Search results for " antagonist"
showing 10 items of 1421 documents
Antihistaminic and anticholinergic activities of mequitazine in comparison with clemizole
1988
Abstract The antihistamine and anticholinergic properties of mequitazine have been investigated and compared with those of clemizole. Both mequitazine and clemizole antagonized the effect of histamine in guinea-pig ileum competitively, the pA2 values calculated by Schild plot were 9.95 ± 0.44 for mequitazine and 10.54 ± 0.44 for clemizole. Mequitazine at 10−7 M produced a parallel shift of the dose-response curve to acetylcholine in the rat duodenum, clemizole and the lower doses of mequitazine failed to modify the effect of acetylcholine. The potency of mequitazine and clemizole as H1-histamine blockers is similar, but only mequitazine at highest concentration used showed anticholinergic a…
Ghrelin reduces hepatic mitochondrial fatty acid beta oxidation.
2007
Ghrelin is a 28-amino-acid peptide secreted during starvation by gastric cells. Ghrelin physiologically induces food intake and seems to alter lipid and glucid metabolism in several tissues such as adipose tissue and liver. Liver has a key position in lipid metabolism as it allows the metabolic orientation of fatty acids between oxidation and esterification. We investigated the effects of peripheral ghrelin administration on 2 crucial parameters of fatty acid oxidation: the levocarnitine (L-carnitine)-dependent entry of the fatty acids in the mitochondria and the mitochondrial fatty acid oxidation. Ghrelin was either given to rats prior to the hepatocyte preparation and culture or used to t…
3H-cyproterone acetate: binding characteristics to human uterine progestagen receptors
1985
The availability of tritium labeled cyproterone acetate (CPA) facilitated the systematic investigation of the binding characteristics of this compound for human uterine progesterone receptors (PgR). The binding parameters of 3H-CPA are compared to those of 3H-R5020 and 3H-progesterone. The rate constants of association (k1M-1sec-1) to PgR were 7.8 X 10(3) for 3H-R5020, 4.5 X 10(4) for 3H-progesterone and 4.0 X 10(4) for 3H-CPA. The rate constants of dissociation (k-1, sec-1) were 3.6 X 10(-5) for 3H-R5020, 21.3 X 10(-5) for 3H-progesterone and 17.8 X 10(-5) for 3H-CPA. The Kd-values (M), as obtained by titration analysis and subsequent Scatchard plot analysis were 1.2 X 10(-9) for 3H-R5020,…
Oestrogen receptor subtype-specific repression of calpain expression and calpain enzymatic activity in neuronal cells - implications for neuroprotect…
2006
Calpains represent a superfamily of Ca2+-activated cysteine-proteases, which are important mediators of apoptosis and necrosis. In the brain, m-calpain and micro-calpain, the two ubiquitous calpain-isoforms, are strongly activated in neurones after an excitotoxic Ca2+ influx occurring, for example, during cerebral ischemia. Because oestrogen and its receptors (ERalpha/ERbeta) can exert neuroprotective activity, we investigated their influence on expression of calpains and their endogenous inhibitor, calpastatin. We found that ectopic expression of ERalpha in human neuroblastoma SK-N-MC cells led to a ligand-independent constitutive down-regulation of m-calpain accompanied by an up-regulatio…
Postnatal weight change is influenced by mother-newborn pair leptin levels
2000
We investigated serum leptin levels in 103 mother-newborn-pairs; Cord leptin was significantly higher than mother's leptin (5.7 ± 5.5 vs. 22.1 ± 19.9 ng/ml; p <0.001). Cord leptin was significantly higher in females than males (6.9 ± 6.3 vs. 3.9 ± 3.6 ng/ml respectively; p <0.001), and correlated with maternal leptin (r = 0.24; p = 0.001), gestational age (r = 0.54; p <0.001), and birth weight (r = 0.56; p <0.001). Neonatal leptin at the 4(th) day significantly correlated with percent weight loss in the first four days of life. These observations shed light on the origin of cord leptin and on the role of leptin in postnatal weight loss. (C) 2000 Elsevier Science Inc.
Neuroprotective Actions of Estradiol and Novel Estrogen Analogs in Ischemia: Translational Implications
2010
This review highlights our investigations into the neuroprotective efficacy of estradiol and other estrogenic agents in a clinically relevant animal model of transient global ischemia, which causes selective, delayed death of hippocampal CA1 neurons and associated cognitive deficits. We find that estradiol rescues a significant number of CA1 pyramidal neurons that would otherwise die in response to global ischemia, and this is true when hormone is provided as a long-term pretreatment at physiological doses or as an acute treatment at the time of reperfusion. In addition to enhancing neuronal survival, both forms of estradiol treatment induce measurable cognitive benefit in young animals. Mo…
Association between CCK-AR gene and schizophrenia with auditory hallucinations
2007
[Objective]: Previous studies on a possible association between CCK-AR polymorphisms and schizophrenia have been controversial. The aim of the present study was to assess a potential association between schizophrenic patients with auditory hallucinations and polymorphisms of the CCK-AR gene.
Inhibitory and excitatory muscarinic receptors modulating the release of acetylcholine from the postganglionic parasympathetic neuron of the chicken …
1992
The effects of muscarinic receptor antagonists on ACh release were studied in the absence or presence of cholinesterase (ChE) inhibition using the isolated perfused chicken heart. Presynaptic inhibitory muscarinic autoreceptor were characterized by determining the potency of various antagonists to enhance [3H]-ACh release evoked by field stimulation (3 Hz, 1 min). The order of potencies was: (±)-telenzepine > atropine > 4-DAMP > silahexocyclium > pirenzepine > hexahydro-siladifenidol > AF-DX 116. The comparison with known pA2 values for M1-, M2- and M3-receptors revealed that the presynaptic autoreceptor meets the criteria of an M1-receptor. Basal, not electrically evoked overflow of unlabe…
Long-term oral anticoagulation for atrial fibrillation in low and middle income countries.
2021
With increasing life-expectancy and changing demographics, non-valvular atrial fibrillation (AF) is currently the most common indication for long-term oral anticoagulation (OAC) in low and middle income countries (LMICs). Due to a decreasing trend in the prevalence of rheumatic heart disease (RHD), valve disease as a primary cause of AF now constitutes a small fraction of all people with AF. Moreover, emerging data also indicate that, patients with significant valve disease and AF may have a risk of stroke similar to, if not lower than, those with non-valvular AF. Previous trials of anticoagulation for AF excluded people from LMICs partly because valvular AF constituted a large proportion o…
A double-blind, randomized, dose response study testing the pharmacological efficacy of synthetic porcine secretin
2000
Background: Biologically derived porcine secretin has been used as a diagnostic agent in clinical gastrointestinal practice for many years. Pure synthetic porcine secretin is now available for investigational clinical use. Aim: To compare the pharmacology of synthetic porcine secretin and biologically derived porcine secretin in healthy volunteers. Methods: Secretin stimulation tests were performed in 12 volunteer subjects in a double-blind, randomized, Latin square crossover design study comparing three doses of synthetic porcine secretin (0.05, 0.2, and 0.4 μg/kg) with a standard dose of biologically derived porcine secretin (1 CU/kg). Duodenal aspirates were analysed for total volume and…