Multiple receptor concept

These concepts of information transduction by membranes may be used to integrate the scattered observations on the biological effects of interactions of 3,6-3-glticans with plant cells. The observation that chemically different groups of compounds may elicit the production of the same response such as wilting or formation of a phytoalexin, may be explained in terms of multiple receptors coupled to a single effector system which initiates the intracellular response. This would be analogous to the adenyl cyclase of the adipocyte which is stimulated by seven different hormones and inhibited by at least three others (124). In the... 

Odorivector molecviles can contain an almost unlimited number of profiles. Of these are only a few explicit, but with increasing conformational freedom a rapidly increasing number of implicit ones are potentially possible. This raises the question about the number of complementary receptor sites necessary to deal unambiguously and efficiently with the transcription of structural into informational modalities. The concept of multiple profile - multiple receptor sites provides no indication how the actual number of receptor site types covild be deduced. However the minimum number required to encode the total olfactory spectrum perceived by man can be estimated by means of basic principles of information theory. For that a few simple assmptions have to be made ... 

Up to this point only speculations have been presented. They were based on the assiomption that the peripheral process in olfaction is mediated by specific receptor sites of a group of membrane bound adenyl cyclases and that the Multiple Profile - Multiple Receptor Site concept is viable. If these assumptions are correct the following extrapolations could be made ... 

The concept of drug development is based on the findings that retinoid receptors (RARs and RXRs) offer a new approach by targeting different genes depending on the activated retinoid receptor complexes. The multiplicity of these retinoid signaling pathways affords potential for therapeutic opportunity as well as retinoid therapy associated undesired side effects. It is possible that the indiscriminate activation of all pathways by nonspecific retinoid ligands could lead to unacceptable side effects so that any enhanced efficacy would be obtained at the cost of enhanced toxicity. 

Kramer MS, Cutler N, Feighner J, Shrivastava R, Carman J, Sramek JJ, Reines SA, Liu G, Snovely D, Wyatt-Knowles E, Hale JJ, Mills SG, MacCoss M, Swain CJ, Harrison T, HiU RG, Hefti F, Scolnick EM, Cascieri MA, Chicchi GG, Sadowski S, Williams AR, Hewson L, Smith D, Rupniak NMJ (1998) Distinct mechanism for antidepressant activity by blockade of central substance P receptors. Science 281 1640-1645 Landgraf R (1995) Intracerebrally released vasopressin and oxytocin measurement, mechanisms and behavioral consequences. J Neuroendocrinol 7 243-253 Landgraf R, Neumann I (2004) Vasopressin and oxytocin release within the brain a dynamic concept of multiple and variable modes of neuropeptide communication. Front Neuroendocrinol 25 150-176... 

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