[The application of N-acetylcysteine in optimization of specific pharmacological therapies]. / Zastosowanie N-acetylocysteiny do optymalizacji specyficznych terapii farmakologicznych.

Based on the analysis of data from clinical trials it could be postulated that N-acetylcysteine has a positive impact on the treatment of various diseases. However, less is known about specific molecular and physiological mechanisms underlying the reported therapeutic effects. N-acetylcysteine (NAC, N-acetyl-L-cysteine) is an amino acid derivative containing a thiol group. It is a precursor of L-cysteine and glutathione. NAC is well absorbed and safe for the body at doses up to 300 mg per kg of body weight. Side effects are relatively rare. NAC is used as an mucolytic agent in adjunctive therapy of respiratory diseases causing the retention of secretions, as well as an antidote in the treatment of paracetamol poisoning. Moreover, NAC protects against the toxic effects of reactive oxygen species and their active metabolites. NAC is involved in free radical scavenging processes via several independent mechanisms, including a direct reduction of free radicals, providing substrates for oxidation-reduction reactions and activation of antioxidant enzymes. In the blood, NAC decreases the level of low density lipoprotein peroxidation. In various tissues, NAC may increase the levels of glutathione and cysteine and stimulate the superoxide dismutase action. NAC is used as a supplement in the treatment of various diseases associated with impaired exterior and intracellular oxidative balance. NAC increases the concentrations of amino acids and their derivatives, including cysteine, cystine, and glutathione. It also stabilizes the antioxidant status of the cells and the intercellular spaces. NAC changes the levels of transcription factors, modifying the transcription of selected genes and acting on the protein translation. It works on the activation of several enzymes in the cells and outside the cells. Based on the analysis of data from clinical trials it can be concluded, that an administration of NAC may be beneficial for these groups of patients, in whom the reversible accumulation and the negative action of free radicals was observed.

Discrete movements of foot epithelium during adhesive locomotion of a land snail.

During the adhesive locomotion of land snails a series of short dark transverse bands, called pedal or foot waves, is visible ifa moving snail's ventral surface is observed through a sheet of glass. Moreover, the mucus secreted from the pedal glands and some pedal epithelial cells forms a thin layer which acts as a glue augmenting adherence, while also acting as a lubricant under the moving parts of the snail's foot. The relationships between velocity and the frequency of pedal waves as well as changes in the volume of small air bubbles under foot waves were analyzed by means of digital recordings made through a glass sheet on which the snails were moving. On the ventral surface of a moving snail foot, the adhering parts of the foot constituted about 80% of the total area, while several moving parts only about 20%. The single moving region of the foot (the pedal wave) amounted to about 3% of snail length. The epithelium in the region of the pedal wave was arched above the substrate and was also more wrinkled than the stationary epithelium, which enabled the forward motion of each specific point of epithelium during the passage of a pedal wave above it. The actual area of epithelium engaged by a pedal wave was at least 30% greater than the area of the epithelium as recorded through a glass sheet. In the region of the pedal wave, the tiny subepithelial muscles acting on the epithelium move it up in the front part of the wave, and then down at the end of the wave, operating vertically in relation to the substrate. In the middle part of the wave, the epithelium only moves forward. In summary, during the adhesive locomotion of snails, the horizontal movement of the ventral surface epithelium proceeds as temporally separate phases of upward, forward and downward movement.

The bi-phased course of electrophysiological response of isolated snail intestine on mechanical stimulation.

The transepithelial potential difference and changes of diameter of isolated snail intestine as index of its motility were studied in immersed bath in control conditions and after gentle stimulation by 60 seconds of washing of the intestinal lumen. Immediate depolarization and 20% augmentation of the lumen were observed during the stimulation. After stimulation, additional transient depolarization of the transepithelial potential difference and gradual diminution of intestine lumen back to control values over a period of 20 minutes occurred. The immediate reaction was greatly influenced by the presence of sodium or chloride ion transport inhibitors, however, the late phase of the response was not. It is hypothesized that changes of transepithelial electrogenic ion transport and of intestinal motility during the stimulation mirror the inflow of intestinal content and after completion of stimulation may be related to its storage.

An evaluation of visfatin levels in obese subjects.

INTRODUCTION: Visfatin is a protein secreted by adipose tissue, which shows insulin mimetic properties. The role of visfatin in the development of obesity, diabetes mellitus, and metabolic syndrome continues to raise controversy. The aim of the study was to evaluate visfatin levels and to attempt to establish the relationship between visfatin and selected anthropometric and biochemical parameters in obese individuals. MATERIAL AND METHODS: The study included 68 obese subjects (15 men and 53 women) aged 37.8 +/- 13.2 years with body mass index (BMI) values of 39.4 +/- 6.4 kg/m(2) without a previous diagnosis of abnormal glucose metabolism. The control group comprised 30 healthy nonobese volunteers (6 men and 24 women) with normal glucose metabolism, aged 38.2 +/- 14.9 years with BMI values of 22.8 +/- 3.0 kg/m(2). RESULTS: We found significantly higher visfatin levels in the obese subjects compared to the control group (median visfatin level of 39.6 v. 17.3 ng/ml, p = 0.0006). In the obese group there was a statistically significant negative correlation between visfatin levels and age (r = -0.26, p = 0.034), waist-to-hip ratio (WHR) (r = -0.28, p = 0.031) and glycated haemoglobin (HbA(1c)) (r = -0.36, p = 0.0037). No statistically significant correlations were found between visfatin levels and the remaining parameters under study. In the control group, visfatin levels did not show any significant correlation with any of the parameters under study. CONCLUSIONS: We found elevated levels of visfatin in obese subjects, which did not correlate with the majority of anthropometric parameters with the exception of WHR (negative correlation). This correlation may suggest that elevated visfatin levels are associated with the distribution of adipose tissue characteristic of gynoid rather than visceral obesity. In the group of obese subjects, visfatin levels decreased with age and glycated haemoglobin levels.

Toluene diisocyanate caused electrophysiological disturbances in the upper airways wall.

OBJECTIVES: Toluene diisocyanate (TDI) due to its widespread use in industry is one of the most common and well-known causes of occupational asthma and Reactive Airways Dysfunction Syndrome (RADS). In this study the impact of TDI on the electrophysiological properties of the airways wall, particularly on the mechanisms of absorption of sodium ions and chloride ions secretion was evaluated. MATERIALS AND METHODS: Isolated rabbit tracheal wall (from outbred stock animals) was mounted in an apparatus for electrophysiological experiments by means of Ussing method and was mechanically stimulated by the jet flux of specified fluid directed onto the mucosal surface of the tissue from a peristaltic pump. The measured parameters were: transepithelial potential difference under control conditions (PD, mV), after mechanical stimulation (dPD or physiological reaction of hyperpolarization, mV) and electric resistance (R, Omega cm2). When TDI (0.035 mM) was added to stimulation fluid, only the immediate reaction was identified and when it was added to incubation fluid and other experimental fluids, the late (post-incubation) reaction was determined. The experiments involving the inhibition of Na+ by amiloride and Cl- by bumetanide were also performed. RESULTS: A series of functional tests for 72 pieces of tracheal wall from 36 animals were performed. It has been shown that short-term exposure to TDI significantly changed the course of reactions to mechanical stimulation. Also after incubation in the presence of TDI, the reactions to mechanical stimulation were changed in relation to control conditions. CONCLUSIONS: The immediate reaction of the isolated rabbit tracheal wall after exposure to TDI depends on the duration of exposure and on the physiological condition of the tissue in respect of sodium and chloride ion transport.

Effect of hibernation on sodium and chloride ion transport in isolated frog skin.

The aim of the study was to evaluate the effect of hibernation on electrophysiological parameters of isolated frog skin under control incubation (Ringer solution) and after inhibition of Na+ and CI- transepithelial transport by application of amiloride and bumetanide. The transepithelial electrical potential difference (PD in mV) was measured before and after mechanical stimulation of isolated frog skin. The tissues were mounted in a modified Ussing chamber. The results revealed a reduced PD of frog skin during hibernation. In February, as compared with November, PD of frog skin incubated in Ringer solution decreased by about 50%. Hibernation also affected hyperpolarization (dPD) of frog skin after mechanical stimulation. In November and December, dPD was about 50% and 30% lower, respectively, compared with the subsequent two months of the experiment. The incubation of frog skin with amiloride, a sodium ion channel blocker, resulted in reduced values of all measured electrophysiological parameters irrespective of the phase of hibernation. After application of chloride ion transport inhibitor (bumetanide), the PD in November and December decreased compared with the control incubation by about 80% and 75%, while in January and February by about 40% and 25%, respectively. In January and February dPD increased by four times and three times as compared with November and December. Hibernation reduces net ion flow in isolated frog skin. During the initial period of hibernation the sensitivity of the skin to mechanical stimulation also decreases. Towards the end of hibernation, on the other hand, excitation of mechanosensitive ion channels takes place.

[Cellular tumor markers in thyroid cancer]. / Komórkowe markery nowotworowe w raku tarczycy.

Thyroid cancer is the most common endocrine malignancy. Most patients with thyroid cancer have a great chance for successful treating. There is, however, a group of patients with poor prognosis. The present researches of thyroid tumor markers have related to permanent diagnostic progress of circulating markers analysis (thyroglobulin, thyroid peroxidase, calcitonin and carcinoembryonic antigen), cellular markers determination and interpretation of results, also. A number of molecular markers have been studied. Diagnostic value of some of them, e.g. TSHR, RET Ras, is well known. Others have investigated continually. Overexpression of BRAF, Met, and p53 has been correlated with aggressiveness of the cancer. Markers said to be of prognostic value in thyroid cancer are CD82, c- myc and Plk-1. The combination of markers: galectin-3, fibronectin and HBME-1 have proven to be sensitive for differentiated thyroid cancer. Further studies on new cellular thyroid markers are essential. The current review presents data concerning the well known cellular markers in thyroid cancer.

[The estimation of serum concentration of vascular endothelial growth factor in patients with non-small cell lung cancer]. / Ocena stezenia naczyniowo-sródblonkowego czynnika wzrostu w surowicy u chorych na niedrobnokomórkowego raka pluca.

UNLABELLED: Vascular endothelial growth factor (VEGF) is main angiogenic factor, which stimulates endothelial cells migration and proliferation. The extensive angiogenesis plays important role in tumor growth and metastasis. AIM OF THE STUDY: Analysis of serum concentrations of vascular endothelial growth factor in patients with non-small cell lung cancer depending on clinicopathologic findings. MATERIAL AND METHODS: The study group consisted of 50 patients with non-small cell lung cancer (16 females and 34 males) ranging in age from 47 - 80 years (mean age 63 +/- 8.2). Serum VEGF concentration was evaluated by ELISA. RESULTS: VEGF concentrations in serum did not differ significantly between groups of patients with different T-, N- and M-factor. Patients with inoperable tumor (IIIB and IV) had significantly higher serum VEGF concentrations compared with resected tumor (I-IlIA) and locally advanced cancer (IIIA). CONCLUSIONS: Serum VEGF may be a marker of tumor progression in non-small cell lung cancer.

[The serum concentration of metalloproteinase 9 and 2 in non-small cell lung cancer patients]. / Stezenie metaloproteinazy 9 i 2 w surowicy chorych na niedrobnokomórkowego raka pluca.

UNLABELLED: Matrix metalloproteinases are responsible for the proteolytic degradation of the basement membrane and extracellular matrix. Elevated expression levels of MMP-9 and MMP-2 have been associated with tumor invasion and metastasis. THE AIM OF THIS STUDY: To determine serum concentrations of metalloproteinases 9 and 2 in non-small cell lung cancer patients depending on tumor stage. MATERIAL AND METHODS: The study group consisted of 50 patients with non-small cell lung cancer (16 females and 34 males) ranging in age from 47 - 80 years (mean age 63 +/- 8.2). MMP-9 and MMP-2 concentrations in serum were evaluated by ELISA. RESULTS: MMP-9 and MMP-2 concentrations in serum did not differ significantly between group with different T- and N-factor. Serum level of MMP-9 was significantly higher in patients with metastases than those without them. Patients with inoperable tumor (IIIB - IV) had significantly higher serum MMP-9 concentrations compared with resected tumor (I - IlIA). CONCLUSIONS: Serum MMP-9 may be a marker of metastasis in non-small cell lung cancer.

Clinical and experimental aspects of cutaneous neurogenic inflammation.

The aim of this paper is to present the state of knowledge on cutaneous neurogenic inflammation. Peripheral effector functions served by afferent sensory neurons underlie the so-called neurogenic inflammation. The mechanism of cutaneous neurogenic inflammation is connected with the release of neuropeptides from the sensory endings. They also exert a number of functions within the immune system. The activity of neuropeptides in the inflammation of the skin can be observed in the form of erythema, edema, hyperthermia and pruritus. Beside these peptides and their receptors, inflammatory skin response, is regulated by tryptase and proteinase-activated receptor 2 (PAR-2). Capsaicin decreases effects of inflammation-induced sensory neuropeptides, which was used in the treatment of diseases caused by inflammation. The activity of transient receptor potential vanilloid receptor 1 (TRP-V1) is associated with the neurogenic inflammation. In inflammatory processes, the neuro-immuno-cutaneous system undergoes activation, which is responsible for triggering and maintaining the inflammatory conditions, both in the healthy skin as well as in the pathological conditions, like psoriasis. Skin exposure to UV radiation influences the neuro-immuno-cutaneous system and causes the release of neuropeptides, thereby eliciting inflammatory response in photodermatosis. In conclusion, understanding the mechanisms and the factors controlling neurotransmitters and their receptors will lead to the identification of novel therapeutic targets for the treatment of cutaneous diseases e.g. pruritus, psoriasis, alopecia areata.

Comparison of the influence of halothane and isoflurane on airway transepithelial potential difference.

Bidirectional transport of Na+ and Cl- ions by the epithelium controls production and composition of airway surface liquid and airway transepithelial potential difference and in these ways supports mucociliary transport. Volatile anesthetics are able to inhibit epithelial ion transport processes when applied at high concentration and have been suggested to elicit depression of airway clearance and both these effects could be involved in postoperative pulmonary complications. The goal of these studies was to reveal possible influence of halothane and isoflurane at lower concentrations on electrogenic ion transport in airway epithelium. These studies were performed on the isolated rabbit tracheal wall mounted in the Ussing chamber. The reaction of the preparation to the gentle mechanical stimulation performed as a jet flux was examined without or in the presence of anesthetics at concentration equivalent to 0.5 minimal anesthetic concentration of volatile anesthetics in pulmonary alveoli (MAC), 1 MAC, 2 MAC, 5 MAC and 10 MAC. The volatile anesthetics at concentrations equivalent to 5 and 10 MAC affected airway transepithelial potential difference and influenced hyperpolarization or depolarization reactions which occurred after mechanical stimulation. The above effects were present when Na+ transport was inhibited by amiloride. The disturbed epithelial Cl- transport may be proposed as an explanation of the action of volatile anesthetics on electrophysiological parameters of the isolated tracheal wall although the influence of anesthetics on tachykinin secretion from C-fiber endings, which are present in the preparation, should also be taken into consideration. The long-lasting action (tens of minutes) of volatile anesthetics on the isolated tracheal wall should be also studied in the future as a model of airway reaction to prolonged volatile anesthesia.

Mebeverine influences sodium ion transport in the distal colon.

The study was performed to check if the well-known intestinal spasmolytic effect of mebeverine is paralleled by any changes in intestinal transepithelial currents. The transepithelial potential difference related to ionic currents of the isolated rabbit distal colon wall was measured by means of Ussing's technique under control conditions and after gentle mechanical stimulation of intestinal epithelial surface by a flux from peristaltic pump and with and without of mebeverine in stimulation fluid. The transient hyperpolarization after mechanical stimulation was diminished after addition of mebeverine to the stimulation fluid when chloride transport was inhibited by bumetanide (BUME) but in the presence of amiloride (AMI), a sodium ion transport inhibitor, the drug did not influence the reaction. It was inferred that mebeverine was able to modulate transepithelial sodium ion transport and in this way to modify interaction between colonic wall and its contents during intestinal passage.

The effect of serotonin on epinephrine modulation of transepithelial ion transport in isolated frog skin.

The aim of this study was to examine the effect of serotonin and epinephrine on ion transport of isolated frog skin. The addition of serotonin after incubation in Ringer solution (RH), bumetanide (BUME), and after initial incubation in amiloride and subsequently in RH, reduced hyperpolarization and did not effect the mechanosensitivity of frog skin. Following incubation of the frog skin with amiloride (AMI), serotonin did not affect the value of hyperpolarization and increased mechanosensitivity. The addition of epinephrine (EPI) on frog skin incubated in RH and AMI did not affect hyperpolarization, but repeated application of this compound after serotonin increased hyperpolarization. After incubation with bumetanide, addition of EPI before and after application of serotonin did not affect the value of the examined parameters of the frog skin. Initial incubation with AMI and later in RH caused a drop in reaction to EPI and no effect on mechanosensitivity. Repeated addition of epinephrine in this group did not affect the reaction value, while it decreased the reaction value during mechanical stimulation. The experimental data presented in this study indicate that serotonin inhibits the sodium ion current. Epinephrine inhibits the chloride ion current, however, after the application of serotonin, EPI stimulates sodium ion transport.

The electrical potential difference through the foot epithelium of the snail Achatina achatina, Lameere during mechanical and chemical stimulation.

An important electrophysiological variable--the transepithelial potential difference reflects the electrogenic transepithelial ion currents, which are produced and modified by ion transport processes in polarized cells of epithelium. These processes result from coordinated function of transporters in apical and basolateral cell membranes and have been observed in all epithelial tissues studied so far. The experiments were performed on isolated specimens of snail foot. In the experiments, the baseline transepithelial electrical potential difference--PD, changes of transepithelial difference during mechanical stimulation--dPD and the transepithelial resistance were measured with an Ussing apparatus. A total of 60 samples of foot ventral surface of 28 snails were studied. The transepithelial electrical potential difference of isolated foot ranged from -6.0 to 10.0 mV under different experimental conditions. Mechanical stimulation of foot ventral surface caused changes of electrogenic ion transport, observed as transient hyperpolarization (electrical potential difference became more positive). When the transepithelial electrical potential difference decreased during stimulation, the reaction was described as depolarization. When amiloride and bumetanide were added to the stimulating fluid so that the sodium and chloride ion transport pathways were inhibited, prolonged depolarization occurred. Under the influence of different stimuli: mechanical (gentle rinsing), chemical (changes of ion concentrations) and pharmacological (application of ion inhibitors), transient changes of potential difference (dPD) were evoked, ranging from about -0.7 to almost 2.0 mV. Changes in transepithelial potential difference of the pedal surface of the snail's foot related to these physiological stimuli are probably involved in the locomotion of the animal and are under control of the part of the nervous system in which tachykinin related peptides (TRP) act as transmitters.

[BRAF gene mutation in thyroid cancer]. / Mutacja genu BRAF w raku tarczycy.

Mutations of genes coding effectors of signaling pathway RET/PTC-RAS-RAF-MEK-ERK, involved in cell growth and proliferation, are important in papillary thyroid cancer development. To earlier discovered mutations of RAS and RET/PTC genes, BRAF gene mutation has been recently added. Mutation of BRAF gene appears in various types of carcinomas, but most frequently in malignant melanomas (66%) and papillary thyroid cancer (average 44%). The BRAF gene protein product belongs to the serine-threonine kinase family and to the RAF proteins subfamily, among which it is the strongest activator of MAP kinases cascade. The most frequently mutation of BRAF gene is thymine to adenine transversion at nucleotide position 1796 (T1796A). This point mutation causes valine to glutamic acid substitution at residue 599 (V599E), that results in constitutive and oncogenic activation of BRAF kinase. The relation between mutations of BRAF, RAS and RET/PTC genes has not been found, although they together exist in two thirds of papillary thyroid cancers. BRAF(TI796A) oncogene appears in papillary thyroid cancer, whereas it has not been found in follicular thyroid cancer and benign thyroid adenomas. For this reason mutated BRAF gene could be specific molecular marker, with relatively high sensitivity in diagnostics of papillary thyroid cancer. In addition, BRAF gene has been demonstrated as a novel prognostic biomarker, which correlates with unfavorable clinicopathological factors, such as extrathyroidal invasion and distant metastasis.

[Iron status with particular consideration of soluble transferrin receptors in children and youth with gastritis, with or without Helicobacter pylori infection]. / Stan gospodarki zielazem ze szczególnym uwzglidnieniem I osoczowych receptorów transferyny u dzieci i mlodziezy z przewleklym zapaleniem blony sluzowej ioladka ze wspólistniejacym zaka eniem Helicobacter pylori lub bez zakaienia.

UNLABELLED: Role of Helicobacter pylori infection in chronic gastritis and gastric and/or duodenal ulcers is well known. Simultaneously there are some articles in literature considering H. pylori as a cause of extra-gastrointestinal illnesses such as atopic dermatitis, chronic urticaria or acne rosacea, hypotrophy, Schoenlein-Henoch disease, atherosclerosis or hypochromic anaemia. The aim of the study. was to asses iron status in aspect of plasmatic transferrin receptors concentration among children and youth with chronic gastritis with or without Helicobacter pylori infection. MATERIALS AND METHODS: Forty one patients were included as a study group. Range of age was 9-18 years. All patients were diagnosed due to chronic abdominal pains. There were 13 males and 28 females. Blood was collected from every patient for blood cell count, iron, transferrin and transferrin receptors concentration (sTfR) assessment before endoscopy of upper gastrointestinal tract. RESULTS: Concentration of sTfR was higher than age norm among 29 (71%) of patients. Among patients with higher level of sTfR 20 (69%) had normal haemoglobin concentration and in this group 10 patients had H. pylori infection. During analysis of 12 patients with nornal level of sTfR normal haemoglobin concentration was found and among five of them H. pylori infection was stated. Among 21 patients without H. pylori infection 14 had normal level of sTfR and 7 had higher level of sTfR which means that 33% had hidden iron deficiency (involuntary of normal Hb concentrations). Among 15 of 20 patients with H. pylori infection level of sTfR was higher which means that 75% patients with infection had hidden iron deficiency (involuntary of normal Hb concentrations). CONCLUSION: Level of plasmatic transferrin receptors can be good and sensitive indicator of iron deficiency and can be helpful in differential diagnosis of hypochromic anaemia and anaemia caused by chronic illness including chronic gastritis with Helicobacter pylori infection.

Oxidative stress markers during a course of hyperthyroidism.

INTRODUCTION: Previous studies have shown the presence of oxidative stress in hyperthyroid patients. The aim of this study was to evaluate the influence of hyperthyroidism on lipid peroxidation, plasma lipoprotein oxidation and antioxidant status. We have estimated the clinical utility of the biochemical parameters analysed as markers of oxidative stress in hyperthyroidism. MATERIAL AND METHODS: Twenty five patients with overt hyperthyroidism because of Graves' disease or toxic multinodular goitre and 20 healthy subjects were included in the study. Lipid peroxidation was evaluated by measurement of peroxides and malondialdehyde with 4-hydroxynonenal (MDA + 4-HNE) concentrations. Autoantibodies against oxidised LDL (anti-oxLDL) were assayed as a marker of lipoprotein oxidation. Changes in the antioxidant defence system were estimated by measurement of total antioxidant status in serum (TAS) and erythrocyte superoxide dismutase activity (SOD). RESULTS: A significant increase in serum concentration of peroxides and MDA + 4-HNE was observed in patients with hyperthyroidism. However, no difference was found in anti-oxLDL concentration and antioxidant status parameters (TAS, SOD) between the control group and the patient group. CONCLUSIONS: Our results indicate an intensification of the oxidative processes caused by an excess of thyroid hormones, which is not accompanied by a response from the antioxidant system. Elevated concentrations of lipid peroxidation products in serum, both peroxides and malondialdehyde with 4-hydroxynonenal, may be useful as markers of oxidative stress during the course of hyperthyroidism.

Postmortem examination of transepithelial ion currents in rabbit colon and trachea in relation to temperature of storage and its importance for interlethal reactions.

Electrical phenomena resulting from transepithelial ion transport have been a subject of clinical, physiological, pharmacologic and toxicologic studies. These examinations concern mainly electric phenomena in live organisms. The changes of transepithelial ion pathways which take place postmortem have not been yet established. The aim of the study was an attempt to trace variability of electrophysiological parameters related to transepithelial ion transport in specimens of rabbit trachea and colon depending on temperature at which specimens were stored after death. It was observed that postmortem electric phenomena in epithelium of airways and alimentary tract of rabbit occur well-ordered but with slower course in trachea samples and in tissues which were preserved at low temperature after death.

Effect of amiloride and bumetanide on transepithelial ion transport in isolated rabbit cecal and colonic wall.

INTRODUCTION: The aim of the study was to compare the effects of amiloride and bumetanide on the baseline transepithelial electrical potential difference (PD) and changes in PD during mechanical stimulation (dPD) in isolated cecal and colonic wall of rabbits. MATERIAL/METHODS: The experiments were performed with a modified Ussing chamber system. Isolated tissue specimens were incubated in Ringer's solution, in amiloride and/or bumetanide, or in dimethyl sulfoxide (DMSO). RESULTS: Under control conditions, i.e. when all the experimental fluids were Ringer's solution, the PD and R values of the rabbit cecum and colon were similar, while during mechanical stimulation, dPD of the colon was twice as high as that of the cecum. Addition of amiloride and/or bumetanide to all experimental fluids diminished the electrophysiological parameters of both tissues. DMSO added to all experimental fluids significantly diminished the values of the electrophysiological parameters of the cecum. Addition of amiloride to the stimulation fluid only diminished the PD and dPD values in the colon, whereas addition of bumetanide to the stimulation fluid only diminished the PD and dPD values in the cecum. It was found that the PD and dPD values of the rabbit cecum depend primarily on chloride ion transport, while those of the colon depend on sodium ion transport.

The influence of ambroxol and capsaicin on the isolated rabbit bladder wall.

Unmyelinated C-fibers endings lye beneath the epithelial layer and release neuropeptides which regulate baseline transepithelial potential difference (PD) and changes of transepithelial potential difference during mechanical stimulation (dPD). Ambroxol can suppress reflexes such as the cough or the corneal reflex which are connected to stimulation of C fibre endings. The study aimed to estimate the influence of ambroxol (ABX) and capsaicin (CAPSA) on PD and dPD in isolated rabbit bladder. The experiments were carried out on 26 bladder specimens of. 2 cm2 surface area each, obtained from 13 rabbits. Ussing apparatus was used. Procedure used for stimulation of sensory receptor involved directing stream onto epithelium. A stimulus lasted 30s, ejecting the 2.5 ml fluid. Amiloride and bumetanide were used to estimate of ionic currents. Each significant reaction was repeated at least 10 times on various specimens. PD ranged between 5 and 10 mV in different experimental conditions. Mechanical stimulation of isolated bladder wall caused increasing dPD about 2 mV defined as hyperpolarization. Application of ABX to the stimulation fluid decreased the hyperpolarization in comparison with control stimulation under conditions of inhibited chloride ion transport. Application of CAPSA to the stimulation fluid decreased the hyperpolarization in comparison with control stimulation under conditions of inhibited sodium ion transport. ABX and CAPSA had no influence on PD after mechanical stimulation. ABX as well as CAPSA influence on transepithelial ion transport pathways in bladder epithelium is dependent on sensory stimulation. ABX can be suspected to suppress bladder contractions.