Central nervous system actions

McCarthy, M.M. and Altemus M. (1997) Central nervous system actions of oxytocin and modulation of behavior in humans. Mol Med Today 3 269-275. 

Cannabis sativa plants contain at least 400 different compounds, of which as many as 60 are structurally related to 5 -tetrahydrocannabinol (5 -THC), the primary psychoactive constituent of cannabis. When cannabis is smoked, hundreds of additional compounds are produced by pyrolysis, which may contribute to both acute and chronic effects (Abood and Martin, 1992). The central nervous system actions of canna-binoids are mediated primarily through the CBj receptor. A second type of cannabinoid receptor, termed the CB2 receptor, is distributed primarily in the periphery (Gifford et ah, 1999). Activation of central cannabinoid receptors modulates neurotransmitter release at... 

Cardiac glycosides affect all excitable tissues, including smooth muscle and the central nervous system. The gastrointestinal tract is the most common site of digitalis toxicity outside the heart. The effects include anorexia, nausea, vomiting, and diarrhea. This toxicity is caused in part by direct effects on the gastrointestinal tract and in part by central nervous system actions. 

The central nervous system actions that result from taking even small amounts of methamphetamine, on the other hand, include extreme alertness, increased energy, decreased appetite, increased respiration, hyperthermia, and euphoria—generally the effects sought by users. But over time, side effects such as irritability, insomnia, confusion, tremors, convulsions, anxiety, paranoia, and aggressiveness begin to intrude. These symptoms are magnified by lack of sleep. Withdrawal often produces severe depression. 

This toxicity may be partially caused by direct effects on the gastrointestinal tract but is also the result of central nervous system actions, including chemoreceptor trigger zone stimulation. 

Lipid solubility plays a major role in determining the rate at which a particular sedative-hypnotic enters the central nervous system. For example, diazepam and triazolam are more lipid-soluble than chlordiazepoxide and lorazepam thus, the central nervous system actions of the former drugs are... 

SAFETY PROFILE Poison by ingestion, intramuscular, subcutaneous, intradermal, intraperitoneal, and intravenous routes. Human systemic effects coma, somnolence. Its central nervous system action is about midway between those of morphine and codeine, and large doses do not produce the... 

Syrup of ipecac is available as a nonprescription product in many countries. It is derived from the dried rhizome and roots of the Cephaelis ipecacuanha or Cephaelis acuminata plant. These plants contain the potent emetic alkaloids emetine and cephaeline, which induce vomiting by both direct local gastrointestinal effects and central nervous system actions. Emesis following syrup of ipecac ingestion typically occurs within 20 min of ingestion and persists for 30-120 min. 

Ahtee, L., Halmekoski, J., Heinonen, H., Koskimies, A. Comparison of the central nervous system actions of taurine and N-pivaloyltaurine. Br. J. Pharmacol. 1979, 66(3), 480 pages. 

Tache Y, Maeda-Hagiwara M. Turkelson CM. Central nervous system action of corticotropin-releasing factor to inhibit gashic emptying in rats. Am J Physiol 1987 253 G241-G245. 

This compound exhibits a central nervous system action in insects like the pyrethroids, but its peripheral action on sensory nerve structures is different from that of other DDT analogues. 

C7H9N402- M.p. 337 C, an alkaloid obtained from cacao seeds or prepared synthetically. Constitutionally it is similar to caffeine, and is also a weak base. It is usually administered as the sodium compound combined with either sodium ethanoate or sodium salicylate, and is employed almost entirely as a diuretic. Physiologically theobromine resembles caffeine, but its effect on the central nervous system is less, while its action on the kidneys, is more pronounced. 

Loperamide is similar ia action and use to diphenoxylate however, it does not need to be formulated with atropiae and is available by prescription and OTC. It is reported to have fewer central nervous system side effects than diphenoxylate. 

P-Endorphin. A peptide corresponding to the 31 C-terminal amino acids of P-LPH was first discovered in camel pituitary tissue (10). This substance is P-endorphin, which exerts a potent analgesic effect by binding to cell surface receptors in the central nervous system. The sequence of P-endorphin is well conserved across species for the first 25 N-terminal amino acids. Opiates derived from plant sources, eg, heroin, morphine, opium, etc, exert their actions by interacting with the P-endorphin receptor. On a molar basis, this peptide has approximately five times the potency of morphine. Both P-endorphin and ACTH ate cosecreted from the pituitary gland. Whereas the physiologic importance of P-endorphin release into the systemic circulation is not certain, this molecule clearly has been shown to be an important neurotransmitter within the central nervous system. Endorphin has been invaluable as a research tool, but has not been clinically useful due to the avadabihty of plant-derived opiates. 

Mode of Motion. Nicotine, anabasine, and imidocloprid affect the ganglia of the insect central nervous system, faciUtating transsynaptic conduction at low concentrations and blocking conduction at higher levels. The extent of ionisation of the nicotinoids plays an important role in both their penetration through the ionic barrier of the nerve sheath to the site of action and in their interaction with the site of action, which is befleved to be the acetylcholine receptor protein. There is a marked similarity in dimensions between acetylcholine and the nicotinium ion. 

Dmg receptors represent another type of receptor family. The central nervous system (CNS) effects of the anxiolytic, diazepam, and the psychotropic actions of the caimabiaoids and phencycUdine have resulted ia the identification of specific receptors for these molecules. This has resulted ia the search for an endogenous ligand for these receptors. Thus, ia these situations, the pharmacological action has preceded the discovery of the receptor which, ia turn, has provided clues ia several iastances to the endogenous ligand. 

General types of physiological functions attributed to quaternary ammonium compounds are curare action, muscarinic—nicotinic action, and ganglia blocking action. The active substance of curare is a quaternary that can produce muscular paralysis without affecting the central nervous system or the heart. Muscarinic action is the stimulation of smooth-muscle tissue. Nicotinic action is primary transient stimulation and secondary persistent depression of sympathetic and parasympathetic ganglia. 

Sahcylamide [65-45-2] is prepared by the reaction of methyl sahcylate with ammonia. Sahcylamide has mild analgesic, antiinflammatory, and antipyretic properties. Sahcylamide is unlike other sahcylates in that it causes sedation and central nervous system depression. Sahcylamide is not hydroly2ed to sahcylate and its action depends on the entire molecule. Sahcylamide has been useful for protection against mil dew and fungus in a variety of soaps, salves, lotions, and oils. The May 1996 price was 8.00/kg (18). 

Side Effects and Toxicity. Adverse effects to the tricycHc antidepressants, primarily the result of the actions of these compounds on either the autonomic, cardiovascular, or central nervous systems, are summarized in Table 3. The most serious side effects of the tricycHcs concern the cardiovascular system. Arrhythmias, which are dose-dependent and rarely occur at therapeutic plasma levels, can be life-threatening. In order to prevent adverse effects, as weU as to be certain that the patient has taken enough dmg to be effective, the steady-state semm levels of tricycHc antidepressant dmgs are monitored as a matter of good practice. A comprehensive review of stmcture—activity relationships among the tricycHc antidepressants is available (42). 

Health and Safety Factors. Carbonyl sulfide is dangerously poisonous, more so because it is practically odorless when pure. It is lethal to rats at 2900 ppm. Studies show an LD q (rat, ip) of 22.5 mg/kg. The mechanism of toxic action appears to iavolve breakdowa to hydrogea sulfide (36). It acts principally on the central nervous system with death resulting mainly from respiratory paralysis. Little is known regarding the health effects of subacute or chronic exposure to carbonyl sulfide a 400-p.g/m max level has been suggested until more data are available (37). Carbon oxysulfide has a reported inhalation toxicity in mice LD q (mouse) = 2900 ppm (37). 

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). 

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