Central nervous system , and

Barbituric acid is the parent of a group of compounds known as barbiturates The bar biturates are classified as sedative-hypnotic agents meaning that they decrease the responsiveness of the central nervous system and promote sleep Thousands of deriva lives of the parent ring system of barbituric acid have been tested for sedative-hypnotic activity the most useful are the 5 5 disubstituted derivatives... 

The toxicity of 2,4-pentanedione is shown in Tables 3 and 11 to be similar to mesityl oxide, and greater than most other 1,2- or 1,4-diketones or monoketones. Inhalation of low levels of 2,4-pentanedione can cause nausea, eye contact can induce stinging, and recurrent exposure to high concentrations (300—400 ppm) can adversely affect the central nervous system and immune system (325). 

Alkyl mercury compounds in the blood stream are found mainly in the blood cehs, and only to a smah extent in the plasma. This is probably the result of the greater stabhity of the alkyl mercuric compounds, as well as their pecuflar solubiUty characteristics. Alkyl mercury compounds affect the central nervous system and accumulate in the brain (17,18). Elimination of alkyl mercury compounds from the body is somewhat slower than that of inorganic mercury compounds and the aryl and alkoxy mercurials. Methylmercury is eliminated from humans at a rate indicating a half-life of 50—60 d (19) inorganic mercurials leave the body according to a half-life pattern of 30—60 d (20). Elimination rates are dependent not only on the nature of the compound but also on the dosage, method of intake, and the rate of intake (21,22). 

Metabolic Functions. Manganese is essential for normal body stmcture, reproduction, normal functioning of the central nervous system, and activation of numerous enzymes (126). Synthesis of the mucopolysaccharide chondroitin sulfate involves a series of reactions where manganese is required in at least five steps (127). These reactions are responsible for formation of polysaccharides and linkage between the polysaccharide and proteins that form... 

CGRP is widely distributed throughout the peripheral and central nervous systems and is found ia sensory neurons and ia the autonomic and enteric nervous systems. In many iastances CGRP is co-localized with other neuroregulators, eg, ACh ia motor neurons, substance P, somatostatin, vasoactive intestinal polypeptide (VIP), and galanin ia sensory neurons. It is also present ia the CNS, with ACh ia the parabigeminal nucleus and with cholecystokinin (CCK) ia the dorsal parabrachial area. CGRP functions as a neuromodulator or co-transmitter. 

Phenol. Phenol monomer is highly toxic and absorption by the skin can cause severe blistering. Large quantities can cause paralysis of the central nervous system and death. Ingestion of minor amounts may damage kidneys, Hver, and pancreas. Inhalation can cause headaches, dizziness, vomiting, and heart failure. The threshold limit value (TLV) for phenol is 5 ppm. The health and environmental risks of phenol and alkylated phenols, such as cresols and butylphenols, have been reviewed (66). 

The ACGIH recommended maximum time-weighted average concentration in the workplace atmosphere for eight-hour daily exposure is 10 ppm. OSHA has set the permissible exposure level at 2 ppm. It maybe desirable to exclude alcohoHcs, persons with chronic disorders of the Hver, kidneys, and central nervous system, and those with nutritional deficiencies from working with chloroform. 

Overexposure to tetrachloroethylene by inhalation affects the central nervous system and the Hver. Dizziness, headache, confusion, nausea, and eye and mucous tissue irritation occur during prolonged exposure to vapor concentrations of 200 ppm (15). These effects are intensified and include incoordination and dmnkenness at concentrations in excess of 600 ppm. At concentrations in excess of 1000 ppm the anesthetic and respiratory depression effects can cause unconsciousness and death. A single, brief exposure to concentrations above 6000 ppm can be immediately dangerous to life. Reversible changes to the Hver have been reported foUowing prolonged exposures to concentrations in excess of 200 ppm (16—22). Alcohol consumed before or after exposure may increase adverse effects. 

Adrenaline (epinephrine) is a catecholamine, which is released as a neurotransmitter from neurons in the central nervous system and as a hormone from chromaffin cells of the adrenal gland. Adrenaline is required for increased metabolic and cardiovascular demand during stress. Its cellular actions are mediated via plasma membrane bound G-protein-coupled receptors. 

The blood-brain barrier (BBB) forms a physiological barrier between the central nervous system and the blood circulation. It consists of glial cells and a special species of endothelial cells, which form tight junctions between each other thereby inhibiting paracellular transport. In addition, the endothelial cells of the BBB express a variety of ABC-transporters to protect the brain tissue against toxic metabolites and xenobiotics. The BBB is permeable to water, glucose, sodium chloride and non-ionised lipid-soluble molecules but large molecules such as peptides as well as many polar substances do not readily permeate the battier. 

Endogenous opioid peptide released both in the central nervous system and in other apparatuses of the body that have many regulatory functions, including inhibition of pain transmission. 

In conclusion, the discovery of incretins has now come to an end in terms of therapeutic strategy of metabolic diseases since new medicines will be put on the market these coming years. However, a lot more needs to be done with regard to the physiological role of the hormones. Whereas the major filed of investigation for GLP-1 now relates to the effect of the peptide on the central nervous system and on (3-cell proliferation, for GIP it remains to understand its role in the numerous tissues where the corresponding receptor is expressed. 

Several splice variants of MOP (formerly MOR-1) have been cloned (MOP-1A to MOR-1X). The B, C, andD variants differ in their amino acid sequence at the C-terminal end [4]. These receptor valiants differ in their distribution in the central nervous system and in the rate of internalization and desensitization upon... 

Discuss the activity of the central nervous system and the peripheral nervous system. 

Pleet, H., Grahan, J.M., Smith, D.W. (1981). Central nervous system and facial defects associated with maternal hypertheimia at four to 14 weeks gestation. Pediatrics 67,785-789. 

In all higher species, locomotion is controlled by a central nervous system and, therefore, it might be argued that this system would provide an "ideal" target for toxins. However, when the nervous system is centrally located there is often in-built protection from blood-borne toxins and this "blood-brain" barrier offers protection, especially against large molecular weight toxins. 

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