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Biomedical subjects

M Tiengo

Publications and source records attributed to M Tiengo.

At least 37 records · Page 2Linked to original sources
PubMed1987

Effects of tenoxicam on nociceptive thalamic neuronal firing in arthritic rats.

The antinociceptive action of tenoxicam, a new non-steroidal anti-inflammatory drug, has been investigated by exploring the spontaneous and evoked electrophysiological patterns of firing of thalamic neurons in arthritic rats. A marked decrease in the firing activity evoked by ankle mobilization has been found to be present at doses of tenoxicam of 0.6 mg/kg i.v. A similar effect is obtainable with aspirin (as reference drug) but with doses of 54 mg/kg i.v. On studying the effects of increasing doses of tenoxicam a progressively longer time-course inhibition has been found and the analysis confirmed a linear correlation. Findings are discussed postulating that the final antinociceptive effect of tenoxicam can be correlated with its anti-inflammatory activity.

Action Potentials↗
PubMed1987

Clomipramine compared with pentazocine as a unique treatment in postoperative pain.

Forty patients who underwent laparotomy for hysterectomy were administered either clomipramine or pentazocine for the treatment of postoperative pain. Both drugs were similarly effective during the eight hours of observation. The results of this study indicate that clomipramine, often used in chronic pain as an adjuvant drug, exerts as well as analgesic effect in acute pain.

Adult↗
PubMed1986

Eseroline depresses the responses of dorsal horn neurons to C-fiber afferents in the spinal rat.

Eseroline not only has some structural features in common with morphine but also has a specific antinociceptive action like opioid drugs. The effects of eseroline on the responses of rat dorsal horn lamina V neurons to C-fiber-related noxious stimuli were investigated. The data obtained showed that 15 min after eseroline administration, the neuronal responses to C-fiber-related afferents were almost totally suppressed. Morphine was used as reference drug. The postulated action of eseroline on opioid receptors was confirmed by reversal of eseroline-driven cell activity after naloxone injection.

Action Potentials↗
PubMed1986

Depressant effects of suprofen, a new non-steroidal anti-inflammatory drug on thalamic evoked neuronal firing in arthritic rats.

The effects of suprofen, a new non-steroidal anti-inflammatory drug, (NSAID), the activity of which is mainly antinociceptive, were compared with those of aspirin (as a reference drug) in a study of spontaneous and evoked firing of thalamic neurons (nucleus lateralis and ventrobasalis) in rats rendered arthritic by injection of Freund's adjuvant into the paw. Suprofen (3.7 mg/kg, i.v.) induced a marked decrease in the firing evoked in arthritic rats by ankle mobilization. This effect, after a rapid onset, lasted on the average for 60 min. A similar effect was obtained with aspirin, but with 54 mg/kg (i.v.) (14 times more than suprofen). With increasing doses of suprofen, it was possible to obtain an increased long-lasting inhibition of the evoked activity, with a significant dose-effect linear regression. The possibility that there are both CNS and peripheral effects of suprofen is discussed in relation to the possible role of aspirin (the reference standard for NSAIDs) in enhancing presynaptic inhibition, thus reducing the effectiveness of incoming sensory stimuli.

Animals↗
PubMed1986

In vitro effects of halothane on lymphocytes.

Many reports indicate that anaesthesia affects several immunological functions that decrease the immune response, but the mechanisms involved are still unknown. We investigated the in vitro effect of halothane on human lymphocyte metabolism and plasma membrane function by evaluating the intracellular concentration of 3',5'-cyclic adenosine-monophosphate (cAMP), phosphodiesterase enzyme activity, NAD+/NADH intralymphocytic ratios and the degree of antibody and lectine-induced 'capping' of surface markers. Our results demonstrated an impaired lymphocyte capping of surface immunoglobulins and concanavalin A receptors 60 min after exposure to halothane at the concentration of 1% in oxygen. This phenomenon was reversible after 24 h and it was unrelated to the presence of adherent cells during the culture. Furthermore, halothane was able to induce a persistent increase in cAMP intracellular concentrations, which was reversible within 48 h. This effect was not dependent on adherent cells or on phosphodiesterase enzyme inhibition. Finally, no alteration in NAD+/NADH ratios after halothane exposure was observed.

Cyclic AMP↗
PubMed1985

Presence of 5-HT-positive neurons in the medial nuclei of the solitary tract.

The main serotoninergic groups have been described in the midbrain raphe; in the region of the solitary tract, serotonin (5-HT) has been localized in varicose processes and terminals. This study shows the presence of serotoninergic neurons located in the medial nuclei of the solitary tract of intracisternally injected rats, and describe the mapping, the morphological and morphometrical characteristics of these neurons in young and old rats. In old rats the number of these neurons is approximately double the amount detected in young rats. The suggestions on the functional meaning of these findings are discussed.

Aging↗
PubMed1985

Nefopam in postoperative pain.

A comparative study between nefopam (Acupan) and pentazocine was carried out in 90 patients for treatment of postoperative pain following gynaecological operations. The results show that nefopam has an analgesic activity comparable with that of pentazocine, but its duration of action seems to be longer-lasting, even if with a longer period of latency. At equieffective analgesic action, nefopam shows a lower interference with the respiratory function. As far as side-effects are concerned a significant increase in drowsiness was observed with both types of treatment; sweating was observed only in nefopam group.

Adult↗
PubMed1985

Comparative study on the electrophysiological responses at thalamic level to different analgesic peptides.

Using electrophysiological methods to detect the extracellular activity of single neurons in the thalamus of anaesthetized rats, their response to mechanical and thermal noxious stimuli were assessed before and after administration of 4 analgesic peptides of various types. Dermophin, a peptide extracted from frog's skin, was found to have an opioid-like antinociceptive activity antagonized by naloxone. Caerulein, which has a similar origin, failed to suppress the nociceptive responses of thalamic neurons evoked by peripheral stimuli. Calcitonin, a peptide found at brain level, induced an alteration of the increased firing characteristic of noxious stimuli, and its action was not reversed by naloxone. FK 33-824, a synthetic peptide, induced a morphine-like action when injected i.c.v. at a dosage 1000 times lower than that of morphine on a molar basis. It is concluded that electrophysiological investigations on peptides endowed with analgesic activity contribute greatly to a more precise profile of the peptides as candidate drugs in pain control.

Analgesics↗
PubMed1984

Dermorphin, a new peptide from amphibian skin, inhibits the nociceptive thalamic neurons firing rate evoked by noxious stimuli.

Dermorphin is the representative of a new class of potent opioid peptides occurring in amphibian skin and possesses the unique feature of having a D-Ala residue incorporated in the peptide molecule. The effect of dermorphin on the spontaneous and evoked neuronal activity by a nociceptive stimulus was studied in the nucleus lateralis anterior and ventrobasal complex of the rat thalamus. The high firing frequency induced by nociceptive stimuli was blocked when dermorphin was injected intraperitoneally at the dose of 1.5 mg/kg. The action starts about 10 min after injection and lasts on average for 120 min. Naloxone, a specific opioid antagonist, injected i.p. at a dose of 1 mg/kg antagonized the effect of dermorphin. The dermorphin time-course is about twice that of morphine (1.5 mg/kg i.p.) under the same experimental conditions.

Action Potentials↗
PubMed1984

Inhibitory effect of eseroline, an opiate like drug, on the rat nociceptive thalamic neurons activated by peripheral noxious stimuli.

Eseroline is a new agent, derived from physostigmine but lacking in pseudocholinesterase activity, that possesses opioid properties in vivo and in vitro in cats and rodents. The electrophysiological effect of this drug has been investigated. Our findings show that Eseroline (5 mg/kg i.p.), suppresses the nociceptive responses evoked by noxious (mechanical and thermal) stimuli, without affecting the spontaneous firing of neurons in the thalamus of anesthetized rat. This effect starts about 5 min after the administration and lasts on average for about 60 min. Naloxone (1 mg/kg i.p.), injected 10 min before Eseroline, antagonized the antinociceptive action of this drug.

Analgesics, Opioid↗