26
|
Lequerica JL, O'Connor JE, Such L, Alberola A, Meseguer I, Dolz M, Torreblanca M, Moya A, Colom F, Soria B. A halocin acting on Na+/H+ exchanger of haloarchaea as a new type of inhibitor in NHE of mammals. J Physiol Biochem 2007; 62:253-62. [PMID: 17615951 DOI: 10.1007/bf03165754] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The capability of halocin H6 (a bacteriocin-like protein produced by haloarchaea Haloferax gibbonsii) to inhibit Na+/H+ exchanger (NHE) in mammalian cells and its cardio-protective efficacy on the ischemic and reperfused myocardium were evaluated in the present study. H6 inhibits NHE activity (measured by a flow cytometry method) in a dose-dependent form of cell lines of mammalian origin (HEK293, NIH3T3, Jurkat and HL-1) as well as in primary cell culture from human skeletal muscle (myocytes and fibroblasts). In vivo, an ischemia-reperfusion model in dogs by coronary arterial occlusion was used (two hours of regional ischemia and three hours of reperfusion). In animals treated with halocin H6 there was a significant reduction of premature ventricular ectopic beats and infarct size, whereas blood pressure and heart rate remained unchanged. Up to date, halocin H6 is the only described biological molecule that exerts a specific inhibitory activity in NHE of eukaryotic cells.
Collapse
|
27
|
Alberola A, González AM, Laguna MA, Pulido FJ. Ring Cleavage of N-Alkylisoxazolium Salts by Lithium Dialkylcuprates: Synthesis of β-Enaminoketones. SYNTHETIC COMMUN 2006. [DOI: 10.1080/00397918608057739] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
28
|
Alberola A, Clarke C, Rawson J. [2+2] Photocyclization in a Solid-State Transformation of a TTF-benzonitrile. Org Lett 2006. [DOI: 10.1021/ol062609w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
29
|
Pereda J, Gómez-Cambronero L, Alberola A, Fabregat G, Cerdá M, Escobar J, Sabater L, García-de-la-Asuneión J, Viña J, Sastre J. Co-administration of pentoxifylline and thiopental causes death by acute pulmonary oedema in rats. Br J Pharmacol 2006; 149:450-5. [PMID: 16953192 PMCID: PMC1978439 DOI: 10.1038/sj.bjp.0706871] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Pentoxifylline exhibits rheological properties that improve microvascular flow and it is widely used in vascular perfusion disorders. It also exhibits marked anti-inflammatory properties by inhibiting tumour necrosis factor alpha production. Thiopental is one of the most widely used drugs for rapid induction of anaesthesia. During experimental studies on the treatment of acute pancreatitis, we observed that when pentoxifylline was administered after anaesthesia with thiopental, most of the rats exhibited dyspnea, signs of pulmonary oedema and died. The aim of the work described here was to investigate the cause of the unexpected toxic effect of the combined treatment with thiopental and pentoxifylline. EXPERIMENTAL APPROACH Pulmonary vascular permeability and arterial blood gases were measured, and a histological analysis was performed. The possible role of haemodynamic changes in the formation of pulmonary oedema was also assessed. KEY RESULTS Co-administration of pentoxifylline and thiopental increased pulmonary vascular permeability and markedly decreased arterial pO2, with one third of rats suffering from hypoxemia. This combined treatment caused death by acute pulmonary oedema in 27% of normal rats and aggravated the respiratory insufficiency associated with acute pancreatitis in which the mortality rate increased to 60%. This pulmonary oedema was not mediated by cardiac failure or by pulmonary hypertension. CONCLUSIONS AND IMPLICATIONS Co-administration of pharmacological doses of pentoxifylline and thiopental caused pulmonary oedema and death in rats. Consequently, pentoxifylline should not be administered when anaesthesia is induced with thiopental to avoid any possible risk of acute pulmonary oedema and death in humans.
Collapse
|
30
|
|
31
|
Such L, Rodriguez A, Alberola A, Lopez L, Ruiz R, Artal L, Pons I, Pons ML, García C, Chorro FJ. Intrinsic changes on automatism, conduction, and refractoriness by exercise in isolated rabbit heart. J Appl Physiol (1985) 2002; 92:225-9. [PMID: 11744664 DOI: 10.1152/jappl.2002.92.1.225] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have studied the intrinsic modifications on myocardial automatism, conduction, and refractoriness produced by chronic exercise. Experiments were performed on isolated rabbit hearts. Trained animals were submitted to exercise on a treadmill. The parameters investigated were 1) R-R interval, noncorrected and corrected sinus node recovery time (SNRT) as automatism index; 2) sinoatrial conduction time; 3) Wenckebach cycle length (WCL) and retrograde WCL, as atrioventricular (A-V) and ventriculoatrial conduction index; and 4) effective and functional refractory periods of left ventricle, A-V node, and ventriculoatrial retrograde conduction system. Measurements were also performed on coronary flow, weight of the hearts, and thiobarbituric acid reagent substances and glutathione in myocardium, quadriceps femoris muscle, liver, and kidney, to analyze whether these substances related to oxidative stress were modified by training. The following parameters were larger (P < 0.05) in trained vs. untrained animals: R-R interval (365 +/- 49 vs. 286 +/- 60 ms), WCL (177 +/- 20 vs. 146 +/- 32 ms), and functional refractory period of the left ventricle (172 +/- 27 vs. 141 +/- 5 ms). Corrected SNRT was not different between groups despite the larger noncorrected SNRT obtained in trained animals. Thus training depresses sinus chronotropism, A-V nodal conduction, and increases ventricular refractoriness by intrinsic mechanisms, which do not involve changes in myocardial mass and/or coronary flow.
Collapse
|
32
|
Such L, O'Connor JE, Sáez GT, Gil F, Beltrán JF, Moya A, Alberola A. Flow cytometric analysis of peroxidative activity in granulocytes from coronary and peripheral blood in acute myocardial ischemia and reperfusion in dogs: protective effect of methionine. CYTOMETRY 1999; 37:140-6. [PMID: 10486526 DOI: 10.1002/(sici)1097-0320(19991001)37:2<140::aid-cyto7>3.0.co;2-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Methionine has shown protective effects in experimental models of myocardial infarction and is highly reactive to oxidative compounds produced by polymorphonuclear leukocytes (PMN), which in turn have been associated with myocardial damage. We have investigated the effect of methionine administration on spontaneous leukocyte peroxidative activity in myocardial ischemia and reperfusion. METHODS In anesthetized dogs, with coronary occlusion (90 min) and reperfusion (90 min), PMN activation was measured by flow cytometric determination of H(2)O(2) with dihydrorhodamine 123, and correlated to hemodynamic parameters and infarct presence. To assess a possible direct effect of methionine, H(2)O(2) and superoxide were measured by flow cytometry in dog leukocyte suspensions following in vitro stimulation with f-MLP. RESULTS PMN peroxidative activity in saline-treated dogs increased significantly after coronary occlusion and after reperfusion. These changes were greater in coronary venous blood than in femoral blood. Methionine administration (150 mg/kg, i.v.) before occlusion totally suppressed PMN activation, both after occlusion and reperfusion. CONCLUSIONS PMN are promptly activated in myocardial ischemia, and methionine administration prevents such activation. However, methionine has no direct effect on spontaneous peroxidative activity, and f-MLP induced peroxidative activity. These in vivo effects of methionine, may additionally contribute to explain its protective role in experimental -788-877-7QQ8-8-7-88-8-8778--8Q78-----8--8-Q-7-Q7----- --------------8888 888888-7777777777777777777777777777777----------------888888888888888888 8877777--87--------8-----------------7-8888-887-----------8----8-8-87777 7777777------------------------------------------------------T7OW
Collapse
|
33
|
Cañizares MA, Arnau A, Alberola A, Pérez A, Hostalet F, Montalvá E, Martín E, Cantó A. [Thymoma. A retrospective study]. Arch Bronconeumol 1999; 35:324-8. [PMID: 10439129 DOI: 10.1016/s0300-2896(15)30069-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We review cases of thymic cell tumor treated between January 1991 and March 1998. Nineteen of the 23 cases studied involved thymoma. Eight (42%) were asymptomatic, 4 (21%) were associated with myasthenia gravis and 7 (37%) were symptomatic. The most common symptom was non-specific chest pain, reported by 4 (47%) patients with symptoms. Classifying the cases of thymoma by Masaoka's system, we found that 12 were cases of thymoma in stage I (63.2%), 4 in stage II (21.1%) and 3 in stage III (15.8%). No stage IV patients were treated. Treatment consisted of full exeresis of the tumor in 17 (89.5%) cases, partial resection in one case (5.2%) and biopsy of the tumor in one non-resectable, case. Adjuvant radiotherapy was applied in seven cases. Chemotherapy was not prescribed. With follow-up ranging from 9 to 96 months, half the patients survived 21 months after surgery. Among the surviving patients, mortality was nil at the end of the study. The results of microscopic, cytologic and blood analyses were of scarce value in differentiating between benign and malignant tumors, even though p53 and bcl2 antigen positivity and clinical stage have been related to poor prognosis in recent years.
Collapse
|
34
|
Wilkins FC, Alberola A, Mizelle HL, Opgenorth TJ, Granger JP. Systemic hemodynamics and renal function during long-term pathophysiological increases in circulating endothelin. THE AMERICAN JOURNAL OF PHYSIOLOGY 1995; 268:R375-81. [PMID: 7864231 DOI: 10.1152/ajpregu.1995.268.2.r375] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Although recent studies have reported endogenous plasma endothelin levels to be elevated two- to fivefold in chronic pathophysiological states, whether such an increase in circulating endothelin levels alone can lead to significant long-term alterations in cardiovascular and renal function is not known. The purpose of this study was to examine the long-term systemic hemodynamic and renal effects of a pathophysiological increase in plasma endothelin concentration in chronically instrumented, conscious dogs (n = 7). Infusion of endothelin-1 (2.5 ng.kg-1.min-1) for 8 days increased plasma concentration of immunoreactive endothelin approximately two- to threefold from 6.7 +/- 0.4 to 16.0 +/- 2.2 pg/ml. Mean arterial pressure increased 21% from a control value of 86.7 +/- 2.1 to 105.0 +/- 2.5 mmHg during the endothelin infusion period. Cardiac output averaged 2,200 +/- 205 ml/min during control and fell by 33% on day 4 of endothelin infusion (1,484 +/- 146 ml/min) and was still 14% below control after day 8 of endothelin infusion (1,885 +/- 154 ml/min). Endothelin increased total peripheral resistance from 42.0 +/- 3.1 to 80.3 +/- 9.1 mmHg.l-1.min. Increasing plasma endothelin two- to threefold was associated with an increase in renal vascular resistance and decreases in glomerular filtration rate and renal plasma flow. Endothelin-1 had no long-term effect on plasma renin activity or aldosterone concentration. These data indicate the importance of pathophysiological levels of endothelin in controlling renal and cardiovascular function in chronic conditions. Furthermore, the results indicate that endothelin may play a role as a mediator of chronic hypertension in pathophysiological states associated with endothelial dysfunction.
Collapse
|
35
|
Salazar FJ, Alberola A, Nakamura T, Granger JP. Role of nitric oxide in the renal hemodynamic response to a meat meal. THE AMERICAN JOURNAL OF PHYSIOLOGY 1994; 267:R1050-5. [PMID: 7943415 DOI: 10.1152/ajpregu.1994.267.4.r1050] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Ingestion of a high-protein meat meal results in significant increases in renal plasma flow (RPF) and glomerular filtration rate (GFR). The mechanism involved in this hemodynamic response to the meat meal has not yet been fully elucidated. The present study was designed to test the hypothesis that nitric oxide (NO) is involved in the renal hyperemic responses to a meat meal. To test this hypothesis, renal hemodynamic response to a meat meal (10 g/kg) was determined in conscious, chronically instrumented dogs with (n = 9) and without (n = 7) an intrarenal NO synthesis inhibition with NG-nitro-L-arginine methyl ester (L-NAME, 3 micrograms.kg-1.min-1 intrarenally). Under control conditions, the meat meal resulted in significant renal hyperemia. Three hours after ingestion of the meat meal, GFR (43 +/- 3 to 59 +/- 6 ml/min) and RPF (128 +/- 10 to 160 +/- 17 ml/min) progressively increased by approximately 40 and 25%, respectively. In contrast, pretreatment with intrarenal infusion of L-NAME abolished the GFR (48 +/- 6 to 52 +/- 6 ml/min) and RPF (129 +/- 20 to 121 +/- 17 ml/min) increases induced by the meat meal. Pretreatment with L-arginine (0.5 mg.kg-1.min-1) plus L-NAME (3 micrograms.kg-1.min-1) did not modify the meat meal-induced changes in GFR (41 +/- 4 to 66 +/- 6 ml/min) and RPF (127 +/- 9 to 182 +/- 14 ml/min). In summary, a meat meal in dogs results in marked increases in RPF and GFR. Intrarenal NO synthesis inhibition abolished the RPF and GFR responses to the meat meal.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
36
|
Pinilla JM, Alberola A, González JD, Quesada T, Salazar FJ. Role of prostaglandins on the renal effects of angiotensin and interstitial pressure during volume expansion. THE AMERICAN JOURNAL OF PHYSIOLOGY 1993; 265:R1469-74. [PMID: 8285291 DOI: 10.1152/ajpregu.1993.265.6.r1469] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This study was undertaken to determine, in anesthetized dogs, the role of renal prostaglandins (PG) in mediating the natriuretic response to increased renal interstitial hydrostatic pressure (RIHP) during extracellular volume expansion (ECVE) with isotonic saline. It was also determined if the intrarenal angiotensin II (ANG II) effects during ECVE are potentiated by the inhibition of PG synthesis. ECVE induced similar elevations of RIHP, natriuresis, and fractional lithium excretion in dogs treated (n = 7) and not treated with a PG synthesis inhibitor (n = 5). In other experimental groups, the effects of the intrarenal maintenance of ANG II levels (n = 6) by infusing captopril and ANG II into the right renal artery were compared with those induced by the simultaneous infusion of captopril, ANG II, and a PG synthesis inhibitor (n = 6). In response to ECVE, renal blood flow and glomerular filtration rate were similar in both kidneys when ANG II levels were maintained constant and were significantly higher in the left kidney when ANG II levels were maintained constant and PG synthesis was inhibited in the right kidney. However, when compared with the left kidney, the ECVE-induced increments of natriuresis and RIHP in the right kidney were reduced by the same magnitude when intrarenal ANG II was maintained constant with (36 and 53%, respectively) and without (40 and 54%, respectively) the simultaneous PG synthesis inhibition. Our results indicate that during ECVE, renal PGs do not play an important role in mediating the RIHP-induced increments in natriuresis and decrements in proximal sodium reabsorption. (ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
37
|
Salazar FJ, Alberola A, Pinilla JM, Romero JC, Quesada T. Salt-induced increase in arterial pressure during nitric oxide synthesis inhibition. Hypertension 1993; 22:49-55. [PMID: 8319991 DOI: 10.1161/01.hyp.22.1.49] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The objective of this study was to determine in conscious dogs the role of endothelium-derived nitric oxide in mediating the arterial pressure and renal response to a prolonged increment of sodium intake. After a control period of 3 days, an inhibitor of nitric oxide synthesis, NG-nitro-L-arginine-methyl ester, was infused intravenously during 5 consecutive days (0.1 micrograms/kg per minute). Sodium intake (80 mmol/d) did not change throughout the experiment in one group (n = 4). In another group (n = 6), 1 day after infusion of this inhibitor was started, sodium intake increased from 80 to 300 mmol/d during 4 consecutive days. Inhibition of nitric oxide synthesis in dogs with normal sodium intake induced a significant decrease in natriuresis and diuresis (P < .05) without changes in arterial pressure. However, in dogs treated with the nitric oxide synthesis inhibitor, mean arterial pressure increased from 95.2 +/- 3.3 to 106.2 +/- 4.0 mm Hg (P < .01) the first day that sodium intake was elevated and remained increased the following 3 days. In a different group of dogs (n = 5), the increment of sodium intake during 4 days did not induce changes in arterial pressure when nitric oxide synthesis was not inhibited. Cumulative sodium balance was higher (P < .01) in dogs treated simultaneously with the nitric oxide synthesis inhibitor and high sodium intake (158 +/- 21 mmol sodium) than in those treated only with the nitric oxide synthesis inhibitor (82 +/- 19 mmol sodium) or with high sodium intake (36 +/- 13 mmol sodium).(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
38
|
Quesada A, Sanchis J, Chorro FJ, Burguera MA, Alberola A, Such L, Lopez-Merino V. Changes in canine ventricular fibrillation threshold induced by verapamil, flecainide and bretylium. Eur Heart J 1993; 14:712-6. [PMID: 8508866 DOI: 10.1093/eurheartj/14.5.712] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The changes produced by verapamil, bretylium and flecainide in both ventricular fibrillation threshold (VFT) and ventricular repetitive response threshold (VRRT) were studied in 20 closed-chest dogs anaesthetized with pentobarbital. Right ventricle endocardium thresholds were determined using bipolar electrode catheters. Increasing intensity stimulus trains (200 ms, 4 ms, 100 Hz, 1 mA steps) were delivered 50 ms after QRS; VRRT and VFT were calculated before and after drug administration. Three study groups were considered according to the drug assayed: (1) verapamil 0.15 mg.kg-1 n = 6; (2) flecainide 2.0 mg.kg-1 n = 7, and (3) bretylium 10.0 mg.kg-1 n = 7. Flecainide significantly increased VRRT (4.8 +/- 1.4 vs 9.4 +/- 1.5 mA, P < 0.05), but the latter failed to change in the other two groups. VFT remained unchanged with verapamil, increased slightly post-flecainide (10.3 +/- 4.6 vs 12.4 +/- 4.1, P < 0.05 mA) and markedly post-bretylium (10.3 +/- 4.6 vs 17.3 +/- 7.5, P < 0.05). VFT changes were significantly correlated (r = 0.77, P < 0.05) with the effective refractory period changes in the bretylium group. Thus, of the three drugs tested, bretylium induced the greatest VFT increases without modifying VRRT, whereas flecainide affected both parameters. Only in the bretylium series were ERP changes significantly correlated to the corresponding VFT changes. This suggests that ventricular fibrillation threshold increase is not a non-specific property of antiarrhythmic drugs. Changes in ventricular repetitive response threshold may provide additional information.
Collapse
|
39
|
Such L, Alberola A, Gil F, Bendala E, Viña J, Morcillo EJ. Effect of glutathione on canine myocardial ischaemia without reperfusion. J Pharm Pharmacol 1993; 45:298-302. [PMID: 8098371 DOI: 10.1111/j.2042-7158.1993.tb05556.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The present study was to evaluate the effect of exogenous glutathione on myocardial damage resulting from permanent (no reperfusion) coronary ligation (3 or 6 h) in anaesthetized dogs. Haemodynamics, infarct size and myocardial glutathione content were determined. Erythrocyte superoxide dismutase (SOD) activity was also determined in coronary venous blood samples. Glutathione was administered by the intraperitoneal route, 100 mg kg-1 as initial dose given 5 min before coronary ligation, and successive doses of 25 mg kg-1 every 40 min throughout the study period. Saline-treated dogs showed myocardial infarction, a decrease in myocardial glutathione content, and a transient increase in SOD activity. Three hours occlusion in glutathione-treated dogs resulted in a small reduction of infarct size, and no changes in myocardial glutathione content and SOD activity. By contrast, administration of glutathione failed to reduce infarct size and failed to prevent myocardial glutathione decrease in dogs subjected to 6 h occlusion. These results indicate that exogenous glutathione is of minor beneficial effect for myocardial damage resulting from permanent coronary occlusion and suggest that endogenous glutathione has a limited role in protecting against myocardial ischaemia without reperfusion.
Collapse
|
40
|
Wilkins FC, Alberola A, Mizelle HL, Opgenorth TJ, Granger JP. Chronic pathophysiologic circulating endothelin levels produce hypertension in conscious dogs. J Cardiovasc Pharmacol 1993; 22 Suppl 8:S325-7. [PMID: 7509977 DOI: 10.1097/00005344-199322008-00085] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Although recent studies have reported endogenous plasma endothelin (ET) levels to be elevated two- to fivefold in chronic pathophysiologic states, whether such an increase in circulating ET levels alone can lead to significant long-term alterations in cardiovascular function is not known. The purpose of this study was to examine the long-term systemic hemodynamic effects of a pathophysiologic increase in circulating ET concentration in chronically instrumented, conscious dogs (n = 4). Infusion of endothelin (2.5 ng/kg/min) for 8 days increased plasma concentration of endothelin two- to threefold. ET increased mean arterial pressure from 85 +/- 3 to 103 +/- 3 mm Hg, which was sustained throughout the period of infusion. Total peripheral resistance was increased by approximately 70%. Cardiac output decreased transiently by 25% and remained below control levels at the termination of ET infusion. These data indicate the importance of pathophysiologic levels of ET in controlling systemic hemodynamics in chronic conditions. Furthermore, ET may play a role as a mediator of chronic hypertension in pathophysiologic states associated with endothelial dysfunction.
Collapse
|
41
|
García-Calvo R, Chorro FJ, Sendra M, Alberola A, Sanchis J, Navarro J, Valentín V, López-Merino V, Such L. The effects of selective stellate ganglion manipulation on ventricular refractoriness and excitability. Pacing Clin Electrophysiol 1992; 15:1492-503. [PMID: 1383961 DOI: 10.1111/j.1540-8159.1992.tb02923.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effects of selective stellate ganglion stimulation or stellectomy on ventricular excitability were studied in 30 open chest mongrel dogs anesthetized with alpha-chloralose. The effective refractory period (ERP) and strength interval curves (stimulus intensity [S2] = twice the diastolic threshold [ERP], and 2, 3, 5, 7, and 14 mA) were determined using bipolar epicardial electrodes placed in the mid-anterior wall of the right ventricle (RV) and the mid-posterolateral wall of the left ventricle (LV) during left stellate ganglion stimulation (LSGSt, n = 8) or right stellate ganglion stimulation (RSGSt, n = 8), or after left stellectomy (LSGEx, n = 7) or right stellectomy (RSGEx, n = 7). LSGEx prolonged ERP-LV (172 +/- 9 vs 167 +/- 8 msec, P < 0.05) and ERP-RV (163 +/- 10 vs 158 +/- 14 msec, P < 0.05). RSGEx prolonged ERP-LV (168 +/- 17 vs 162 +/- 15 msec, P < 0.01) and ERP-RV (166 +/- 14 vs 160 +/- 13 msec, P < 0.01), and the times of the strength interval curves obtained for each S2 intensity in both ventricles. LSGSt decreased ERP-LV (157 +/- 11 vs 163 +/- 12 msec, P < 0.01) and ERP-RV (147 +/- 18 vs 157 +/- 17 msec, P < 0.05), and the times of the strength interval curves obtained for each S2 intensity in both ventricles. RSGSt did not significantly decreased ERP-LV (152 +/- 11 vs 156 +/- 9 msec); however, it significantly shortened the times of the strength interval curves obtained for S2 intensities of 2 and 7 mA in the LV, and shortened ERP-RV (139 +/- 10 vs 145 +/- 7 msec, P < 0.01) and the times of the strength interval curve for S2 intensities of 2, 3, and 5 mA in the RV. A significant interaction (MANOVA test) was observed between the ventricle studied and the ganglion stimulated for S2 intensities of 2 and 3 mA, and between the effect of stimulation and the ganglion stimulated for S2 intensities of 3 and 14 mA. To conclude, selective stellectomy prolonged epicardial ventricular refractoriness in both the mid-anterior wall of the RV and the mid-posterolateral wall of the LV; the magnitude of the epicardial excitability variations in both areas was different during selective stellate ganglion stimulation.
Collapse
|
42
|
Pastor J, López M, Pampliega A, Alberola A. Intraocular tolerance and pharmacokinetics of polyanhydrides loaded with 5-fluorouracil. Exp Eye Res 1992. [DOI: 10.1016/0014-4835(92)90766-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
43
|
Alberola A, Pinilla JM, Quesada T, Romero JC, Salom MG, Salazar FJ. Role of nitric oxide in mediating renal response to volume expansion. Hypertension 1992; 19:780-4. [PMID: 1592480 DOI: 10.1161/01.hyp.19.6.780] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The objective of the present study was to determine the role of endothelium-derived nitric oxide in mediating the renal response to extracellular volume expansion with isotonic saline (5% body weight). In anesthetized dogs (n = 7) and before volume expansion, nitric oxide synthesis was inhibited in the right kidney by continuous intrarenal infusion of NG-nitro-L-arginine-methyl ester (1 microgram/kg/min). Arterial pressure and renal hemodynamics of both kidneys did not change significantly either during nitric oxide synthesis inhibition or during 5% volume expansion. However, in response to extracellular volume expansion, increases in natriuresis, diuresis, and fractional excretion of lithium (an index of proximal sodium reabsorption) were inhibited in the right kidney by 27%, 28%, and 41%, respectively, when compared with the contralateral kidney. Increases of renal interstitial hydrostatic pressure during 5% volume expansion were not statistically different between both kidneys. In another group of dogs (n = 4), the administration of L-arginine (0.5 mg/kg/min) into the right renal artery prevented the renal effects induced by the nitric oxide synthesis inhibitor during volume expansion. The findings in this study suggest that nitric oxide production plays an important role in regulating the renal response to extracellular volume expansion. The proximal tubule seems to be involved in the reduced renal excretory response to volume expansion during nitric oxide synthesis inhibition.
Collapse
|
44
|
Alberola A, Such L, Gil F, Zaragoza R, Morcillo EJ. Protective effect of N-acetylcysteine on ischaemia-induced myocardial damage in canine heart. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1991; 343:505-10. [PMID: 1881461 DOI: 10.1007/bf00169553] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The glutathione redox pathway is an important antioxidant system in the myocardium. N-Acetylcysteine is a low molecular weight glutathione precursor that has been used clinically to replenish glutathione stores. The present study was aimed at evaluating the protective effect of N-acetylcysteine on myocardial damage resulting from permanent coronary occlusion (without reperfusion) in anaesthetized dogs. N-Acetylcysteine (150 mg kg-1 i.v.) administered 2 min before occlusion reduced infarct size in dogs subjected to 24 h ischemia. The infarct size as a percentage of the area at risk was 86.8 +/- 3.6% (n = 11) in control (saline-treated) dogs and 68.2 +/- 2.4% (n = 7; P less than 0.05 vs control) in N-acetylcysteine-treated animals. Haemodynamic variables (heart rate, mean arterial pressure and rate-pressure product) were similar in the control and the treated group. Regional myocardial blood flow was determined with radioactive microspheres in ischaemic and non-ischaemic zones before occlusion and 3 h post-occlusion. N-Acetylcysteine did not influence the regional distribution of myocardial blood flow. The myocardial content of reduced glutathione was significantly (P less than 0.05) decreased 3 h post-occlusion (0.53 +/- 0.19 mumol/g-1; n = 5) compared to either pre-occlusion values (0.94 +/- 0.03 mumol/g-1; n = 8) or values 3 h post-occlusion in sham-operated animals (0.93 +/- 0.15 mumol/g-1; n = 5). Depletion of myocardial glutathione 3 h post-occlusion was not observed in dogs treated with N-acetylcysteine (0.87 +/- 0.11 mumol/g-1; n = 5).(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
45
|
Paya R, Chorro FJ, Sanchis J, Alberola A, Dalli E, Lopez-Merino V. Changes in canine ventricular refractoriness induced by trains of subthreshold high-frequency stimuli. J Electrocardiol 1991; 24:63-9. [PMID: 2056269 DOI: 10.1016/0022-0736(91)90082-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Epicardial electrodes were applied to 12 thoractomized dogs to determine the effects of trains of subthreshold conditioning stimuli (TSc) on ventricular refractoriness when delivered preceding a premature suprathreshold stimulus (S2). Several factors were analyzed: (1) the influence of TSc pulse frequency (100-900 Hz); (2) the delay between TSc and S2 (1 or 10 ms); (3) the distance between the electrodes for the emission of TSc and S2 (same electrodes or different electrodes at 3 mm); and (4) S2 current intensity (two- or fourfold diastolic threshold). The TSc (mean current intensity 0.33 mA, range 0.1-0.7) were found to significantly prolong the effective ventricular refractory period (EVRP) at all train pulse frequencies. The EVRP increment was progressively greater as pulse frequency was increased, the maximum EVRP increment being at 900 Hz (mean 50.8 +/- 32.3 ms; maximum increment 130 ms). On increasing S2 current intensity, the EVRP increment was less (maximum value 35 ms) and less consistent (in four of six dogs); in two cases the EVRP was shortened. The increase in delay between TSc and S2 attenuated the EVRP prolongation, which was present in only three of six dogs tested, and the EVRP was shortened in two dogs. There was no EVRP prolongation at any TSc pulse frequency when TSc and S2 were delivered at different electrodes. Thus TSc decreases myocardial ventricular excitability, prolonging EVRP in direct proportion to TSc pulse frequency. However, this property is limited by S2 current intensity as well as the time and distance between TSc and S2.
Collapse
|
46
|
Coronado P, Fernandez-Sanchez C, Rodriguez J, Alberola A. Ziegler-natta polymerization of 3-methoxy-4-phenylbut-1-ene with the heterogeneous catalyst AlEt3-VCl3: influence of pyridine as donor ligand. Eur Polym J 1990. [DOI: 10.1016/0014-3057(90)90053-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
47
|
Chorro FJ, Pardo JD, Sanchis J, López-Merino V, Valentín V, Alberola A, García-Belenguer R. [Experimental study of the effects of ATP on sinus automatism and atrioventricular node conduction]. Rev Esp Cardiol 1989; 42:329-36. [PMID: 2772369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A study was made of 14 thoracotomized dogs under i.v. sodium thiopental anesthesia; the effects of 1.5 mg/kg intravenous ATP on sinus node automatism and atrio-ventricular conduction were investigated. In 7 dogs (group A) ATP was administered under control conditions and following successive intravenous administrations of atropine (1 mg/kg), aminophylline (5 mg/kg) and propranolol (0.6 mg/kg). The remaining 7 dogs (group B) received ATP following atropine (1 mg/kg), isoproterenol (0.4 microgram/kg/min.), and aminophylline (5 mg/kg). An analysis was made of the percentage variations in cardiac cycle length during spontaneous rhythm and of the AH interval during atrial pacing at a fixed rate. In group A the negative dromotropic and chronotropic effects of ATP under control conditions decreased in 5 cases following atropine, although the average decrease was not statistically significant. On adding aminophylline, a statistically significant decrease was observed in the effects of ATP, and following propranolol the drop in negative chronotropic effect of ATP provoked by aminophylline was maintained. In group B, and following prior atropinization, the negative chronotropic and dromotropic effects of ATP were maintained in the presence of isoproterenol. As in group A, aminophylline significantly reduced the effects of ATP. To conclude: in the thoracotomized dog under sodium thiopental anesthesia, 1) atropine does not prevent the negative chronotropic and dromotropic actions of ATP, although the effect of the latter is decreased in a large percentage of cases; 2) sympathetic beta stimulation following prior atropinization does not prevent ATP action; 3) aminophylline in the atropinized dog noticeably reduces the effects of ATP, and 4) this action of aminophylline is effective in the presence of sympathetic beta stimulation.
Collapse
|
48
|
Alberola A, Antolín LF, Cuadrado P, González AM, Laguna MA, Pulido FJ. The Reactions of 3-Unsubstituted Isoxazolium Salts with 1,2-Dinucleophiles. Synthesis of 4-Functionalized 3-Aminoisoxazoles and 3-Aminopyrazoles. SYNTHESIS-STUTTGART 1988. [DOI: 10.1055/s-1988-27512] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
49
|
Romero FJ, Montoro A, Sáez GT, Alberola A, Gil F, Vina J, Such L. Myocardial glutathione alterations in acute coronary occlusion in the dog. FREE RADICAL RESEARCH COMMUNICATIONS 1987; 4:27-30. [PMID: 3506894 DOI: 10.3109/10715768709088085] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Glutathione (GSH) decreases in dog myocardium upon acute coronary occlusion when compared with sham-operated dogs. Total glutathione content (GSHeq = GSH + 2GSSG) remains unchanged throughout the experiment (6 h after surgery) in both sham- and acute coronary occlusion-operated dogs. GSSG and GSH/GSSG ratio increases and decreases respectively in all animals but tends to reach the normal value after 6 h in sham-operated dogs. Both parameters (GSSG and GSH/GSSG ratio) remain altered in acute coronary occlusion-operated ones. This alteration of glutathione status in ischemic myocardium is discussed.
Collapse
|
50
|
Alberola A, Antolin LF, Gonzalez AM, Laguna MA, Pulido FJ. Base-induced ring cleavage of 4-functionalized-3-unsubstituted isoxazoles. Synthesis of 5-aminoazoles and 4-cyanoazoles. J Heterocycl Chem 1986. [DOI: 10.1002/jhet.5570230414] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|