Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Butaclamol”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources

Heterosynaptic stimulation modulates the duration of post-tetanic potentiation at an Aplysia synapse without affecting other aspects of synaptic transmission.

Repetitive stimulation of an axon in the right visceropleural connective to the abdominal ganglion of Aplysia californica produces post-tetanic potentiation (PTP) of a unitary monosynaptic EPSP recorded from cell R15. PTP decays within one half hour following cessation of repatitive stimulation. Stimulation of the left visceropleural connective speeds the rate of decay of PTP, but does not affect the amount of potentiation which is developed or the size of the non-potentiated EPSP. The effect of heterosynaptic left connective stimulation is similar to the previously reported effects of low doses of serotonin but different from the effects of heterosynaptic branchial nerve stimulation. As previously reported, branchial nerve stimulation causes a reduction in the size of the EPSP, and can also speed the rate of decay of PTP. Effects of branchial nerve and left connective stimulation are blocked by SQ10,631, a serotonin antagonist. The left connective effect on the rate of decay of PTP, like the serotonin effect, appears to be mediated by a cyclic nucleotide. The data are consistent with the existence of two separable serotonergic receptors presynaptic to the homosynaptic pathway; one receptor mediates a change in the rate of decay of PTP, one mediates a change in the size of the EPSP. The possible physiological significance of heterosynaptic control of PTP is considered.

4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone↗

Retina contains guanine nucleotide sensitive and insensitive classes of dopamine receptors.

Calf retina contains high affinity, stereospecific and saturable binding sites, characterized as dopaminergic, for 3H-spiropheridol (Bmax from Scatchard analysis = 38 +/- 4 fmoles/mg protein) and for 3H-ADTN (2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene). The 3H-ADTN sites include a discrete and saturable sub-set of sites sensitive to guanine nucleotide inhibition (Bmax = 50 +/- 6 fmoles/mg protein) and a separate saturable sub-set of sites insensitive to guanine nucleotides (Bmax = 63 +/- 7 fmoles/mg protein). The binding of agonists to 3H-spiroperidol sites is also inhibited by guanine nucleotides.

Adenylyl Cyclases↗

[3H]spiperone binding in the nigrostriatal system in human brain.

The characteristics of [3H]spiperone binding in human brain were compared in three areas of the nigrostriatal pathway: areas containing the nerve terminals (caudate nucleus, putamen and pallidum); the area containing the cell bodies (substantia nigra pars compacta); the area containing the dendrites (pars reticulata). The affinity constants were calculated from saturation binding curves and from the kinetics of association and dissociation. The pharmacological profiles of the receptors was also established by displacement studies. The affinity constants and pharmacological profiles were similar in the striatum and the substantia nigra, although the latter contained a much smaller number of sites. In the substantia nigra, however, curved Scatchard plots were obtained, indicating that a second lower affinity site binding [3H]spiperone was also present. A considerable proportion (50%) of [3H]spiperone binding to nigral membranes could be displaced by the serotonin antagonist cinanserine , compared to the striatum (20%). The effect of post-mortem conditions on binding levels was studied in the rat. A loss of 20% occurred during the first hours after death, but was stable by 6 h until at least 24 h.

Aged↗

Pharmacological characterization and autoradiographic localization of dopamine receptors in the rat adrenal medulla.

The pharmacological profile and the anatomical localization of dopamine D1-like and D2-like receptors were studied in sections of rat adrenal medulla, with radioligand binding and autoradiographic techniques, respectively. [3H]([R]-(+)-chloro-2,3,4,5-tetrahydro-5-phenyl-1 H-3benzazepin-al hemimaleate) (SCH 23390) was used as a ligand for dopamine D1-like receptors and [3H]spiperone was used as a ligand for dopamine D2-like receptors. Radioligand binding and light microscope autoradiography did not show specific [3H]SCH 23390 binding in sections of rat adrenal medulla. This suggests that rat adrenal medulla does not express dopamine D1-like receptors. [3H]Spiperone was specifically bound to sections of rat adrenal medulla. The binding was time-, temperature- and concentration-dependent, with a dissociation constant (Kd) of 1.05 nM and a maximum density of binding sites (Bmax) of 100.2 +/- 3.8 fmol/mg tissue. The pharmacological profile of [3H]spiperone binding to rat adrenal medulla was similar to that displayed by neostriatum, which is known to express dopamine D2 receptors. Light microscope autoradiography showed the accumulation of specifically bound [3H]spiperone as silver grains within sections of adrenal medulla. Silver grains were found primarily over the cellular membrane of chromaffin cells. The above data indicate that chromaffin cells of the rat adrenal medulla express dopamine receptors belonging to the dopamine D2 receptor subtype. These receptors are probably involved in the modulation of catecholamine release from chromaffin cells, as documented by functional studies.

Adrenal Medulla↗

Methodology of 3H-spiperone binding to lymphocytes.

Alterations in lymphocyte binding capacity for the dopamine antagonist 3H-spiperone may be of great interest in psychiatric and neurological disorders: an increase in capacity noted in lymphocytes of schizophrenic patients and their families may well turn out to be a phenotypic vulnerability marker. Since the 3H-spiperone binding assay with lymphocytes does not fulfill common receptor-binding assay criteria and depends more on crucial analytical conditions, shortcomings in binding assay might possibly lead to irreproducible results. A detailed methodological description of the binding assay and subsequent calculations has therefore been given in this paper.

Binding, Competitive↗