Organization of spontaneous rhythm of the small intestine in healthy individuals and patients with stomach and colorectal cancer.

The distribution of the main frequencies of spontaneous rhythm of the small intestine in the 12.0-8.0 cycle/min range (by the aboral frequency gradient) was studied by the electrogastroenterographic method in healthy individuals and patients with stomach and colorectal cancer before and after gastrectomy and total removal of the large intestine. Organization of spontaneous rhythm of the small intestine on an empty stomach and after mixed food load in healthy individuals and changes in this organization in patients with stomach and colorectal cancer before and after total gastrectomy and complete removal of the large intestine were evaluated. The authors hypothesize that the stomach normally coordinates the small intestinal rhythm, while in stomach cancer this coordination is impaired. Changes in spontaneous rhythm of the small intestine (both in the proximal and distal portions) were detected in patients with colorectal cancer.

Spontaneous activity of the stomach and large intestine in healthy individuals and patients with tumors before and after gastrectomy and colectomy.

We studied the distribution of main frequencies of spontaneous activity (in the range of 2-4 cycles/min) of the stomach and large intestine in healthy individuals and patients with stomach and colon cancer before and after gastrectomy and resection or total colectomy. The rhythm was recorded noninvasively (from body surface) with Ag/AgCl electrodes connected to a 3-channel portable electrogastrograph. We determined general peculiarities of rhythm formation in the stomach and large intestine in healthy individuals on an empty stomach and after mixed feeding and evaluated changes in spontaneous activity in patients with stomach and colon cancer before and after gastrectomy, resection, or total colectomy. Rhythmic activity of the stomach was coordinated with that of the large intestine in healthy individuals, but not in patients with tumors before the start of specific therapy. Multichannel cutaneous electrogastroenterography and recording of spontaneous electrical activity in the epigastric and perianal regions reflect functional relationships between the stomach and large intestine.

[Electrogastrography in diagnosis of ulcerative pyloroduodenal stenosis]. / Elektrogastrografiia v diagnostike iazvennogo piloroduodenal'nogo stenoza.

Skin electrogastrogram was made in 40 healthy controls and 32 patients with ulcerative pyloroduodenal stenosis in fasting condition and after mixed meal. Fasting frequency of gastric bioelectric activity (BA) was similar in the patients and the controls (2.65 +/- 0.008; 2.65 +/- 0.008; p < 0.01). BA frequency unstability factor (FUF) was not so high in patients compared to controls (13.9 +/- 0.07; 15.3 +/- 0.11; p < 0.01). The meal produced a significant rise in the frequency, amplitude and a decrease in FUF of gastric BA in the patients and controls but in patients a fall in FUF was greater. A rise in the amplitude of gastric BA in patients was more pronounced than in controls (250.6 +/- 5.17%, 162.0 +/- 2.23%; p < 0.01). In patients the amplitude increased greater in compensated stenosis, weaker--in decompensated stenosis. The changes in gastric BA amplitude varied with severity of pyloroduodenal stenosis.

[The blocking action of platelet-activating factor (PAF) on the calcium currents of the atrial fibers in the frog and guinea pig]. / Blokiruiushchee deistvie faktora aktivatsii trombotsitov (PAF) na kal'tsievye toki volokon predserdiia liagushki i morskoi svinki.

The effects of platelet-activating factor (PAF) on the myocardial cell membrane Ca-current (ICa) and Ca-action potential (Ca-AP) were investigated. In double sucrose-gap voltage-clamped frog atrial trabeculae PAF (2 X 10(-7) M) reduced ICa-amplitude to 40-50%; at the same time the IK-amplitude was increased to the same value. These changes of ICa and IK amplitudes were protected by simultaneous action of PAF and PAF antagonist BN 52021 (4 X 10(-6) M). In the partially depolarized (K+0 = 15-20 mM) of the guinea pig myocardial auricles PAF decreased Ca-AP amplitude and Vmax of its upstroke and shortened the Ca-AP duration (intracellular microelectrodes) like the isometric tension responses. These effects were prevented by PAF antagonist U-66985. Histamine was also able to protect from the PAF-induced changes of Ca-AP and tension responses. Our data demonstrated both by direct and by indirect methods of ICa registration in myocardia membrane that PAF induces reversed blocking of ICa. Because the blocking effects of PAF on frog and guinea pig myocardium are identical, these results imply that the mechanisms of PAF action on cold- and warm-blooded animals are similar in principle. The coupling of ICa and IK changes confirm our earlier supposition that PAF-induced Ca-AP shorting can be explained by IK augmentation.

[Interactions of PAF and its antagonists in the guinea pig atrial myocardium]. / Vzaimodeistvie PAF i ego antagonistov v miokarde predserdiia morskoi svinki.

The effects of platelet activating factor (PAF) and three its antagonists on the transmembrane intracellular potentials and stimulated (0.5 Hz) contraction amplitude (CA) of the left auricle has been studied. PAF (1-5 X 10(-7) M) was added to the standard Tyrode solution or the same perfusing solution with 15 mM K+, and 6 mM Ca++ (t = 30 degrees C, pH = 7,2). PAF induced the straight cardio-depressing action: the CA always was suppressed during 20 min. The electrical activity was depressed in parallel; in the Tyrode the action potential (AP) duration was lowered, but in the atrial depolarized preparations PAF resulted in a decrease of the slow calcium potential (Ca-AP) amplitude from 100% to 20.2 +/- 2.0%. After 20 min PAF-acting the perfusing solutions contained also one of PAF-antagonists. Antagonist U-66985 led to the weakening of the PAF-depressing effects in the myocardium U-66985 is also able to increase electrical and mechanical activity in myocardium depressed by the blood serum from patients with virulent infections.

[Cardiodepressive effect of platelet activating factor]. / Issledovanie kardiodepressornogo deistviia faktora aktivatsii trombotsitov.

The cardiodepressive effect of PAF has been studied on the electrical and mechanical activities of isolated auricles of guinea pig. Intracellular resting potential, action potential (AP) and isometric contractions elicited by electrical stimulation (0.5 Hz) were measured. PAF (10(-7) M) induced negative inotropic effect, which reached its peak after 5 min with 23.5 +/- 6.6% in respect to prechallenge values (n = 8). After 20 min negative inotropic effect relaxed to 39.6 +/- 8.8%. 1 min after the beginning of washing in Tyrode solution, positive inotropic effect of PAF was evident, that reached its peak (217 +/- 49.5%) after 2 min, decayed after 5-10 min to normal values. PAF did not modify the resting membrane potential, produced a decrease in the amplitude and Vmax of the upstroke AP, shortened the AP duration. Ca-AP and contractions, elicited in partially depolarized myocardium were decreased by PAF (10(-7) M). PAF-produce the change of the AP and the negative effect on auricle contractile force was inhibited in muscles pretreated with 3mM 4 aminopyridine. Histamine (10(-4) M) was also capable of neutralizing the depressant effect of PAF. The obtained results suggested that PAF effects on the membrane of cardiac cells could be related to a change in Ca and K conductance.

[Cardiodepressive effect of blood serum in severe forms of purulent infection]. / Kardiodepressornoe deistvie syvorotki krovi pri tiazhelykh formakh gnoinoi infektsii.

The effect of human blood serum from patients with purulent infections (sepsis, purulent resorptive fever) has been studied on the electrical and mechanical activities of isolated auricles of guinea pig. The intracellular resting potentials (RP), action potentials (AP) and isometric contractions elicited by electrical stimulation (1 Hz) were measured. The patient serum diluted by Tyrode solution (1:1) didn't change RP values and AP amplitude but caused a decrease in the AP plateau phase duration (P less than less than 0.05). In 75% cases a replacement of the healthy donor serum by the serum from patients caused a decrease in the contraction amplitude. This cardiodepressive effect was reversible: washing of the preparation by the control Tyrode solution or by the donor serum restored the normal contractility. These data were compared with those obtained in studying the action of staphylococcus alpha-toxin on a preparation of guinea pig myocardium]

[Intensification of human myocardial contractile activity as affected by blood serum]. / Usilenie sokratitel'noi aktivnosti miokarda cheloveka pod vliianiem syvorotki krovi.

The effect of human serum diluted in Tyrode solution (1:1) on the cardiac contractility has been studied. Fragments of the right auricle myocardium from patients with congenital and acquired heart disease have been used to study serum effect on the contraction force. Myocardial strips were repeatedly stimulated with electrical impulses at a frequency of 0.1 to 1.5 Hz. All the perfusion solutions were maintained at 31-33 degrees C and Ca++ ion concentration was 2 +/- 0.2 mM/l. The serum increased the contraction force in the isolated myocardial fibers from patients with congenital and acquired heart disease. Positive inotropic serum action on the myocardium of patients with acquired heart disease was accompanied by a marked diminution of mechanical oscillations. At the same time human serum does not affect the form of force-frequency curves in both types of the preparations. The results suggest that human serum increases calcium ion homeostasis in the cardiac cells of patients during contraction-relaxation cycle.

[Role of K+, Na+, and Ca2+ ions in the cardiodepressive action of blood plasma in burn shock and the crush syndrome]. / Rol'ionov K+, Na+ i Ca2+ v kardiodeppressornom deistvii plazmy krovi pri ozhogovm shoke i sindrome dlitel'nogo razdavlivaniia.

Ion-selective electrodes were employed to measure the concentration of K+, Na+ and Ca2+ in blood plasma of rabbits with burn shock or crush syndrome (CS). No significant changes in the plasma concentration of Na+, and Ca2+ were found under both pathological conditions. The plasma concentration of K+ in burn shock significantly increased from 3.06 +/- 0.73 (control) to 5.28 +/- 2.65 mM (n = 10), whereas in CS from 3.42 +/- 1.03 to 4.92 +/- 1,29 mM (n = 8). The rise of K+ concentration in the control plasma to the maximal values seen in the "burn" and "syndrome" plasma led to an increase in the duration of intracellular action potentials (AP) but did not substantially change the amplitude of isometric contractions of the papillary muscles of rabbit heart. Meanwhile the similar rise of the duration of intracellular AP during perfusion of the papillary muscles with the "burn" and "syndrome" plasma was accompanied by an appreciable drop of the amplitude of isometric contractions. It is suggested that elevation of K+ concentration in blood plasma, inducing an increase in the duration of intracellular AP of cardiocytes may be responsible for changes in the ECG in burn and CS. At the same time inhibition of myocardial contractility in burn shock and CS is virtually not linked with hyperkalemia.

[Effect of lysosomal enzymes on myocardial electrical and contractile activity in burn shock]. / Vliianie lizosomal'nykh fermentov na élektricheskuiu i sokratitel'nuiu aktivnost' miokarda pri ozhogovom shoke.

Marked depression of the amplitude of isometric contractions of myocardial preparations, which was induced by lysosomal enzymes from the liver of control animals, was demonstrated in isolated rabbit papillary muscles. The decrease of contractility was not accompanied by remarkable changes in the amplitude or in the duration of intracellular action potentials. The negative inotropic action of lysosomal enzymes was similar to that of blood plasma of the burnt animals. Based on the appearance and subsequent activation of lysosomal enzymes in blood of the animals by the 20th to 60th min after thermal injury it is suggested that lysosomal enzymes might be one of factors that depress myocardial contractility in burn shock.

[Effect of staphylococcal toxin and antistaphylococcal gamma-globulin on the electrical and contractile activity of the guinea pig myocardium]. / Vliianie stafilokokkovogo toksina i ego kompleksa s antistafilokokkovym gamma-globulina na élektricheskuiu i sokratitel'nuiu aktivnost' miokarda morskoi svinki.

A study was made of the action of staphylococcal toxin (ST) and its combination with antistaphylococcal gamma-globulin (ASGG) on intracellular potentials (rest potential--RP, and action potential--AP), and isometric contractions of guinea-pig auricle. ST (initial concentration 18.10(-2)Lh) diluted with normal Tyrode's solution at 1:1000, 1:100 and 1:10 (spontaneously active preparations), and Tyrode's solution with 13.5 mM KCl (evoked activity of preparations), significantly increased the duration of AP of myocardial cells. In evoked activity of preparations, RP and the amplitude of AP declined as the concentration of ST was raised. The amplitude of isometric contractions and maximal rates of their growth and fall increased under the effect of ST (1:1000) and decreased at 1:100 and 1:10. ASGG combined with ST (1:100) did not produce any protective effect on the myocardium. On the contrary, it provoked a still greater inhibition of contractility. The inhibitory action of combined ST and ASGG was seen at all ratios of ST to ASGG (use was made of ASGG shortage, equivalent amount and excess as regards ST) and reached 50% for all study characteristics of contractility. Anatoxin (inactivated toxin) combined with ASGG also produced a cardiodepressant action which was manifested in an approximately 50% decrease in the maximal rate of the growth and fall of contractions in the absence of significant changes in the contraction amplitude.

[Disorder of electromechanical coupling in the cells of the myocardium in protracted crush syndrome]. / Narushenie élektromekhanicheskogo sopriazheniiav kletkakh miokarda pri sindrome dlitel'nogo razdavlivaniia.

Experiments on papillary muscles of normal (control) rabbits and of those with the compression syndrome (CS) were made to explore the action of the control and "syndromic" blood plasma on electric and contractile activity of the myocardium. Isometric contractions of myocardial preparations were recorded at varying stimulation frequencies (0.1-2 Hz). Intracellular rest potentials (RP) and action potentials (AP) were led away with the aid of glass microelectrodes filled with 2.5 M KCl. The replacement of Tyrode solution by the control plasma raised the amplitude of papillary muscle contractions, that being greater as regards the muscles from rabbits with the CS. The "syndromic" plasma (diluted by Tyrode solution in a 1:1 ratio) markedly inhibited the amplitude of contractions of papillary muscles from both the control rabbits and animals with the CS. Reduction of the contractions induced by the "syndromic" plasma seen in all the preparations was followed by two patterns of changes in electrical activity of myocardial fibers. In one pattern, the RP, the amplitude and duration of the AP declined. In the other, on the contrary, the changes were reduced to a greater AP duration. The conclusion is made about the absence of a direct relationship between the decrease in myocardial contractility and changes in intracellular potentials induced by the "syndromic" plasma. It is suggested that the "syndromic" plasma deranges the process of stimulation and contraction coupling in heart papillary muscles.

[Positive inotropic action of plasma on the papillary muscle of rabbit heart]. / Polozhitel'noe inotropnoe deistvie plazmy krovi na papilliarnuiu myshtsu serdtsa krolika.

Experiments on the papillary muscles of the rabbit heart were made to examine the effect of blood plasma on isometric contractions and intracellular rest potentials (RP) and action potentials (AP) of individual myocardial fibers. The replacement of the perfusate (Tyrode's solution) with plasma diluted with the solution (1:1) led to an increase in the amplitude of rhythmical contractions of the papillary muscles at stimulation frequencies of 0.1 to 2 Hz. The positive inotropic action of the plasma was accompanied by the shortening of the length of the intracellular AP. The increased amplitude of contractions does not appear to be associated with the action of catecholamines that might occur in the plasma, since the beta-adrenoblocker propranolol did not abolish the inotropic plasma effect. The removal (dialysis) of low-molecular plasma components with a molecular weight less than 50 000 daltons led to the elimination of the positive inotropic effect of the plasma. This allowed a suggestion that the factor that increases the contraction amplitude might occur in the low-molecular part of the plasma.

[Effect of cooling on rhythmo-inotropic relations in pathologically altered myocardium]. / Vliianie okhlazhdeniia na ritmo-inotropnye otnosheniia v patologicheski izmenennom miokarde.

Fragments of the right atrium auricle from patients with congenital and acquired heart diseases were used to study the effect of the Tyrode solution temperature over the 60-minute cessation of electrical stimulation of the preparations on the recovery of the amplitude of rhythmic contractions after the pause. The lack of stimulation within 34 to 24 degrees C does not lower the contraction amplitude after warming of the preparations and renewal of rhythmic stimulation. The hypothermal pause at a temperature of 10-14 degrees C leads to the development of contractures and suppresses the myocardial contractility. The positive inotropic action of dopamin (1.10(-6) g/ml), isadrin (1.10(-7) g/ml) and strophanthine (1.10(-6) g/ml) on the myocardium in patients with acquired heart diseases is remarkably diminished after the hypothermal pause.

[Mechanical oscillations in the pathologically altered myocardium]. / Issledovanie mekhanicheskikh ostsilliatsii v patologicheski izmennom miokarde.

In pathologically altered myocardium (auricles) of patients with acquired heart diseases, there have been found mechanical oscillations of the tone which occurred after basic contracture induced by electrical stimulation. The oscillations were recorded at a normal ionic composition of Tyrode solution and a temperature of 32-34 degrees C. No mechanical oscillations were normally observed in the myocardium of patients with congenital heart diseases. It was shown that oscillations might affect the time course of the frequency-power curves.

[Study of mechanical oscillations of guinea pig atrial myocardium during cooling]. / Issledovanie mekhanicheskikh ostsilliatsii v miokarde predserdiia morskoi svinki pri okhlazhdenii.

Spontaneous mechanical oscillations--period damping oscillations of isometric tension, that occur immediately after discontinuance of the preparation contraction, induced by an external stimulation were studied in the guinea-pig auricle within the temperature range 17-7 degrees C. The mechanical oscillations were established to appear at 17 degrees C. With temperature decrease the amplitude of the oscillations rose and reached maximum at 9 degrees C and then fell down. The mechanical oscillations were not attended by oscillations of the membrane potential. The amplitude and magnitude of mechanical oscillations increased with Ca2+ concentration elevation in the medium and dropped down with its diminution. Addition of caffeine (10 mM) or KCI (20 mM) to the Tirode solution resulted in complete suppression of mechanical oscillations in the presence of the drastically decreased rhythmic contractions. It is assumed that the appearance of mechanical oscillations may be caused by the increased content of Ca2+ ions in the myoplasma of myocytes. This increase is consequent on the slowing down of the sequestering ability of sarcoplasmatic reticulum (SR) on cooling. It is suggested that SR may be a greater of mechanical oscillations.