Lubomir N. Kasakov

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The present study explores the possible involvement of a purinergic mechanism in mechanosensory transduction in the bladder using P2X(3) receptor knock-out (P2X(3)-/-) and wild-type control (P2X(3)+/+) mice. Immunohistochemistry revealed abundant nerve fibers in a suburothelial plexus in the mouse bladder that are immunoreactive to anti-P2X(3).(More)
alpha, beta-Methylene ATP has advantages over ATP in producing desensitisation of the P2-purinoceptor since it is degraded more slowly than ATP and does not initiate synthesis of prostaglandins. Following desensitisation of the excitatory P2-purinoceptors in the guinea-pig urinary bladder, the excitatory responses to non-adrenergic, non-cholinergic nerve(More)
1 A number of criteria for considering adenosine 5'-triphosphate (ATP) as a neurotransmitter in the guinea-pig urinary bladder have been examined. In addition, the effect of tachyphylaxis to ATP on the response to non-adrenergic, non-cholinergic nerve stimulation has been re-examined.2 Quinacrine fluorescence histochemistry revealed a population of nerve(More)
Concomitant release of noradrenaline (NA) (using tritium labelling), adenosine 5'-triphosphate (ATP) (using the luciferin-luciferase firefly technique) and neuropeptide Y (using the enzyme-linked immunosorbant assay) during electrical stimulation of the guinea-pig vas deferens has been demonstrated. In addition it has been shown: (1) that release of NA and(More)
Demonstration of release of ATP from smooth muscle preparations during stimulation of purinergic nerves is complicated by the difficulty in showing whether it comes from nerve or muscle. ATP released during relaxation of the guinea-pig taenia coli and contraction of bladder strips in response to purinergic nerve stimulation was measured in the superfusate(More)
Activator protein 1 (AP-1) and nuclear factor kappa B (NF-kappa B) represent mammalian transcription factors which bind to distinct enhancer motifs. The specific mu-receptor opioid agonist, Tyr, D-Ala2, Gly, N-Me-Phe4, Gly-ol5 (DAMGO), was found to increase AP-1 and NF-kappa B activity in primary cultures of neurons from rat cerebral cortex. Acute (2 h, 4(More)
1. Several alpha 1- and alpha 2-adrenoceptor agonists and antagonists were examined for effects on spontaneous and stimulus-evoked release of [3H]noradrenaline from sympathetic nerves in guinea-pig vas deferens. 2. Prazosin (0.1 and 1 microM), phentolamine (30 microM) and yohimbine (10 microM) each enhanced the stimulus-evoked release of [3H]noradrenaline.(More)
Primary cultures of rat cortex, conveniently prepared from newborn animals, were used to study opioid effects on 45Ca2+ uptake and glutamate release. 45Ca2+ uptake, induced by treatment with glutamate or NMDA, was largely blocked by the NMDA antagonist MK-801. K+ depolarization-induced 45Ca2+ uptake was also reduced by MK-801, indicating that the effect was(More)
1. The distribution of NADPH-diaphorase positive and catecholamine-containing nerve structures, and functional noradrenergic-nitrergic interactions, were studied in the rat anococcygeus muscle. 2. The morphological findings demonstrated NADPH-diaphorase positive neurons mostly as aggregates in intramural ganglia, nerve tracts and few single nerve fibres(More)
Based on template hexapeptides Ac-Arg-Tyr-Tyr-Arg-Trp-Lys-NH(2) and Ac-Arg-Tyr-Tyr-Arg-Ile-Lys-NH(2) analogues and corresponding deacylated homologues were synthesized substituting ornithine, diaminobutanoic (Dab) and diaminopropanoic (Dap) acids for lysine at position 6. The aim was to investigate the effect of the newly synthesized compounds on the(More)