Acta Gastroenterol Latinoam. 1999;29(2):51-6.
[Autonomic nervous system and gastric stress in rats]

[Article in Spanish]

Laudanno OM, Cesolari J, Giolito I, Bedini O, San Miguel P.

Catedras de Gastroenterologia e Histologia, Facultad de Ciencias Medicas, Universidad Nacional de Rosario, Argentina.

The role of the autonomic nervous system on gastric stress was studied in different groups of Wistar rats (n = 10). The experimental stress model consisted of immobilization and immersion in 15 degrees C water during 6 hours. The percentage of the gastric mucosa macroscopic lesional area was tabulated, and at the same time cortisol, melatonin, noradrenaline, adrenaline, dopamine and serotonin blood levels were measured. The stress control showed a necrotic area (80%) and in blood there was only and increase in noradrenaline and adrenaline. The following dose dependent drugs were studied: beta adrenergics agonists and antagonists, alpha 1 postsinaptical adrenergic antagonists, anticholinergics and cholinergics, endorphin and GABA receptors. Isoproterenol, prazosim, doxasine, tramadol and vigabatrin yielded a remarkable gastric mucosa protection in stress with an area close to 0% (p < 0.001). In contrast, propanolol, acetylholine, atropine, naloxone and flumazenil showed no difference in control stress (p > 0.5). All the drugs under study yielded similar vasoactive amines than the control stress. It is concluded that the protective gastric mechanism of the autonomic nervous system in stress, could be linked to its receptors with an increase in the splanchnic microcirculation.

Tramadol reference source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10491715&dopt=Abstract tramadol Ultram




Agents Actions. 1987 Apr;20(3-4):310-3.
Anaphylactoid reactions and histamine release do not occur after application of the opioid tramadol.

Barth H, Giertz H, Schmal A, Lorenz W.

After an i.v. application of 100 mg tramadol in 13 healthy volunteers no change in plasma histamine concentration could be detected,( systemic anaphylactoid reactions did not occur, cutaneous reactions were not rated as anaphylactoid since itching and erythema were seen only once after tramadol whereas erythema was also observed twice after saline, blood pressure and heart rate were only very slightly and transiently elevated without any abnormalities in ECG-readings and only side effects typical for opioid therapy were observed.

Tramadol reference source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2440284&dopt=Abstract tramadol Ultram




Neuropsychobiology. 1989;20(3):164-8.
Dose- and time-dependent action of morphine, tramadol and flupirtine as studied by radioelectroencephalography in the freely behaving rat.

Dimpfel W, Spuler M, Nickel B.

Pro Science Private Research Institute GmbH, Linden, FRG.

The necessity of testing psychoactive drugs in awake freely moving animals has led to the development of a telemetry-based system which enables the pharmacologist to follow centrally active molecules in their time- and dose-dependent effects on electric brain activity in terms of changes in spectral power density of extracellularly recorded field potentials (tele-EEG). This report describes the effect of three analgesics with respect to bioelectric changes in frontal cortex, thalamus, striatum and reticular formation. Two opiate drugs, morphine and tramadol, behaved very similarly despite a tenfold difference in dosage, whereas flupirtine, a nonopiate analgesic, changed the frequency content of the EEG signals in an entirely different manner. The frequency pattern produced by the opiates closely resembles that of centrally acting serotonin uptake inhibitors and thus is consistent with the view of a serotonergic prevalence of neurochemical interactions within the recorded brain areas. In contrast, the action of flupirtine obviously can be attributed to a clonidine-like effect on noradrenergic alpha 2-receptors. The results are discussed with respect to already known influences of these drugs on indoleaminergic and catecholaminergic transmission.

Tramadol reference source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2548117&dopt=Abstract tramadol Ultram




Zhongguo Yao Li Xue Bao. 1989 Jul;10(4):289-93.
Analgesic effect of tramadol in the rat.

Dhasmana KM, Banerjee AK, Rating W, Erdmann W.

The analgesic effect of tramadol was studied in the rat using tail flick and hot plate tests following intrathecal and subcutaneous administrations. Tramadol had only a short-lasting analgesic effect (20 min) on intrathecal administration which may be due to rapid removal from the subarachnoid space. Its analgesic effects were antagonized by pretreatment with naloxone. It seems that the opiate system may involve in the analgesic effect of tramadol, while the noradrenergic, serotonergic and cholinergic systems may play a modulating role.

Tramadol reference source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2624109&dopt=Abstract tramadol Ultram




Fam Pract. 1999 Aug;16(4):407-13.
Diffusion of new drugs in Danish general practice.

Steffensen FH, Sorensen HT, Olesen F.

Danish Epidemiology Science Centre at the Department of Epidemiology and Social Medicine, University of Aarhus.

OBJECTIVES: There is a large variation in implementing research findings in clinical practice. We examined whether the concept of early or late adopters is universal for the diffusion of all new drugs, and whether it is associated with non-scientific factors in general practice. METHODS: We identified all prescriptions for five new drugs from the population-based prescription database in North Jutland County, Denmark (490000 inhabitants) from 1993 to 1996, and calculated the period from release of the drugs to the issuing of the first prescription by each GP. Logistic regression was performed to predict early or late prescribing from physician characteristics, practice activity and the number of prescriptions, adjusted for age and sex. RESULTS: The distributions of the diffusion time of the drugs by 95 solo practitioners were asymmetrical, with a long upper tail representing the late prescribers. The shape and slope of the diffusion curve were highly drug dependent. There was poor agreement of the three adopter categories (early, intermediate and late prescribers) between the five drugs (kappa < 0.35), but being a late prescriber was the most consistent condition. Late prescribing of tramadol, compared with intermediate prescribing, was associated with female physicians (odds ratio (OR) 5.7; 95% CI 1.5-21.3), smaller list size (OR 0.1; 95% CI 0.0-0.8), a strong general restrictive attitude to pharmacotherapy (OR 0.07; 95% CI 0.01-0.68) and a tendency to lower diagnostic activity per patient (OR 0.4; 95% CI 0.1-1.9). CONCLUSIONS: The slope and shape of the diffusion curve are both dependent on physician and drug characteristics, but late prescribers share some common characteristics.

Tramadol reference source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10493713&dopt=Abstract tramadol Ultram