Wyniki wyszukiwania

1

Reefs in experimental gastroenterology - cyclic activities of the gastrointestinal tract

100%

Zabielski R.

Journal of Physiology and Pharmacology. Supplement

|

2004

|

tom 55

|

nr 2

19-32

The activity of the upper gastrointestinal tract is periodic. It concerns the gastrointestinal and gallbladder motility, gastrointestinal blood flow, gastric, intestinal, pancreatic and biliary secretions, rate of nutrient absorption, and many other physiological events. Nowadays, the periodic activity of the gastrointestinal tract is considered as a basic physiological pattern in conscious animals and humans. Unfortunately, there are considerable species- and age-related as well as individual differences, therefore experimental protocols should consider first describing the individual periodic pattern in the examined animals. A lot of confusion may appear with data interpretation if the periodic activity is neglected, in particular when low physiological-like doses of test substances are used. For instance, the effect of CCK or VIP administration on the exocrine pancreas may differ from negligible effect to strong one depending of the phase of pancreatic secretion. The action of secretagogues on the gastrointestinal tract will also be discussed in terms of the ultradian and circadian cycles.

2

Neural control of the release and action of secretin

72%

Chey W. Y., Chang T-M.

Journal of Physiology and Pharmacology. Supplement

|

2003

|

tom 54

|

nr 4

105-112

The release and physiological actions of secretin on pancreatic exocrine secretion and gastric secretion of acid and motility are regulated by neuro-hormonal control. The release of secretin by duodenal acidification is mediated by a secretin releasing peptide (SRP). The release and action of SRP are neurally mediated depending on vagal afferent pathway. SRP activity in acid perfusate of the duodenum was substantially decreased when rats were treated with tetradotoxin (TTX), perivagal application of capsaicin, a ß-adrenergic blocker, Met-enkephalin (MEK) or vagotomy. The release of secretin by SRP was abolished in rats treated with TTX, mucosal or perivagal application of capsaicin, MEK or vagotomy. Both release of secretin and pancreatic exocrine secretion (PES) elicited by duodenal acidification were also inhibited dose-dependently by Met-enkepahlin, 5-HT2 antagonist, ketanserin and 5-HT3 antagonist, ondansetron. Stimulation of PES and inhibition of gastric acid secretion and motility by secretin in a physiological dose are also dependent on the vagal afferent pathway as these effects of secretin are abolished by perivagal capsaicin treatment or vagotomy. In conscious rats, vagotomy, vagal ligation, or perivagal colchicine but not capsaicin treatment reduced the number of secretin binding sites in the forestomach suggesting another mode of neural regulation that affects gastric motility. Except in the rat, stimulation of PES by secretin in a physiological dose is profoundly inhibited by atropine indicating the importance of a cholinergic input. In isolated and perfused rat pancreas, electrical field stimulation potentiated secretin-stimulated PES that was suppressed by atropine and anti-GRP serum, suggesting the roles of intrapancreatic cholinergic and GRP-containing neurons. In rats, secretin-stimulated PES was inhibited by a NO synthase inhibitor suggesting mediation by NO. However, the neuropeptides and neurotransmitters involved in regulation of the release and action of secretin and their sites of action remain to be elucidated.

3

The short history of gastroenterology

72%

Srodka A.

Journal of Physiology and Pharmacology. Supplement

|

2003

|

tom 54

|

nr 3

9-21

In this paper research on the stomach and bowel physiology is presented in a historical perspective. The author tries to show how digestive processes were interpreted by the ancients and how they tried to adjust them to the dominating humoral theory of disease. It is pointed out that the breakthrough which created a new way of understanding of the function of the digestive system was made by Andreas Vesalius and his modern model of anatomy. The meaning of acceptance of chemical processes in digestion by iatrochemics representatives in XVII century is shown. Physiological research in XIX century, which decided about a rapid development of physiology, especially the physiology of the gastrointestinal tract, is discussed. Experiments were performed by all main representatives of this discipline: Claude Bernard, Jan Ewangelista Purkynì, Rudolph Heidenhain and especially Ivan Pavlov, who, thanks to the discoveries in the secretion physiology, explained basic functions of the central nervous system. The XX century was dominated by the research showing the important role of the endocrine system and biological agents in the regulation of secretion and motility of the digestive system. The following discoveries are discussed: Ernest Sterling (secretin), John Edkins (gastrin) and André Latarjet and Lester Dragstedt (acetylcholine). It is underlined that Polish scientists play an important role in the development of the gastroenterological science - among others; Walery Jaworski, who made a historical suggestion about the role of the spiral bacteria in etiopathogenesis of the peptic ulcer, Leon Popielski, who stated the stimulating influence of histamine on the stomach acid secretion, Julian Walawski, who discovered enterogastrons - hormones decreasing secretion. As a supplement, there is the list of achievements in the field of the physiology and pathology of the gastrointestinal tract awarded with Nobel Prize and the list of most important Polish papers in this field.

4

Gastric secretion - from Pavlov's NERVISM to Popielski's histamine as direct secretagogue of oxyntic glands

72%

Konturek S. J.

Journal of Physiology and Pharmacology. Supplement

|

2003

|

tom 54

|

nr 3

43-68

Gastric acid and pepsin secretions result from the interplay of neurohormonal factors with stimulatory and inhibitory actions on oxyntic glands. At the turn of XIX century, the notion of nervism or entire neural control of digestive functions, developed by Pavlov prevailed. However, in the second part of XX century, hormonal control has been thought to play a major role in the mechanism of gastric secretion, especially gastrin, which was isolated and synthesized in 1964 by Gregory. Polish traces in gastroenterological history started with the discovery of histamine, a non-nervous and non-gastrin compound in oxyntic mucosa by L. Popielski in 1916, who found that this amine is the most potent and direct stimulant of gastric acid secretion. This histamine concept was supported by leading American gastroenterologists such as A.C. Ivy, championed later by C.F. Code, and clinically applied for testing gastric secretion by K. Kowalewski. Recently, it received a strong support from pharmacological research when J. Black designed H2-receptors antagonists, which were first discovered by M.I. Grossman and S.J. Konturek to inhibit not only histamine-, but also meal- and vagally-induced gastric acid secretion, thus reinforcing the notion of the crucial significance of histamine in the control of gastric secretion as the final common chemostimulator. In conclusion, Polish traces appear to be substantial in gastric history due: 1) to discovery by Popielski that histamine is a major, direct stimulus of gastric secretion; 2) to clinical application of this agent by Kowalewski in testing maximal gastric secretory activity; and 3) to clinical use of histamine H2-antagonists in control of gastric acid secretion and treatment of peptic ulcers.

5

Helicobacter pylori infection in pathogenesis of gastroesophageal reflux disease

72%

Thor P. J., Blaut U.

Journal of Physiology and Pharmacology. Supplement

|

2006

|

tom 57

|

nr 3

81-90

Gastroesophageal reflux disease (GERD) refers to the very common and constantly increasing conditions where reflux of gastric contents into the esophagus leads to development of characteristic symptoms. The esophagus, LES and stomach can be envisioned as single functional unit controlled by neuro-hormonal factors. The abnormalities that contribute to GERD can start in any component of this unit, resulting particularly from disturbances in their control system. It is extremely important to identify factors and mechanisms leading to functional failure of this system so that causative therapy can be effectively applied. The key-role has been attributed to parasympathetic dysfunction, which may adversely affect motor activity of this area by increasing transient LES relaxation number and impairing LES pressure, esophageal acid clearance and motility of the proximal stomach. Recently, numerous investigations have been performed to elucidate the role of Helicobacter pylori (Hp) infection in GERD pathogenesis with the most concern given to its potency to increase gastric acid secretion. However, it appeared that this infection leads to much more complex changes in gastric mucosa including modification of afferent neural signals and specific gastric hormones release. Plasma ghrelin level is low in subjects infected and increases significantly after eradication. Since ghrelin, beside potency to increase gastric secretion has strong prokinetic action on LES functional unit, this phenomenon together with impaired vagal control may contribute to the Hp infection or eradication - related GERD development. Thus, ghrelin and vagal activity could be the missing links that partially explains relationship between GERD and Hp infection.

6

Gastric secretion in H.pylori infection

72%

McColl K. E. L., El-Omar E., Gillen D.

Journal of Physiology and Pharmacology. Supplement

|

1997

|

tom 48

|

nr 1

7

Helicobacter pylori infection and gastric secretion in duodenal and gastric ulcer patients - the effect of eradication after one year

72%

Laszewicz W., Zaremba-Woroniecka A., Gabryelewicz A.

Journal of Physiology and Pharmacology. Supplement

|

1997

|

tom 48

|

nr 1

8

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Prostaglandin E receptor subtypes involved in stimulation of gastroduodenal bicarbonate secretion in rats and mice

72%

Takeuchi K., Ukawa H., Furukawa O., Kawauchi S., Araki H., Sugimoto Y., Ishikawa A., Ushikubi F., Narumiya S.

Journal of Physiology and Pharmacology

|

1999

|

tom 50

|

nr 2

9

SU-840, a novel synthetic flavonoid derivative of sophoradin, with potent gastroprotective and ulcer healing activity

72%

Brzozowski T., Konturek S. J., Kwiecien S., Pajdo R., Drozdowicz D., Sliwowski Z., Muramatsu M.

Journal of Physiology and Pharmacology

|

1998

|

tom 49

|

nr 1

10

Effect of local injection with basic fibroblast growth factor (BFGF) and neutralizing antibody to BFGF on gastric ulcer healing, gastric secretion, angiogenesis and gastric blood flow

72%

Ernst H., Konturek P. C., Hahn E. G., Stosiek H. P., Brzozowski T., Konturek S. J.

Journal of Physiology and Pharmacology

|

2001

|

tom 52

|

nr 3

11

Helicobacter pylori and its involvement in gastritis and peptic ulcer formation

58%

Konturek S. J., Konturek P. C., Konturek J. W., Plonka M., Czesnikiewicz-Guzik M., Brzozowski T., Bielanski W.

Journal of Physiology and Pharmacology. Supplement

|

2006

|

tom 57

|

nr 3

29-50

Modern gastroenterology started in early 19th century with the identification by W. Prout of the inorganic (hydrochloric) acid in the stomach and continued through 20th century with the discoveries by I.P. Pavlov of neuro-reflex stimulation of gastric secretion for which he was awarded first Nobel Prize in 1904. When concept of nervism or complete neural control of all digestive functions reached apogeum in Eastern Europe, on the other side of Europe (in United Kingdom), E. Edkins discovered in 1906 that a hormone, gastrin, may serve as chemical messenger in stimulation of gastric acid secretion, while L. Popielski revealed in 1916 that histamine is the most potent gastric secretagogue. K. Schwartz, without considering neural or hormonal nature of gastric secretory stimulation, enunciated in 1910 famous dictum; “no acid no ulcer” and suggested gastrectomy as the best medication for excessive gastric acid secretion and peptic ulcer. In early 70s, J.W. Black, basing on earlier L. Popielski’s histamine concept, identified histamine-H2 receptors (H2-R) and obtained their antagonists, which were found very useful in the control of gastric acid secretion and ulcer therapy for which he was awarded in 1972 second Nobel Prize in gastrology. With discovery by G. Sachs in 1973 of proton pumps and their inhibitors (PPI), even more effective in gastric acid inhibition and ulcer therapy than H2-R antagonists, gastric surgery, namely gastrectomy, practiced since first gastric resection in 1881 by L. Rydygier, has been considered obsolete for ulcer treatment. Despite of the progress in gastric pharmacology, the ulcer disease remained essentially “undefeated” and showed periodic exacerbation and relapses. The discovery of spiral bacteria in the stomach in 1983 by B.J. Marshall and R.J. Warren, Australian, clinical researches, awarded in 2005 the Nobel Prize for the third time in gastrology, has been widely considered as a major breakthrough in pathophysiology of gastritis and peptic ulcer, which for the first time can be definitively cured by merely eradication of germ infecting stomach. This overview presents the mechanism of induction of gastritis and peptic ulcer by the H. pylori infection and describes accompanying changes in gastric acid and endocrine secretion as well as the effects of germ eradication on gastric secretory functions and gastroduodenal mucosal integrity

12

Gastric analysis with fractional test meals [ethanol, caffeine, and peptone meal], augmented histamine or pentagastrin tests, and gastric pH recording

58%

Kwiecien S., Konturek S. J.

Journal of Physiology and Pharmacology. Supplement

|

2003

|

tom 54

|

nr 3

69-82

For centuries it was recognized that the stomach produces a juice, which has acidic properties, however, it was not until 1824 when Prout demonstrated the presence of hydrochloric acid in gastric juice. At the same time experiments on a patient with gastric fistula began by W. Beaumont showing alterations of acid secretion after meals and under various psychological conditions. After the discovery by L. Popielski in 1920 that histamine is a direct stimulant of oxyntic glands, histamine started to be used in the 1930s in gastric secretory tests. Then in 1949 the dose of histamine was established by K. Kowalewski to induce in humans maximal gastric secretion and in 1953 Kay from UK, using a similar dose of histamine (0.04 mg/kg), introduced augmented histamine test to determine maximal acid output. The digestive period of gastric secretion can be divided into 3 phases: cephalic phase, gastric phase, and intestinal phase. When an acidified meal reaches the antrum or proximal part of the small intestine, the inhibitory autoregulatory mechanisms are triggered. Using a peptone meal as a physiological stimulant of gastric secretion, Fordtran and Walsh designed in 1973 the intragastric titration method. Histamine stimulates H1 and H2 receptors, producing some side effects so Betazole (Histalog), an analogue of histamine was introduced, because of smaller side effects than with histamine. In 1967, pentagastrin, which contains a C-terminal amino-acid sequence of gastrin and does not exert serious side effects, was applied first in Poland as a stimulant of gastric acid secretion instead of histamine. At the present time, a 12 or 24 h pH-metry with a magnetic recording of gastric acidity using the Digitrapper was found to have a greater diagnostic value in assessment of gastric acid secretion under natural conditions including meal than classic gastric secretory tests. This technique has been widely used in detecting the duodeno-gastric or gastro-esophageal reflux (GERD) and testing various drugs affecting gastric acid secretion and healing acid-pepsin disorders.

13

Helicobacter pylori infection and gastric secretion in duodenal and gastric ulcer patients - the effect of eradication after one year

58%

Laszewicz W., Zaremba-Woroniecka A., Gabryelewicz A.

Journal of Physiology and Pharmacology

|

1997

|

tom 48

|

nr 3

14

Effect of central and peripheral actions of histamine and its metabolite N-alpha methyl histamine on gastric secretion and acute gastric lesions

58%

Kwiecien S., Brzozowski T., Konturek P. C., Konturek S. J., Pawlik M., Pajdo R., Drozdowicz D., Ptak A., Hahn E. G.

Journal of Physiology and Pharmacology

|

2001

|

tom 52

|

nr 4,1

Nalpha-methylhistamine (Nalpha-MH) is one of unusual metabolite of histamine that was found in Helicobacter pylori-infected stomach and is believed to interact with specific histamine H1,H2 and H3-receptors to stimulate gastric acid secretion and gastrin release from isolated G-cells but the effects of Nalpha-MH on gastric mucosal integrity have been little studied. This study was designed; 1) to compare the effect of intraperitoneal (i.p.), intracerebroventricular (i.c.v.) and gastric topical (intragastric i.g.) application of exogenous Nalpha-MH with that of standard histamine on gastric secretion in rats equipped with gastric fistula (series A) and 2) to compare the effect of i.c.v. administration of histamine and Nalpha-MH with that of peripheral (i.p. and i.g) application of these amines on gastric lesions induced by 100% ethanol (series B) in rats with or without capsaicin-induced deactivation of sensory nerves. The area of gastric lesions was determined planimetrically, gastric blood flow (GBF) was assessed by H2-gas clearance method and venous blood was collected for determination of plasma gastrin levels by RIA. Nalpha-MH and histamine (0.1—10 mg/kg i.p. or i.g.) dose-dependently increased gastric acid output (series A); whereas i.c.v. administration of histamine or Nalpha-MH inhibited dose-dependently this secretion; the dose attenuating gastric acid output by 50% (ED50) being 4 and 6 µg/kg i.c.v. Both, Nalpha-MH and histamine (2 mg/kg i.p. and i.g.) attenuated significantly the area of gastric lesions induced by 100% ethanol (series B) while producing significant rise in the GBF and plasma immunoreactive gastrin increments. Central application of Nalpha-MH and histamine (0.01—5 µg/kg i.c.v.) inhibited ethanol-induced gastric damage whereas higher doses ranging from 10—100 µg/kg of histamine and Nalpha-MH were significantly less effective. Capsaicin-induced deactivation of sensory nerves by itself augmented significantly ethanol damage and attenuated significantly the protective and hyperemic effects of histamine and its methylated analog applied i.p. but failed to affect significantly those caused by i.c.v. administration of these amines. We concluded that: 1) central histamine and Nalpha-MH inhibits gastric acid secretion and exhibits gastroprotective activity against ethanol in similar manner to that afforded by parenteral and topical histamine and N- MH, 2) central N-alphaMH- and histamine-induced protection involve the enhancement in gastric microcirculation unrelated to neuropeptides released from capsaicin-sensitive afferent nerves, and 3) the major difference between central and peripheral histamine and its methylated analog is the influence on gastric acid secretion which does not appear to play any major role in gastroprotective activity of these agents.

15

Eradication of Helicobacter pylori and gastrin-somatostatin link in duodenal ulcer patients

58%

Konturek J. W., Bielanski W., Konturek S. J., Domschke W.

Journal of Physiology and Pharmacology

|

1996

|

tom 47

|

nr 1

16

Dysfunction in gastric myoelectric and motor activity in Helicobacter pylori positive gastritis patients with non-ulcer dyspepsia

58%

Thor P., Lorens K., Tabor S., Herman R., Konturek J. W., Konturek S. J.

Journal of Physiology and Pharmacology

|

1996

|

tom 47

|

nr 3

17

Gastric secretion and ulcer healing in mouse stomach infected with cytotoxin expressing strain of Helicobacter pylori

58%

Brzozowski T., Konturek P. C., Konturek S. J., Karczewska E., Pajdo R., Stachura J., Ghiara P., Hahn E. G.

Journal of Physiology and Pharmacology

|

1998

|

tom 49

|

nr 3

18

Brain-gut axis; historical background and present development

58%

Konturek S. J.

Journal of Physiology and Pharmacology. Supplement

|

2001

|

tom 52

|

nr 2

19

Brain-gut and appetite regulating hormones in the control of gastric secretion and mucosal protection

51%

Konturek S. J., Brzozowski T., Konturek P. C., Schubert M. L., Pawlik W. W., Padol S., Bayner J.

Journal of Physiology and Pharmacology. Supplement

|

2008

|

tom 59

|

nr 2

The progress in basic and clinical gastrology indicates that gastric mucosal integrity represents a balance between offensive and defensive factors. The main offensive factors appear to be gastric acid and pepsin under health conditions, while the non-steroidal anti-inflammatory drugs (NSAID) and Helicobacter pylori (H. pylori), infecting this mucosa, are currently considered the most important “aggressive” factors under pathological conditions. To the list of the aggressive factors, also stress, certain cytokines (TNF-, IL-8, IL-11 and IL-18) and oxygen or nitrogen free radicals should be added. The aims of this review is the presentation of the involvement of aggressive and protective factors in the control of gastric acid secretion and appetite regulating hormones in maintaining gastric mucosal integrity and its protection against damaging factors.

20

Helicobacter pylori and impaired gastric secretory functions associated with duodenal ulcer and atrophic gastritis

51%

Konturek P. C., Konturek S. J., Bobrzynski A., Kwiecien N., Obtulowicz W., Stachura J., Hahn E. G., Rembiarz K.

Journal of Physiology and Pharmacology

|

1997

|

tom 48

|

nr 3

Ograniczanie wyników

Reefs in experimental gastroenterology - cyclic activities of the gastrointestinal tract

Neural control of the release and action of secretin

The short history of gastroenterology

Gastric secretion - from Pavlov's NERVISM to Popielski's histamine as direct secretagogue of oxyntic glands

Helicobacter pylori infection in pathogenesis of gastroesophageal reflux disease

Gastric secretion in H.pylori infection

Helicobacter pylori infection and gastric secretion in duodenal and gastric ulcer patients - the effect of eradication after one year

Prostaglandin E receptor subtypes involved in stimulation of gastroduodenal bicarbonate secretion in rats and mice

SU-840, a novel synthetic flavonoid derivative of sophoradin, with potent gastroprotective and ulcer healing activity

Effect of local injection with basic fibroblast growth factor (BFGF) and neutralizing antibody to BFGF on gastric ulcer healing, gastric secretion, angiogenesis and gastric blood flow

Helicobacter pylori and its involvement in gastritis and peptic ulcer formation

Gastric analysis with fractional test meals [ethanol, caffeine, and peptone meal], augmented histamine or pentagastrin tests, and gastric pH recording

Helicobacter pylori infection and gastric secretion in duodenal and gastric ulcer patients - the effect of eradication after one year

Effect of central and peripheral actions of histamine and its metabolite N-alpha methyl histamine on gastric secretion and acute gastric lesions

Eradication of Helicobacter pylori and gastrin-somatostatin link in duodenal ulcer patients

Dysfunction in gastric myoelectric and motor activity in Helicobacter pylori positive gastritis patients with non-ulcer dyspepsia

Gastric secretion and ulcer healing in mouse stomach infected with cytotoxin expressing strain of Helicobacter pylori

Brain-gut axis; historical background and present development

Brain-gut and appetite regulating hormones in the control of gastric secretion and mucosal protection

Helicobacter pylori and impaired gastric secretory functions associated with duodenal ulcer and atrophic gastritis