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Greenwood MP, Mecawi AS, Hoe SZ, Mustafa MR, Johnson KR, Al-Mahmoud GA, Elias LLK, Paton JFR, Antunes-Rodrigues J, Gainer H, Murphy D, Hindmarch CCT. A comparison of physiological and transcriptome responses to water deprivation and salt loading in the rat supraoptic nucleus. Am J Physiol Regul Integr Comp Physiol 2015; 308:R559-68. [PMID: 25632023 DOI: 10.1152/ajpregu.00444.2014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 01/21/2015] [Indexed: 01/16/2023]
Abstract
Salt loading (SL) and water deprivation (WD) are experimental challenges that are often used to study the osmotic circuitry of the brain. Central to this circuit is the supraoptic nucleus (SON) of the hypothalamus, which is responsible for the biosynthesis of the hormones, arginine vasopressin (AVP) and oxytocin (OXT), and their transport to terminals that reside in the posterior lobe of the pituitary. On osmotic challenge evoked by a change in blood volume or osmolality, the SON undergoes a function-related plasticity that creates an environment that allows for an appropriate hormone response. Here, we have described the impact of SL and WD compared with euhydrated (EU) controls in terms of drinking and eating behavior, body weight, and recorded physiological data including circulating hormone data and plasma and urine osmolality. We have also used microarrays to profile the transcriptome of the SON following SL and remined data from the SON that describes the transcriptome response to WD. From a list of 2,783 commonly regulated transcripts, we selected 20 genes for validation by qPCR. All of the 9 genes that have already been described as expressed or regulated in the SON by osmotic stimuli were confirmed in our models. Of the 11 novel genes, 5 were successfully validated while 6 were false discoveries.
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Affiliation(s)
| | - Andre S Mecawi
- Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia; Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, Seropedica, Brazil
| | - See Ziau Hoe
- Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Mohd Rais Mustafa
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kory R Johnson
- Clinical Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Ghada A Al-Mahmoud
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, Al Tarfa, Doha, Qatar
| | - Lucila L K Elias
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Julian F R Paton
- School of Physiology and Pharmacology, University Walk, Bristol, United Kingdom; and
| | - Jose Antunes-Rodrigues
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Harold Gainer
- Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - David Murphy
- School of Clinical Sciences, University of Bristol, Bristol, United Kingdom; Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Charles C T Hindmarch
- School of Clinical Sciences, University of Bristol, Bristol, United Kingdom; Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia;
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Faarup P, Holstein-Rathlou NH, Nørgaard T, Harrison AP, Bastholm L, Thatt L, Johansen FF, Hegedüs V. Functionally induced changes in water transport in the proximal tubule segment of rat kidneys. Int J Nephrol Renovasc Dis 2011; 4:73-84. [PMID: 21694951 PMCID: PMC3108790 DOI: 10.2147/ijnrd.s15459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Indexed: 11/23/2022] Open
Abstract
To eliminate freezing artifacts in the proximal tubule cells, two cryotechniques were applied to normal rat kidneys, ie, freeze substitution and special freeze drying. In addition, salt depletion and salt loading were applied to groups of rats to evaluate whether the segmental structure of the proximal tubule could be altered. In the superficial part of the renal cortex of normal kidneys, the typical first segment structure in the proximal tubule was generally present in the early postglomerular fraction of the tubule. However, in the second segment, a special cellular phenomenon was constantly present, comprising a significant intercellular space that was easily identified using a light microscope. In the third segment, in which the presence of basolateral interdigitations is minimal, the small lateral space, which was found to be present in cryopreparations between neighboring cells from the normal kidney, was found to be enlarged by heavy salt loading of short duration. It is concluded that these cryotechniques demonstrate quantitative structural variations between superficial and deep nephrons, as well as the presence of extracellular areas between the cells of the second and the third segment, representing a structural background for the essential transport of water from the proximal tubules to the peritubular capillaries.
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Affiliation(s)
- Poul Faarup
- Department of Biomedical Sciences, Panum Institute University of Copenhagen
| | | | | | - Adrian Paul Harrison
- Department of Animal and Veterinary Basic Sciences, Faculty of Life Sciences, Copenhagen University, Denmark
| | - Lone Bastholm
- Department of Biomedical Sciences, Panum Institute University of Copenhagen
| | - Lisbeth Thatt
- Department of Biomedical Sciences, Panum Institute University of Copenhagen
| | | | - Viktor Hegedüs
- Department of Biomedical Sciences, Panum Institute University of Copenhagen
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