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Biomedical subjects

F Berti

Publications and source records attributed to F Berti.

At least 163 records · Page 9Linked to original sources
PubMed1979

The role of histamine H1- and H2-receptors in the generation of thromboxane A2 in perfused guinea-pig lungs.

1. When isolated perfused lungs from normal and ovalbumin sensitized guinea-pigs were challenged with histamine and 2-methylhistamine (agonists for H1-receptor), a release of thromboxane A2-like substance was observed. The effect of histamine on production of thromboxane A2 (TXA2) in sensitized lungs, was more pronounced than in normal lungs (P less than 0.01). 2. Specific activation of histamine H2-receptors in normal lungs with large doses (100 micrograms) of dimaprit and 4-methylhistamine, does not produce thromboxane-like or prostaglandin-like substances. 3. Perfusion of the lungs with pyrilamine (10 micrograms/ml) inhibited the release of arachidonate metabolites induced by histamine H1-receptor stimulation, whereas cimetidine (5 micrograms/ml) was ineffective. 4. It is concluded that only the stimulation of histamine H1-receptors appears to be responsible for generation of thromboxane A2 and other prostaglandin-like substances in normal guinea-pig lungs. In sensitized lungs, an increased ability of histamine to release TXA2 could be due to a possible interconversion of H2 into H1-receptors.

Adenosine Triphosphate↗
PubMed1978

Genotype dependent response of morphine and methionine-enkephalin on the electrically induced contractions of the mouse vas deferens.

Analgesia and locomotor activity are genetically differentiated in C 57 and DBA mice. In fact, DBA strain, unlike C 57, is very sensitive to the analgesic effects of morphine. On the contrary, morphine elicits an increase of locomotor activity only in C 57 mice. We have used this genetic approach to study the in vitro response of vas deferens contractions to morphine and methionine-enkephalin. The results obtained are the following: 1. The percentage of morphine inhibition of the electrically evoked contractions of the longitudinal muscle of the vas deferens is greater in DBA strain, which is sensitive to the analgesic effects of morphine, than in C 57 mice in which morphine exerts a stimulating effect of the locomotor activity; 2. Met-enkephalin has been found to be more active than morphine on the same preparation; 3. The inhibitory effects of Met-enkephalin appear to be greater in C 57 than in DBA mice; 4. Different doses of Naltrexone are required to reverse the effects of morphine and Met-enkephalin; 5. Cumulative doses of Met-enkephalin and morphine induce different responses in the vas deferens of C 57 and DBA mice. The results emphasize the usefulness to study analgesic activity in these strains of mice.

Animals↗
PubMed1978

Pharmacological activity of PGI2 and its metabolite 6-oxo-PGF1alpha on human uterus and fallopian tubes.

The actions of prostacyclin (PGI2) and its stable metabolite 6-OXO-PGF1alpha were investigated in strips of normal human uterus and in fallopian tubes. Both compounds were also compared with natural prostaglandins (PGE2, PGF2alpha and PGD2). PGI2 showed biphasic response both in uterus and fallopian tubes qualitatively and quantitatively similar to that induced by PGE2 and PGD2; prostacyclin was also able to inhibit the spasmus induced by PGF2alpha but not that induced by BaCl2 and vasopressin. 6-0XO-PGF1alpha on the other hand induced only small contractions on both tissues investigated. The authors discusse the possible implication of these findings in the physiology of the reproductive system.

Epoprostenol↗
PubMed1978

Inhibition of harmaline induced tremors by 16 (S)-16-methyl PGE2 in different mammalian species: a correlation with central cyclic nucleotides and prostaglandins.

Harmaline, an alcaloid of Paganum Armala, induces tremors of central origin and increases cerebellar cGMP without affecting cortical and cerebellar prostaglandin levels. 16(S)-16-methyl PGE2 protects the animals against the seizures induced by the alcaloid and prevents the concomitant rise in cerebellar cGMP. Experiment performed in cats and limited to pharmacological observations, confirmed that, the PGE2 derivative, is a powerful antitremorogenic agent at doses that are devoid of appreciable side effects.

Alkaloids↗
PubMed1977

The mode of action of aescin and the release of prostaglandins.

The horse-chestnut saponin Aescin, an anti-exudative compound, induces contraction of isolated portal vein of rat and rabbit. This effect appears to be mediated by Prostaglandins of Falpha type. The ability of Aescin to stimulate generation and release of Prostaglandins has been demonstrated in isolated lung of the rat. Mass-fragmentographic analysis of the lung effluent indicate that when Aescin is perfused through this organ the release of PGF2alpha is increased. The capability of Aescin to generate Prostaglandins is discussed in connection with its anti-exudative activity.

Animals↗
PubMed1976

A cholinoceptor antiserum: its pharmacological properties.

1 Sera of rabbits immunized against a nocotinic receptor-rich fraction, obtained from the electric organ of Torpedo marmorata, were tested for their pharmacological activity on different in vitro preparations. 2 Sera containing antibodies against the nicotinic receptor blocked neuromuscular transmission in the phrenic-nerve hemidiaphragm preparation without affecting the muscle responses evoked by direct electrical stimulation. Complement inactivated sera were still active. Immune sera, incubated for 15 min with a receptor-rich fraction, lost their activity. 3 The immune sera antagonized the responses elicited by acetylcholine on the frog rectus abdominis. 4 The immune sera tested in vitro decreased the compound action potential evoked in the superior cervical ganglion of the rat by electrical stimulation of the preganglionic nerve. 5 The sera did not show any activity on muscarinic receptors of the guinea-pig ileum preparation. 6 It is concluded that in sera obtained from immunized rabbits a substance is present with curare-like action, and that this activity is probably due to the presence of antibodies against the nicotinic receptor.

Action Potentials↗