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Athanasiou LV, Katsogiannou EG, Spanou VM, Dedousi A, Katsoulos PD. Potential Acute Renal Injury in Sheep with Bluetongue Serotype 4. Pathogens 2021; 10:pathogens10020159. [PMID: 33546448 PMCID: PMC7913749 DOI: 10.3390/pathogens10020159] [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: 12/29/2020] [Revised: 01/31/2021] [Accepted: 02/01/2021] [Indexed: 11/28/2022] Open
Abstract
Bluetongue is a vector-borne disease with epidemic potential. Recently, outbreaks of Bluetongue were reported across Greece, caused by the Bluetongue virus (BTV) serotype 4. Regarding its pathogenesis, BTV infection involves various target organs with limited data referring to the kidneys. The objective of this study was to identify the possible impact of BTV infection on kidneys using common renal biomarkers. Urine and blood samples collected from 30 sheep with clinical signs of bluetongue (BTV sheep) and 30 clinically healthy sheep (normal sheep) from the same farms were finally selected and included in the study from an initial population of 47 sheep per group, based on the absence of active urine sediment. Complete urinalysis was performed and urine protein to creatinine ratio (UPC) and urine gamma-glutamyl transferase to creatinine (UGGTC) ratio were determined. Blood urea nitrogen (BUN), creatinine, total proteins, albumin (ALB), and inorganic phosphate (P) were determined in serum samples. UPC and UGGTC were significantly higher (p < 0.05) in BTV sheep compared to normal, whereas urine specific gravity (USG) was significantly lower (p < 0.05). Cylindruria was also detected in BTV sheep, and absence of azotemia in BTV and normal sheep. All these findings are indicative of renal tubular injury and/or dysfunction and suggestive of an association between BTV infection and acute damage of renal tissue.
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Affiliation(s)
- Labrini V. Athanasiou
- Department of Medicine, Faculty of Veterinary Medicine, University of Thessaly, 43100 Karditsa, Greece; (L.V.A.); (E.G.K.); (V.M.S.)
| | - Eleni G. Katsogiannou
- Department of Medicine, Faculty of Veterinary Medicine, University of Thessaly, 43100 Karditsa, Greece; (L.V.A.); (E.G.K.); (V.M.S.)
| | - Victoria M. Spanou
- Department of Medicine, Faculty of Veterinary Medicine, University of Thessaly, 43100 Karditsa, Greece; (L.V.A.); (E.G.K.); (V.M.S.)
| | - Anna Dedousi
- Veterinary Research Institute, HAO-Demeter, 57001 Thessaloniki, Greece;
| | - Panagiotis D. Katsoulos
- Clinic of Farm Animals, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece
- Correspondence: ; Tel./Fax: +30-231-099-4455
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Lumbers ER, Kandasamy Y, Delforce SJ, Boyce AC, Gibson KJ, Pringle KG. Programming of Renal Development and Chronic Disease in Adult Life. Front Physiol 2020; 11:757. [PMID: 32765290 PMCID: PMC7378775 DOI: 10.3389/fphys.2020.00757] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 06/11/2020] [Indexed: 12/18/2022] Open
Abstract
Chronic kidney disease (CKD) can have an insidious onset because there is a gradual decline in nephron number throughout life. There may be no overt symptoms of renal dysfunction until about two thirds or more of the nephrons have been destroyed and glomerular filtration rate (GFR) falls to below 25% of normal (often in mid-late life) (Martinez-Maldonaldo et al., 1992). Once End Stage Renal Disease (ESRD) has been reached, survival depends on renal replacement therapy (RRT). CKD causes hypertension and cardiovascular disease; and hypertension causes CKD. Albuminuria is also a risk factor for cardiovascular disease. The age of onset of CKD is partly determined during fetal life. This review describes the mechanisms underlying the development of CKD in adult life that results from abnormal renal development caused by an adverse intrauterine environment. The basis of this form of CKD is thought to be mainly due to a reduction in the number of nephrons formed in utero which impacts on the age dependent decline in glomerular function. Factors that affect the risk of reduced nephron formation during intrauterine life are discussed and include maternal nutrition (malnutrition and obesity, micronutrients), smoking and alcohol, use of drugs that block the maternal renin-angiotensin system, glucocorticoid excess and maternal renal dysfunction and prematurity. Since CKD, hypertension and cardiovascular disease add to the disease burden in the community we recommend that kidney size at birth should be recorded using ultrasound and those individuals who are born premature or who have small kidneys at this time should be monitored regularly by determining GFR and albumin:creatinine clearance ratio. Furthermore, public health measures aimed at limiting the prevalence of obesity and diabetes mellitus as well as providing advice on limiting the amount of protein ingested during a single meal, because they are all associated with increased glomerular hyperfiltration and subsequent glomerulosclerosis would be beneficial.
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Affiliation(s)
- Eugenie R Lumbers
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, Newcastle, NSW, Australia
| | - Yoga Kandasamy
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, Newcastle, NSW, Australia.,Department of Neonatology, Townsville University Hospital, Douglas, QLD, Australia
| | - Sarah J Delforce
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, Newcastle, NSW, Australia
| | - Amanda C Boyce
- School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Karen J Gibson
- School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Kirsty G Pringle
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, Newcastle, NSW, Australia
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Abstract
PURPOSE OF REVIEW To review the studies and practice guidelines on the preeclampsia risks in kidney donors and recipients. RECENT FINDINGS There is a small increased risk of gestational hypertension and preeclampsia in pregnancies that follow kidney donation. Kidney Disease Improving Global Outcomes (KDIGO) Clinical Practice Guideline (2017) and the 2015 American Society of Transplantation (AST) consensus conference statement recommends counseling kidney donors about this increased risk. There is no observed increase in fetal complications or eclampsia post-kidney donation. Preeclampsia is more commonly observed in kidney transplant recipients than the general population and these patients should be co-managed with an obstetrician with experience in managing high risk pregnancies. Although preeclampsia has not been found to have a deleterious effect on renal graft function, it can cause premature delivery. Risk calculators have been proposed and an elevated pre-pregnancy creatinine seems to be an important risk. KDIGO Clinical Practice Guidelines (2009) recommends attempting pregnancy when kidney function is stable with proteinuria of less than 1 g per day. The use of novel biomarkers for preeclampsia has not been published in this population. Preeclampsia is an important concern for female kidney donors and recipients of child-bearing age. These individuals should be appropriately counseled.
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Affiliation(s)
- Pratik B Shah
- Section of Nephrology, University of Chicago Medicine, Chicago, IL, USA
| | - Manpreet Samra
- Division of Nephrology, University of Illinois at Chicago, Chicago, IL, USA
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Briffa JF, Wlodek ME, Moritz KM. Transgenerational programming of nephron deficits and hypertension. Semin Cell Dev Biol 2018; 103:94-103. [PMID: 29859996 DOI: 10.1016/j.semcdb.2018.05.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 05/28/2018] [Accepted: 05/29/2018] [Indexed: 01/16/2023]
Abstract
Exposure to a sub-optimal environment in the womb can result in poor fetal growth and impair the normal development of organs. The kidney, specifically the process of nephrogenesis, has been shown to be impacted by many common pregnancy exposures including an inadequate diet, poor placental function, maternal stress as well as maternal smoking and alcohol consumption. This can result in offspring being born with a reduced nephron endowment, which places these individuals at increased risk of hypertension and chronic kidney disease (CKD). Of recent interest is whether this disease risk can be passed on to subsequent generations and, if so, what are the mechanisms and pathways involved. In this review, we highlight the growing body of evidence that a low birth weight and hypertension, which are both major risk factors for cardiovascular and CKD, can be transmitted across generations. However, as yet there is little data as to whether a low nephron endowment contributes to this disease transmission. The emerging data suggests transmission can occur both through both the maternal and paternal lines, which likely involves epigenetic mechanisms such chromatin remodelling (DNA methylation and histone modification) and non-coding RNA modifications. In addition, females who were born small and/or have a low nephron endowment are at an increased risk for pregnancy complications, which can influence the growth and development of the next generation. Future animal studies in this area should include examining nephron endowment across multiple generations and determining adult renal function. Clinically, long term follow-up studies of large birth cohorts need to be undertaken to more clearly determine the impact a sub-optimal environment in one generation has on the health outcomes in the second, and subsequent, generation.
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Affiliation(s)
- Jessica F Briffa
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - Mary E Wlodek
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - Karen M Moritz
- Child Health Research Centre and School of Biomedical Sciences, The University of Queensland, St. Lucia, QLD, Australia.
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Sontrop JM, Garg AX. Considerations for Living Kidney Donation Among Women of Childbearing Age: Evidence from Recent Studies. CURRENT TRANSPLANTATION REPORTS 2016. [DOI: 10.1007/s40472-016-0082-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Pringle KG, Sykes SD, Lumbers ER. Circulating and intrarenal renin-angiotensin systems in healthy men and nonpregnant women. Physiol Rep 2015; 3:3/10/e12586. [PMID: 26471758 PMCID: PMC4632955 DOI: 10.14814/phy2.12586] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The urinary excretion of renin-angiotensin system (RAS) proteins could reflect the activity of the intrarenal RAS. We hypothesized that the rates of excretion of RAS components into human urine are independent of circulating levels of these proteins and reflect the intrarenal RAS. There are no reports of the simultaneous measurement of prorenin, active renin, angiotensinogen (AGT), and angiotensin-converting enzyme (ACE) excretion in healthy individuals. Therefore, we measured plasma prorenin, ACE, and AGT and urinary renin (uRenin), prorenin (uProrenin), ACE (uACE), and AGT (uAGT) in men and nonpregnant women. Plasma (p) AGT was higher in women then men. Women who were taking estrogen had significantly higher pAGT. In women, pProrenin was negatively correlated with pAGT. There were no correlations between pProrenin, pAGT, and pACE and their urinary counterparts in either men or women. In men, uProrenin/creatinine ratios were lower than in women. There was no effect of estrogen use on urinary excretion of pProrenin, renin, AGT, and ACE. In men, there were significant correlations between uACE/creat and uRen/creat and uAGT/creat; uProrenin/creat and plasma cystatin C levels; and uRenin/creat and uNa/K were also positively correlated. No associations were found in women. In conclusion, urinary excretion of prorenin is sexually dimorphic and is not affected by estrogen use in women. Our data also suggest that the relationship between renal handling of sodium and urinary renin is sexually dimorphic. Since we found no associations between plasma RAS proteins and their urinary counterparts, and the ratio of uProrenin:pProrenin was strikingly different between men and women, levels of urinary RAS proteins in individuals with normal kidney function are most likely the result of tubular secretion, rather than ultrafiltration.
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Affiliation(s)
- Kirsty G Pringle
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia Mothers and Babies Research Centre, Hunter Medical Research Institute, Newcastle, New South Wales, Australia
| | - Shane D Sykes
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia Mothers and Babies Research Centre, Hunter Medical Research Institute, Newcastle, New South Wales, Australia
| | - Eugenie R Lumbers
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia Mothers and Babies Research Centre, Hunter Medical Research Institute, Newcastle, New South Wales, Australia
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Turner AJ, Brown RD, Boyce A, Gibson KJ, Persson AEG. Fetal tubuloglomerular feedback in an ovine model of mild maternal renal disease. Physiol Rep 2015; 3:3/7/e12448. [PMID: 26169542 PMCID: PMC4552528 DOI: 10.14814/phy2.12448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Fetuses of pregnant ewes, which were subtotally nephrectomized prior to mating, were studied to assess whether mild maternal renal impairment would affect fetal tubuloglomerular feedback (TGF) under control conditions and after the inhibition of macula densa-derived nitric oxide (NO). Based on previous observations we hypothesized that, the TGF curve of fetuses of subtotally nephrectomized (STNx) ewes would resemble that of a volume expanded fetus with a high production rate of NO and that inhibition of neuronal nitric oxide synthase (nNOS) would increase the sensitivity of the TGF system in these fetuses. Renal function studies were performed on anaesthetized fetal sheep (133–140 days gestation; term ∼150 days; Isoflurane 2–4% in oxygen). Fetuses were removed from the uterus and placed in a water bath (39.5°C) while maintaining umbilical blood flow. Glomerular filtration rate (GFR) and urine flow rate were markedly increased in fetuses of STNx ewes compared to fetuses of untreated ewes. Interestingly, and contrary to our hypothesis, the fetuses of STNx ewes exhibited no difference in TGF sensitivity in the presence or absence of 7-nitroindazole (7NI; nNOS inhibitor), compared to fetuses of untreated ewes, although sensitivity and reactivity increased in both groups after 7NI. There was however, a decrease in the stop flow pressure and net filtration pressure with an increase in the filtration coefficient (Kf). These factors suggest that maternal renal impairment drives the glomerular hypertrophy which has previously been found to be present in the neonatal period. Thus, we conclude that at ∼138 days gestation, the fetal kidney has matured functionally and fetuses of STNx ewes are able to maintain fluid and electrolyte homeostasis even in the presence of increased transplacental flux.
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Affiliation(s)
- Anita J Turner
- Australian School of Advanced Medicine Macquarie University, Sydney, New South Wales, Australia Department of Physiology, School of Medical Sciences University of New South Wales, Sydney, New South Wales, Australia
| | - Russell D Brown
- Department of Physiology, School of Medical Sciences University of New South Wales, Sydney, New South Wales, Australia Department of Medical Cell Biology, Division of Integrative Physiology, University of Uppsala, Uppsala, Sweden
| | - Amanda Boyce
- Department of Physiology, School of Medical Sciences University of New South Wales, Sydney, New South Wales, Australia
| | - Karen J Gibson
- Department of Physiology, School of Medical Sciences University of New South Wales, Sydney, New South Wales, Australia
| | - A Erik G Persson
- Department of Physiology, School of Medical Sciences University of New South Wales, Sydney, New South Wales, Australia Department of Medical Cell Biology, Division of Integrative Physiology, University of Uppsala, Uppsala, Sweden
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8
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Garg AX, Nevis IF, McArthur E, Sontrop JM, Koval JJ, Lam NN, Hildebrand AM, Reese PP, Storsley L, Gill JS, Segev DL, Habbous S, Bugeja A, Knoll GA, Dipchand C, Monroy-Cuadros M, Lentine KL. Gestational hypertension and preeclampsia in living kidney donors. N Engl J Med 2015; 372:124-33. [PMID: 25397608 PMCID: PMC4362716 DOI: 10.1056/nejmoa1408932] [Citation(s) in RCA: 185] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND Young women wishing to become living kidney donors frequently ask whether nephrectomy will affect their future pregnancies. METHODS We conducted a retrospective cohort study of living kidney donors involving 85 women (131 pregnancies after cohort entry) who were matched in a 1:6 ratio with 510 healthy nondonors from the general population (788 pregnancies after cohort entry). Kidney donations occurred between 1992 and 2009 in Ontario, Canada, with follow-up through linked health care databases until March 2013. Donors and nondonors were matched with respect to age, year of cohort entry, residency (urban or rural), income, number of pregnancies before cohort entry, and the time to the first pregnancy after cohort entry. The primary outcome was a hospital diagnosis of gestational hypertension or preeclampsia. Secondary outcomes were each component of the primary outcome examined separately and other maternal and fetal outcomes. RESULTS Gestational hypertension or preeclampsia was more common among living kidney donors than among nondonors (occurring in 15 of 131 pregnancies [11%] vs. 38 of 788 pregnancies [5%]; odds ratio for donors, 2.4; 95% confidence interval, 1.2 to 5.0; P=0.01). Each component of the primary outcome was also more common among donors (odds ratio, 2.5 for gestational hypertension and 2.4 for preeclampsia). There were no significant differences between donors and nondonors with respect to rates of preterm birth (8% and 7%, respectively) or low birth weight (6% and 4%, respectively). There were no reports of maternal death, stillbirth, or neonatal death among the donors. Most women had uncomplicated pregnancies after donation. CONCLUSIONS Gestational hypertension or preeclampsia was more likely to be diagnosed in kidney donors than in matched nondonors with similar indicators of baseline health. (Funded by the Canadian Institutes of Health Research and others.).
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Affiliation(s)
- Amit X Garg
- The authors' affiliations are provided in the Appendix
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9
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Satué K, Domingo R, Redondo J. Relationship between progesterone, oestrone sulphate and cortisol and the components of renin angiotensin aldosterone system in Spanish purebred broodmares during pregnancy. Theriogenology 2011; 76:1404-15. [DOI: 10.1016/j.theriogenology.2011.06.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 05/17/2011] [Accepted: 06/07/2011] [Indexed: 12/19/2022]
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Brandon AE, Boyce AC, Lumbers ER, Kumarasamy V, Gibson KJ. Programming of the renin response to haemorrhage by mild maternal renal impairment in sheep. Clin Exp Pharmacol Physiol 2011; 38:102-8. [PMID: 21182536 DOI: 10.1111/j.1440-1681.2010.05473.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. The aim of the present study was to test the hypothesis that the renin response to mechanisms activated by haemorrhage is programmed by exposure to maternal renal dysfunction. 2. In 26-27-day-old lambs born to ewes that had reduced renal function (STNxL, n=10) and lambs born to ewes with normal renal function (ConL, n=6), 1.6 mL/kg per min of blood was removed over 10 min. 3. Under basal conditions, the STNxL group had increased mean arterial pressure (P < 0.05). In response to haemorrhage, mean arterial pressure decreased in the STNxL group (P < 0.001), but there was no significant change in the ConL group. 4. Although plasma renin level increased in both groups (P < 0.05), the peak response was reduced and delayed in the STNxL group. In contrast, the rise in arginine vasopressin (AVP) level was similar in both groups and occurred over the same time course. At 24 h, both plasma renin and AVP level were the same as those measured before haemorrhage in both groups. Kidney renin level was similar in the two groups. 5. The attenuated renin response to haemorrhage in the STNxL group might explain the inability to maintain arterial pressure after haemorrhage. The results of the present study suggest that the renin response of the postnatal kidney to reductions in blood volume can be affected by the intrauterine environment. If these changes persist into adulthood, it suggests that permanent programming has occurred. Thus, the ability of an individual to respond to acute severe reductions in blood volume might be determined during intrauterine life.
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Affiliation(s)
- Amanda E Brandon
- Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia.
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11
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Satué K, Domingo R. Longitudinal study of the renin angiotensin aldosterone system in purebred Spanish broodmares during pregnancy. Theriogenology 2011; 75:1185-94. [PMID: 21220157 DOI: 10.1016/j.theriogenology.2010.11.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 11/11/2010] [Accepted: 11/22/2010] [Indexed: 11/29/2022]
Abstract
During pregnancy, the coordinated interaction of the components of the renin-angiotensin-aldosterone system (RAAS) plays a vital role in accommodating the cardiovascular, haemodynamic and haematological needs imposed by foetal development and the placenta. This significantly influences the birth weight of the neonate and foetal viability. Although the evolution of each of the components of this system has been widely described in various species, it has not yet been clarified in the mare. Thus, the objectives of the present research were: 1) to establish reference values for renin (REN), angiotensin II (ANG-II) and aldosterone (ALD) concentrations in Spanish broodmares, and 2) to analyse the evolution of the aforementioned components during pregnancy. Thirty-one Purebred Spanish broodmares aged between 5 and 15 years old were studied for 11 months of pregnancy and compared to a control group composed of 11 non-pregnant Spanish mares. Morning venous blood samples were drawn on a monthly basis during pregnancy and pre-treated to prevent degradation until subsequent analysis. Serum REN, ANG-II and ALD concentrations were analysed by competitive immunoassay. This study found that pregnancy in Purebred Spanish broodmares is characterised by a gradual increase in REN concentrations, variable fluctuations in ALD concentrations, and no significant modifications in ANG-II concentrations. These results could provide potentially valuable information in understanding the physiological basis of the RAAS in mares, since we have been able to establish specific reference ranges for these components, as well as obtaining information on their evolution during pregnancy. As is often the case in other animal species, the increase in RAAS activity is a natural physiological process that occurs during pregnancy in Spanish broodmares. This may also be related to certain metabolic and hormone responses that contribute to the control of homeostasis in pregnant mares.
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Affiliation(s)
- K Satué
- Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Cardenal Herrera University, Valencia, Spain.
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13
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Reduced nephron endowment due to fetal uninephrectomy impairs renal sodium handling in male sheep. Clin Sci (Lond) 2010; 118:669-80. [PMID: 20067444 DOI: 10.1042/cs20090479] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Reduced nephron endowment is associated with development of renal and cardiovascular disease. We hypothesized this may be attributable to impaired sodium homoeostasis by the remaining nephrons. The present study investigated whether a nephron deficit, induced by fetal uninephrectomy at 100 days gestation (term=150 days), resulted in (i) altered renal sodium handling both under basal conditions and in response to an acute 0.9% saline load (50 ml.kg-1 of body weight.30 min-1); (ii) hypertension and (iii) altered expression of renal channels/transporters in male sheep at 6 months of age. Uninephrectomized animals had significantly elevated arterial pressure (90.1+/-1.6 compared with 77.8+/-2.9 mmHg; P<0.001), while glomerular filtration rate and renal blood flow (per g of kidney weight) were 30% lower than that of the sham animals. Total kidney weight was similar between the groups. Renal gene expression of apical NHE3 (type 3 Na+/H+ exchanger), ENaC (epithelium Na+ channel) beta and gamma subunits and basolateral Na+/K+ ATPase beta and gamma subunits were significantly elevated in uninephrectomized animals, while ENaC alpha subunit expression was reduced. Urine flow rate and sodium excretion increased in both groups in response to salt loading, but this increase in sodium excretion was delayed by approximately 90 min in the uninephrectomized animals, while total sodium output was 12% in excess of the infused load (P<0.05). In conclusion, the present study shows that animals with a congenital nephron deficit have alterations in tubular sodium channels/transporters and cannot rapidly correct for variations in sodium intake probably contributing to the development of hypertension. This suggests that people born with a nephron deficit should be monitored for early signs of renal and cardiovascular disease.
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Brandon AE, Boyce AC, Lumbers ER, Gibson KJ. Maternal renal dysfunction in sheep is associated with salt insensitivity in female offspring. J Physiol 2008; 587:261-70. [PMID: 19001051 DOI: 10.1113/jphysiol.2008.158808] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
To examine the programming effects of maternal renal dysfunction (created by subtotal nephrectomy in ewes prior to mating; STNx), renal and cardiovascular function were studied in 6-month-old male and female offspring of STNx and control pregnancies. After studies were conducted on a low salt diet (LSD) some female offspring underwent salt loading (0.17 M NaCl in the drinking water for 5-7 days; HSD). On LSD both male and female offspring of STNx had similar mean arterial pressures (MAP), heart rates, cardiac outputs and renal function to those measured in offspring of control ewes. In female STNx offspring on a HSD, plasma sodium levels increased and haematocrits fell, indicating volume expansion (P < 0.05). Plasma renin levels were not suppressed despite the increases in plasma sodium concentrations, but aldosterone levels were reduced. In control animals plasma renin levels fell (P < 0.05) but there was no change in plasma aldosterone concentrations. There was a positive relationship between GFR and MAP which was present only in female STNx offspring. In conclusion, in STNx offspring there was an impaired ability to regulate glomerular filtration independent of arterial pressure, renin release was insensitive to a high salt intake and control of aldosterone secretion was abnormal. This study provides evidence of abnormal programming of the renin-angiotensin system and glomerular function in offspring of pregnancies in which there is impaired maternal renal function.
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Affiliation(s)
- A E Brandon
- Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
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15
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Brandon AE, Boyce AC, Lumbers ER, Zimanyi MA, Bertram JF, Gibson KJ. Glomerular hypertrophy in offspring of subtotally nephrectomized ewes. Anat Rec (Hoboken) 2008; 291:318-24. [PMID: 18228586 DOI: 10.1002/ar.20651] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We have shown that fetuses whose mothers underwent subtotal nephrectomy (STNx) before pregnancy had high urine flow rates and sodium excretions, but lower hematocrits, plasma chloride, and plasma renin levels compared with controls. To see if these functional differences in utero persist after birth and are the result of altered renal development, we studied 8 lambs born to STNx mothers (STNxL) and 10 controls (ConL) in the second week of life. These lambs were of similar body weights, nose-rump lengths and abdominal girths. Their kidney weights were not different (ConL 36.1 +/- 1.9 vs. STNxL 39.8 +/- 3.3 g), nor were kidney dimensions or glomerular number (ConL 423,520 +/- 22,194 vs. STNxL 429,530 +/- 27,471 glomeruli). However, STNxL had 30% larger glomerular volumes (both mean and total, P < 0.01) and there was a positive relationship between total glomerular volume and urinary protein excretion (P < 0.05) in STNxL. Despite this change in glomerular morphology, glomerular filtration rate, tubular function, urine flow, and sodium excretion rates were not different between STNxL and ConL, nor were plasma electrolytes, osmolality, and plasma renin levels. Thus while many of the functional differences seen in late gestation were not present at 1-2 weeks after birth, the alteration in glomerular size and its relationship to protein excretion suggests that exposure to this altered intrauterine environment may predispose offspring of mothers with renal dysfunction to renal disease in adult life.
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Affiliation(s)
- Amanda E Brandon
- Department of Physiology and Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
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16
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Boyce AC, Gibson KJ, Thomson CL, Lumbers ER. Interactions between maternal subtotal nephrectomy and salt: effects on renal function and the composition of plasma in the late gestation sheep fetus. Exp Physiol 2007; 93:262-70. [PMID: 17933860 DOI: 10.1113/expphysiol.2007.039149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Effects of altered maternal salt intake between 122 and 127 days gestation (term is 150 days) were studied in eight fetuses carried by ewes which had renal insufficiency caused by subtotal nephrectomy (STNxF) and seven fetuses carried by intact ewes (IntF). Plasma sodium and osmolality were increased in ewes with subtotal nephrectomy on a high-salt intake (0.17 m NaCl in place of drinking water for 5 days; P < 0.05). The STNxF had normal body weights. A high maternal salt intake did not affect fetal blood pressure or heart rate. Plasma osmolality was higher in STNxF (P < 0.001), and plasma sodium and osmolality were increased by high salt (P < 0.001 and P < 0.04, respectively). The STNxF had higher urinary osmolalities (P = 0.002), which were also increased by a high maternal salt intake (P = 0.03). Renal blood flow fell in STNxF in response to a high maternal salt intake, but increased in IntF (P = 0.003). In STNxF but not IntF, glomerular filtration rate and urinary protein excretion were positively related to fetal plasma renin levels (P < or = 0.01). It is concluded that the salt intake of pregnant ewes with renal insufficiency affects maternal and fetal osmolar balance, fetal plasma sodium and fetal renal function. Since STNxF also had altered renal haemodynamic responses to high maternal salt and evidence of renin-dependent glomerular filtration and protein excretion, we suggest that interactions between dietary salt and pre-existing maternal renal disease impair glomerular integrity and function in the fetus.
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Affiliation(s)
- Amanda C Boyce
- Department of Physiology and Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
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