Receptors distribution

In the periphery, dopamine receptor levels are generally lower than those observed in brain, particularly in comparison to striatal dopamine receptor levels. Due to these low levels, knowledge of receptor distribution in the periphery is not yet comprehensive. Nevertheless, Dl-like receptors have been reported in the parathyroid gland and in the tubular cells of the kidney. D2-like dopamine receptors have also been observed in the kidney. In addition, dopamine D2 and D4 receptors have been found in the adrenal cortex, where they modulate aldosterone secretion. The... 

Mansueto et al. suggested that the susceptibility of embryos to toxicants could be first related to their interaction with egg membrane where they could provoke changes of permeability, of transmembrane potential, and of receptors distribution which could in turn drastically interfere with normal cell physiology. Cima et al. observed that TBT alters, immediately after the entry of... 

Blue, M.E. Yagaloff, K.A. Mamounas, L.A. Hartig, P.R. and Molliver, M.E. Correspondence of 5-HT2 receptor distribution with serotonin innervation in rat cerebral cortex. Abstr Soc Neurosci 12 145, 1986. 

Bonaventure, P., Nepomuceno, D., Kwok, A. et al. Reconsideration of 5-hydroxytryptamine (5-HT)7 receptor distribution using [3H]5-carboxamidotryptamine and [3H]8-hydroxy-2-(di-n-propylamino)tatraline Analysis in brain of 5-HT 1A knock-out and 5-HT1A,1B double knock-out mice. /. Pharmacol. Exp. Ther. 302 240-248, 2002. 

Distribution in guinea pig (HI and H2) and rodent (H3, H4) brain. For the H1 receptor, distribution is very different across species. Contradictory findings have been reported. 

The site of drug action and receptor distribution are being investigated 949 The mechanism of drug action may be elucidated by studying its binding 949... 

Insel, T. R., and Shapiro, L. 1992. Oxytocin receptor distribution reflects social organization in monogamous and polygamous voles. Proceedings of the National Academy of Sciences 89 5981—5985. 

Kodaira K, Fujishiro K, Wada T, Male K, Satoi T, Tsukiyama E, Fukumoto T, Uchida T, Yamazaki S, Okamura T (1993) A study on cerebral nicotine receptor distribution, blood flow, oxygen consumption, and other metabolic activities-a study on the effects of smoking on carotid and cerebral artery blood flow. Yakubutsu Seishin Kodo 13 157-165... 

R.M. Cohen, T.A. Podruchny, A.L.W. Bokde, R.E. Carson, P. Herscovitch, D.A. Kiesewetter, W.C. Eckelman, T. Sunderland, Higher in vivo muscarinic-2 receptor distribution volumes In ageing subjects with an apolipoprotein E-s4 allele. Synapse... 

In addition, the neuroanatomy of OT receptor distribution patterns is species-specific. Wide variability in patterns of receptor distribution exists across even closely related species (Insel and Shapiro, 1991 Insel et al., 1999). These cross-species disparities necessitate caution when one makes general statements about the relationships between OT and specific behaviors. For example, primates and humans have a circadian rhythm of CSF OT, while rodents do not (McCarthy and Altemus, 1997). There are important limits to the extent to which the results of specific gene knockout models may be extrapolated to other species. Ultimately, primate models may be necessary to assess the functions of OT in the primates and humans. 

Prairie vole young show high levels of stress in response to social isolation, while montane vole offspring show minimal behavioral or physical response to separation (Insel et ah, 1997). Prairie voles are much more vocal than montane voles during social separation (Winslow et al., 2000). It is suggested that this difference is related to diversity in OT receptor distribution across vole species. This phenomenon is an interesting parallel to the differences in pup vocalization (and therefore socialization) seen between OT knockout pups and their wild-type counterparts. 

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). 

These natural chemicals are small chain peptides that bind to opiate receptors distributed throughout the brain—including the limbic system, where their activation produces feelings of happiness, euphoria, serenity, and fearlessness. 

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