been reported to have actions at each level of the hypothalamo-pituitary-adrenal (HPA) axis, suggesting that the peptide plays a role in the organization of the neuroendocrine responses to stress. We examined the mechanism by which AM regulates the central nervous system branch of the HPA axis as well as the possible role of AM in the modulation of the releases of two other hormones, prolactin and GH, whose secretions also are altered by stress. Intracerebroventricular administration of AM led to elevated plasma corticosterone levels in unrestrained, conscious male rats. This effect was abrogated by pretreatment with a CRH antagonist, suggesting that AM activates the HPA axis by causing the release of CRH into hypophyseal portal vessels. In addition, AM given intracerebroventricularly stimulated the release of prolactin but did not alter the secretion of GH. We propose that AM produced in the brain may be an important neuromodulator of the hormonal stress response.

Effect of different types of stressors on peptide messenger ribonucleic acids in the hypothalamic paraventricular nucleus

1993 ◽  
Vol 128 (6) ◽  
pp. 485-492 ◽  
Author(s):  
Sandra Ceccatelli ◽  
Catello Orazzo
Keyword(s):  
Paraventricular Nucleus ◽  
Immobilization Stress ◽  
Thyrotropin Releasing Hormone ◽  
Hypothalamic Paraventricular Nucleus ◽  
Male Rats ◽  
Mrna Levels ◽  
Corticotropin Releasing Hormone ◽  
Ribonucleic Acids ◽  
Releasing Hormone ◽  
Different Types

Using in situ hybridization we have studied the effects of different types of stressors, such as ether, immobilization, cold and swimming, on the expression of several peptide messenger ribonucleic acids (mRNAs) in the hypothalamic paraventricular nucleus of adult male rats. Paraventricular nucleus sections were hybridized using synthetic oligonucleotide probes complementary to mRNA for corticotropin-releasing hormone, neurotensin, enkephalin and thyrotropin-releasing hormone. A clear upregulation of neurotensin mRNA was seen after ether and, to a lesser extent, after immobilization stress, whereas after the two other stressors neurotensin mRNA was undetectable, as in control rats. An increase in enkephalin mRNA was observed in a selective region of the dorsal part of the medioparvocellular subdivision of the paraventricular nucleus only after ether and immobilization stress. No significant changes were seen in corticotropin-releasing hormone and thyrotropin-releasing hormone mRNA levels in any of the experimental paradigms. The present results show selective changes for various peptide mRNAs in the paraventricular nucleus after various types of stress. Significant effects could be demonstrated only on neurotensin and enkephalin mRNA after ether and immobilization stress. This suggests that adaptive changes in the rate of synthesis, processing and transport of the peptide may develop over a longer period of time.

A stress-induced anxious state in male rats: Corticotropin-releasing hormone induces persistent changes in associative learning and startle reactivity

2005 ◽  
Vol 57 (8) ◽  
pp. 865-872 ◽  
Author(s):  
Richard J. Servatius ◽  
Kevin D. Beck ◽  
Roberta L. Moldow ◽  
Gabriel Salameh ◽  
Tara P. Tumminello ◽  
...  
Keyword(s):  
Associative Learning ◽  
Male Rats ◽  
Corticotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Anxious State

Stress and Anxiety in Schizophrenia and Depression: Glucocorticoids, Corticotropin-Releasing Hormone and Synapse Regression

2008 ◽  
Vol 42 (12) ◽  
pp. 995-1002 ◽  
Author(s):  
Maxwell R. Bennett Ao
Keyword(s):  
Neural Networks ◽  
Nmda Receptors ◽  
Receptor Activation ◽  
Stressful Events ◽  
Childhood And Adolescence ◽  
Corticotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Spine Stability ◽  
The Stability ◽  
Crh Receptors

Stress during childhood and adolescence has implications for the extent of depression and psychotic disorders in maturity. Stressful events lead to the regression of synapses with the loss of synaptic spines and in some cases whole dendrites of pyramidal neurons in the prefrontal cortex, a process that leads to the malfunctioning of neural networks in the neocortex. Such stress often shows concomitant increases in the activity of the hypothalamic–pituitary–adrenal system, with a consequent elevated release of glucocorticoids such as cortisol as well as of corticotropin-releasing hormone (CRH) from neurons. It is very likely that it is these hormones, acting on neuronal and astrocyte glucocorticoid receptors (GRs) and CRH receptors, respectively, that are responsible for the regression of synapses. The mechanism of such regression involves the loss of synaptic spines, the stability of which is under the direct control of the activity of N-methyl-d-aspartate (NMDA) receptors on the spines. Glutamate activates NMDA receptors, which then, through parallel pathways, control the extent in the spine of the cytoskeletal protein F-actin and so spine stability and growth. Both GR and CRH receptors in the spines can modulate NMDA receptors, reducing their activation by glutamate and hence spine stability. In contrast, glucocorticoids, probably acting on nerve terminal and astrocyte GRs, can release glutamate, so promoting NMDA receptor activation. It is suggested that spine stability is under dual control by glucocorticoids and CRH, released during stress to change the stability of synaptic spines, leading to the malfunctioning of cortical neural networks that are involved in depression and psychoses.

Immobilization stress rapidly decreases hypothalamic corticotropin-releasing hormone secretion in vitro in the male 344/N Fischer rat

Life Sciences ◽  
1993 ◽  
Vol 53 (3) ◽  
pp. 233-240 ◽  
Author(s):  
Giovanni Cizza ◽  
Richard Kvetnansky ◽  
Maria E. Tartaglia ◽  
Marc R. Blackman ◽  
George P. Chrousos ◽  
...  
Keyword(s):  
Immobilization Stress ◽  
Hormone Secretion ◽  
Corticotropin Releasing Hormone ◽  
Releasing Hormone
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