Influence of valve replacement on plasma endothelin-1 level in mitral stenosis.

BACKGROUND AND AIM OF THE STUDY: The rise of pressure in the pulmonary circulation during the course of mitral stenosis leads to pathomorphological changes and a reduction in vascular compliance. Endothelial dysfunction is also promoted, with increased expression of endothelin. This aim of this study was to evaluate whether the increase in endothelin-1 levels in pulmonary hypertension due to advanced mitral stenosis is reversible after valve replacement. METHODS: Thirty-nine patients with isolated, longlasting post-rheumatic mitral stenosis were enrolled. During preoperative Swan-Ganz catheterization blood samples were withdrawn from the pulmonary artery and capillaries for measurement of endothelin-1 (ET-1). Similar examinations were performed six months after mitral valve replacement. Hemodynamic parameters were measured also during 25-W exercise effort. RESULTS: The mean preoperative hemodynamic parameters of the pulmonary circulation were moderately increased. Mean plasma levels of ET-1 were about three-fold higher than normal. Capillary levels of ET-1 were significantly higher than those in the pulmonary artery (1.78+/-1.22 versus 1.03+/-1.16 pg/ml, p <0.05). There was no significant correlation between ET-1 level and any hemodynamic or clinical parameters, except NYHA functional class. After surgery, pulmonary capillary levels of ET-1 fell significantly, but were still high (1.78+/-1.22 versus 1.41+/-1.00 pg/ml); ET-1 levels in the pulmonary artery were unchanged. Patients with persistently high ET-1 levels had significantly worse exercise hemodynamic parameters, especially of pulmonary arterial compliance. CONCLUSION: In patients with long-lasting, severe mitral stenosis, ET-1 levels remained increased and the ET-1 concentration gradient across the pulmonary circulation persisted for six months after valve replacement. High ET-1 capillary levels are correlated with poor exercise tolerance and poor exercise compliance of the pulmonary vessels.

Valve replacement for aortic stenosis with severe congestive heart failure and pulmonary hypertension.

BACKGROUND AND AIMS OF THE STUDY: Significant pulmonary hypertension in aortic stenosis is evidence of severe dysfunction of the left ventricle. It is also a predictor of a bad prognosis in the natural course of the disease. This study was performed to evaluate the changes in the hemodynamic parameters of pulmonary circulation at rest and effort in patients who had significant pulmonary hypertension preoperatively and underwent valve replacement. MATERIALS AND METHODS: The study consists of 11 male patients with aortic stenosis with an average peak transvalvular gradient of 68 mmHg and impaired left ventricular function (mean ejection fraction 38%). Six patients were in NYHA functional class III, and five were in class IV. The patients underwent Swan-Ganz catheterization before urgent valve replacement. RESULTS: Significant pulmonary hypertension was found in all subjects, and a below normal cardiac index in eight. Urgent valve replacement was performed in all patients: two of them were operated on during pulmonary edema and cardiogenic shock which developed soon after diagnosis-one of them died. Patients were followed up six months after surgery, and all of them showed major clinical improvement (six in NYHA class I, four in class II). Mean pulmonary artery systolic pressure dropped from 77 mmHg preoperatively to 32 mmHg, and the pulmonary artery mean pressure from 47 mmHg to 17 mmHg, pulmonary wedge pressure from 32 mmHg to 9 mmHg, and pulmonary vascular resistance from 4.74 to 1.8 Wood units. The cardiac index came back to normal in all patients (2.18 vs. 3.0 l/min/m2). Swan-Ganz catheterization was also performed during exercise (work load; 50 Watts in three patients, 100 Watts in six patients). The reaction of the hemodynamic parameters on exercise in most patients was almost normal. CONCLUSION: Our data indicate that in aortic stenosis, even with severe left heart failure, pulmonary hypertension can be fully reversible and a significant improvement in both rest and effort hemodynamic parameters can be expected.

[Correlation of selected hemodynamic parameters of pulmonary circulation and indices of pulmonary function in patients with mitral stenosis]. / Zaleznosc wybranych parametrów hemodynamiczynych krazenia plucnego i wskazników mechaniki oddychania u chorych z dominujacym zwezeniem lewego ujscia zylnego.

The aim of this study was to test if the lung compliance and other indices of pulmonary function correlated with hemodynamic parameters in patients with secondary pulmonary hypertension due to mitral stenosis. 36 patients (mean age 50 years) with mitral stenosis (mean mitral valve area-1.2 cm2), without history of lung diseases were analyzed in the study. 16 patients (group A) were in the II-nd and 20 patients (group B) were in the III-rd and IV-th NYHA class. All patients underwent Swan-Ganz catheterization with evaluation of pulmonary pressures, resistances and pulmonary veins compliance. Pulmonary function tests (spirometry, plethysomography, lung compliance) were also performed. In both analyzed groups the pulmonary artery pressure and pulmonary vein compliance correlated significantly with pulmonary compliance.

Prognostic significance of changes in the compliance of the pulmonary venous system after isosorbiddinitrate in patients with mitral stenosis.

It is agreed that a stiff pulmonary venous bed can cause severe pulmonary hypertension. This condition can also influence the clinical and hemodynamic outcome of mitral valve replacement (MVR). This study has been aimed at assessing whether changes in the pulmonary venous compliance (PVcomp) after application of isosorbiddinitrate (ISDN) can be of prognostic value in patients 6 months after MVR. PVcomp was calculated according to the Hirakawa equation in 34 patients with isolated mitral stenosis (MS) before and after ISDN. In 19 patients (group I) there was an increase of PVcomp by more than 15% (5.3 vs. 8.1 ml/mmHg), while 15 patients (group II) showed no differences in PVcomp after ISDN, despite the significant decrease in PAP and PWP in both groups (measured with the use of Swan-Ganz thermodilution catheters). Six months after MVR a significant decrease in PAP, PWP, PVR and an increase in SVI was observed in both groups during rest. During effort (25 W), significant increases in PAP and PWP were recorded in most of patients from the group II, as opposed to group I. It is concluded that significant increase in PVcomp after ISDN in patients with MS can be a prognostic of good clinical results 6 months after MVR.

[Evaluation of changes in pulmonary vein compliance in prognosis of clinical results after mitral valve replacement]. / Ocena zmian podatnosci zylnego systemu plucnego w prognozowaniu efektów klinicznych wymiany zastawki mitralnej.

Irreversible decrease in pulmonary venous compliance (PVcomp) can influence on the clinical results of mitral valve replacement (MVR). The study has been aimed at assessing whether changes in the PVcomp after the application of isosorbiddinitrate (ISDN) can be of prognostic significance in pts with mitral stenosis (MS). Right heart catheterization was performed with 34 pts with MS using a Swan-Ganz catheter in supine position, before and after the application of ISDN. Pulmonary artery pressure (PAP), pulmonary wedge pressure (PWP), stroke volume index (SVI), pulmonary vascular resistance (PVR) and heart rate (HR) were calculated according to standard formulas: PVcomp was calculated according to Hirakawa equation. The whole group was divided into 2 subgroups: I--increase of PVcomp after ISDN > 15% (19 pts), II--decrease or no change of PVcomp after ISDN (15 pts). ISDN increased PVcomp from 5.27 to 8.08. ml/m3 in group I, and decrease from 6.74 to 6.31 ml/m3 in group II. There were no differences between both groups during rest and effort before MVR. Six months after MVR decrease in PAP, PWP, PVR and increase in SVI was observed in both groups, but more significant in group I. However during effort (25 W), significant increases in PAP (21.9 vv 36.5 mmHg), PWP (12.9 vs 24.5 mmHg) and HR (80 vs 98 beat/min) with no improvement of PVcomp (5.82 vs 5.68 ml/m2) were recorded in most of pts from group II as opposed to group I. As can be concluded, significant increase in PVcomp after ISDN in pts with MS can be a prognostic of good clinical results after MVR.

[Surgical treatment for mitral valve defects with preponderance of mitral stenosis and high pulmonary vascular resistance. Clinical and hemodynamic observations 6 months after valve replacement]. / Leczenie operacyjne wady mitralnej z przewaga zwezenia i wysokim naczyniowym oporem plucnym. Obserwacje kliniczne i hemodynamiczne w 6 miesiecy od wymiany zastawki.

10 patients with isolated or predominant mitral stenosis (mean mitral valve area 0.9 cm) and high preoperative values of pulmonary vascular resistance (mean 7.2 Wood units) were chosen for further hemodynamic postoperation evaluation. The patients had normal function of the aortic valve and no significant stenosis of coronary arteries. Hemodynamic evaluation was done by floating Swan-Ganz catheter preoperatively at rest and 6 months after mitral valve replacement at rest and during bicycle cycloergometer test in the supine position. Significant improvement in NYHA class was noted. Preoperatively 6 patients were in NYHA III class, 4 in NYHA IV class. After mitral valve replacement 4 patients were in class III and 6 in class II. Before mitral valve replacement only 3 patients were able to perform 25 Watt test. After surgery all except one performed at least 25 W. There was a significant decrease of pulmonary vascular resistance from 7.2 +/- 2.2 preoperatively to 3.1 +/- 1.9 Wood units at rest after the operation. Post operation during exercise pulmonary vascular resistance attained 4.2 +/- 1.9 Wood units. These changes were due to a fall in mean pulmonary artery pressure 49 +/- 13 at rest preoperatively to 25 +/- 6 mm Hg (rest) and 43 +/- 14 mm Hg (23 W) postoperatively and a rise in stroke volume index from 24 +/- 7 ml (m2) beat preoperatively to 32 +/- 9 at rest and 33 +/- 6 (25 W) postoperatively. Despite clinical and hemodynamic improvement there was no full recovery of pulmonary hemodynamics.

Pulmonary hemodynamics at rest and effort, 6 and 12 months after mitral valve replacement: a slow regression of effort pulmonary hypertension.

An analysis of pulmonary hemodynamics in 22 patients with postrheumatic mitral valve disease using a floating Swan-Ganz type catheter at rest and effort in supine cycloergometer test was done before, 6 and 12 months after mitral valve replacement. Pulmonary hemodynamics data were recorded and calculated at rest and during effort. The most significant changes in almost all analyzed parameters occurred between preoperative and 6 month examination values. However further modest changes mainly during effort were observed between the 6-month and 1-year follow-ups. The mean workload during the bicycle ergometer test rose significantly from 22 +/- 26 W before to 48 +/- 20 W at 6 months and 57 +/- 22 W at 12 months after mitral valve replacement (P < 0.005). We noted a significant improvement in functional class 6 months after mitral valve replacement and a further slight improvement 12 months after. There was a small statistically insignificant decrease in systolic pulmonary pressure between 6 and 12 month measurements. Systolic pulmonary pressure at rest dropped slightly from 39.0 +/- 9.4 to 34.6 +/- 9.4 mmHg. During the bicycle test after 3 min (25 W) the decrease of systolic pulmonary pressure between the 6- and 12-month measurements was statistically significant. Systolic pulmonary artery pressure dropped from 61 +/- 12.4 to 50 +/- 12.3 mmHg. At the same time the drop in pulmonary wedge pressure was smaller and statistically not significant. Pulmonary wedge pressure at rest 6 months after mitral valve replacement was 14.3 +/- 6 mmHg, and after 12 months was 12.7 +/- 4.5; at 25 W, 24.6 +/- 6 vs. 22.1 +/- 5.5, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

[Pulmonary venous compliance. Indirect evaluation based on pulmonary capillary pressure registration]. / Podatnosc zylnego lozyska plucnego. Ocena posrednia w oparciu o rejestracje kapilarnego cisnienia plucnego.

The compliance of pulmonary venous system (PV comp) is one of the most important factors influencing left ventricular filling pressure. The decrease of PV comp could be also one of the most important factors promoting secondary pulmonary hypertension. The aim of the study was to assess diagnostic value of PV comp based on some haemodynamic data in patients (pts) with isolated mitral stenosis (MS). PV comp was estimated according to Hirakawa equation (dV/dP = 0.4 * k2 x SV/(v - d), where k2 = 0.075 * PWP + 0.9) in 78 pts with MS, during preoperative right heart catheterisation with Vygon 5155-180 thermodilution catheters. The mean PV comp for the entire group of pts was 4.5 +/- 2.4 ml/mmHg. In pts with atrial fibrillation PV comp was significantly lower as compared with pts on sinus rhythm (3.7 +/- 1.9 vs 6.4 +/- 2.3, p < 0.0001. There was also a significant difference between NYHA I/II vs III/IV class as far as PV comp was concerned (5.1 +/- 2.3 vs 3.9 +/- 2.3, (p < 0.05). In the group with low PV comp less than 4 ml/mmHg pulmonary vascular resistance, RA, PA and amplitude of V-wave of PWP were significantly higher and stroke volume index of RV was lower than in the group with PV comp above 4 ml/mmHg. PWP did not differentiate the analysed groups. A decrease of PV comp is a sign of advanced mitral stenosis.

Influence of isosorbide dinitrate (ISDN) on compliance of the pulmonary venous system.

Irreversible poor pulmonary venous compliance can worsen the natural course of patients with high pulmonary capillary wedge pressure, especially those with mitral stenosis, but nitrates (isosorbide dinitrate--ISDN), which have venodilatory properties, could increase this compliance in most patients. The aim of this study was to assess the hemodynamic effects of ISDN in patients with mitral stenosis, with special emphasis on the pulmonary venous compliance. Pulmonary venous compliance was estimated according to the Hirakawa equation (dV/dp = 0.4 x k2 x sV/(v-d)) in 39 patients with mitral stenosis during preoperative right heart catheterization with Vygon 5155-180 thermodilution catheters at rest and during exercise (25 W) in the supine position. This procedure was repeated after the application of 3.75 mg of Iso-Mack spray. Overall, ISDN increased pulmonary venous compliance significantly both at rest and during exercise (6.0 to 7.5 ml/mmHg and 6.0 to 7.6 ml/mmHg, respectively). The patients were divided into two groups according to their level of ISDN response; those with a good response of an increase of 15% or more in pulmonary venous compliance (Group I), and those with an increase of less than 15% (Group II). There were significant differences between these two groups in stroke volume index and heart rate. In Group I, while the mean right atrial pressure, mean pulmonary artery pressure and mean pulmonary wedge pressure all decreased significantly, there was a simultaneous insignificant decrease in the stroke volume index and an also insignificant increase in the heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of isosorbide dinitrate on pulmonary venous compliance]. / Wplyw dwuazotanu izosorbidu (ISDN) na podatnosc zylnego lozyska plucnego.

Irreversible poor pulmonary venous compliance (PV comp) could worsened natural course of patients (pts) with high pulmonary capillary wedge pressure especially pts with mitral stenosis. Nitrates (isosorbide dinitrate-ISDN) possessing venous dilating action could increase PV comp in most of pts. The main aim of that study was to assess hemodynamic effects of ISDN, in pts with MS, with special emphasis on PV com changes. PV comp was estimated according to Hirakawa equation (dV/dp = 0.4*k2*SV/(v-d) in 35 pts with MS, during preoperative right heart catheterisation with VYGON 5155-180 thermodilution catheters during rest and effort in supine position (25W). The same protocol was performed after Iso-Mack sprawy 3.75 mg. According to the PV comp response to ISDN, pts were divided in two groups: good responders (I)-15% and higher increase in PV comp and poor responders (II). ISDN increased PV comp in the whole group according to the response to ISDN, there were significant differences in stroke volume index (SVI) and heart rate (HR). In the group of good responders mean right atrial pressure (RA), mean pulmonary artery pressure (PAP), mean pulmonary wedge pressure (PWP) decreased significantly with simultaneous slight not significant decrease in SVI and not significant increase of HR. In the group of poor responders SVI decreased significantly by about 20% with significant increase of HR. In conclusion significant decrease in pulmonary pressures (PAP, PWP) in pts with good response to ISDN are secondary to the increase of PV comp, while among poor responders the same effects are due to diminished flow secondary to the decrease of the systemic venous return.

[Effect of improper pulmonary venous compliance on clinical results of mitral valve replacement]. / Wplyw nieprawidlowej podatnosci zylnego systemu plucnego na kliniczne wyniki wymiany zastawki mitralnej.

The pulmonary venous vascular volume and its compliance (PVcomp) are important factors influencing filling of the left ventricle. It seems that a poor PVcomp effects the value and reversibility of secondary pulmonary hypertension. Basing on Hirakawa's method PVcomp (= 0.4'' x SV/V-d) was calculated in 34 patients with isolated mitral stenosis (SM). Basing on the mean value of PVcomp the group was divided into those with poor (< = 4.3 ml/mmHg) and good (4.4 and more ml/mmHg) PVcomp. Prior mitral valve replacement (MVR) the groups did not differ in values of PAP, PWP, SVI, PVR assessed at rest. During exercise (25 Watt) in the supine position significant higher values of PAP and PWP were observed in patients with poor compliance. Six months after MVR the PAP and PWP values normalized in all patients. In the patients with the initial good PVcomp values significantly higher values of SVI and a decrease in PVR was found. During exercise (25 Watts) significantly higher values of PAP and PVR were registered in patients with initial poor PVcomp values. Pulmonary venous compliance may be an independent factors influencing the clinical outcome of mitral valve replacement 6 months after the procedure.

[Factors influencing survival in patients with coronary disease. I. Characteristics of examined patients and survival curves]. / Czynniki wplywajace na przezywalnosc chorych z choroba wiencowa--Czesc I. Charakterystyka badanych chorych i krzywe przezycia.

The group of 683 patients with the significant narrowing (> 70%) of at least one coronary vessel diagnosed by coronarography performed between 1976-1988 in the Institute of Cardiology in Warsaw was followed during one to seven years. The number of patients with a poor left ventricular function was high in the group treated surgically and non surgically. Ejection fraction < 50% was found in 27% and 43% respectively, LVEDP > 12 mmHg (66% and 69%), EDVI > 100 ml/m2 (58% and 70%). Survival curves were calculated in the two different subsets of patients treated surgically and non surgically. Despite some favorite trend toward a better outcome for patients treated surgically the differences were not statistically significant for a whole group. However we showed a significantly higher probability of survival in the subgroup of the three vessel disease treated surgically compared to other treatment. There were no significant differences in survival in patients with one, two, or three vessel disease treated surgically (survival probability of 0.82; 0.78; 0.84 respectively after 7 years). In patients treated non surgically the growing number of diseased vessels worsened the prognosis (survival probability of 0.84; 0.78; 056 respectively). In our observation the differences for better outcome in patients with poor left ventricular function treated surgically did not reach a statistical significance.

[Factors influencing survival in patients with coronary heart disease. II. Multivariate logistic function analysis]. / Czynniki wplywajace na przezywalnosc chorych z choroba wiencowa--Czesc II--Analiza metoda funkcji logistycznej wielu zmiennych.

A group of 683 patients with the significant narrowing (> 70%) of at least one coronary vessel diagnosed by coronarography performed between 1976-1988 in the Institute of Cardiology in Warsaw was followed during one to seven years. Two hundred ninety of them were treated surgically, 393 non surgically. A multivariate logistic function (MLF) analysis of 10 variables is presented obtained from anamnesis and hemodynamic data and their significance upon survival after 2, 4 and 6 years. In the group treated non surgically the number of narrowed vessels was a factor independently significant after 2, 4 and 6 years. After 4 and 6 years the ejection fraction and the left ventricle end diastolic volume index were also significant. In the group treated surgically none of those were significant after 2 years. After 4 and 6 years anamnesis of arterial hypertonia was significant after 6 years also left ventricle end diastolic volume index. Coefficients calculated from multivariate logistic function analysis allow the calculation of probability of survival for an individual patient.

[Causes of occurrence of wave V of pulmonary wedge pressure in patients with acquired heart valve diseases]. / Przyczyny pojawiania sie fali V cisnienia kapilarnego plucnego u chorych z nabytymi zastawkowymi wadami serca.

It is believed that a significant V wave in pulmonary capillary wedge pressure (PWP) is a sign of mitral regurgitation. Of 358 patients with acquired valvular heart disease in 24-cases a significant V wave (15 mm Hg of PWP) was recorded during right heart catheterization. All patients underwent right heart catheterization with a flow- directed, balloon-tipped, thermodilution catheters (Edwards Labs). Mean pulmonary, capillary wedge, and right atrial pressures were monitored and recorded. Cardiac output was determined by thermodilution technique using iced 5% dextrose. After measurements of flow, pulmonary and systemic resistance morphology of V wave from PWP recordings was assessed. We measured dp/dt of the ascending limb of V wave and Libanoff and Rodbard V wave index (dp/dt:CI). Nine patients with significant V wave had no signs of mitral regurgitation and had mainly significant mitral stenosis (group III). Group II (6 patients) consisted of patients with different combinations of acquired left heart valve disease and mitral regurgitation. Group I (9 pts) consisted of patients with isolated mitral regurgitation. There were no differences in right atrial, pulmonary, and capillary wedge pressures, cardiac index, pulmonary and systemic valvular resistance among groups I, II and III. There were significant differences as far as dp/dt V wave was concerned (gr I--136 +/- 31.4, gr II--112.2 +/- 30.7, gr III--72.7 +/- 31.2 mm Hg/s). Libanoff's index of V wave was also significantly different in all three groups--gr I--12.7 +/- 6.2; gr II--8.0 +/- 2.3; gr III--4.8 +/- 1.7 mm Hg/s). It seems that V wave in PWP recordings is not only a sign of mitral regurgitation, but also could be a sign of decreased pulmonary veins compliance.

[Effect of intravenous administration of nitroglycerin and regitine on hemodynamics in mitral valve insufficiency]. / Wplyw dozylnego podania nitrogliceryny i regityny na hemodynamike w niedomykalnosci mitralnej.

During exercise in subjects with congestive heart failure and mitral regurgitation the rise in systemic arterial pressure is usually accompanied by increase in systemic vascular resistance. That could cause decrease of cardiac output not only because of a lack of myocardial reserve, but also because of an increase of mitral regurgitant volume. In such situation decrease in left ventricular preload could further increase the regurgitant volume and cardiac output. Whether changes in pre-or afterload can cause significant changes in mitral regurgitation, nitroglycerin and phentolamine was assessed in that group of patients. 22 patients with significant mitral regurgitation (3+,4+) was randomly divided into two groups. The first one received short intravenous infusion of nitroglycerin at a rate of 170 micrograms/min. The second one received phentolamine intravenously 1-1,5 mg/min. Patients underwent right heart catheterization with Swan-Ganz thermodilution catheter. Mean pulmonary, pulmonary capillary wedge, and right atrial pressure were monitored and recorded. Cardiac output was determined by thermodilution technique using iced 5% dextrose. If there were no contraindications (PWP greater than 30 mm Hg) an effort test was performed (cycloergometer, supine position). The same protocol was repeated during administration of nitroglycerin and phentolamine. Nitroglycerin significantly decreased right atrial and capillary wedge pressure (from 22.9 to 15.6 mm Hg). There were no significant differences in cardiac output, pulmonary and systemic vascular resistance. Pulmonary artery pressure decreased after nitroglycerin but the difference was not significant. All above effects of nitroglycerin persisted during effort. Phentolamine decreased significantly right atrial, pulmonary and capillary wedge pressure with simultaneous increase of cardiac output (30%) and decrease of pulmonary and systemic vascular resistance. In summary, nitroglycerin decreases only symptoms and theoretically could worsen forward flow in patients with mitral regurgitation and heart failure, especially in subjects with a significant increase of systemic vascular resistance during effort.

[Consequences of late diagnosis and long-term conservative treatment of patients with congenital heart defects]. / Konsekwencje póznych rozpoznan oraz wieloletniego zachowawczego leczenia chorych z wrodzonymi wadami serca.

Of adult patients of the Cardiac Defects Clinic, National Institute of Cardiology (in Warsaw) we can distinguish several groups of patients with congenital heart defects among which those who were diagnosed after the age of 18 or those who despite of early and correct diagnosis, not underwent surgery on the childhood due to many reasons. In this paper we analyzed the group of 218 patients treated in our clinic between 1981-1987; 103 women aged 13-64 (mean-32 years) and 115 men aged 15-58 (mean-28 years). We classified congenital heart defects into 6 group: ASD, VSD, Tetralogy of Fallot, Persistent Ductus Arteriosus, Coarctation of Aorta and others (19.2%). We classified the range of health care before admission to our Department into the following categories: cardiosurgery (palliative or total correction); no therapy after congenital heart defects diagnosis; medical treatment after diagnosis; admission to our clinic immediately after the diagnosis of a heart defect. We compared that range of health care with qualifications of our Institute-(1. qualification for operation, 2. contraindication for operation, 3. operation unnecessary as the defect is not significant). We conclude basing on our results that, late diagnosis of a congenital heart defect does not finally effect on cardiosurgery possibilities. the majority of patients with C.H.D. have been waiting for many years for a specialist diagnosis and optimal therapeutic decision. long term conservative therapy of the patients with C.H.D. significantly reduces the changes of surgical correction.

[Effect of padan on active sodium transport in the epithelium of isolated frog skin]. / Wplyw padanu na aktywny transport sodu w nablonku izolowanej skóry zaby.

The effects of " Padan " (hydrochloride of 1.3-di/ carbomylothio /-2-N-dimethylamino/propane/ upon transport capabilities of plasmatic membrane have been checked. The experiment was performed on isolated skin of Rana temporaria frogs. Assessment of transporting activity of membrane in relation to sodium ion involved a method developed by Ussing with so called "short-circuit" technique. The effects of the pesticide on the external and internal surface of the frog's skin have been examined, final concentrations of the compound being 3.4 X 10(-6) M to 3.4 X 10(-3) M. The results indicate that " Padan ", whether administered to the external or internal surface of the membrane, decreases the value of membrane potential and short-circuit current, which is indicative of membrane transport inhibition. The effect varies with pesticide concentration in the medium, though it is statistically significant only in concentration 3.4 X 10(-3) M. On the other hand, membrane resistance usually gets increased as the compound concentration in the medium increases. The results indicate that cellular membrane should be considered while explaining the mechanism of toxic effects of " Padan " upon organism.

Changes in bioelectrical parameters of isolated frog skin epithelium caused by monocrotophos.

The effect of monocrotophos on the bioelectric parameters of frog skin: potential difference (PD), short-circuit current (SCC), the rate of active sodium ion transport, resistance (R), summed ionic permeability, was studied and it was demonstrated that the tested pesticide added to the medium on the external surface of the skin at the concentrations 4.5 X 10(-3)M and 1.1 X 10(-2)M had no significant effects on these parameters. This might have been connected with the presence on the skin surface mechanisms protecting it against the action of this pesticide. After addition to the medium on the internal side of the skin in a higher concentration it produced an irreversible increase in SCC value and decreased tissue resistance. It seems that the most likely cause of the observed changes were disturbances in the molecular structure of the plasma membrane with its stabilization of the sodium channels in the open position.

Effect of certain pesticides on active sodium transport in the epithelium of isolated frog skin.

Investigations were carried out on the effects of several pesticides (Lindan, 2,4-D, p,p-Metoxychlor, Carbaryl, Monolinuron) on the transport ability of the plasma membrane. The experiments were done on isolated skin of the frogs Rana temporaria. The so called short-circuit current technique was used for quantitative evaluation of the transport activity in relation to sodium ions. The effect of the studied substances was studied during 3 hours after their addition to the medium on the external surface of frog skin after a preceding control period of 1-2 hours. A series of long-term experiments was performed also in which the animals were exposed to those pesticides for 14-20 days. The results of the acute experiments failed to demonstrate any significant effect of the studied substances on the plasma membrane, but some weak effects could have been observed in some experiments, at least. The results obtained in the long-term experiment showed that an effect on the plasma membrane could be postulated as regards 2,4-D and Carbaryl. It does not mean, however, that this effect is the only mechanism of the toxic action of these substances on the organism.