1
|
Osorio H, Toro JC, Schorwer K, Riveros A, Cardenas J. Pioneros de un Siglo de Enseñanza Anatómica en la Ciudad de Concepción, Chile. INT J MORPHOL 2020. [DOI: 10.4067/s0717-95022020000300650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
2
|
García-Arroyo FE, Tapia E, Blas-Marron MG, Gonzaga G, Silverio O, Cristóbal M, Osorio H, Arellano-Buendía AS, Zazueta C, Aparicio-Trejo OE, Reyes-García JG, Pedraza-Chaverri J, Soto V, Roncal-Jiménez C, Johnson RJ, Sánchez-Lozada LG. Vasopressin Mediates the Renal Damage Induced by Limited Fructose Rehydration in Recurrently Dehydrated Rats. Int J Biol Sci 2017; 13:961-975. [PMID: 28924378 PMCID: PMC5599902 DOI: 10.7150/ijbs.20074] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [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: 03/14/2017] [Accepted: 05/26/2017] [Indexed: 12/26/2022] Open
Abstract
Recurrent dehydration and heat stress cause chronic kidney damage in experimental animals. The injury is exacerbated by rehydration with fructose-containing beverages. Fructose may amplify dehydration-induced injury by directly stimulating vasopressin release and also by acting as a substrate for the aldose reductase-fructokinase pathway, as both of these systems are active during dehydration. The role of vasopressin in heat stress associated injury has not to date been explored. Here we show that the amplification of renal damage mediated by fructose in thermal dehydration is mediated by vasopressin. Fructose rehydration markedly enhanced vasopressin (copeptin) levels and activation of the aldose reductase-fructokinase pathway in the kidney. Moreover, the amplification of the renal functional changes (decreased creatinine clearance and tubular injury with systemic inflammation, renal oxidative stress, and mitochondrial dysfunction) were prevented by the blockade of V1a and V2 vasopressin receptors with conivaptan. On the other hand, there are also other operative mechanisms when water is used as rehydration fluid that produce milder renal damage that is not fully corrected by vasopressin blockade. Therefore, we clearly showed evidence of the cross-talk between fructose, even at small doses, and vasopressin that interact to amplify the renal damage induced by dehydration. These data may be relevant for heat stress nephropathy as well as for other renal pathologies due to the current generalized consumption of fructose and deficient hydration habits.
Collapse
Affiliation(s)
| | - Edilia Tapia
- Laboratory of Renal Physiopathology. INC Ignacio Chávez. Mexico City. Mexico.,Dept. of Nephrology. INC Ignacio Chávez. Mexico City. Mexico
| | | | - Guillermo Gonzaga
- Laboratory of Renal Physiopathology. INC Ignacio Chávez. Mexico City. Mexico
| | - Octaviano Silverio
- Laboratory of Renal Physiopathology. INC Ignacio Chávez. Mexico City. Mexico
| | - Magdalena Cristóbal
- Laboratory of Renal Physiopathology. INC Ignacio Chávez. Mexico City. Mexico.,Dept. of Nephrology. INC Ignacio Chávez. Mexico City. Mexico
| | - Horacio Osorio
- Laboratory of Renal Physiopathology. INC Ignacio Chávez. Mexico City. Mexico.,Dept. of Nephrology. INC Ignacio Chávez. Mexico City. Mexico
| | - Abraham S Arellano-Buendía
- Laboratory of Renal Physiopathology. INC Ignacio Chávez. Mexico City. Mexico.,Dept. of Nephrology. INC Ignacio Chávez. Mexico City. Mexico
| | - Cecilia Zazueta
- Dept. of Cardiovascular Biomedicine. INC Ignacio Chávez. Mexico City. Mexico
| | | | - Juan G Reyes-García
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, IPN Mexico City. Mexico
| | | | - Virgilia Soto
- Dept. of Pathology. INC Ignacio Chávez. Mexico City. Mexico
| | | | | | - Laura G Sánchez-Lozada
- Laboratory of Renal Physiopathology. INC Ignacio Chávez. Mexico City. Mexico.,Dept. of Nephrology. INC Ignacio Chávez. Mexico City. Mexico
| |
Collapse
|
3
|
García-Arroyo FE, Cristóbal M, Arellano-Buendía AS, Osorio H, Tapia E, Soto V, Madero M, Lanaspa MA, Roncal-Jiménez C, Bankir L, Johnson RJ, Sánchez-Lozada LG. Rehydration with soft drink-like beverages exacerbates dehydration and worsens dehydration-associated renal injury. Am J Physiol Regul Integr Comp Physiol 2016; 311:R57-65. [PMID: 27053647 DOI: 10.1152/ajpregu.00354.2015] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [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: 08/13/2015] [Accepted: 03/31/2016] [Indexed: 12/18/2022]
Abstract
Recurrent dehydration, such as commonly occurs with manual labor in tropical environments, has been recently shown to result in chronic kidney injury, likely through the effects of hyperosmolarity to activate both vasopressin and aldose reductase-fructokinase pathways. The observation that the latter pathway can be directly engaged by simple sugars (glucose and fructose) leads to the hypothesis that soft drinks (which contain these sugars) might worsen rather than benefit dehydration associated kidney disease. Recurrent dehydration was induced in rats by exposure to heat (36°C) for 1 h/24 h followed by access for 2 h to plain water (W), a 11% fructose-glucose solution (FG, same composition as typical soft drinks), or water sweetened with noncaloric stevia (ST). After 4 wk plasma and urine samples were collected, and kidneys were examined for oxidative stress, inflammation, and injury. Recurrent heat-induced dehydration with ad libitum water repletion resulted in plasma and urinary hyperosmolarity with stimulation of the vasopressin (copeptin) levels and resulted in mild tubular injury and renal oxidative stress. Rehydration with 11% FG solution, despite larger total fluid intake, resulted in greater dehydration (higher osmolarity and copeptin levels) and worse renal injury, with activation of aldose reductase and fructokinase, whereas rehydration with stevia water had opposite effects. In animals that are dehydrated, rehydration acutely with soft drinks worsens dehydration and exacerbates dehydration associated renal damage. These studies emphasize the danger of drinking soft drink-like beverages as an attempt to rehydrate following dehydration.
Collapse
Affiliation(s)
- Fernando E García-Arroyo
- Laboratory of Renal Physiopathology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico; Department of Nephrology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico
| | - Magdalena Cristóbal
- Laboratory of Renal Physiopathology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico; Department of Nephrology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico
| | - Abraham S Arellano-Buendía
- Laboratory of Renal Physiopathology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico; Department of Nephrology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico
| | - Horacio Osorio
- Laboratory of Renal Physiopathology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico; Department of Nephrology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico
| | - Edilia Tapia
- Laboratory of Renal Physiopathology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico; Department of Nephrology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico
| | - Virgilia Soto
- Department of Pathology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico
| | - Magdalena Madero
- Department of Nephrology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico
| | - Miguel A Lanaspa
- Division of Renal Diseases and Hypertension, University of Colorado, Aurora, Colorado; and
| | - Carlos Roncal-Jiménez
- Division of Renal Diseases and Hypertension, University of Colorado, Aurora, Colorado; and
| | - Lise Bankir
- INSERM, Centre de Recherche des Cordeliers, Paris, France
| | - Richard J Johnson
- Division of Renal Diseases and Hypertension, University of Colorado, Aurora, Colorado; and
| | - Laura-Gabriela Sánchez-Lozada
- Laboratory of Renal Physiopathology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico; Department of Nephrology, Instituto Nacional de Cardiología-Ignacio Chávez, Mexico City, Mexico;
| |
Collapse
|
4
|
Tapia E, Sánchez-Lozada LG, García-Niño WR, García E, Cerecedo A, García-Arroyo FE, Osorio H, Arellano A, Cristóbal-García M, Loredo ML, Molina-Jijón E, Hernández-Damián J, Negrette-Guzmán M, Zazueta C, Huerta-Yepez S, Reyes JL, Madero M, Pedraza-Chaverrí J. Curcumin prevents maleate-induced nephrotoxicity: relation to hemodynamic alterations, oxidative stress, mitochondrial oxygen consumption and activity of respiratory complex I. Free Radic Res 2014; 48:1342-54. [PMID: 25119790 DOI: 10.3109/10715762.2014.954109] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The potential protective effect of the dietary antioxidant curcumin (120 mg/Kg/day for 6 days) against the renal injury induced by maleate was evaluated. Tubular proteinuria and oxidative stress were induced by a single injection of maleate (400 mg/kg) in rats. Maleate-induced renal injury included increase in renal vascular resistance and in the urinary excretion of total protein, glucose, sodium, neutrophil gelatinase-associated lipocalin (NGAL) and N-acetyl β-D-glucosaminidase (NAG), upregulation of kidney injury molecule (KIM)-1, decrease in renal blood flow and claudin-2 expression besides of necrosis and apoptosis of tubular cells on 24 h. Oxidative stress was determined by measuring the oxidation of lipids and proteins and diminution in renal Nrf2 levels. Studies were also conducted in renal epithelial LLC-PK1 cells and in mitochondria isolated from kidneys of all the experimental groups. Maleate induced cell damage and reactive oxygen species (ROS) production in LLC-PK1 cells in culture. In addition, maleate treatment reduced oxygen consumption in ADP-stimulated mitochondria and diminished respiratory control index when using malate/glutamate as substrate. The activities of both complex I and aconitase were also diminished. All the above-described alterations were prevented by curcumin. It is concluded that curcumin is able to attenuate in vivo maleate-induced nephropathy and in vitro cell damage. The in vivo protection was associated to the prevention of oxidative stress and preservation of mitochondrial oxygen consumption and activity of respiratory complex I, and the in vitro protection was associated to the prevention of ROS production.
Collapse
Affiliation(s)
- E Tapia
- Department of Nephrology, National Institute of Cardiology I. Ch. , Mexico City , Mexico
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Osorio H, Coronel I, Arellano A, Franco M, Escalante B, Bautista R. Ursodeoxycholic acid decreases sodium-glucose cotransporter (SGLT2) expression and oxidative stress in the kidney of diabetic rats. Diabetes Res Clin Pract 2012; 97:276-82. [PMID: 22429686 DOI: 10.1016/j.diabres.2012.02.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 02/15/2012] [Accepted: 02/23/2012] [Indexed: 12/28/2022]
Abstract
UNLABELLED Oxidative stress has been associated with diabetic complications like nephropathies. Recent studies indicate that ursodeoxycholic acid (UDCA) may be beneficial preventing diabetes-induced oxidative stress and secondary complications. Thus, we study if the UDCA-treatment decreases the expression of sodium-glucose cotransporter (SGLT2) and the oxidative stress in the kidney of diabetic rats. METHODS The diabetes model was established by intraperitoneal injection of streptozotocin (50mg/kg). SGLT2 expression was evaluated by western blot and RT-PCR. Oxidative stress was assessed by catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase activities (SOD) and immunohistochemical analysis of 3-nitrotyrosine (3-NT). RESULTS Streptozotocin-induced diabetes caused hyperglycemia and lower body weight. The SGLT2 expression and mRNA levels increased in cortex of kidney from diabetic rats. The CAT activity decreased in cortex and medulla from diabetic rats, otherwise the GPx activity increased. Furthermore the 3-NT staining of kidney from diabetic rats increased compared to control rats. The UDCA treatment was able to decrease hyperglycemia and prevents the SGLT2 over-expression, restores the CAT and GPX activities and decreases 3-NT staining. CONCLUSION The UDCA treatment prevents the over-expression of SGLT2 and oxidative stress in kidney of diabetic rats.
Collapse
Affiliation(s)
- Horacio Osorio
- Department of Nephrology, Instituto Nacional de Cardiología Ignacio Chavez México City, 14080, Mexico.
| | | | | | | | | | | |
Collapse
|
6
|
Osorio H, Schorwer K, Coronado C, Delgado J, Aravena P. Proximal Femoral Epiphysis Anatomy in Chilean Population: Orthopedic and Forensic Aspects. INT J MORPHOL 2012. [DOI: 10.4067/s0717-95022012000100046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
7
|
Bautista-Pérez R, Arellano A, Franco M, Osorio H, Coronel I. Sphingosine-1-phosphate induced vasoconstriction is increased in the isolated perfused kidneys of diabetic rats. Diabetes Res Clin Pract 2011; 94:e8-11. [PMID: 21775010 DOI: 10.1016/j.diabres.2011.06.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 06/09/2011] [Accepted: 06/26/2011] [Indexed: 11/18/2022]
Abstract
We observed that in isolated perfused rat kidneys, sphingosine-1-phosphate produces S1P(2) receptor-mediated vasoconstriction, and this response increased in kidneys of diabetic rats. These results suggest that the antagonists of S1P(2) receptor may have potential as drugs to control diabetes-induced vascular complications.
Collapse
Affiliation(s)
- Rocio Bautista-Pérez
- Department of Nephrology, Instituto Nacional de Cardiologia Ignacio Chavez, México City, Mexico.
| | | | | | | | | |
Collapse
|
8
|
Franco M, Bautista R, Tapia E, Soto V, Santamaría J, Osorio H, Pacheco U, Sánchez-Lozada LG, Kobori H, Navar LG. Contribution of renal purinergic receptors to renal vasoconstriction in angiotensin II-induced hypertensive rats. Am J Physiol Renal Physiol 2011; 300:F1301-9. [PMID: 21367914 DOI: 10.1152/ajprenal.00367.2010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To investigate the participation of purinergic P2 receptors in the regulation of renal function in ANG II-dependent hypertension, renal and glomerular hemodynamics were evaluated in chronic ANG II-infused (14 days) and Sham rats during acute blockade of P2 receptors with PPADS. In addition, P2X1 and P2Y1 protein and mRNA expression were compared in ANG II-infused and Sham rats. Chronic ANG II-infused rats exhibited increased afferent and efferent arteriolar resistances and reductions in glomerular blood flow, glomerular filtration rate (GFR), single-nephron GFR (SNGFR), and glomerular ultrafiltration coefficient. PPADS restored afferent and efferent resistances as well as glomerular blood flow and SNGFR, but did not ameliorate the elevated arterial blood pressure. In Sham rats, PPADS increased afferent and efferent arteriolar resistances and reduced GFR and SNGFR. Since purinergic blockade may influence nitric oxide (NO) release, we evaluated the role of NO in the response to PPADS. Acute blockade with N(ω)-nitro-l-arginine methyl ester (l-NAME) reversed the vasodilatory effects of PPADS and reduced urinary nitrate excretion (NO(2)(-)/NO(3)(-)) in ANG II-infused rats, indicating a NO-mediated vasodilation during PPADS treatment. In Sham rats, PPADS induced renal vasoconstriction which was not modified by l-NAME, suggesting blockade of a P2X receptor subtype linked to the NO pathway; the response was similar to that obtained with l-NAME alone. P2X1 receptor expression in the renal cortex was increased by chronic ANG II infusion, but there were no changes in P2Y1 receptor abundance. These findings indicate that there is an enhanced P2 receptor-mediated vasoconstriction of afferent and efferent arterioles in chronic ANG II-infused rats, which contributes to the increased renal vascular resistance observed in ANG II-dependent hypertension.
Collapse
Affiliation(s)
- Martha Franco
- Department of Nephrology, Instituto Nacional de Cardiología Ignacio Chávez, México City, Mexico.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Bautista-Pérez R, Arellano A, Franco M, Osorio H, Coronel I. Enalaprilat-Mediated Activation of Kinin B 1 Receptors and Vasodilation in the Rat Isolated Perfused Kidney. Pharmacology 2011; 87:195-203. [DOI: 10.1159/000324513] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 01/13/2011] [Indexed: 01/06/2023]
|
10
|
Osorio H, Bautista R, Rios A, Franco M, Arellano A, Vargas-Robles H, Romo E, Escalante B. Effect of phlorizin on SGLT2 expression in the kidney of diabetic rats. J Nephrol 2010; 23:541-546. [PMID: 20349407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2009] [Indexed: 05/29/2023]
Abstract
BACKGROUND The purpose of our study was to determine whether increased SGLT2 expression in the kidney of diabetic rats was associated with the development of hypertension and to investigate the effect of phlorizin (P) on blood pressure and SGLT2 expression in diabetic rats. METHODS The animals were divided into two groups: Control (C) and streptozotocin-induced diabetic (D) rats were used to evaluate SGLT2 activity in brush border membrane vesicles (BBMV) using a rapid filtration technique. Others animals were divided into two groups: Normal (NSD) or high salt diet (4%)(HSD), and subdivided in four groups: C, C+P, D, D+P. Systolic blood pressure (SBP) was recorded for 30 days by the use of a telemetric system and at day 30 urine samples (24 h) were collected to evaluate renal function and SGLT2 expression in the renal cortex. RESULTS At day 30, diabetic animals with NSD or HSD exhibited hyperglycemia, lower body weight, glycosuria, diuresis, decrease natriuresis, increased SBP values and SGLT2 expression. In diabetic rats, phlorizin treatment decreased hyperglycemia and prevented development of hypertension, decreased SGLT2 activity in BBMV but did not modify SGLT2 expression. CONCLUSIONS In conclusion, SGLT2 inhibition prevented the development of hypertension in diabetic rats as well as hyperglycemia, suggesting a hypertensive mechanism associated with SGLT2 activity and the likelihood that increased SGLT2 expression may be associated with progression of diabetic renal complications.
Collapse
Affiliation(s)
- Horacio Osorio
- Department of Molecular Biomedicine, Center for Advanced Research and Study of the National Polytechnical Institute (CINVESTAV) Mexico City, Mexico
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Osorio H, Bautista R, Rios A, Franco M, Santamaría J, Escalante B. Effect of treatment with losartan on salt sensitivity and SGLT2 expression in hypertensive diabetic rats. Diabetes Res Clin Pract 2009; 86:e46-9. [PMID: 19800706 DOI: 10.1016/j.diabres.2009.09.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 08/24/2009] [Accepted: 09/07/2009] [Indexed: 11/21/2022]
Abstract
Sodium-glucose cotransporters (SGLTs) in the kidney, may be involved in hypertension, diabetes and salt sensitivity. We evaluate the effect of losartan on blood pressure (BP) and SGLT2 expression in diabetic rats with high or normal salt diet. Losartan prevented an increase in BP and SGLT2 expression in diabetic rats.
Collapse
MESH Headings
- Animals
- Antihypertensive Agents/therapeutic use
- Blood Pressure
- Diabetes Complications/drug therapy
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Experimental/physiopathology
- Diuresis
- Gene Expression Regulation
- Glomerular Filtration Rate
- Hypertension/complications
- Hypertension/drug therapy
- Hypertension/genetics
- Hypertension/physiopathology
- Kidney Cortex/pathology
- Losartan/therapeutic use
- Male
- Rats
- Rats, Wistar
- Receptor, Angiotensin, Type 1/drug effects
- Receptor, Angiotensin, Type 1/physiology
- Sodium, Dietary
- Sodium-Glucose Transporter 2/genetics
Collapse
Affiliation(s)
- Horacio Osorio
- Department of Molecular Biomedicine, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV) México City, Mexico
| | | | | | | | | | | |
Collapse
|
12
|
Abstract
Tamoxifen is an antiestrogen used in the adjuvant endocrine therapy of early breast cancer and malignant breast disorders. It is also used in women with anovulatory infertility caused by its stimulating effect on the secretion of the pituitary gonadotrophic hormones. In males it could increase the endogenous production of androgens. Because of these properties tamoxifen may be misused in some sports to treat the androgens suppression caused by the extensive abuse of anabolic androgenic steroids. A method for identification and confirmation of tamoxifen metabolites is described. Hydroxymetoxytamoxifen is detected in urine by gas chromatography and mass spectrometry in a selective ion monitoring method followed by the routine postrun in the screening of anabolic steroids. Once the hydroxymetoxytamoxifen is detected, confirmation of reported metabolites could be performed with a 5973 mass selective detector in the scan mode after solid-phase extraction by cationic exchange. This study also reports an excretion profile for a single dose of tamoxifen equivalent to 40 mg administrated orally to two males volunteers.
Collapse
Affiliation(s)
- H Báez
- Laboratorio de Análisis Antidoping, Facultad Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | | | | | | |
Collapse
|
13
|
Abstract
Hydraulic conductivity (Lp) of cava vein endothelium was obtained with a new method that measures fluid flow at constant volume. Dogs were anesthetized with pentobarbital sodium. A vessel segment was removed, cannulated, and hung free from a force transducer calibrated to measure weight. Hydraulic pressure difference drove fluid across the vessel wall. This fluid was washed out from the vessel surface by external perfusion, causing a weight loss that was transmitted to a Grass polygraph through the force transducer. Shifting the polygraph balance caused a voltage output which was used to activate a controller operating a microsyringe pump. By injecting fluid into the vessel lumen, this servomechanism counteracted weight changes and kept volume and pressure at a fixed level. Recording the volume injected allowed continuous monitoring of fluid flow. This avoided the problems caused by frequent pressure and volume resetting in previous methods. Fluid flow was a linear function of the applied pressure (r = 0.87). Lp was 0.91 +/- 0.05 (SD) X 10-7 cm X s-1 X cmH2O-1. This value was very similar to those in continuous capillaries and arterial endothelium.
Collapse
|
14
|
Osorio H, Betanzo L, Mallea F, Germany M. [Treatment of patients with maxillo-facial fractures. Analysis of 50 cases]. Trib Odontol (B Aires) 1977; 61:169-78. [PMID: 279144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|