1,721,002 research outputs found
BINDING PROFILE OF TRAZODONE AND DAPIPRAZOLE TO SOME BRAIN RECEPTORS
No full textTrazodone and dapiprazole displace ligands binding to rat brain alpha-1 adrenoceptors. The displacement of 3H-ligands to alpha-2, serotonin1 (5-HT1), dopamine, beta and opiate receptors is either absent or takes place at relatively higher concentrations. Trazodone, unlike dapiprazole, also inhibits binding to serotonin2 (5-HT2) receptors. Some pharmacological effects show a satisfactory correlation with these data. The psychopharmacological effects of trazodone and dapiprazole are similar, whereas the binding inhibition to 5-HT2 receptors is different, which could indicate that the psychopharmacological effects do not primarily depend on these receptors. The displacement of the binding to alpha-1 adrenoceptors by dapiprazole has a time course similar to that of its brain concentrations as well as to that of sedative and alpha-blocking effects. Dapiprazole and trazodone have antinociceptive effects and inhibit the binding to opiate receptors, although at relatively high concentrations
Distribution and excretion of 3H-dapiprazole in the rat
No full textTissue distribution as well as biliary, urinary and fecal excretion of 3H-dapiprazole was studied in the rat. The product is found in many tissues, including the brain. About 23 and 57% of the dose is excreted in the urine and feces and about 65% is eliminated in the bile. © 1985
Specific [(3)H]corticosterone uptake in the hippocampus and septum varies with social settings in mice: Hormone-receptor autoregulation may be involved.
No full textSpecific [3H]corticosterone uptake in hippocampus and septum was reduced in socially deprived, as well as in crowding-stressed mice, in comparison with grouped ones. Its magnitude was related to hierarchic rank in the group but unrelated to agressiveness which, in turn, was unaffected by adrenalectomy and corticosterone replacement. A complex, regulatory interplay may exist between limbic specific corticosterone receptors and hypophyso-adrenal activity
Manifestations of acute opiate withdrawal contracture in rabbit jejunum after mu-, kappa- and delta-receptor agonist exposure.
No full text1. Following a 5 min in vitro exposure to morphine (1.3 x 10(-7) M), U-50,488H (2.5 x 10(-8) M) and deltorphin (1.6 x 10(-8)-6.5 x 10(-9) M), the rabbit isolated jejunum exhibited a precipitated contracture after the addition of naloxone (2.75 x 10(-7) M). 2. The precipitated responses to U-50,488H and deltorphin but not to morphine were reproducible in the same tissue. 3. The precipitated contractures were blocked completely by tetrodotoxin (3 x 10(-7) M), partially by atropine (1.5 x 10(-7) M) and not affected by hexamethonium (1.4 x 10(-5) M). 4. Naloxone administration (2.75 x 10(-7) M) before the agonist prevented the development of the adaptive response to morphine and U-50,488H but not to deltorphin. 5. The selective antagonists norbinaltorphimine (2.7 x 10(-8)-2.7 x 10(-9) M) and naltrindole (1.1 x 10(-7) M) prevented the adaptive response development only to the respective agonists. 6. The opioid agonists partially inhibited the spontaneous activity of the tissue. This study has shown that independent activation of mu-, kappa- and delta-opioid receptors can induce dependence in this isolated tissue. Rabbit jejunum is a suitable tissue for studying the acute effects of opioids on the adaptative processes determined by their administration
OCULAR PHARMACOKINETICS OF DAPIPRAZOLE
No full textDapiprazole is a drug having specific alpha1 adrenergic blocking properties. Following topical instillation on the eye, it crosses the corneal epithelium reaching high concentrations in the ocular tissue and producing a prompt miotic and hypotensive effect. The high concentration ratio between ciliary bodies and iris versus aqueous humor suggests a peculiar affinity for these structures containing adrenoceptors of the alpha type. The very low concentrations in the plasma, as compared to those after systemic administration, and in the fellow eye indicate that the systemic absorption is negligible. © 1986
Tissue distribution, urinary, fecal and biliary excretion of 14C bendazac L-lysine salt in rats.
No full textThe distribution of bendazac in the plasma and some rat tissues was studied after single oral administration of 14C bendazac L-lysine salt. The drug is distributed in varying amounts in the liver, kidneys, spleen, muscle, plasma and lens. In these tissues, the drug kinetics is similar, except for the lens where elimination of the drug is slower. More than 80% of the radioactivity administered is excreted through the urine and feces. Fecal excretion is due to the high biliary excretion.The distribution of bendazac in the plasma and some rat tissues was studied after single oral administration of 14C bendazac L-lysine salt. The drug is distributed in varying amounts in the liver, kidneys, spleen, muscle, plasma and lens. In these tissues, the drug kinetics is similar, except for the lens where elimination of the drug is slower. More than 80% of the radioactivity administered is excreted through the urine and feces. Fecal excretion is due to the high biliary excretion
PRE-TREATMENT WITH K+ CHANNEL BLOCKERS 4-AP AND TEA PREVENTS THE DEVELOPMENT OF OPIOID DEPENDENCE IN GUINEA-PIG ILEUM (GPI) UNMASKING OPIOID AND ADENOSINE A1 CONSTITUTIVE ACTIVITY
No full textOCULAR DISPOSITION OF ACETAMINOPHEN AND ITS METABOLITES FOLLOWING INTRAVENOUS ADMINISTRATION IN RABBITS
No full textTime-courses of both 'total' (unchanged plus metabolized) and unmetabolized acetaminophen were investigated in plasma and ocular tissues of rabbit after intravenous administration. The drug freely diffuses across the haemato-ocular barriers, reaching eye levels equal to those in the plasma; ocular concentrations are higher than those of all other investigated drugs. The time-course in aqueous is superimposable to that observed in the plasma; in other ocular tissues it is much slower. There is evidence of an ocular metabolism or a concentration into the eye of minor metabolites formed elsewhere
Inhibitory effect of the adenosine A1 and k-opioid systems on the expression of the μ-withdrawal response in the guinea-pig ileum: Reversal by cholecystokinin.
No full textFACILITATING EFFECT OF AMPHETAMINE ON THE RESPONSE OF RABBIT AORTIC STRIPS TO ADRENALINE, DOPAMINE AND SEROTONIN
No full textAmphetamine increased the response of rabbit aortic strips to adrenaline, dopamine and serotonin at consistently lower doses than those exerting a direct contracting effect. The amphetamine-facilitated contraction had the same shape as that produced by biogenic amines alone, whereas the contraction produced by amphetamine alone was more delayed and flatter. Serotonin and dopamine facilitated each other, but less markedly and with a narrower interval between facilitating and contracting doses than amphetamine. Pargyline exerted no facilitating effect on biogenic amines. Phentolamine and prazosin inhibited the direct response to adrenaline, dopamine and amphetamine, and the amphetamine-facilitated response to adrenaline and dopamine; they were inactive against serotonin alone and combined with a facilitating dose of amphetamine or dopamine. Cyproheptadine inhibited the direct response to serotonin and amphetamine, and the amphetamine-facilitated response to serotonin; it was inactive against dopamine and adrenaline both alone and combined with a facilitating dose of amphetamine or serotonin
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