Stimulants pharmacology

Psychostimulants are able to induce a number of dose-dependent behaviour-activating features including the activation of fight-or-flight-type responses. A fine line can exist between therapy and potential for misuse or abuse and sometimes the differentiation appears to be somewhat arbitrary. Psychomotor stimulant pharmacology involves an augmented release of noradrenaline, dopamine, and to a lesser extent serotonin, into the synaptic cleft. Increased availability of monoamines is predominantly caused by inhibition of the corresponding monoamine... 

Researchers at the MoneU Center (Philadelphia, Pennsylvania) are using a variety of electrophysical and biochemical techniques to characterize the ionic currents produced in taste and olfactory receptor cells by chemical stimuli. These studies are concerned with the identification and pharmacology of the active ion channels and mode of production. One of the techniques employed by the MoneU researchers is that of "patch clamp." This method aUows for the study of the electrical properties of smaU patches of the ceU membrane. The program at MoneU has determined that odors stimulate intraceUular enzymes to produce cycUc adenosine 3, 5 -monophosphate (cAMP). This production of cAMP promotes opening of the ion channel, aUowing cations to enter and excite the ceU. MoneU s future studies wiU focus on the connection of cAMP, and the production of the electrical response to the brain. The patch clamp technique also may be a method to study the specificity of receptor ceUs to different odors, as weU as the adaptation to prolonged stimulation (3). 

Compounds that have agonistic properties at glutamate or aspartate receptors are also CNS stimulants, readily cause convulsions, and presumably could also be employed as analeptics. Three separate excitatory amino acid receptor subtypes have been characterized pharmacologically, based on the relative potency of synthetic agonists. These three receptors are named for their respective prototypical agonists A/-methyl-D-aspartate [6384-92-5]... 

Research for an antidepressant among non-tricyclic compounds with pharmacological effects qualitatively different from those of the conventional tricyclic compounds led to the preparation and testing of a series of indazole derivatives for reserpine-like activity in mice. l-[3-(Dimethylamino)propyl]-5-methyl-3-phenyl-l//-indazole (FS-32 692) antagonizes reserpine-induced effects and potentiates amphetamine-induced self-stimulation and l-Dopa-induced increase in motor activity. FS-32 produces an anticholinergic action mainly on the central nervous System, while the action of imipramine occurs centrally as well as peripherally (79AF511). 

According to Georgadze the three sophora alkaloids sophocarpine (a), sophocarpidine (h) and sophoridine (c) only differ in degree and not in character of their pharmacological activity thus on intravenous injection each causes a rise and then a fall i i blood pressure and their activity in this direction is in decreasing order (a), (c), (b). In small doses they stimulate, and in larger doses depress, the isolated heart of either cold- or warm-blooded animals and then their decreasing order of activity is (c), (b), (a). 

Pharmacological Action. As already pointed out, cularine shows some resemblance to papaverine and hydrastine in action (p. 196). The M.L.D. (mgm./kilo.) for mice by intravenous injection of ochotensine is 10-6 i 0-54 so that it seems to be the most toxic of the fifteen corydalis alkaloids examined by Anderson and Chen, who also state that it stimulates isolated guinea-pig or rabbit uterus, inhibits isolated rabbit-intestine and induces a fall in blood pressure on intravenous injection in etherised cats. 

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