scholarly journals Sensitization of sodium appetite: evidence for sustained molecular changes in the lamina terminalis

2014 ◽  
Vol 307 (12) ◽  
pp. R1405-R1412 ◽  
Author(s):  
Seth W. Hurley ◽  
Zhongming Zhang ◽  
Terry G. Beltz ◽  
Baojian Xue ◽  
Alan Kim Johnson
Keyword(s):  
Mrna Expression ◽  
Neural Plasticity ◽  
Salt Intake ◽  
Sodium Intake ◽  
Lamina Terminalis ◽  
Mk 801 ◽  
Molecular Alterations ◽  
Sodium Appetite ◽  
History Of ◽  
The Brain

Animals with a history of sodium depletions exhibit increases in salt intake, a phenomenon described as the sensitization of sodium appetite. Using a novel experimental design, the present experiments investigated whether putative molecular markers of neural plasticity and changes in the message for components of the brain renin-angiotensin-aldosterone-system (RAAS) accompany the sensitization of sodium appetite. An initial set of experiments examined whether the glutamatergic N-methyl-d-aspartate receptor antagonist MK-801 would attenuate sodium appetite sensitization and prevent changes in mRNA expression associated with sensitization. Rats with repeated sodium depletions exhibited enhanced sodium appetite and mRNA expression for components of the RAAS in areas along the lamina terminalis (LT), a region of the brain that is important for the regulation of body fluid homeostasis, and these effects were significantly attenuated by MK-801 pretreatment. A second set of experiments investigated whether successive sodium depletions would elevate sodium intake and induce a pattern of fos-B staining consistent with the Δ fos-B isoform in areas along the LT. The pattern of fos-B staining in the subfornical organ was consistent with the characteristics of Δ fos-B expression. Specifically, fos-B/Δ fos-B expression was increased 4 days after the last of a series of sodium depletions, fos-B/Δ fos-B expression was nearly absent in control rats, and the quantity of fos-B/Δ fos-B staining was directly associated with a history of sodium depletions. These findings demonstrate that the sensitization of sodium appetite is associated with sustained molecular alterations in the LT that are indicative of neural plasticity and upregulation of the central RAAS.

Blood Pressure and Intra-Erythrocyte Sodium during Normal and High Salt Intake in Middle-Aged Men: Relationship to Family History of Hypertension, and Neurogenic and Hormonal Variables

1984 ◽  
Vol 66 (4) ◽  
pp. 427-433 ◽  
Author(s):  
Ottar Gudmundsson ◽  
Hans Herlitz ◽  
Olof Jonsson ◽  
Thomas Hedner ◽  
Ove Andersson ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Family History ◽  
Salt Intake ◽  
Sodium Intake ◽  
Positive Family History ◽  
Sodium Content ◽  
High Salt Intake ◽  
History Of ◽  
Family History Of Hypertension ◽  
Erythrocyte Sodium

1. During 4 weeks 37 normotensive 50-year-old men identified by screening in a random population sample were given 12 g of NaCl daily, in addition to their usual dietary sodium intake. Blood pressure, heart rate, weight, urinary excretion of sodium, potassium and catecholamines, plasma aldosterone and noradrenaline and intra-erythrocyte sodium content were determined on normal and increased salt intake. The subjects were divided into those with a positive family history of hypertension (n = 11) and those without such a history (n = 26). 2. Systolic blood pressure and weight increased significantly irrespective of a positive family history of hypertension. 3. On normal salt intake intra-erythrocyte sodium content was significantly higher in those with a positive family history of hypertension. During high salt intake intra-erythrocyte sodium content decreased significantly in that group and the difference between the hereditary subgroups was no longer significant. 4. In the whole group urinary excretion of noradrenaline, adrenaline and dopamine increased whereas plasma aldosterone decreased during the increased salt intake. 5. Thus, in contrast to some earlier studies performed in young subjects, our results indicate that moderately increased sodium intake acts as a pressor agent in normotensive middle-aged men whether there was a positive family history of hypertension or not. We confirm that men with positive family history of hypertension have an increased intra-erythrocyte sodium content, and that an increase in salt intake seems to increase overall sympathetic activity.

scholarly journals Signal Transduction of Mineralocorticoid and Angiotensin II Receptors in the Central Control of Sodium Appetite: A Narrative Review

2021 ◽  
Vol 22 (21) ◽  
pp. 11735
Author(s):  
Michele Iovino ◽  
Tullio Messana ◽  
Giuseppe Lisco ◽  
Aldo Vanacore ◽  
Vito Angelo Giagulli ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Salt Intake ◽  
Sodium Intake ◽  
Zona Glomerulosa ◽  
Narrative Review ◽  
Mitogen Activated Protein Kinase ◽  
Central Control ◽  
Ang Ii ◽  
Sodium Appetite ◽  
Mesh Terms

Sodium appetite is an innate behavior occurring in response to sodium depletion that induces homeostatic responses such as the secretion of the mineralocorticoid hormone aldosterone from the zona glomerulosa of the adrenal cortex and the stimulation of the peptide hormone angiotensin II (ANG II). The synergistic action of these hormones signals to the brain the sodium appetite that represents the increased palatability for salt intake. This narrative review summarizes the main data dealing with the role of mineralocorticoid and ANG II receptors in the central control of sodium appetite. Appropriate keywords and MeSH terms were identified and searched in PubMed. References to original articles and reviews were examined, selected, and discussed. Several brain areas control sodium appetite, including the nucleus of the solitary tract, which contains aldosterone-sensitive HSD2 neurons, and the organum vasculosum lamina terminalis (OVLT) that contains ANG II-sensitive neurons. Furthermore, sodium appetite is under the control of signaling proteins such as mitogen-activated protein kinase (MAPK) and inositol 1,4,5-thriphosphate (IP3). ANG II stimulates salt intake via MAPK, while combined ANG II and aldosterone action induce sodium intake via the IP3 signaling pathway. Finally, aldosterone and ANG II stimulate OVLT neurons and suppress oxytocin secretion inhibiting the neuronal activity of the paraventricular nucleus, thus disinhibiting the OVLT activity to aldosterone and ANG II stimulation.

Hypertension and nutrition in the young: early intervention?

1986 ◽  
Vol 64 (6) ◽  
pp. 849-851 ◽  
Author(s):  
W. H. Weidman
Keyword(s):  
Blood Pressure ◽  
Body Size ◽  
Early Intervention ◽  
Family History ◽  
Children And Adolescents ◽  
Salt Intake ◽  
Sodium Intake ◽  
Primary Hypertension ◽  
Dietary Sodium ◽  
History Of

The few studies, carried out on infants, children, and adolescents, relating blood pressure to sodium intake have shown a weak positive correlation in some but not all individuals. The effect of body size on blood pressure confounds the interpretation of the effect of dietary sodium on blood pressure. There appear to be sodium-sensitive and sodium-unsensitive infants, children, and adolescents and is probably genetically transmitted. Most infants, children, and adolescents in industrialized populations have a salt intake far greater than required, and reduction in dietary sodium is safe and may be beneficial to those individuals with a family history of primary hypertension.

scholarly journals Water deprivation-partial rehydration induces sensitization of sodium appetite and alteration of hypothalamic transcripts

2016 ◽  
Vol 310 (1) ◽  
pp. R15-R23 ◽  
Author(s):  
Daniela T. B. Pereira-Derderian ◽  
Regina C. Vendramini ◽  
José V. Menani ◽  
Silvana Chiavegatto ◽  
Laurival A. De Luca
Keyword(s):  
Water Deprivation ◽  
Behavioral Plasticity ◽  
Spontaneously Hypertensive Rat ◽  
Sodium Intake ◽  
Renin Angiotensin System ◽  
Male Adult ◽  
Spontaneously Hypertensive ◽  
Sodium Appetite ◽  
Wistar Kyoto ◽  
The Brain

iSodium intake occurs either as a spontaneous or induced behavior, which is enhanced, i.e., sensitized, by repeated episodes of water deprivation followed by subsequent partial rehydration (WD-PR). In the present work, we examined whether repeated WD-PR alters hypothalamic transcripts related to the brain renin-angiotensin system (RAS) and apelin system in male normotensive Holtzman rats (HTZ). We also examined whether the sodium intake of a strain with genetically inherited high expression of the brain RAS, the spontaneously hypertensive rat (SHR), responds differently than HTZ to repeated WD-PR. We found that repeated WD-PR, besides enhancing spontaneous and induced 0.3 M NaCl intake, increased the hypothalamic expression of angiotensinogen, aminopeptidase N, and apelin receptor transcripts (43%, 60%, and 159%, respectively) in HTZ at the end of the third WD-PR. Repeated WD-PR did not change the daily spontaneous 0.3 M NaCl intake and barely changed the need-induced 0.3 M NaCl intake of SHR. The same treatment consistently enhanced spontaneous daily 0.3 M NaCl intake in the normotensive Wistar-Kyoto rats. The results show that repeated WD-PR produces alterations in hypothalamic transcripts and also sensitizes sodium appetite in HTZ. They suggest an association between the components of hypothalamic RAS and the apelin system, with neural and behavioral plasticity produced by repeated episodes of WD-PR in a normotensive strain. The results also indicate that the inherited hyperactive brain RAS is not a guarantee for sensitization of sodium intake in the male adult SHR exposed to repeated WD-PR.

Sodium appetite during captopril blockade of endogenous angiotensin II formation

1984 ◽  
Vol 247 (2) ◽  
pp. R356-R365 ◽  
Author(s):  
K. E. Moe ◽  
M. L. Weiss ◽  
A. N. Epstein
Keyword(s):  
Angiotensin Ii ◽  
Water Conservation ◽  
Salt Intake ◽  
Urinary Sodium Excretion ◽  
Sodium Depletion ◽  
Angiotensin I ◽  
Sodium Deficiency ◽  
Sodium Appetite ◽  
High Doses ◽  
The Brain

Angiotensin II and aldosterone increase in response to sodium deficiency to promote sodium and water conservation. In addition, they may act synergistically to arouse a sodium appetite. If so, then blockade of endogenous angiotensin should decrease the appetite. In experiments reported here, captopril (SQ 14,225) was given peripherally to rats to block conversion of angiotensin I to angiotensin II. It both enhanced and suppressed sodium depletion-induced sodium appetite. The appetite was suppressed when captopril was given in high doses, which block conversion centrally as well as peripherally. The same doses of captopril had no effect on urinary sodium excretion or on sodium appetite aroused by mineralocorticoid treatment. Low doses, which block conversion only in the periphery, enhanced salt intake elicited by depletion, and the enhancement was abolished by captopril given directly into the brain. Therefore the enhancement was probably due to a captopril-induced increase of peripheral angiotensin I, which gained access to the brain and was converted there to angiotensin II.

Central infusion of the AT1 receptor antagonist losartan inhibits thirst but not sodium appetite in cattle

1997 ◽  
Vol 272 (6) ◽  
pp. R1940-R1945 ◽  
Author(s):  
J. R. Blair-West ◽  
D. A. Denton ◽  
M. J. McKinley ◽  
R. S. Weisinger
Keyword(s):  
Water Intake ◽  
Salt Intake ◽  
Sodium Intake ◽  
High Water ◽  
Salt Appetite ◽  
Ang Ii ◽  
Sodium Depletion ◽  
Water Restriction ◽  
Sodium Appetite ◽  
High Water Intake

Experiments in cattle compared the effects of intracerebroventricular (i.c.v.) infusions of losartan and PD-123319 on water intake caused by water restriction, i.c.v. infusion of hypertonic NaCl, or i.c.v. infusion of angiotensin II (ANG II). The effects of these receptor antagonists on sodium intake caused by sodium depletion were also examined. Losartan infusion caused dose-dependent inhibition of the high water intake caused by the physiological stimulus of water restriction or by ANG II infusion but did not affect salt appetite. PD-123319 infused at equimolar or greater (in ANG II experiments) doses did not affect water intake or salt intake due to sodium depletion. The results of these i.c.v. infusion experiments confirm our earlier proposal that the physiological regulation of water intake in cattle may be mediated by ANG II acting centrally via AT1 receptors. The dose of losartan that inhibited thirst in cattle did not inhibit sodium appetite, nor did an equimolar dose of PD-123319.

Circulating angiotensin II mediates sodium appetite in adrenalectomized rats

2001 ◽  
Vol 281 (3) ◽  
pp. R723-R729 ◽  
Author(s):  
G. H. M. Schoorlemmer ◽  
A. K. Johnson ◽  
R. L. Thunhorst
Keyword(s):  
Intravenous Infusion ◽  
Sodium Intake ◽  
Peripheral Circulation ◽  
Ang Ii ◽  
Sodium Depletion ◽  
Sodium Appetite ◽  
Brain Ventricle ◽  
The Brain ◽  
Adrenalectomized Rats

We investigated the role of circulating ANG II in sodium appetite after adrenalectomy. Adrenalectomized rats deprived of their main access to sodium (0.3 M NaCl) for 9 h drank 14.1 ± 1.5 ml of the concentrated saline solution in 2 h of access. Intravenous infusion of captopril (2.5 mg/h) during the last 5 h of sodium restriction reduced sodium intake by 77 ± 12% ( n = 5) without affecting the degree of sodium depletion and hypovolemia incurred during deprivation. Functional evidence indicates that this dose of captopril blocked production of ANG II in the peripheral circulation, but not in the brain; that is, injection of ANG I into the lateral brain ventricle stimulated intake of both water and 0.3 M NaCl. Intravenous infusion of ANG II (starting 10–15 min before 0.3 M NaCl became available) in adrenalectomized, captopril-treated rats restored both sodium intake and blood pressure to values seen in rats not treated with captopril. Longer (20 h) infusions of captopril in 22-h sodium-restricted rats also blocked sodium appetite, but reduced or prevented sodium depletion. Intravenous infusion of ANG II after these long captopril infusions stimulated sodium intake, but intake was less than in controls not treated with captopril. These results indicate that most or all of the sodium appetite of adrenalectomized rats is mediated by circulating ANG II.

The effect of increasing the salt intake of pregnant dairy cows on the salt appetite and growth of their calves

2003 ◽  
Vol 77 (1) ◽  
pp. 181-185 ◽  
Author(s):  
M. O. Mohamed ◽  
C. J. C. Phillips
Keyword(s):  
Birth Weight ◽  
Dairy Cows ◽  
Dry Matter ◽  
Neonatal Period ◽  
Salt Intake ◽  
Sodium Intake ◽  
Late Pregnancy ◽  
Salt Appetite ◽  
High Sodium ◽  
Sodium Appetite

AbstractAn increased sodium appetite has been demonstrated in cattle following supplementation with sodium in the neonatal period, but it is unclear whether the sodium appetite of calves can be influenced in utero by the dam’s sodium intake during pregnancy. Twenty-two non-lactating, pregnant dairy cows received either a diet of silage and concentrates or the same diet with 70 g NaCl per day added to it for the last 2 months of pregnancy. The sodium supplement increased the birth weight of their calves but after 6 weeks there was no difference between treatments in calf weight. In addition to milk, calves in both treatments were offered a choice of concentrates with normal or high sodium concentrations (5·8 and 10·8 g/kg dry matter, respectively). Calves from the cows that had received supplementary sodium during pregnancy ate more of the high sodium concentrate than calves from cows without the sodium supplement, demonstrating that sodium appetite could be entrained by the sodium intake of the dam during late pregnancy.

scholarly journals Amphetamine-induced sensitization of hypertension and lamina terminalis neuroinflammation

2020 ◽  
Vol 318 (3) ◽  
pp. R649-R656
Author(s):  
Seth W. Hurley ◽  
Terry G. Beltz ◽  
Fang Guo ◽  
Baojian Xue ◽  
Alan Kim Johnson
Keyword(s):  
Blood Pressure ◽  
Mrna Expression ◽  
Pressor Response ◽  
Lamina Terminalis ◽  
Negative Consequences ◽  
Long Term Effects ◽  
Stimulant Use ◽  
Amphetamine Administration ◽  
History Of

Psychomotor stimulants are prescribed for many medical conditions, including obesity, sleep disorders, and attention-deficit/hyperactivity disorder. However, despite their acknowledged therapeutic utility, these stimulants are frequently abused, and their use can have both short- and long-term negative consequences. Although stimulants such as amphetamines acutely elevate blood pressure, it is unclear whether they cause any long-term effects on cardiovascular function after use has been discontinued. Previous work in our laboratory has demonstrated that physiological and psychosocial stressors will produce sensitization of the hypertensive response, a heightened pressor response to a hypertensinogenic stimulus delivered after stressor exposure. Here, we tested whether pretreatment with amphetamine for 1 wk can sensitize the hypertensive response in rats. We found that repeated amphetamine administration induced and maintained sensitization of the pressor response to angiotensin II following a 7-day delay after amphetamine injections were terminated. We also found that amphetamine pretreatment altered mRNA expression for molecular markers associated with neuroinflammation and renin-angiotensin-aldosterone system (RAAS) activation in the lamina terminalis, a brain region implicated in the control of sympathetic nervous system tone and blood pressure. The results indicated amphetamine upregulated mRNA expression underlying neuroinflammation and, to a lesser degree, message for components of the RAAS in the lamina terminalis. However, we found no changes in mRNA expression in the paraventricular nucleus. These results suggest that a history of stimulant use may predispose individuals to developing hypertension by promoting neuroinflammation and upregulating activity of the RAAS in the lamina terminalis.

scholarly journals L2HGDH Missense Variant in a Cat with L-2-Hydroxyglutaric Aciduria

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 682
Author(s):  
Matthias Christen ◽  
Nils Janzen ◽  
Anne Fraser ◽  
Adrian C. Sewell ◽  
Vidhya Jagannathan ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Genetic Defect ◽  
Clinical Signs ◽  
Missense Variant ◽  
Microcytic Anemia ◽  
Abnormal Behavior ◽  
Functional Candidate Gene ◽  
History Of ◽  
The Brain ◽  
Hydroxyglutaric Acid

A 7-month-old, spayed female, domestic longhair cat with L-2-hydroxyglutaric aciduria (L-2-HGA) was investigated. The aim of this study was to investigate the clinical signs, metabolic changes and underlying genetic defect. The owner of the cat reported a 4-month history of multiple paroxysmal seizure-like episodes, characterized by running around the house, often in circles, with abnormal behavior, bumping into obstacles, salivating and often urinating. The episodes were followed by a period of disorientation and inappetence. Neurological examination revealed an absent bilateral menace response. Routine blood work revealed mild microcytic anemia but biochemistry, ammonia, lactate and pre- and post-prandial bile acids were unremarkable. MRI of the brain identified multifocal, bilaterally symmetrical and T2-weighted hyperintensities within the prosencephalon, mesencephalon and metencephalon, primarily affecting the grey matter. Urinary organic acids identified highly increased levels of L-2-hydroxyglutaric acid. The cat was treated with the anticonvulsants levetiracetam and phenobarbitone and has been seizure-free for 16 months. We sequenced the genome of the affected cat and compared the data to 48 control genomes. L2HGDH, coding for L-2-hydroxyglutarate dehydrogenase, was investigated as the top functional candidate gene. This search revealed a single private protein-changing variant in the affected cat. The identified homozygous variant, XM_023255678.1:c.1301A>G, is predicted to result in an amino acid change in the L2HGDH protein, XP_023111446.1:p.His434Arg. The available clinical and biochemical data together with current knowledge about L2HGDH variants and their functional impact in humans and dogs allow us to classify the p.His434Arg variant as a causative variant for the observed neurological signs in this cat.

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