PubMed Health⌕ Search

Biomedical subjects

T Gerner

Publications and source records attributed to T Gerner.

33 records · Page 2Linked to original sources
PubMed1985

Inhibitory effects of dopamine and isoprenaline on antral motor activity stimulated by acetylcholine or physostigmine in vitro.

Continuous pressure recordings were made in guinea-pig antral pouches in vitro. The antral phasic activity was stimulated by acetylcholine and by the cholinesterase inhibitory agent physostigmine. Dopamine and isoprenaline both significantly impaired antral pressure responses to physostigmine, whereas the acetylcholine-induced response was not significantly reduced. This suggests that both dopamine and isoprenaline to some extent act by reducing the spontaneously released acetylcholine, suggesting that both drugs act on intramural cholinergic neural pathways.

Acetylcholine↗
PubMed1979

The effects of mepyramine and cimetidine on the motor responses to histamine, cholecystokinin, and gastrin in the fundus and antrum of isolated guinea-pig stomachs.

Guinea-pig stomachs were isolated in organ baths, and recordings made of fundal and antral responses. Cholecystokinin (CCK-PZ), 0.38 U/ml, gastrin, 0.05 microgram/ml, and acetylcholine, 10(-4)M, produced typical responses: raised base line in the fundus and increased amplitudes of rhythmic contractions in the antrum. The antral responses to gastrin were too small to quantitate. Both fundal and antral responses to 5 x 10(-4)M histamine consisted of an increase in base line without an alteration in amplitudes. Mepyramine, 3.2 x 10(-5)M, reduced the spontaneous activity in the fundus. It also inhibited fundal responses to gastrin and responses to histamine and CCK-PZ in both pouches. The fundal response to acetylcholine was unaffected by mepyramine, but the antral response seemed to be partially reduced (p less than 0.06). Cimetidine affected neither spontaneous activity nor motor responses. The results indicate that the motor response to histamine is mediated via H1-receptors and that these receptors may also be involved in the fundal response to CCK-PZ and gastrin. The inhibition of the antral responses by mepyramine may be due to unspecific anticholinergic action.

Acetylcholine↗
PubMed1979

Pressure responses to OP-CCK compared to CCK-PZ in the antrum and fundus of isolated guinea-pig stomachs.

To document that the previously demonstrated excitatory effects of cholecystokinin-pancreozymin--about 20% purified and containing approximately 500 U/mg (CCK-PZ 20%)--on isolated guinea-pig antrum and fundus are caused by the hormone itself, and not by impurities, the effect of the synthetic C-terminal octapeptide (OP-CCK) was tested and compared with that of CCK-PZ 20%. The qualitative effects were similar for the two hormones, characterized by increased amplitudes of rhythmic activity in the antrum and by elevated basal tension in the fundus. The calculated maximal responses were about the same for the two substances, but OP-CCK was 3--6 times more potent than CCK-PZ 20%. Atropine and tetrodotoxin markedly reduced the antral response to OP-CCK, while the fundal response was only slightly, but significantly, reduced. This indicates that the antral response to OP-CCK is mediated mainly through local neural cholinergic pathways, while the fundal response is less dependent on these, corresponding to our previous results for CCK-PZ 20%. While previous reports indicate that OP-CCK shares the pharmacological characteristics of partially purified CCK-PZ with regard to its effect on other organs, the present study confirms a corresponding relationship between OP-CCK and CCK-PZ 20% on gastric motility in guinea-pigs, suggesting that the actions of CCK-PZ 20% are displayed by the hormone itself, and not by impurities.

Animals↗
PubMed1978

The inhibitory effect of secretin and glucagon on pressure responses to cholecystokinin-pancreozymin in isolated guinea-pig stomach.

Pressure responses in guinea-pig antral and fundal pouches were investigated in vitro. Secretin and glucagon in concentrations that did not significantly alter spontaneous activity significantly reduced antral responses to cholecystokinin, but had no depressive effect on the fundal responses. The antral inhibition of CCK-PZ may be specific, since responses to acetylcholine were unaffected by secretin and glucagon. The changes produced by secretin and glucagon in the antral dose-response curve to CCK-PZ suggest that the inhibition might be of a non-competitive type.

Acetylcholine↗
PubMed1978

Interactions of cholecystokinin (CCK-PZ) and gastrin on motor activity of isolated guinea-pig antrum and fundus.

Pressure responses to cholecystokinin (CCK-PZ, approximately 500 U/mg) and gastrin (human synthetic gastrin) were investigated in isolated guinea-pig antral and fundal pouches. Both drugs stimulated motor activity, in the antrum mainly by increasing amplitudes and rhythmic activity, in the fundus by increasing basal tension. Antral responses to gastrin were markedly smaller than to CCK-PZ, while the differences were less pronounced in the fundus. Prestimulation with gastrin, being an agonist by itself, significantly reduced the antral responses to submaximal doses of CCK-PZ, while no inhibition was found in the fundus. When pre-exposed to gastrin, the antral dose-response curve to CCK-PZ was flattened, with reduced maximal response, simulating a non-competitive interaction. It seems that gastrin behaves like a partial agonist to CCK-PZ on guinea-pig antral smooth muscle.

Animals↗
PubMed1977

The influence of graded distension and carbachol on the motor response to cholecystokinin in isolated guinea-pig antrum and fundus.

Graded distension increased the motor response to cholecystokinin and acetylcholine both in antral and fundal pouches. The increase became even more obvious when the pressure responses were converted into changes in wall tension. The responses to cholecystokinin were additive with low doses (10(-7)M) of carbachol, but diminished or abolished by prestimulation with higher doses. The results indicate that the increased response to cholecystokinin after distension is due to increased smooth muscle stretch.

Acetylcholine↗
PubMed1977

The role of local cholinergic pathways in the motor response to cholecystokinin and gastrin in isolated guinea-pig fundus and antrum.

Both cholecystokinin (CCK-PZ) and gastrin stimulated antral rhythmic activity and raised fundal basal pressure. The antral motor effects were significantly blocked by pretreatment with atropine or tetrodotoxin. The fundal motor responses were almost unaffected. It is concluded that CCK-PZ and gastrin exert their antral motor effects essentially through local cholinergic neural pathways, while the motor responses in the fundus are almost entirely independent of these pathways.

Animals↗
PubMed1976

Pressure-responses to cholecystokinin in the fundus and antrum of isolated guinea-pig stomachs.

Cholecystokinin produced dose-dependent increases in motor activity in antral and fundal pouches of isolated guinea-pig stomachs. The response was immediate; the motor activity increased to a peak within 2 min, then decreased somewhat, but stabilized within 5 min at a value that was higher than before addition of cholecystokinin. In the antral pouches the response consisted of an increase in the amplitude of the rhythmic contractins; in the fundal pouch it was seen as an increase in basal pressure. The antral response was significantly greater in pouches distended to an initial basal pressure of 15-25 cm H2O than in undistended pouches. The fundal reponse was not enhanced by distension.

Animals↗
PubMed1975

The heterogeneity of the serum activity of gamma-glutamyl transpeptidase in hepatobiliary diseases as studied by agarose gel electrophoresis.

Using electrophoresis on agarose gel, the serum activity of gamma-GT in various hepatobiliary diseases has been separated into several electrophoretic fractions. Predominance of activity was always found in fractions corresponding to either alpha1-, alpha2- or beta-globulins. The predominant activity fractions have been related to the various disease states and to the zymogram patterns of gamma-GT found in bile and tissue homogenates of liver, bile duct and pancreas. Bile disclosed activity in the beta-region, tissue homogenates of liver mostly in the alpha1- and alpha2- areas, bile dict showed very faint activity in the alpha1- position, while extracts of pancreas revealed activity in the regions of alpha2, alpha2-beta and beta-gamma. In serum, dominance of alpha1-activity was found in all cases associated with alcoholism and alcoholic cirrhosis, this activity also appeared as the most frequent dominant one in biliary obstruction. Predominance of alpha2 and/or the beta-fraction in most cases occurred associated with malignant processes involving liver and/or pancreas.

Alcoholism↗
PubMedDate not supplied

Persistent sciatic artery. Case report.

In a man with ischemia of the right leg due to embolism of popliteal artery, arteriography following failure of embolectomy via the common femoral artery revealed the internal iliac artery continuing as an aneurysmally dilated sciatic artery distally to the popliteal artery. The aneurysm was ligated and bypass established from the common femoral to the popliteal artery.

Aneurysm↗