Impaired capsaicin-induced decrease in heart rate and coronary flow in isolated heart of diabetic rats

The effect of capsaicin (0.1μM) on heart rate and coronary flow was studied in Langendorff-perfused heart from streptozotocin-induced (50 mg/kg i.v.) diabetic rats where sensory neuropathy developed. In hearts from animals 4- and 8-week diabetes baseline heart rate and coronary flow decreased from 317.9±2.9 b.p.m. and 13.4±0.7 ml/min to 255.1±12.7 and 219.8±2.8 b.p.m. and 8.9±0.6 and 10.0±0.1 ml/min (P<0.05), respectively. Capsaicin significantly decreased both variables in either normal or 4-week diabetic animals its effects, however, on coronary flow or heart rate were missing in preparations from 8-week diabetic rats. Endothelin-1 (0.1 nM), the putative mediator of the capsaicin effect, significantly decreased heart rate and coronary flow irrespective of the presence or absence of diabetes. In the femoral nerve of streptozotocin-treated animals conduction velocity involving both fast conducting A- and slow-conducting C-fibres was decreased proportional to the duration of the pre-existing diabetic state. It is concluded that in insulin deficient diabetes the diminished responses evoked by capsaicin on heart rate and coronary flow are signs of sensory neuropathy. This is related to a feeble endothelin release from sensory nerve endings without changes in post-receptor mechanisms mediating the endothelin effects

Analysis of the effect of locally applied inhomogeneous static magnetic field-exposure on mouse ear edema - a double blind study

The effect static magnetic field (SMF)-exposure may exert on edema development has been investigated. A 6 h long whole-body (WBSMF) or local (LSMF), continuous, inhomogeneous SMF-exposure was applied on anesthetized mice in an in vivo model of mustard oil (MO)-induced ear edema. LSMF was applied below the treated ear, below the lumbar spine, or below the mandible. Ear thickness (v) was checked 8 times during the exposure period (at 0, 0.25, 1, 2, 3, 4, 5, and 6 h). The effect size of the applied treatment (eta) on ear thickness was calculated by the formula eta = 100% x (1-vj/vi), where group i is the control group and j is the treated group. Results showed that MO treatment in itself induced a significant ear edema with an effect of 9% (p11% in both cases compared to SMF-exposure alone (p<0.001). In these cases SMF-exposure alone without MO treatment reduced ear thickness significantly (p<0.05), but within estimated experimental error. In cases of LSMF-exposure on the head, a significant SMF-exposure induced ear thickness reduction was found (eta = 5%, p<0.05). LSMF-exposure on the spine affected ear thickness with and without MO treatment almost identically, which provides evidence that the place of local SMF action may be in the lower spinal region

Basic aspects of the pharmacodynamics of tolperisone, a widely applicable centrally acting muscle relaxant

Tolperisone (2-methyl-1-(4-methylphenyl)-3-piperidin-1-ylpropan-1-one hydro-chloride) was introduced in the clinical practice more than forty years ago and is still evaluated as a widely applicable compound in pathologically elevated skeletal muscle tone (spasticity) and related pains of different origin. In the present review, basic pharmacodynamic effects measured on whole animals, analyses of its actions on cell and tissue preparations and molecular mechanism of action on sodium and calcium channels are summarized as recently significantly new data were reported

Thrittene radioimmunoassay: description and application of a novel method

In the present paper the development andapplication of a novel thrittene radioimmunoassay (RIA)are described. 125I-labeling of Tyr(0)-thrittene was performedby the iodogen-method and the mono-iodinatedpeptide, as RIA tracer, was separated by reversed-phasehigh performance liquid chromatography (HPLC). TheRIA results show that the antiserum used in the radioimmunoassayturned to be C-terminal specific, without significantaffinity to other members of the somatostatinpeptide hormone family. Detection limit of the assay was0.2 fmol/ml. This highly specific and sensitive thritteneRIA was used to investigate the distribution of thrittene inthe rat gastrointestinal tract and other tissue samples. Differentareas of the gastrointestinal tract and other tissueswere removed from rats and after extraction the sampleswere processed for thrittene radioimmunoassay. Highestconcentrations were found in the duodenum samplesfollowed by jejunum and ileum, however, all the examinedtissues contained highly enough thrittene for themeasuremen