Epinephrine definition

Epimerization of sugar, mechanisms 778 Epimers, definition of 163 Epinephrine (adrenaline) 542,553, 553s Episomes. See plasmid Epithelial cells 29 Epitheliocytes 25 Epoxides, alkyation by 254 Epoxide hydrolases 591 EPR (electron paramagnetic resonance) spectroscopy 398, 399 of glutamate mutase 873 in study of phosphotransferases 639 EPSP (enolpyruvoylshikimate-3-phosphate) 687s... 

Two synonyms, two definitions, and an expression of admiration. The word norepinephrine is synonymous with noradrenalin, and the word epinephrine is synonymous with adrenalin. The distinctions are that the first in each case is American and the second British. And the term chiral indicates a potential asymmetry in a molecule that would allow eventual separation into two optical isomers. The term racemic refers to a mixture of these two isomers which has not yet been separated into the individual components. A racemic mixture is called a racemate and, from the point of view of the human animal (which is completely asymmetric), must be considered as a mixture of two structurally identical but... 

Although no free epinephrine is excreted under the conditions of those experiments just described, it is permissible to question whether they are representative of the fate of epinephrine as it is secreted in the body, or whether conjugation is a mode of inactivation of catechol pressor amines administered as drugs. The relatively minute amounts of adrenaline or noradrenaline secreted normally and the limitations of present analytical methods definitely handicap a direct approach to the problem. However, it has been possible to study the fate of adrenaline secreted by the body in a more or less physiological type of experiment. 

In experimental animals the effect of ephedrine administered intravenously is similar to that of epinephrine. The arterial pressure — systolic, diastolic, and mean pressure — rises and vagal slowing occurs. Compared with epinephrine, the pressor response to ephedrine occurs somewhat more slowly and lasts about ten times longer. Furthermore, it requires more ephedrine than epinephrine to obtain an equivalent pressor response. How much more depends on the species tested, type and degree of anesthesia, dose level, and individual variability of the test animal. It is, therefore, almost impossible to give a definite figure for the relative potency of ephedrine and epinephrine. It is commonly accepted that it requires about 250 times more ephedrine than epinephrine to achieve equipressor responses. 

Two additional carriers with extensive homology to the GABA transporter are the Na+-coupled nor -epinephrine (Pacholczyk et al1991) and proline transporters (Fremeau et al., 1992) from human and rat brain, respectively. However, Cl" dependence has not yet been definitively demonstrated for the cloned carriers. 

Dihydroxyphenylalanine (for structure see diagram 11) is an amino acid isolated (from the pods and sprouts of Vida fd>a) and first definitely identified in 1913 by Guggenheim (323), who showed it to be identical with synthetic material previously prepared (280). It is widely distributed in certain types of plants (beans, etc.) but is not a normal protein constituent. However, it plays an important part in mammalian metabohsm of tyrosine, as it is the precursor of adrenaline (epinephrine), noradrenaline (arterenol, norepinephrine), and melanin. In this review these substances will be considered only insofar as they account for a portion of normal tyrosine metabolism. 

The mechanism of action of the phenothiazines is still not definitely known. They tend to block important effector substances such as acetylcholine, epinephrine, and histamine. The phenothiazines produce uncoupling of phosphorylation from oxidation. They appear to act at all steps along the electron transport chain. Cytochrome oxidase, succinoxidase, and adenosine triphosphatase are inhibited. Some data indicate that the phenothiazines may decrease the permeability of storage granules for brain amines. 

Molecular dimensions can be added to the definition of mental diseases. Using Bayes s Theorem, we can calculate the probability of a specific biochemical manifestation being related to specific manifestations of a mental disease. For example, one can calculate the probability of a person s aggressiveness being related to epinephrine-rdated brain processes. 

Although these results are not definitive they support the hypothesis that glucose metabolites may be involved in the depression of A6 desaturase activity evoked by glucagon and epinephrine through c AMP synthesis. 

Phrases such as strong suspicion and impaired fertility are not quantitatively defined, leaving the definitions open to interpretation. Is impaired fertility a decline in sperm motility (e.g., 200 ppm), or a complete lack of reproduction (750 ppm) Should this even be relevant if the exposure concentrations are no higher than 20 ppm Also, note the requirement that the impaired fertility should be in the absence of other toxic effects, but what does the rest of the sentence mean Lawyers have interpreted it to mean that the impaired fertility must be a direct effect on the reproductive system, not a secondary response to another primary effect. For example, an effect on the adrenal glands to increase the secretion of epinephrine may be a primary effect, but this has a secondary effect of increasing the heart rate. 

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