Receptors quantitative aspects

Esteban, J. M., Ahn, C., Battifora, H., and Felder, B. 1994a. Quantitative immunohistochemical assay for hormonal receptors Technical aspects and biological significance. J. Cell Biochem. 79 138-145. 

In this chapter, we undertake a review of the quantitative aspects of dopamine neurotransmission of relevance to the spatial and temporal specificity of the dopamine signal. The kinetics of dopamine release and clearance are considered in order to estimate the temporal and spatial concentration distribution of dopamine. The location of receptors and their sensitivity to dopamine are taken into account. We then consider the regulation of ion channels by the G proteins activated by dopamine, and how this might explain the effects of dopamine on the whole cell. Finally, we consider the regulation by dopamine of corticostriatal inputs to the spiny cells. 

Kahn, C. R., Freychet, P., Neville, D. M., Jr., and Roth, J., 1974, Quantitative aspects of the insulin-receptor interaction in liver plasma membranes, /. Biol. Chem. 249 2249. 

Differences in receptor distribution are due to species differences in region-specific gene expression. Across vole species, OT receptor coding sequences and promoter sequences are virtually identical species diversity in receptor expression appears to relate to quantitative and regional differences rather than qualitative aspects of the receptor when expressed (Insel et al., 1997). 

Buchheim believed that the mode of action of drugs should be investigated by scientific means in order to quantify their effects and introduce a more rational basis for therapy. The second section of this book deals with drug-receptor interactions within the body and the quantitation of these resulting effects. In addition, toxicological aspects of drug-receptor interactions and the treatment of toxicological problems are discussed. 

This chapter provides an overview of factors affecting dermal absorption. Factors influencing absorption are among others related to the skin (e.g. anatomical site, difference between species, metabolism, etc.) and the exposure conditions (e.g. area dose, vehicle, occlusion and exposure duration). In order to provide relevant information for the risk assessment of pesticides, dermal absorption studies should take these aspects into account. With respect to the methods being used nowadays for the assessment of dermal absorption, it is important to realize that neither in vitro nor in vivo animal studies have been formally validated. Available data from various in vitro studies, however, indicate that the use of the total absorbed dose (i.e. the amount of test substance in the receptor medium plus amount in the skin) could be used in a quantitative manner in risk assessment. Tape stripping of the skin can be adequate to give a good indication of test chemical distribution, and hence its immediate bioavailability. 

A number of methods are available today for investigating the various aspects of this process of matrix degradation and tissue invasion. Study of degradation aims to identify and quantitate at mRNA or protein level a series of markers involved in the disruption of ECM molecules. These markers— hydrolases, their activators, inhibitors, receptors, degradation products, etc.— may be found to be involved or even crucial to invasive and metastatic aggressiveness. 

Carbohydrate-specific hepatic receptor-mediated clearance mechanisms include the asialoglycoprotein, S04-GalNAc and Man receptors [235,236]. The asialoglycoprotein receptor on liver hepatocytes is most significant and accounts for the short circulatory half-life of proteins lacking terminal SA [237]. Reliable quantitative analysis of SA will be an important aspect of quality control for glycoprotein pharmaceuticals. For glycoproteins produced in recombinant S. cerevisiae and insect cells which possess terminal Man or Gn moieties, the Man receptor presumably represents a major clearance mechanism [229]. 

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