Evaluation of selected protein biomarkers of renal function in rats with an experimental model of acute cyclophosphamide-induced cystitis treated with N-acetylcysteine.

The administration of cyclophosphamide (CP) is associated with the risk of developing cystitis as well as kidney injury. The aim of the study was to verify the uroprotective effect of N-acetylcysteine (NAC), as well as the evaluation of renal function in the experimental model of acute CP-induced cystitis. Rats from group 1 received intraperitoneally only a single dose of 200 mg/kg b.w. of CP. Individuals from groups 2 and 3 additionally received a single dose of 200 mg/kg b.w. of NAC, respectively, orally (p.o.) and intraperitoneally (i.p.). After the administration of the drugs, animals were subject to individual monitoring in metabolic cages to assess 24-hour diuresis and basic vital signs, and then finally sacrificed for the purpose of collecting blood and organs for histopathological analysis. Classic renal parameters (creatinine, urea, uric acid, electrolytes) as well as new markers reflecting renal function, within the filtration-resorption range - cystatin C (CysC), renal tubular integrity - kidney injury molecule-1 (KIM-1) and the condition of the glomerular filtration barrier (nephrin) were determined in the obtained serum and urine samples. In group 1 histopathological development of cystitis was confirmed with the absence of significant pathomorphological disorders of the kidneys, and the initial results of the parameters determined were obtained. In both groups 2 and 3, a decrease of inflammatory changes in urinary bladder was observed, while there were still no morphological disturbances in kidneys. The administration of NAC in both groups 2 and 3 also resulted in a decrease of concentrations in urine and a reduction in 24-hour excretion with urine of all assessed proteins (CysC, KIM-1 and nephrin). NAC, thus exhibited a uroprotective effect, which was accompanied by a functional nephroprotective effect (more accentuated during intraperitoneal administration of this compound), manifested by the reduction of urinary excretion of proteins indicative of developing renal dysfunction.

Melatonin and serotonin effects on gastrointestinal motility.

The gastrointestinal tract represents the most important extra pineal source of melatonin. Presence of melatonin (M) suggests that this hormone is somehow involved in digestive pathophysiology. Release of GI melatonin from serotonin-rich enterochromaffin EC cells of the GI mucosa suggest close antagonistic relationship with serotonin (S) and seem to be related to periodicity of food intake. Food deprivation resulted in an increase of tissue and plasma concentrations of M. Its also act as an autocrine and paracrine hormone affecting not only epithelium and immune system but also smooth muscle of the digestive tract. Low doses M improve gastrointestinal transit and affect MMC. M reinforce MMCs cyclic pattern but inhibits spiking bowel activity. Pharmacological doses of M delay gastric emptying via mechanisms that involve CCK2 and 5HT3 receptors. M released in response to lipid infusion exerts a modulatory influence that decreases the inhibitory effects of the ileal brake on gastric emptying. On isolated bowel S induces dose dependent increase in tone and reduction in amplitude of contraction which is affected by M. M reduced the tone but not amplitude or frequency of contraction. M is a promising therapeutic agent for IBS with activities independent of its effects on sleep, anxiety or depression. Since of its unique properties M could be considered for prevention or treatment of colorectal cancer, ulcerative colitis, gastric ulcers and irritable bowel syndrome.

Dysfunction of the autonomic nervous system activity is responsible for gastric myoelectric disturbances in the irritable bowel syndrome patients.

The pathogenesis of the irritable bowel syndrome (IBS) is still unsolved. Lately most attention has been focused on visceral hypersensitivity related to dysfunction of the autonomic nervous system (ANS). The aim of this study was to evaluate changes in the ANS activity and gastric motility in constipation-predominant IBS patients using the heart rate variability (HRV) and gastric myoelectric activity (EGG) recording. 23 patients (45+/-13 yrs) matching Manning criteria and 30 healthy volunteers (47+/-5 yrs) participated in the study. EGG and HRV in fasted and fed subjects with fasted serum catecholamine levels were measured in both groups. Fasting IBS pts showed gastric dysrrhythmia (29+/-14% vs. 11+/-7%), DP was 128.860 +/- 112.000 vs. 46.000+/- 23.200microV2, DF 2.37+/-0.8 vs. 2.9+/-0.2cpm. Feeding (300 kcal) improved dysrrhythmia to 20+/-13% vs. 8+/-5%, DP decreased to 74.500+/-57.720 vs. 165.600+/-89.000microV(2) and DF increased to 2.53+/-0.7 vs. 3.2+/-0.3cpm. In fasted and fed IBS pts SWC (channels 3-4) was about 60+/-11 vs. 84+/-8% and 68+/-14 vs. 92+/-8% respectively. In IBS pts resting HRV parameters were lower (LF - 650.3 vs. 811.6 ms2; HF - 508.8 vs. 854.6 ms2); with higher LF/HF ratio in IBS patients (1.52 vs. 1.2). The serum fasting level of adrenaline and noradrenaline in IBS pts were higher 1.28+/-0.06 vs. 0.65+/-0.05 nmol/L, and 3.54+/-1.2 vs. 2.89+/- 08 nmol/L, p<0.05 respectively. Increased sympathetic drive in IBS pts reflected by high catecholamine levels and LH/HF ratio is responsible for gastric dysrrhythmias and low DF and coupling. Meal has negligible effect on EGG parameters improvement. The ANS dysfunction observed in IBS patients is most probably responsible for disturbances in gastric myoelectric activity presented as gastric dysrrhythmias resulting in gastric emptying delay and dyspeptic symptoms.

Peripheral mechanisms of intestinal dysmotility in rats with salsolinol induced experimental Parkinson's disease.

Gastrointestinal dysmotility in Parkinson's disease (PD) has been attributed in part to peripheral neurotoxine action. Our purpose was the evaluation of the salsolinol effect on intramuscular interstitial cells of Cajal (ICC), duodenal myoelectrical activity (DMA) and vagal afferent activity (VAA) in rats with experimental PD. Twenty rats were divided into 2 equal groups. Experimental PD was produced in one group by 3 weeks of the intraperitoneal salsolinol injections (50 mg/kg/day), whereas the 2-nd group served as control. DMA and VAA were recorded in both groups during fasting and stepwise--gastric distension (GD) of 10 ml. Subsequently fragments of duodenum were removed and intramuscular ICC were assessed as c-Kit antigen percentage in the duodenal muscular zone. Analyses of the fasting DMA and VAA recordings didn't reveal differences between the compared groups. During GD increase of DMA dominant frequency (p=0.04) and VAA frequency (p<0.01) was observed in the controls whereas in the salsolinol group both parameters remained unchanged. Image analysis of duodenum revealed decreased c-Kit expression in the salsolinol-injected animals (p=0.05). The results of our study may suggest the direct effect of salsolinol on both ICC and neuronal pathways of gastro-duodenal reflexes.

Peripheral mechanisms of intestinal dysmotility in the morphine tolerant and dependent rats.

Changes of intestinal motility and transit produced by tolerance to and dependence upon morphine have been partly attributed to peripheral mechanisms. We evaluated the effect of chronic peripheral morphine administration and peripheral mu-receptor blockade on vagal afferent activity (VAA) and c-Kit positive intramuscular cells of Cajal (ICCs). Ten rats were subjected to chronic subcutaneous morphine infusion for 72 h with subsequent VAA recording. Potential frequency was evaluated within recordings before and after mu receptor blockade by (D)-Phe -Cys -Tyr -(D)-Trp -Orn -Thr -Phe -Thr (CTOP) i.p. injections. Afterwards the rats were sacrificed and intramuscular c-Kit antigen expression was assessed by image analysis within removed fragments of duodenum and ascending colon. An equal group of rats served as a control for VAA and c-Kit expression. Analysis of VAA revealed similar frequencies of potentials in morphine tolerant / dependent rats before CTOP and in the controls. CTOP increased potential frequency in the morphine group which effect was visible mostly within the first 20 minutes (p=0.01). The morphine infused animals presented also higher c-Kit expression in both the duodenum (p<0.001) and the ascending colon (p<0.001) in comparison to the control group. Results of our study may indicate the involvement of both the intestinal wall and the long vago-vagal reflexes in tolerance to and dependence upon opioids.

The effects of baclofen on the feeding behaviour and body weight of vagally stimulated rats.

UNLABELLED: It is hypothesised that the GABA(B) receptor agonist baclofen increases or has no effect on food intake, and electrical stimulation of vagal nerves decreases food intake. The aim of this study was to evaluate the effects of baclofen in vagally stimulated rats. MATERIAL AND METHODS: Thirty two Wistar rats were divided into five groups: group A scheduled for microchip implantation for vagal stimulation, group B for sham operation, group C for microchip implantation and baclofen medication, group D for baclofen medication only and group E for gastric motility evaluation under influence of baclofen. The following parameters were then evaluated: food intake and body mass, gastric motility, leptin, insulin, and glucose serum levels. RESULTS: In the comparison of groups B and A, daily food intake and body weight gain decreased by 17% (p<0.05) and by 22% (p<0.05), respectively. Baclofen alone (group D) did not significantly change either food intake nor diurnal body weight compared to the controls, but when used in conjunction with the microchip (group C) it did significantly reduce effect of vagal neuromodulation (p<0.05). Furthermore, a significant decrease in leptin and glucose levels was detected in group C: 677 to 165 pg/ml (p<0.05) and 5,93 to 4,88 mmol/l (p<0.05), respectively. The administration of baclofen stimulated significantly gastric motility and elicited irregular motor migrating complex (327+/-200 against control 255+/-52 cmH2O/s). CONCLUSIONS: These results suggest that microchip vagal neuromodulation through increased vagal afferent activity induces an alteration in the feeding behaviour and decreases nocturnal food intake and body weight. These effects were partially attenuated by baclofen. The data suggests that GABA(B) receptors play an important role in the pathomechanism of attenuation of food intake induced by vagal nerve stimulation.

Loss of interstitial cells of Cajal after pulsating electromagnetic field (PEMF) in gastrointestinal tract of the rats.

Exposure to the magnetic field has remarkably increased lately due to fast urbanization and widely available magnetic field in diagnosis and treatment. However, biological effects of the magnetic field are not well recognized. The myoelectric activity recorded from the gastrointestinal and urinary systems is generated by specialized electrically active cells called interstitial cells of Cajal (ICCs). Thus it seems rational that ICC have significant vulnerability to physical factors like an electromagnetic field. The aim of this study was to evaluate the influence of pulsating electromagnetic field (PEMF) (frequency 10 kHz, 30ms, 300 muT burst, with frequency 1Hz) on ICCs density in the rat gastrointestinal tract. Rats were divided into two groups (n=32). The first group was exposed to PEMF continuously for 1, 2, 3, and 4 weeks (n = 16), and the second group (n=16) served as a control. Tissue samples of the rat stomach, duodenum and proximal colon were fixed and paraffin embedded. The tangential sections of 5 microm thickness were stained immunohistochemically with anti-c-Kit (sc-168) antibody and visualized finally by DAB as chromogen (brown end product). C-Kit positive branched ICC-like cells were detected under the light microscope, distinguished from the c-kit-negative non-branched smooth muscle cells and from the c-kit positive but non-branched mast cells and quantitatively analyzed by MultiScan computer program. Apoptosis detection was performed with rabbit anti-Bax polyclonal antibody (Calbiochem, Germany) and LSAB 2 visualization system. The surface of c-Kit immunopositive cells decreased after exposure to PEMF in each part of the gastrointestinal tract. Reduced density of ICCs was related to exposure time. The most sensitive to PEMF were ICCs in the fundus of the stomach and in the duodenum, less sensitive were ICCs in the colon and pacemaker areas of the stomach. No marked changes in ICC density in the pyloric part of the stomach were observed. We demonstrate that the PEMF induced apoptosis dependent decrease in ICC expression.

Encoding meal in integrated vagal afferent discharge.

Vagal afferents are integral part of the negative feedback loop induced by constitution and size of food stomach and jejunum. Aim of this study was to assess vagal discharge in response to food and gastric distension in rats. Electrophysiological recordings of vagal afferents in fasted (n=32), fed rats (n=20) and during gastric balloon distension (n=12) were performed. After 60 minutes of fasted nerve recording tube feeding was done. Fasted rats also underwent gastric distension via oesophagus. Vagal afferents discharges were analysed with dual time-amplitude window discriminator. Total vagal afferent discharge in fasted and fed rats revealed 0.3 +/- 0.12 vs 0.56 +/- 0.22 Hz (p<0.05). We observed two distinct discharge patterns: high amplitude low frequency (HALF) and low amplitude high frequency (LAHF). HALF spikes were observed more frequent in fasted than in fed rats (0.05 +/- 0.02 vs. 0.03 +/- 0.016 Hz (p<0.05). Conversely LAHF spikes in fed rats predominated over their occurrence in fasted rats: 0.52 +/- 0.2 vs. 0.25 +/- 0.12 Hz (p<0.05). Left vagal afferents discharge rises with gastric distension of 6, 8 and 10 ml and were: 0.46 +/- 0.22 Hz, 0.65 +/- 0.31 Hz, 0.86 +/- 0.33 Hz (p<0.05) respectively. Similar discharge showed right vagal afferents: 0.41 +/- 0.08 Hz, 0.51 +/- 0.13 Hz and 0.77 +/- 0.27 Hz (p<0.05) for 6, 8 and 10 ml of distension, respectively. We conclude that interdigestive information from gastrointestinal tract is encoded in high amplitude low frequency of spikes pattern in the vagus nerves.

Capasaicin induced deafferentation enhances the effect of electrical vagal nerve stimulation on food intake and body mass.

Study was based on hypothesis that electrical stimulation (ES) with parameters obtained from analysis of vagal afferent discharge fed state may fake brain with satiety state. We evaluated effect of denervation of vagal capsaicin-sensitive afferents on food intake and body weight in rats with ES of vagal nerves using microchip (MC). Group A was scheduled to MC implantation, B to sham operation only, C to MC implantation and capsaicin vagal deafferentation, and D to capsaicin denervation only. ES lasted 24 days. MC parameters were 0.05 Hz, 0.1s, 0.55 V. ES of left vagus significantly reduced total food intake as well as the mean daily intake in groups A and C in comparison to control and D group (ANOVA, F=18.55, p=0.0038). Body weight was lower in group A (3462 g) and C (2727 g) then in control (3814 g) and D (3568 g) (F=25.68, p=0.00068). Leptin decreased in C (165 pg/mL) in comparison to A (625 pg/mL), B (677 pg/mL), and D (612 pg/mL) (p<0,05), mainly due to ES (F=7.27, p=0.019). Glucose was decreased in A (F=5.55, p=0.036) - by 11% and by 16% in C group. Proper vagal neuromodulation results in central and peripheral effects causing food intake and body weight downregulation.

Effects of vagal neuromodulation and vagotomy on control of food intake and body weight in rats.

Food induced neurohumoral signals are conduced to data processing brain centers mainly as vagal afferent discharge resulting in food intake regulation. The aim of this study was to evaluate effects of vagal nerve neuromodulation in control of food intake with fed-pattern microchip (MC) pacing. Experiments were performed on 60 rats divided on 5 groups: I group 0,05Hz left vagal pacing, II - pacing of both vagal nerves with MC 0,05Hz, III- left vagal MC 0,1Hz pacing, IV - pacing of both vagal nerves with MC 0,1 Hz was performed. In group V left vagal pacing was combined with right side abdominal vagotomy. Body weight and total food intake decreased by 12% and 14% (I), 26% and 30%(II), 8% and 21%(III), 14% and 30%(IV), 38% and 41%(IV), respectively (p<0.05). Effects of both vagal nerves stimulation on final body weight and food intake was significantly more effective than only single nerve MC pacing however most effective was stimulation with 0,1Hz combined with right vagotomy. We conclude that vagal stimulation reduce food intake and body weight by increasing vagal afferent signals. Our results suggest that information in vagal afferents can be modulated resulting in changes of feeding behaviour and body weight.

The effect of transcutaneous nerve stimulation (TENS) on gastric electrical activity.

UNLABELLED: TENS became widely accepted method of treatment pain syndromes in clinical practice. Lately has been shown that its affects also gastrointestinal tract by releasing NANC neurotransmitter VIP. The aim of this study was to evaluate the effects of TENS on gastric myoelectric activities measured by electrogastrography (EGG). Eighteen healthy men (mean age 23 +/- 1.7) were included in the study. Healthy volunteers were divided on 3 groups each 6 persons: with normogastria occurring at 94.5 +/- 7% of recording time--group A, with predominant bradygastria (36.6 +/- 14%)--group B and with tachygastria (33 +/- 14%)--group C. In fasted condition EGG (Synectics, Sweden) was recorded with skin electrodes. TENS 15 min was performed with use of Sinus 5 stimulator (6 Hz, 0.1 ms duration, intensities 10-20 mA, Zimmer, Germany). Stimulating electrodes were placed on non-dominant hand. RESULTS: None of the subjects during TENS reported any side effects or symptoms, during the all studies. In group A in the fasting recordings, after TENS, an decrease of the normal values in the range 2-4 cpm down to 78.5 +/- 21% of recording time (p = 0.03) occurred. The dominant frequency in the bradygastric region increased up to 17.7 +/- 7% of the total recording. In group B TENS decreased bradygastria level from 36.6 +/- 14% to 20.6 +/- 15% (p = 0.02). TENS did not significantly affect tachygastria in group C. Amplitude of the EGG signal after TENS in group B and C increased by 40 and 150% respectively (p < 0.05). Significant decrease of the amplitude was observed in group A (13%). We conclude that TENS by activating centrally mediated somato-visceral reflexes affects gastric electrical activity. Our results suggest that TENS may be useful in treatment of the gastric dysrhythmia.

Double-blind crossover study of ranitidine and ebrotidine in gastro-esophageal reflux disease.

Gastroesophageal reflux disease (GERD) is multifactorial disorder in which acid exposure has a central role in the mucosal damage, and the mainstay of medical treatment is the suppression of gastric acid secretion justifying the use of H2 receptors antagonists. In our study we compared the effects of ranitidine and ebrotidine, a novel H2 antagonist with gastroprotective properties, on the motor, pH and endoscopic aspects of GERD in randomized cross-over trial in humans. Twenty patients with endoscopic evidence of erosive esophagitis were included in the study. Esophageal manometry and 24-hour pH-metry were done with the use Synectics (Sweden) systems. The same examinations were repeated after 20 days period of treatment with either ranitidine or ebrotidine, given in single dose 300 and 800 mg (nocte) respectively. The pressure within the lower esophageal sphincter (LES) in the untreated and treated with ebrotidine or ranitidine patients remained lowered. Patients with GERD showed increase in duration and decrease in amplitude and propagation of peristaltic waves in the esophageal body which were not improved after treatment. Complete healing after 40 days of treatment was comparable with ebrotidine and ranitidine and averaged about 40%. The pH-metry showed improvement in treated patients in the reflux frequency and time pH below 4, ranitidine being more effective than ebrotidine. It can be concluded that GERD patients showed weaker primary peristalsis unrelated to LES pressure and treatment. Treatment with ebrotidine or ranitidine reduced significantly the endoscopic and self-assessment score, ebrotidine and ranitidine being equally effective in healing of esophageal mucosal lesions.

Effects of continuous microchip (MC) vagal neuromodulation on gastrointestinal function in rats.

Afferent fibers from gastrointestinal tract outnumber efferents ten times in vagal nerves. Modifying the afferent input makes possible to change discharge of vagal efferents affecting gastrointestinal functions in process known as neuromodulation (NM). Lately it has been used in the treatment of pain and hyperactive neurogenic bladder in urology. MC induced NM may therefore provide a concurrent to pharmacology tool, in treatment of gastrointestinal disorders. The aim of this study was to investigate the effects of long term neuromodulation procedure with use of MC on gastric motility, secretion and weight control in conscious rats. Experiments were performed on 30 Wistar male rats (250-350 g) divided in two groups: sham operated and microsurgically implanted with MC on left vagal nerve below diaphragm. Following stimulation parameters were used: frequency of 0.5-30 Hz, amplitude of 0.55 V, impulse duration of 10 ms in monophasic fashion. In both groups food intake and body weight were measured through the period of 2 weeks after recovery period. Then gastric fistula was implanted in gastric antrum and fasted gastric motility recorded with use of PowerLab system (Australia). Gastric emptying and secretion were also tested with use of phenol red and automatic titration methods. On the daily basis glucose level with standard test and leptin after MC implantation were measured. Recording of vagal activity in fasted rats showed burst of action potentials about 5 +/- 2.5 in period of 5000 sec, each burst with spike frequency up to 35 Hz. Food (5 ml of Intralipid--intragastrically) almost doubled amount of bursts to 12 +/- 5 in period of 5000 sec with increase in frequency at spike up to 50 Hz. MC induced vagal activity showed continuous spike activity similar to fed pattern. MC induced NM decreases daily food intake by 6% (33.6 +/- 4.8 vs control 35.5 +/- 4.8 g, p < 0.01). Body weight gain in rats before MC implantation decreased by 20% within 2 weeks after recovery (34.8 +/- 9.08 vs control 23.56 +/- 4.15 g). Fasting control glucose level also decreased of 5.5% (93.15 +/- 9.3 vs control 98.5 +/- 11.2 mg%, p < 0.05). Frequency of gastric contractions did not change significantly in MC versus control but amplitude of contractions increased of about 66.7% (2.0 +/- 0.8 vs 1.17 +/- 0.52) at the dominant frequency 0.08 Hz range and about 71.5% (1.17 +/- 0.35 vs 0.68 +/- 0.47, p < 0.05) at the frequency 0.12 Hz. in FFT analysis PowerLab (chart v = 4.01). BAO decreased by 29.25% without H+ concentration changes (0.2 +/- 0.14 vs 0.14 +/- 0.12 mmol/30 min, p < 0.05) but MAO did not change in MC rats (0.37 +/- 0.25 vs 0.42 +/- 0.28 mmol/30 min, p 0.05). Gastric emptying of isotonic solution increased by 10% (90.46 +/- 5.34 vs 80.39 +/- 9.95) percent of marker passing to duodenum/5 min, p < 0.0001). Our results suggest that MC induced NM affect brain-gut axis via influencing metabolic and gastric function and decreases body weight.

Pancreatic carcinoma-induced changes in gastric myoelectric activity and emptying.

BACKGROUND/AIMS: Twenty patients with histologically confirmed pancreatic carcinoma without any endoscopic evidence of gastroduodenal obstruction were included in the study. The aim was to determine changes in gastric myoelectric activity and liquid/solid gastric emptying induced by pancreatic tumor. METHODOLOGY: According to TNM/UICC classification patients were divided into two groups A (T2) and B (T3) due to extent of tumor invasion (mainly to retroperitoneum space). In all patients electrogastrography, solid and liquid gastric emptying tests were performed. RESULTS: In the majority of patients of groups A and B the most commonly reported complaints included upper abdominal pain (60% vs. 80%) and icterus (80% vs. 60%). Dyspeptic symptoms were observed in 40% patients of group A and 90% in group B. In group electrogastrography recordings showed dysrhythmia patterns, mostly bradygastria, in 50% of group A patients and in 80% of group B. Liquid/solid gastric emptying were delayed in 20/40% of group A patients and 50/80% of group B. Disorders of gastric myoelectric activity and emptying correlated with tumor stage and location across analyzed groups but not with histology and hyperbilirubinemia levels. CONCLUSIONS: It was observed that solid gastric emptying is affected earlier compared to liquid gastric emptying. Delayed gastric emptying may be attributed to gastric dysrhythmia and/or abdominal pain but not mechanical effects of tumor growth that occur during the course of disease.

Early effects of standard and pylorus-preserving pancreatectomy on myoelectric activity and gastric emptying.

BACKGROUND/AIMS: The main concern about pylorus preserving pancreatectomy (PPP) is delayed gastric emptying (GE). Both cancer and surgical procedures cause damage to the enteric nervous system and induce profound changes in gastric motility and emptying. The aim was to evaluate the effects of primary disease and type of surgical procedure used (standard pancreatoduodenectomy, SP vs. PPP) on myoelectric activity (MA), and solid and liquid GE in pancreatectomy patients. METHODOLOGY: Twenty-eight subjects were included, 18 after Whipple (group A) and 10 after a Traverso (group B) procedure. MA was captured by cutaneous electrodes (Synectics) and simultaneously LGE tested with ultrasonography. On separate days, the SGE of a radiolabelled meal was measured. MA and GE studies were done before and within three months after surgery. RESULTS: Before surgery LGE/SGE were delayed in 5/8 patients in group A and 2/2 in group B. Gastric dysrhythmia was observed in 6 patients in group A and 1 in group B. After PPP, the nasogastric tube was removed within 8.4+/-4.9 days and after SP within 4.6+/-4.1 days. GE studies showed accelerated LGE/SLG in 16/12 and delayed in 6/5 patients, respectively, in group A and B. Dysrhythmia was observed in 16 patients in group A and in 4 in group B. There was a strong relationship between SGE delay and dysrhythmia in patients after PPP. CONCLUSIONS: We conclude that papilla of Vater neoplasia damages mechanisms responsible for gastric emptying to a lesser extent than pancreatic cancer. In patients after PPP, post-operative MA disturbances are partially responsible for delayed GE.

Microchip vagal pacing reduces food intake and body mass.

BACKGROUND/AIMS: Morbid obesity is an increasing problem worldwide. In many patients pharmacotherapy is ineffective and these cases are treated by surgery. Different types of gastroplasty and gastric bypasses have been described. However, all of these ablative surgical methods are irreversible and often replace obesity by other disorders. Neuromodulation of vagal activity is a method of inducing significant changes in stomach motility. We developed a pre-programmed microchip able to pace vagal afferent activity by changing current parameters. The aim of our study was to evaluate long-term effects of vagal neuromodulation on food intake and body mass in rabbits. METHODOLOGY: Twenty-seven healthy male adult New Zealand white rabbits were included into the study and divided into three groups: A, B and C, 9 animals each. Microchips were implanted by laparotomy access. Anesthesia was obtained by continuous intravenous infusion of propofol. Microchips were fixed in the preperitoneal pocket and two electrodes were positioned on the posterior vagus in group A by forward, and in group B by backward pacing. Control group C was sham operated by laparotomy and only vagal nerves preparation was performed. The following parameters were estimated: daily solid food and liquids intake, amount of feces, body mass and heart rate. RESULTS: Within four weeks after operation body mass in group B had decreased up to 12% (P = 0.029), whereas in group A and C changed to -3% and +2%, respectively. An 87% solid food intake was observed in group A, 60% in group B (P < 0.01), and 143% in group C, compared to preoperative period. No significant differences were observed between groups A, B and C for liquids intake. Total feces weight changes corresponded to solid food intake. Heart rate decreased intraoperatively to 78% and 74% in groups A and B, respectively. CONCLUSIONS: Microchip mediated functional gastroplasty significantly reduces food intake and body mass. Obtained results encourage using similar treatment in morbid obesity human patients. However, further studies are required.

[Sphincter of Oddi motility disturbances--etiologic factor or the consequence of choledocholithiasis]. / Zaburzenia motoryki zwieracza Oddiego--czynnik etiologiczny czy skutek przewodowej kamicy zólciowej.

UNLABELLED: Choledocholithiasis is often found in patients after cholecystectomy done previously for cholelithiasis. AIM: To evaluate the effects of cholecystectomy and common bile stones' presence on sphincter of Oddi (SO) motility. MATERIAL: 13 patients with common bile duct stones (2 men and 11 women, age 54 to 85 yrs) were studied. They were divided in two groups: A--6 pts age 54 to 85 yrs (with biliary lithiasis) and group B of 7 pts age 55-71 after cholecystectomy. Cholecystectomized group was further divided into 2 groups according to administration (B1 group) or not (B2) a premedication. METHOD: Sphincter of Oddi manometry was done in all patients as the part of routine ERCP. A water-perfused, low-compliance, triple-lumen manometric system (Synectics Medical Sweden) was used to record the SO tonic and phasic activity. Common bile duct (CBD) pressure, basal SO pressure, SO phasic contractions frequency, duration and amplitude as well as direction of propagation peristaltic waves, motility index (MI) and AuC (area under curve) were measured. RESULTS: The CBD pressure, the basal SO pressure and the frequency of phasic SO waves tended to be lower in patients after cholecystectomy (p > 0.05). We observed profound changes in the motility pattern of SO phasic activity. There was significantly less anterograde and more retrograde waves in patients from group B than A (18.9% vs. 68.8%; p < 0.01 and 52.4% vs. 10.4% respectively; p = 0.01). In the group B1 comparing with group B2 we found significant decrease of frequency (1.8/min +/- 0.53 vs. 3.3/min +/- 0.77; p < 0.05) and increase of the mean amplitude of phasic SO activity (223.2 mmHg +/- 22.9 vs. 137.3 mmHg +/- 25.0; p < 0.01). The duration of pressure waves was prolonged (with long "plateau" or multipeaked) with rapid pressure increase, what resulted in high AuC index (1155.61 +/- 100.42 vs. 515.23 +/- 210.9; p < 0.01). However no difference in MI was observed. CONCLUSION: Our results confirm hypothesis that cholecystectomy influences the pattern of phasic SO motility. Moreover increased percent of retrograde propagation of SO phasic contractions probably contributes to subsequent common duct stones development rather than being the consequences of their presence.

[Interstitial cells of Cajal and their pacemaker function]. / Komórki Cajala i ich funkcja rozrusznikowa.

Interstitial cells of Cajal are known more than 100 years. These cells are proved now as slow wave pacesetters. Ultrastructure and physiologic pacemaker's activity is well described by many authors. Dysfunction of these cells is associated with different pathological states in gastrointestinal tract. Strong relationships between GI motility diseases and qualitative and quantitative changes of ICC are observed. Nowadays most of the gastroenterologists agree that evaluation of these cells should become routine diagnostic procedure. We gave a short review of recent achievements and ideas on interstitial cells of Cajal function in gastroenterology.

[The role of leptin in metabolic regulation]. / Rola leptyny w regulacji metabolizmu.

Leptin discovery--the hormone derived from adipose tissue became a challenging event in understanding food intake and energy balance regulation. Leptin serum level correlates with fat stores and reacts according to changes in energy balance. Although leptin is thought of as a factor preventing obesity, in most of the cases obesity develops in association with increase in serum leptin level which indicates leptin resistance. It may be possible that the primary role of leptin is to mediate the signal for the switch between the starved and fed state. There is a lot of evidence that leptin has systemic effects apart from those related to energy homeostasis, including regulation of neuroendocrine, immune and reproductive function.

[Value of electrogastrographic parameters in evaluation of gastric myoelectrical activity]. / Wartosc parametrów elektrogastrograficznych w ocenie czynnosci mioelektrycznej zoladka.

Electrogastrography (EGG) is presently the only non-invasive method for the evaluation of gastric myoelectrical activity. In relation to the more and more described disturbances of the basic electrical rhythm in different pathological units EGG has been applied on a still larger scale. However, the data obtained from the EGG record do not reflect directly the gastric motility. This method allows only to make an indirect evaluation of the gastric motor disturbances. It still entails a great number of investigations so as to attain a better precisions of the evaluations of its clinical usefulness in gastroenterological diagnostics. This thesis presents the basic information on the methodology, the parameters under evaluation and the clinical application of the EGG method.