V J Lotti

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The intrinsic activity of the potent dopamine (DA) agonist 4-propyl-9-hydroxynaphthoxazine [(+)-PHNO] was examined in receptor binding assays for the following receptors: DA, alpha-1 and alpha-2 adrenergic, serotonin-1 and -2, neuroleptic, beta adrenergic, anxiolytic, adenosine A-1, gamma-aminobutyric acid, muscarinic and opiate. (+)-PHNO exhibited strong(More)
A new, competitive, nonpeptide cholecystokinin (CCK) antagonist, asperlicin, was isolated from the fungus Aspergillus alliaceus. The compound has 300 to 400 times the affinity for pancreatic, ileal, and gallbladder CCK receptors than proglumide, a standard agent of this class. Moreover, asperlicin is highly selective for peripheral CCK receptors relative to(More)
Specific 125I-CCK receptor binding was significantly increased in brain tissue taken from guinea pig or mouse following chronic (2-3 week) daily administration of haloperidol (2-3 mg/kg/day). Scatchard analysis indicated the increase in CCK binding was due to an increased receptor number (B max) with no change in affinity (Kd). In guinea pigs, the increased(More)
The binding of biologically active 125I-Bolton-Hunter (BH)-NPY to rat brain membranes was saturable and reversible and regulated by inorganic cations and guanyl nucleotides consistent with other neurotransmitter receptor systems. The concentration of specific 125I-NPY binding differed in various brain regions, being highest in the hippocampus and lowest in(More)
Specific 125I-NPY binding in various brain regions of spontaneous hypertensive (SH) rats and age-matched normotensive (WKY) rats was compared. SH rats exhibited significantly greater 125I-NPY binding than WKY rats in the hippocampus (43%) and cortex (18%), but not hypothalamus, midbrain, striatum or pons-medulla. Scatchard analysis indicated that the(More)
The relative order of activity of thyrotropin-releasing hormone (TRH) and various analogs in contracting the isolated guinea pig antrum and duodenum correlated with their potencies in activating thyroid-stimulating hormone (TSH) release. The action of TRH in both tissues was selectively antagonized by the putative pituitary TRH receptor antagonist,(More)
Tifluadom, a benzodiazepine kappa-opiate agonist, stereoselectively inhibited the binding of 125I-CCK to pancreatic membranes (IC50 = 47 nM). Several other opiate agonists were ineffective. Scatchard analysis indicated the inhibition of CCK binding by tifluadom was competitive in nature. Tifluadom (1 microM) did not displace 125I-CCK binding to brain tissue(More)
The substance P antagonist, [D-Pro4-D- Trp7 ,9,10]substance P4-11, caused a pig parallel shift to the right of the cholecystokinin (CCK-8) dose-response curve in guinea pig ileum longitudinal muscle without changing the maximal contraction. The shift of the CCK-8 dose response was markedly reduced after desensitization of the tissues to substance P (SP).(More)
A series of pyridinyltetrahydropyridine derivatives was synthesized and evaluated as adrenoceptor and tetrabenazine antagonists. 4-(3-Fluoro-2-pyridinyl)-1,2,5,6-tetrahydropyridine proved to be the most potent and selective alpha 2-adrenoceptor antagonist of the series as measured in vitro by displacement of [3H]clonidine and [3H]prazosin from membrane(More)
The low affinity site in the Schild plot of (-)-propranolol as an antagonist of isoproterenol in the field stimulated rat vas deferens was absent after reserpinization or treatment with rauwolscine. The apparent dependence of intact catecholamine stores and functional alpha 2-adrenoreceptors for demonstration of the low affinity site for propranolol in this(More)