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Salt-Sensitive Hypertension in GR +/- Rats Is Accompanied with Dysregulation in Adrenal Soluble Epoxide Hydrolase and Polyunsaturated Fatty Acid Pathways. Int J Mol Sci 2021; 22:ijms222413218. [PMID: 34948014 PMCID: PMC8708190 DOI: 10.3390/ijms222413218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 01/23/2023] Open
Abstract
Mutations within the glucocorticoid receptor (GR) gene locus lead to glucocorticoid resistance which is characterized by several clinical symptoms such as adrenal gland hyperplasia and salt-sensitive hypertension, although the underlying mechanisms are still unknown. We studied GR haploinsufficient (GR+/−) Sprague Dawley rats which, on a standard diet, showed significantly increased plasma aldosterone and corticosterone levels and an adrenocortex hyperplasia accompanied by a normal systolic blood pressure. Following a high salt diet, these rats developed salt-sensitive hypertension and maintained elevated enzyme-soluble epoxide hydrolase (sEH) in adrenal glands, while sEH was significantly decreased in wild-type rats. Furthermore, GR+/− rats showed dysregulation of the equilibrated linoleic and arachidonic acid pathways, with a significant increase of less active metabolites such as 8,9-DiHETrE. In Sprague Dawley rats, GR haploinsufficiency induced steroid disturbances, which provoked hypertension only in combination with high salt intake, which was accompanied by disturbances in sEH and fatty acid metabolism. Our results suggest that sEH inhibition could be a potential target to treat hypertension in patients with GR haploinsufficiency.
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Quirós Cognuck S, Reis WL, Silva MS, Almeida-Pereira G, Debarba LK, Zorro SV, Mecawi AS, Franci CR, Elias LLK, Antunes-Rodrigues J. Sex- and age-dependent differences in the hormone and drinking responses to water deprivation. Am J Physiol Regul Integr Comp Physiol 2020; 318:R567-R578. [PMID: 31967852 DOI: 10.1152/ajpregu.00303.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Maintenance of the volume and osmolality of body fluids is important, and the adaptive responses recruited to protect against osmotic stress are crucial for survival. The objective of this work was to compare the responses that occur in aging male and female rats during water deprivation. For this purpose, groups of male and female Wistar rats aged 3 mo (adults) or 18 mo (old) were submitted to water deprivation (WD) for 48 h. The water and sodium (0.15 M NaCl) intake, plasma concentrations of oxytocin (OT), arginine vasopressin (AVP), corticosterone (CORT), atrial natriuretic peptide (ANP), and angiotensin II (ANG II) were determined in hydrated and water-deprived animals. In response to WD, old male and female rats drank less water and saline than adults, and both adult and old females drank more water and saline than respective males. Dehydrated old animals displayed lower ANG II plasma concentration and CORT response compared with the respective normohydrated rats. Dehydrated adult males had higher plasma ANP and AVP as well as lower CORT concentrations than dehydrated adult females. Moreover, plasma OT and CORT levels of old female rats were higher than those in the dehydrated old male rats. Relative expression of ANG II type 1 receptor mRNA was decreased in the subfornical organ of adult and old male rats as well as adult female rats in response to WD. In conclusion, the study elucidated the effect of sex and age on responses induced by WD, altering the degree of dehydration induced by 48 h of WD.
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Affiliation(s)
- Susana Quirós Cognuck
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Wagner L Reis
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Marcia S Silva
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Gislaine Almeida-Pereira
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Lucas K Debarba
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Sandra V Zorro
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - André S Mecawi
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Celso R Franci
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Lucila L K Elias
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - José Antunes-Rodrigues
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
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Hardy RN, Simsek ZD, Curry B, Core SL, Beltz T, Xue B, Johnson AK, Thunhorst RL, Curtis KS. Aging affects isoproterenol-induced water drinking, astrocyte density, and central neuronal activation in female Brown Norway rats. Physiol Behav 2018; 192:90-97. [PMID: 29518407 PMCID: PMC6019141 DOI: 10.1016/j.physbeh.2018.03.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/26/2018] [Accepted: 03/03/2018] [Indexed: 01/22/2023]
Abstract
Age-dependent impairments in the central control of compensatory responses to body fluid challenges have received scant experimental attention, especially in females. In the present study, we found that water drinking in response to β-adrenergic activation with isoproterenol (30 μg/kg, s.c.) was reduced by more than half in aged (25 mo) vs. young (5 mo) ovariectomized female Brown Norway rats. To determine whether this age-related decrease in water intake was accompanied by changes in central nervous system areas associated with fluid balance, we assessed astrocyte density and neuronal activation in the SFO, OVLT, SON, AP and NTS of these rats using immunohistochemical labeling for GFAP and c-fos, respectively. GFAP labeling intensity was increased in the SFO, AP, and NTS of aged females independent of treatment, and was increased in the OVLT of isoproterenol-treated rats independent of age. Fos immunolabeling in response to isoproterenol was reduced in both the SFO and the OVLT of aged females compared to young females, but was increased in the SON of female rats of both ages. Finally, fos labeling in the AP and caudal NTS of aged rats was elevated after vehicle control treatment and did not increase in response to isoproterenol as it did in young females. Thus, age-related declines in water drinking are accompanied by site-specific, age-related changes in astrocyte density and neuronal activation. We suggest that astrocyte density may alter the detection and/or processing of signals related to isoproterenol treatment, and thereby alter neuronal activation in areas associated with fluid balance.
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Affiliation(s)
- Rachel N Hardy
- Oklahoma State University - Center of Health Sciences, Tulsa, OK 74107, United States
| | - Zinar D Simsek
- Oklahoma State University - Center of Health Sciences, Tulsa, OK 74107, United States
| | - Brandon Curry
- Oklahoma State University - Center of Health Sciences, Tulsa, OK 74107, United States
| | - Sheri L Core
- Oklahoma State University - Center of Health Sciences, Tulsa, OK 74107, United States
| | - Terry Beltz
- University of Iowa, Iowa City, IA, United States
| | - Baojian Xue
- University of Iowa, Iowa City, IA, United States
| | | | | | - Kathleen S Curtis
- Oklahoma State University - Center of Health Sciences, Tulsa, OK 74107, United States.
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Begg DP. Disturbances of thirst and fluid balance associated with aging. Physiol Behav 2017; 178:28-34. [DOI: 10.1016/j.physbeh.2017.03.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 02/22/2017] [Accepted: 03/02/2017] [Indexed: 01/25/2023]
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Santollo J, Torregrossa AM, Daniels D. Sex differences in the drinking response to angiotensin II (AngII): Effect of body weight. Horm Behav 2017; 93:128-136. [PMID: 28571936 PMCID: PMC5544541 DOI: 10.1016/j.yhbeh.2017.05.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 05/05/2017] [Accepted: 05/28/2017] [Indexed: 12/20/2022]
Abstract
Sex differences in fluid intake stimulated by angiotensin II (AngII) have been reported, but the direction of the differences is inconsistent. To resolve these discrepancies, we measured water intake by male and female rats given AngII. Males drank more than females, but when intake was normalized to body weight, the sex difference was reversed. Weight-matched males and females, however, had no difference in intake. Using a linear mixed model analysis, we found that intake was influenced by weight, sex, and AngII dose. We used linear regression to disentangle these effects further. Comparison of regression coefficients revealed sex and weight differences at high doses of AngII. Specifically, after 100ng AngII, weight was a predictor of intake in males, but not in females. Next, we tested for differences in AngII-induced intake in male and females allowed to drink both water and saline. Again, males drank more water than females, but females showed a stronger preference for saline. Drinking microstructure analysis suggested that these differences were mediated by postingestive signals and more bottle switches by the females. Finally, we probed for differences in the expression of components of the renin-angiotensin system in the brains of males and females and found sex differences in several genes in discrete brain regions. These results provide new information to help understand key sex differences in ingestive behaviors, and highlight the need for additional research to understand baseline sex differences, particularly in light of the new NIH initiative to balance sex in biomedical research.
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Affiliation(s)
- Jessica Santollo
- Department of Biology, University of Kentucky, Lexington, KY 40506, USA.
| | - Ann-Marie Torregrossa
- Behavioral Neuroscience Program, Department of Psychology, The State University of New York at Buffalo, Buffalo, NY 14260, USA
| | - Derek Daniels
- Behavioral Neuroscience Program, Department of Psychology, The State University of New York at Buffalo, Buffalo, NY 14260, USA
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de Souza Mecawi A, Ruginsk SG, Elias LLK, Varanda WA, Antunes‐Rodrigues J. Neuroendocrine Regulation of Hydromineral Homeostasis. Compr Physiol 2015; 5:1465-516. [DOI: 10.1002/cphy.c140031] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Thunhorst RL, Xue B, Beltz TG, Johnson AK. Age-related changes in thirst, salt appetite, and arterial blood pressure in response to aldosterone-dexamethasone combination in rats. Am J Physiol Regul Integr Comp Physiol 2015; 308:R807-15. [PMID: 25833938 DOI: 10.1152/ajpregu.00490.2014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 03/26/2015] [Indexed: 11/22/2022]
Abstract
This work examined the effects of age on daily water and sodium ingestion and cardiovascular responses to chronic administration of the mineralocorticoid, aldosterone (ALDO) either alone or together with the glucocorticoid, dexamethasone (DEX). Young (4 mo), adult (12 mo), and aged (30 mo) male Brown Norway rats were prepared for continuous telemetry recording of blood pressure (BP) and heart rate (HR). Baseline water and sodium (i.e., 0.3 M NaCl) intake, BP, and HR were established for 10 days. Then ALDO (60 μg/day sc) was infused alone, or together with DEX (2.5 or 20 μg/day sc), for another 10 days. Compared with baseline levels, ALDO stimulated comparable increases in daily saline intake at all ages. ALDO together with the higher dose of DEX (i.e., ALDO/DEX20) increased daily saline intake more than did ALDO, but less so in aged rats. Infusion of ALDO/DEX20 increased mean arterial pressure (MAP), and decreased HR, more than did infusion of ALDO. The changes in MAP in response to both treatments depended on age. For all ages, MAP and saline intake increased simultaneously during ALDO, while MAP always increased before saline intake did during ALDO/DEX20. Contrary to our predictions, MAP did not increase more in old rats in response to either treatment. We speculate that age-related declines in cardiovascular responses to glucocorticoids contributed to the attenuated increases in sodium intake in response to glucocorticoids that were observed in older animals.
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Affiliation(s)
- Robert L Thunhorst
- Department of Psychology, University of Iowa, Iowa City, Iowa; François M. Abboud Cardiovascular Center, University of Iowa, Iowa City, Iowa
| | - Baojian Xue
- Department of Psychology, University of Iowa, Iowa City, Iowa; François M. Abboud Cardiovascular Center, University of Iowa, Iowa City, Iowa
| | - Terry G Beltz
- Department of Psychology, University of Iowa, Iowa City, Iowa
| | - Alan Kim Johnson
- Department of Psychology, University of Iowa, Iowa City, Iowa; Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa; and Department of Pharmacology, University of Iowa, Iowa City, Iowa; and François M. Abboud Cardiovascular Center, University of Iowa, Iowa City, Iowa
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Abstract
The present study investigated whether salt appetite in the elderly is impaired similar to thirst because of the commonality of their physiological substrates and whether alterations in salt appetite are related to mood. Elderly (65–85 years, n 30) and middle-aged (45–58 years, n 30) men and women were compared in two test sessions. Thirst, psychophysical ratings of taste solutions, dietary Na and energy intakes, seasoning with salt and sugar, number of salty and sweet snacks consumed, preferred amounts of salt in soup and sugar in tea, and an overall measure of salt appetite and its relationship with mood, nocturia and sleep were measured. Elderly participants were found to be less thirsty and respond less to thirst. In contrast, no impairment of salt appetite was found in them, and although they had a reduced dietary Na intake, it dissipated when corrected for their reduced dietary energy intake. Diet composition and Na intake were found to be similar in middle-aged and elderly participants, despite the lesser intake in elderly participants. There were no age-related differences in the intensity of taste or hedonic profile of Na, in salting habits, in tests of salting soup, or number of salty snacks consumed. No relationship of any measure of salt appetite with mood measured by the Positive and Negative Affect Schedule, frequency of nocturia, or sleep duration was observed. The age-related impairment of the physiology of mineralofluid regulation, while compromising thirst and fluid intake, spares salt appetite, suggesting that salt appetite in humans is not regulated physiologically. Intact salt appetite in the elderly might be utilised judiciously to prevent hyponatraemia, increase thirst and improve appetite.
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Thunhorst RL, Beltz T, Johnson AK. Age-related declines in thirst and salt appetite responses in male Fischer 344×Brown Norway rats. Physiol Behav 2014; 135:180-8. [PMID: 24952266 DOI: 10.1016/j.physbeh.2014.06.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 05/28/2014] [Accepted: 06/11/2014] [Indexed: 12/14/2022]
Abstract
The F344×BN strain is the first generational cross between Fischer 344 (F344) and Brown Norway (BN) rats. The F344×BN strain is widely used in aging studies as it is regarded as a model of "healthy" aging (Sprott, 1991). In the present work, male F344×BN rats aged 4mo (young, n=6) and 20mo (old, n=9) received a series of experimental challenges to body fluid homeostasis to determine their thirst and salt appetite responses. Corresponding urinary responses were measured in some of the studies. Following sodium depletion, old rats ingested less saline solution (0.3M NaCl) than young rats on a body weight basis, but both ages drank enough saline solution to completely repair the accrued sodium deficits. Following intracellular dehydration, old rats drank less water than young rats, again on a body weight basis, and were less able than young rats to drink amounts of water proportionate to the osmotic challenge. Compared with young rats, old rats drank less of both water and saline solution after combined food and fluid restriction, and also were refractory to the stimulatory effects of low doses of captopril on water drinking and sodium ingestion. Age differences in urinary water and sodium excretion could not account for the age differences in accumulated water and sodium balances. These results extend observations of diminished behavioral responses of aging animals to the F344×BN rat strain and support the idea that impairments in behavior contribute more to the waning ability of aging animals to respond to body fluid challenges than do declines in kidney function. In addition, the results suggest that behavioral defense of sodium homeostasis is less diminished with age in the F344×BN strain compared to other strains so far studied.
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Affiliation(s)
- Robert L Thunhorst
- Department of Psychology, University of Iowa, Iowa City, IA 52242-1407, United States; The Cardiovascular Center, University of Iowa, Iowa City, IA 52242-1407, United States.
| | - Terry Beltz
- Department of Psychology, University of Iowa, Iowa City, IA 52242-1407, United States
| | - Alan Kim Johnson
- Department of Psychology, University of Iowa, Iowa City, IA 52242-1407, United States; Department of Health and Human Physiology, University of Iowa, Iowa City, IA 52242-1407, United States; Department of Pharmacology, University of Iowa, Iowa City, IA 52242-1407, United States; The Cardiovascular Center, University of Iowa, Iowa City, IA 52242-1407, United States
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