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Biomedical subjects

M Papp

Publications and source records attributed to M Papp.

At least 109 records · Page 6Linked to original sources
PubMed1984

Ranitidine inhibits the trophic effect of caerulein on the pancreas in rats (preliminary data).

The aim of this study was to establish whether ranitidine treatment influences the trophic effect of caerulein on the pancreas of rats. Ranitidine (20 mg/kg b.w.), caerulein (1 microgram/kg b.w.) were applied for 7 days alone, or combined with caerulein, given intraperitoneally twice a day. Saline treated rats served as control. Caerulein increased pancreatic weight, total pancreatic protein, trypsin, amylase and RNA contents. Ranitidine when given alone did not influence pancreatic growth and composition. When ranitidine, however, was combined with caerulein, it abolished the trophic effect of caerulein on the pancreas. The trophic effect of caerulein on rat pancreas could be abolished by H2-receptor antagonist (ranitidine) treatment. The authors suggest that the drug exerts its inhibitory effect on the acinar cells directly.

Amylases↗
PubMed1984

Neuroeffector transmission of the hepatic and pancreatico-duodenal isolated arteries of the dog.

Direct evidence has been obtained that the neurogenic responses of the hepatic and pancreatico-duodenal arteries of the dog are mainly due to norepinephrine released from varicosities and that this effect is mediated via alpha 1-adrenoceptors. In addition, there is a prazosin-resistant response to nerve stimulation that is certainly not mediated via alpha 2-adrenoceptors. These vessels are 10-100 times less sensitive to applied norepinephrine than the great majority of peripheral arteries; however, the pA2 value for prazosin (7.5) is the same as in other systems. The varicose terminal plexus is located deep in the media, as shown by electron microscopic study. Findings indicate that these gastrointestinal arteries are mainly controlled by adrenergic innervation, that their density is as high as that of any other vessel, and that these arteries might be much less influenced by the circulating catecholamines than others. The neuroeffector transmission of hepatic and pancreatico-duodenal arteries is subject to presynaptic modulation. Muscarinic (oxotremorine) and P1 (adenosine) receptor agonists are effective inhibitors of transmission, whereas xylazine surprisingly has no effect.

Animals↗
PubMed1984

Development of intraductal protein plugs in rats fed with ethanol for 18 months.

The pancreatic tissue damage was investigated histologically in rats kept on liquid diet containing 6% ethanol for 18 months. Rats kept on a liquid diet without ethanol served as controls. The daily ethanol intake was 1.2 g/100 g b.w. The daily intake of liquid food was 26 ml/100 g b.w. (26 cal/100 g b.w.) (108 Joule/100 g b.w.) without ethanol and about the same (24 ml/100 g b.w.) with ethanol. Mortality rate was 75% in the group fed with ethanol and 30% in the control group. Ethanol decreased both body weight and pancreatic weight but did not effect the relative pancreatic weight. In histological sections no difference in character, intensity or extent of the damage was observed between the ethanol fed rats and controls. In both groups there were protein plugs in the pancreatic ducts and ductules. The noncalcified intraductal protein plugs are thought to have been induced by the protein precipitant effect of the tissue fixative applied in histology.

Alcoholism↗
PubMed1981

Comparative histochemical and immunofluorescent observations in thiamine deficient encephalopathies.

Histochemical and immunohistological examinations were carried out at different stages of thiamine-deficient encephalopathy in rats. The respiratory enzymatic activity decreased in the most damaged area correlating well with the neuropathological findings. There was an inverse relationship between the damaged area and its marginal zone; the latter showed an increase of the same enzymatic activity. The capillary network and the activity of the vessel walls seemed to be almost unimpaired. The immunohistological investigations showed only a moderate extravasation of the plasma proteins.

Acetylcholinesterase↗
PubMed1980

Incorporation of 3H-2,3-DL-valine into pancreatic proteins of adrenalectomized rats stimulated with pancreozymin-CCK and secretin.

Incorporation of labelled valine was investigated in bilaterally adrenalectomized rats stimulated with pancreozymin-CCK and secretin 14 days after operation. The growth of rats, the blood pressure, the amount of pancreatic juice and the amylase output was less in the adrenalectomized animals as compared with sham operated or adrenalectomized and corticosterone substituted controls. The amylase concentration in the pancreatic juice reveals no difference between the groups but the output of amylase remained below that of the controls. The incorporation of labelled valine was higher in the pancreatic tissue and proteins in the adrenalectomized animals than in the controls. It is assumed that the adrenalectomy causes primarily a depletion in the metabolic activity and systemic blood pressure; diminished pancreatic juice secretion and output of amylase are only secondary consequences which are not compensable by hormonal stimulation of pancreatic secretion.

Adrenalectomy↗
PubMed1980

Exit routes for secretory proteins from the dog pancreas.

UNLABELLED: The relative importance of the pancreatic venous and lymphatic routes for the transport of enzymes away from the pancreas was investigated. The activities of lipase and amylase were compared in arterial plasma, pancreaticoduodenal lymph and venous plasma, pancreatic interstitial fluid and juice in 31 anaesthetized dogs. Enzyme activities were determined before, during and after stimulation of the acinar parenchyma by 4 U/kg b.w. secretin + CCK-PZ for 60 min. During stimulation either is the juice secreted into the duodenum or we ligated the main pancreatic duct. Enzyme output was calculated as the volume x enzyme activity. Initial activities of both enzymes were higher in lymph than in plasma samples. Pancreatic stimulation raised the level of both enzymes in plasma. Stimulation raised lymph lipase activity higher than in plasma, even without duct ligation. Duct ligation increased enzyme activities to considerably higher values in oedema fluid than in lymph. When enzyme output in the stimulated juice for 60 min was considered 100%, output in plasma volume (5% of b.w.) was about 15% both for lipase and for amylase during stimulated secretion, 25--30% for both enzymes when duct had been ligated. Lymphatic enzyme output was found negligible. CONCLUSIONS: during pancreatic stimulation biologically important amounts of secretory proteins enter the blood circulation. The lymphatic transport is negligible, since pancreatic lymph flow is several hundred times less than blood flow.

Amylases↗
PubMed1978

The hepatic tissue spaces.

In a controlled study concerned with the site of intrahepatic lymph formation, liver tissue from normal dogs, cats, rats and from cats with ligated hepatic lymph vessels, was subjected to light and electron microscopy. It was found that the periportal space named after Mall by whom it had been described, represents an interstitial gap of submicroscopic size. It is bordered on the one side by the hepatocytes of the limiting plate and on the other by the connective tissue fibres and processes of the connective tissue cells of the portal canal. The relationships between the perisinusoidal (Disse) space and the periportal tissue-gap have been clarifed and their role in the formation of hepatic lymph is discussed.

Animals↗
PubMed1977

Absorption of pancreatic lipase from the duodenum into lymphatics.

A significantly higher lipase activity was measured in the duodenal lymph samples of 15 dogs than in each of corresponding arterial blood plasma samples collected prior to, during and after maximal hormonal stimulation of pancreatic secretion. The result may be evaluated as a sign of pancreatic lipase absorption by the duodenum into lymphatics.

Animals↗