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1.
Regul Toxicol Pharmacol ; 143: 105461, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37490962

RESUMO

The in vitro H295R steroidogenesis assay (OECD TG 456) is used to determine a chemical's potential to interfere with steroid hormone synthesis/metabolism. As positive outcomes in this assay can trigger significant higher tiered testing, we compiled a stakeholder database of reference and test item H295R data to characterize assay outcomes. Information concerning whether a Level 5 reproductive toxicity study was triggered due to a positive outcome in the H295R assay was also included. Quality control acceptance criteria were not always achieved, suggesting this assay is challenging to conduct within the guideline specifications. Analysis of test item data demonstrated that pairwise significance testing to controls allowed for overly sensitive statistically significant positive outcomes, which likely contribute to the assay's high positive hit rate. Complementary interpretation criteria (e.g., 1.5-fold change threshold) markedly reduced the rate of equivocal and positive outcomes thus improving identification of robust positive effects in the assay. Finally, a case study (positive H295R outcome and no endocrine adversity in vivo) is presented, which suggests that stricter data interpretation criteria could refine necessary in vivo follow-up testing. Overall, the described additional criteria could improve H295R data interpretation and help inform on how to best leverage this assay for regulatory purposes.


Assuntos
Disruptores Endócrinos , Sistema Endócrino , Linhagem Celular Tumoral , Disruptores Endócrinos/toxicidade
2.
J Heart Lung Transplant ; 42(8): 1093-1100, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37019731

RESUMO

BACKGROUND: The French national protocol for controlled donation after circulatory determination of death (cDCD) includes normothermic regional perfusion (NRP) in case of abdominal organ procurement and additional ex-vivo lung perfusion (EVLP) before considering lung transplantation (LT). METHODS: We made a retrospective study of a prospective registry that included all donors considered for cDCD LT from the beginning of the program in May 2016 to November 2021. RESULTS: One hundred grafts from 14 donor hospitals were accepted by 6 LT centers. The median duration of the agonal phase was 20 minutes [2-166]. The median duration from circulatory arrest to pulmonary flush was 62 minutes [20-90]. Ten lung grafts were not retrieved due to prolonged agonal phases (n = 3), failure of NRP insertion (n = 5), or poor in situ evaluation (n = 2). The remaining 90 lung grafts were all evaluated on EVLP, with a conversion rate of 84% and a cDCD transplantation rate of 76%. The median total preservation time was 707 minutes [543-1038]. Seventy-one bilateral LTs and 5 single LTs were performed for chronic obstructive pulmonary disease (n = 29), pulmonary fibrosis (n = 21), cystic fibrosis (n = 15), pulmonary hypertension (n = 8), graft-versus-host disease (n = 2), and adenosquamous carcinoma (n = 1). The rate of PGD3 was 9% (n = 5). The 1-year survival rate was 93.4%. CONCLUSION: After initial acceptance, cDCD lung grafts led to LT in 76% of cases, with outcomes similar to those already reported in the literature. The relative impacts of NRP and EVLP on the outcome following cDCD LT should be assessed prospectively in the context of comparative studies.


Assuntos
Transplante de Pulmão , Obtenção de Tecidos e Órgãos , Humanos , Estudos Retrospectivos , Preservação de Órgãos/métodos , Perfusão/métodos , Pulmão , Doadores de Tecidos , Morte , Sobrevivência de Enxerto
4.
Cancer Radiother ; 25(6-7): 517-522, 2021 Oct.
Artigo em Francês | MEDLINE | ID: mdl-34175225

RESUMO

The oligometastatic disease concept suggests that patients with a limited number of metastases have a favorable prognosis. Radical local treatment of oligometastatic patients has then increased given developments in imaging (mainly positron emission tomography and brain magnetic resonance imaging) and access to effective and better tolerated treatments. Stereotactic radiotherapy has the advantage of being noninvasive, allowing a good rate of local control and a limited number of side effects. A better definition of oligometastatic disease, particularly for non-small cell lung cancer (NSCLC), has recently been published. For patients with NSCLC, two randomized phase II trials also suggested that the addition of a radical local treatment results in encouraging survival data, with a good safety profile. A single-arm phase II finally showed a benefit when combining a radical local treatment with an anti-PD1 immunotherapy. This review describes the definitions of oligometastatic disease, the main prospective findings including radiation therapy, and prospects for oligometastatic NSCLC patients.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/radioterapia , Radiocirurgia , Anticorpos Monoclonais Humanizados/uso terapêutico , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/secundário , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/secundário , Ensaios Clínicos Fase II como Assunto , Humanos , Inibidores de Checkpoint Imunológico/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Imageamento por Ressonância Magnética , Cuidados Paliativos , Tomografia por Emissão de Pósitrons , Prognóstico , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
5.
Diagn Interv Imaging ; 102(1): 19-26, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33020025

RESUMO

PURPOSE: The purpose of this study was to compare efficacy and tolerance between radiofrequency ablation (RFA) and surgery for the treatment of oligometastatic lung disease. MATERIALS AND METHODS: This retrospective study reviewed patients treated in two institutions for up to 5 pulmonary metastases with a maximal diameter of 4cm and without associated pleural involvement or thoracic lymphadenopathy. Patient demographics, tumor characteristics, treatment outcome, and length of hospital stay were compared between the two groups. Efficacy endpoints were overall survival (OS), progression-free survival (PFS) and pulmonary or local tumor progression rates. RESULTS: Among 204 patients identified, 78 patients (42 men, 36 women; mean age, 53.3±14.9 [SD]; age range: 15-81 years) were treated surgically, while 126 patients (59 men, 67 women; mean age, 62.2±10.8 [SD]; age range: 33-80 years) were treated by RFA. In the RFA cohort, patients were significantly older (P<0.0001), with more extra-thoracic localisation (P=0.015) and bilateral tumour burden (P=0.0014). In comparison between surgery and RFA cohorts, respectively, the 1- and 3-year OS were 94.8 and 67.2% vs. 94 and 72.1% (P=0.46), the 1- and 3-year PFS were 49.4% and 26.1% vs. 38.9% and 14.8% (P=0.12), the pulmonary progression rates were 39.1% and 56% vs. 41.2% and 65.3% (P>0.99), and the local tumour progression rates were 5.4% and 10.6% vs. 4.8% and 18.6% (P=0.07). Tumour size>2cm was associated with a significantly higher local tumor progression in the RFA group (P=0.010). Hospitalisation stay was significantly shorter in the RFA group (median of 3 days; IQR=2 days; range: 2-12 days) than in the surgery group (median of 9 days; IQR=2 days; range: 6-21 days) (P<0.01). CONCLUSION: RFA should be considered a minimally-invasive alternative with similar OS and PFS to surgery in the treatment of solitary or multiple lung metastases measuring less than 4cm in diameter without associated pleural involvement or thoracic lymphadenopathy.


Assuntos
Ablação por Cateter , Neoplasias Hepáticas , Neoplasias Pulmonares , Ablação por Radiofrequência , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Neoplasias Hepáticas/cirurgia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento , Adulto Jovem
6.
Cancer Radiother ; 24(1): 67-72, 2020 Feb.
Artigo em Francês | MEDLINE | ID: mdl-32037126

RESUMO

Concomitant radiochemotherapy has been the standard of care for unresectable stage III non-small cell lung cancer (NSCLC), irrespective of histological sub-type or molecular characteristics. Currently, only 15-30 % of patients are alive five years after radiochemotherapy, and this figure remains largely unchanged despite multiple phase III randomised trials. In recent years, immune-checkpoint blockades with anti-PD-(L)1 have revolutionised the care of metastatic NSCLC, becoming the standard front- and second-line strategy. Several preclinical studies reported an increased tumour antigen release, improved antigen presentation, and T-cell infiltration in irradiated tumours. Immunotherapy has therefore recently been evaluated for patients with locally advanced stage III NSCLC. Following the PACIFIC trial, the anti-PD-L1 durvalumab antibody has emerged as a new standard consolidative treatment for patients with unresectable stage III NSCLC whose disease has not progressed following concomitant platinum-based chemoradiotherapy. Immunoradiotherapy therefore appears to be a promising association in patients with localised NSCLC. Many trials are currently evaluating the value of concomitant immunotherapy and chemoradiotherapy and/or consolidative chemotherapy with immunotherapy in patients with locally advanced unresectable NSCLC.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/terapia , Anticorpos Monoclonais/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/imunologia , Quimioterapia Adjuvante , Ensaios Clínicos como Assunto , Humanos , Neoplasias Pulmonares/imunologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Radioterapia Adjuvante
7.
Rev Mal Respir ; 36(4): 519-526, 2019 Apr.
Artigo em Francês | MEDLINE | ID: mdl-31010758

RESUMO

Lung cancer is the leading cause of cancer-related mortality and more than half of the cases are diagnosed at a metastatic stage. Major progress in terms of systemic treatments has been achieved in recent decades. Access to new anti-PD-(L) 1 immunotherapies and targeted therapies for non-small cell lung cancer (NSCLC) with oncogenic addiction such as EGFR mutation or ALK rearrangement have led to improved outcomes. Patients with limited progression of their disease during systemic treatment may be a particular subgroup. This oligoprogressive state is characterized by a limited number of sites in progression, implying that the other sites remain controlled and therefore sensitive to systemic treatments. The advent of non-invasive techniques such as stereotactic radiotherapy, radiofrequency, and mini-invasive surgery has led to a precise re-evaluation of local ablative treatments in this situation. Local treatment of the oligoprogressive lesion(s) may allow modification of the natural history of the disease, maintenance of effective systemic targeted treatment and, ultimately, to improved survival. Data validating an aggressive local therapeutic approach in oligoprogressive NSCLC patients are currently limited and essentially retrospective. Several international trials are underway that could confirm the clinical benefit of radical local treatment in oligoprogressive advanced NSCLC patients.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Comportamento de Escolha , Terapia Combinada , Progressão da Doença , Humanos , Estadiamento de Neoplasias , Pneumonectomia/métodos , Inibidores de Proteínas Quinases/uso terapêutico , Radiocirurgia/métodos , Radioterapia/métodos
8.
Ann Cardiol Angeiol (Paris) ; 67(6): 482-488, 2018 Dec.
Artigo em Francês | MEDLINE | ID: mdl-30463686

RESUMO

AIM OF THE STUDY: To establish efficacy and security of invasive treatments for chronic thromboembolic pulmonary hypertension (CTEPH) in elderly patients (≥80 years old): pulmonary endarterectomy (PEA) and balloon pulmonary angioplasty (BPA). PATIENTS AND METHODS: Between 2014 and 2017, 549 CTEPH patients were addressed to our hospital for PEA (364 patients) or BPA (225). From this total, patients 80 years old and over were: 17 treated by PEA and 21 by BPA. Demographic characteristics as well as hemodynamic parameters, results and complications were compared for both groups (Young - Y - versus Old - O). RESULTS: Elderly BPA patients presented a higher functional class (mean O: 3,16 versus Y: 2,73; P=0,001), with similar hemodynamics parameters compared with the younger patients. Indication for BPA in the elderly was the presence of comorbidities contraindicating surgery in 33% of cases vs. 9,3% in the younger group (P=0,005). Response to treatment was comparable in both groups with significant reductions of mPAP, PVR and improvement of functional class. Complications rate was alike between groups for hemoptysis, reperfusion lesions or mortality, with the exception of a higher incidence of contrast-induced nephropathy, without need for dialysis, in the elderly group (O: 8,4% versus 2,6%; P=0,010). Elderly PEA patients were more often male (O: 76,5% versus Y: 50,1%; P=0,034) and with a lower creatinine clearance (O: 57,6±13,4 versus Y: 72,2±21,2mL/min/m2; P=0,004). Functional class, hemodynamics, surgical times and in-hospital stay was similar between groups. There is a non-significant trend towards higher in-hospital mortality in the elderly group, CONCLUSIONS: In our experience, treatment of CPC PE in elderly patients, either by PEA or BPA is effective with acceptable complication rates.


Assuntos
Angioplastia com Balão , Endarterectomia , Hipertensão Pulmonar/cirurgia , Embolia Pulmonar/cirurgia , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Feminino , Humanos , Hipertensão Pulmonar/complicações , Masculino , Pessoa de Meia-Idade , Embolia Pulmonar/complicações
9.
PLoS One ; 10(6): e0131940, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26121334

RESUMO

OBJECTIVE: Pulmonary artery smooth muscle cells (PA-SMCs) in pulmonary arterial hypertension (PAH) show similarities to cancer cells. Due to the growth-suppressive and pro-apoptotic effects of p53 and its inactivation in cancer, we hypothesized that the p53 pathway could be altered in PAH. We therefore explored the involvement of p53 in the monocrotaline (MCT) rat model of pulmonary hypertension (PH) and the pathophysiological consequences of p53 inactivation in response to animal treatment with pifithrin-α (PFT, an inhibitor of p53 activity). METHODS AND RESULTS: PH development was assessed by pulmonary arterial pressure, right ventricular hypertrophy and arterial wall thickness. The effect of MCT and PFT on lung p53 pathway expression was evaluated by western blot. Fourteen days of daily PFT treatment (2.2 mg/kg/day), similar to a single injection of MCT (60 mg/kg), induced PH and aggravated MCT-induced PH. In the first week after MCT administration and prior to PH development, p53, p21 and MDM2 protein levels were significantly reduced; whereas PFT administration effectively altered the protein level of p53 targets. Anti-apoptotic and pro-proliferative effects of PFT were revealed by TUNEL and MTT assays on cultured human PA-SMCs treated with 50 µM PFT. CONCLUSIONS: Pharmacological inactivation of p53 is sufficient to induce PH with a chronic treatment by PFT, an effect related to its anti-apoptotic and pro-proliferative properties. The p53 pathway was down-regulated during the first week in the rat MCT model. These in vivo experiments implicate the p53 pathway at the initiation stages of PH pathogenesis.


Assuntos
Hipertensão Pulmonar/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/efeitos dos fármacos , Benzotiazóis/farmacologia , Proliferação de Células/efeitos dos fármacos , Humanos , Hipertensão Pulmonar/induzido quimicamente , Hipertensão Pulmonar/genética , Hipertrofia Ventricular Direita/metabolismo , Masculino , Monocrotalina/toxicidade , Ratos , Ratos Wistar , Tolueno/análogos & derivados , Tolueno/farmacologia , Proteína Supressora de Tumor p53/genética
10.
Rev Mal Respir ; 28(2): 139-51, 2011 Feb.
Artigo em Francês | MEDLINE | ID: mdl-21402229

RESUMO

INTRODUCTION: Pulmonary arterial hypertension (PAH) is a severe disease that has undergone a dramatic improvement in therapeutic management over the past 20 years. Among the new therapeutic options, surgery has the potential to dramatically improve or, in some cases, cure PAH. BACKGROUND: Surgical treatment of PAH includes pulmonary endarterectomy which can cure PAH when the cause is obstruction of the pulmonary arteries by fibrous tissue resulting from pulmonary embolism, by tumours as angiosarcomas, and echinococcus cysts. Transplantation is required in end-stage PAH after failure of medical treatment. Atrial septostomy and Potts procedure are palliative surgical procedures that can delay transplantation. VIEWPOINT: Extracorporeal cardiopulmonary support is the latest surgical improvement, not only as a bridge to transplantation in end-stage PAH but also during recovery after transplantation or pulmonary endarterectomy. CONCLUSIONS: Surgery is part of the therapeutic management of PAH. Dialogue between physicians and surgeons is a prerequisite for any reasoned therapeutic decision.


Assuntos
Hipertensão Pulmonar , Endarterectomia , Circulação Extracorpórea , Hipertensão Pulmonar Primária Familiar , Transplante de Coração , Humanos , Hipertensão Pulmonar/cirurgia , Transplante de Pulmão , Seleção de Pacientes , Cuidados Pós-Operatórios
11.
J Cardiovasc Surg (Torino) ; 50(3): 391-4, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18948876

RESUMO

Celiac artery aneurysms are rare but potentially fatal because of the risk of rupture. Atherosclerosis and fibrous dysplasia are the two most common etiologies. Median arcuate ligament compression of the celiac artery is common but usually asymptomatic. We report three cases of post-stenotic celiac artery aneurysm with median arcuate ligament compression admitted to our hospital over the past two years. Although the incidence is rare with only 8 cases reported in the literature, a median arcuate ligament may have a role in the development of celiac artery aneurysms and its presence can influence the surgical strategy.


Assuntos
Aneurisma/cirurgia , Arteriopatias Oclusivas/complicações , Artéria Celíaca/cirurgia , Ligamentos , Procedimentos Cirúrgicos Vasculares , Idoso , Anastomose Cirúrgica , Aneurisma/diagnóstico por imagem , Aneurisma/etiologia , Arteriopatias Oclusivas/diagnóstico por imagem , Arteriopatias Oclusivas/cirurgia , Artéria Celíaca/diagnóstico por imagem , Constrição Patológica , Artéria Hepática/cirurgia , Humanos , Ligamentos/diagnóstico por imagem , Ligadura , Masculino , Pessoa de Meia-Idade , Reimplante , Veia Safena/transplante , Artéria Esplênica/cirurgia , Tomografia Computadorizada por Raios X , Resultado do Tratamento
12.
Eur Respir J ; 32(2): 513-6, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18669791

RESUMO

Once the diagnosis of pulmonary arterial hypertension is established, wheezing and chronic cough are rarely described during the course of the disease. The present study reports on two nonsmoking patients with severe pulmonary arterial hypertension, confirmed by right-heart catheterisation, who developed chronic cough, wheezing and irreversible obstructive lung disease masquerading as adult-onset severe refractory asthma. In both cases, extrinsic proximal airway obstruction by dilated pulmonary arteries was demonstrated by fibreoptic bronchoscopy and computed tomography of the chest. The present observations add dilatation of the central pulmonary arteries with compression of the mainstem bronchi to the list of masqueraders of asthma in patients with pulmonary arterial hypertension.


Assuntos
Asma/diagnóstico , Hipertensão Pulmonar/diagnóstico , Pneumopatias/diagnóstico , Adulto , Brônquios/metabolismo , Broncoscopia/métodos , Cateterismo Cardíaco , Tosse/diagnóstico , Diagnóstico Diferencial , Humanos , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Circulação Pulmonar
13.
Thorac Cardiovasc Surg ; 55(1): 39-43, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17285472

RESUMO

OBJECTIVE: Mediastinal goiters are frequently diagnosed, particularly in the elderly population. However, factors associated with an increased risk of median sternotomy have not been analyzed systematically. METHODS: Between 1980 and 2004, a total of 185 patients underwent surgery for mediastinal goiters in our institution. There were 126 women and 59 men with a median age of 68 years (range 24 to 94 years). The goiters were left-sided in 77 patients, right-sided in 69 patients, and bilateral in 39 patients. RESULTS: Clinical presentation was mainly dyspnea (37 %), palpation of a cervical mass (35 %), superior vena cava syndrome (5 %), dysphagia (4 %) and dysphonia (4 %). Goiters measured between 5 and 23 cm (median 10 cm) and were prevascular (38 %), retrovascular and paratracheal (33 %), and retrotracheal (27 %). Aberrant intrathoracic goiters were observed in 4 patients (2 %). The large majority of goiters could be removed transcervically, regardless of the location and extension of the goiters. A sternotomy was required in 13 patients (6 %), mainly because of recurrent goiter ( P = 0.1), ectopic goiter ( P < 0.001), or invasive carcinoma ( P < 0.001). Superior vena cava syndrome, emergent airway compression, dysphagia, retrotracheal goiter, or crossover goiters were not found to be associated with an increased risk of sternotomy. One patient (0.5 %) died postoperatively from massive intraoperative carcinomatous pulmonary emboli. Histology demonstrated a thyroid carcinoma in 18 patients (10 %). CONCLUSIONS: Surgery for mediastinal goiters should always be considered, even in elderly patients because of the high risk of tracheal compression and the low morbidity of the surgery. Most mediastinal goiters are benign and can be removed through a cervical approach. Sternotomy should only be performed in cases of previous cervical thyroidectomy, invasive carcinoma, or ectopic goiter.


Assuntos
Bócio Subesternal/cirurgia , Esterno/cirurgia , Toracotomia/métodos , Tireoidectomia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Bócio Subesternal/diagnóstico por imagem , Humanos , Masculino , Mediastino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Resultado do Tratamento
14.
J Clin Invest ; 86(2): 430-43, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2166755

RESUMO

Acute PTH administration enhances final urine acidification in the rat. HCl was infused during 3 h in rats to determine the parathyroid and renal responses to acute metabolic acidosis. Serum immunoreactive PTH (iPTH) concentration significantly increased and nephrogenous adenosine 3H,5H-cyclic monophosphate tended to increase during HCl loading in intact and adrenalectomized (ADX) rats despite significant increments in plasma ionized calcium. Strong linear relationships existed between serum iPTH concentration and arterial bicarbonate or proton concentration (P less than 0.0001). Serum iPth concentration and NcAMP remained stable in intact time-control rats and decreased in CaCl2-infused, nonacidotic animals. Urinary acidification was markedly reduced in parathyroidectomized (PTX) as compared with intact rats during both basal and acidosis states; human PTH-(1-34) infusion in PTX rats restored in a dose-dependent manner the ability of the kidney to acidify the urine and excrete net acid. Acidosis-induced increase in urinary net acid excretion was observed in intact, PTX, and ADX, but not in ADX-thyroparathyroidectomized rats. We conclude that (a) acute metabolic acidosis enhances circulating PTH activity, and (b) PTH markedly contributes to the renal response against acute metabolic acidosis by enhancing urinary acidification.


Assuntos
Acidose/sangue , Rim/fisiopatologia , Hormônio Paratireóideo/sangue , Acidose/fisiopatologia , Adrenalectomia , Amônia/urina , Animais , Bicarbonatos/sangue , Cálcio/sangue , AMP Cíclico/metabolismo , Taxa de Filtração Glomerular , Concentração de Íons de Hidrogênio , Magnésio/sangue , Masculino , Fosfatos/urina , Ratos , Ratos Endogâmicos , Fatores de Tempo
15.
Am J Physiol ; 248(1 Pt 2): F100-3, 1985 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2982273

RESUMO

Volume expansion inhibits the proximal reabsorption of water, bicarbonate, and chloride. The present work tested a hypothetical role of parathyroid hormone (PTH) in the expansion effect. We studied 19 Sprague-Dawley rats during a plasma-replete euvolemic state and following 10% body wt colloid-free expansion. In group I, six intact rats, volume expansion decreased plasma ionized calcium concentration ([Ca2+]P) from 2.28 +/- 0.06 to 2.11 +/- 0.04 meq/liter and increased nephrogenous cAMP (NcAMP) from 29 +/- 5 to 66 +/- 10 pmol X min-1 X g kidney wt-1. In group II, six acutely thyroparathyroidectomized (TPTX) rats, [Ca2+]P also fell from 2.18 +/- 0.08 to 1.80 +/- 0.08 meq/liter but NcAMP did not rise significantly (9 +/- 3 vs. 17 +/- 5 pmol X min-1 X g kidney wt-1). These data strongly suggest that stimulation of PTH activity occurred during expansion in intact animals. In group III, seven TPTX rats, volume expansion inhibited proximal reabsorption of total CO2 by 11%, of chloride by 24%, and of water by 19%. Volume expansion-induced reduction in bicarbonate, chloride, and water reabsorption was smaller in TPTX than in intact rats previously studied. We conclude that volume expansion inhibits proximal reabsorption in part by decreasing the active transcellular NaHCO3 and NaCl transport secondary to stimulation of PTH activity.


Assuntos
Espaço Extracelular/efeitos dos fármacos , Soluções Isotônicas/farmacologia , Túbulos Renais Proximais/metabolismo , Hormônio Paratireóideo/fisiologia , Absorção , Animais , Bicarbonatos/farmacologia , Cálcio/metabolismo , AMP Cíclico/biossíntese , Taxa de Filtração Glomerular , Masculino , Néfrons/metabolismo , Glândulas Paratireoides/fisiologia , Ratos , Ratos Endogâmicos , Solução de Ringer , Tireoidectomia
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