FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W1992194033> ?p ?o ?g. }

• W1992194033 endingPage "310" @default.
• W1992194033 startingPage "303" @default.
• W1992194033 abstract "Abstract: The relationship between intrasynaptosomal total (Ca T ) and free ([Ca 2+ ] i ) calcium and 45 Ca accumulation was studied under physiological and K + ‐depolarised conditions in rat cortical synaptosomes. Under physiological conditions, Ca T (10.7 m M ) was ∼ 10,000 times higher than [(Ca 2+ ] i (118 n M ), showing that there is a large reservoir of sequestered calcium in synaptosomes. 45 Ca accumulation was rapid (initial rate, 3.4 nmol/mg protein/min), substantial (7 nmol/mg protein in 2 min), and depolarisation dependent, and reached equilibrium after 5 min. At equilibrium, only 10% of Ca T was freely exchangeable. This pool was much larger than the free Ca 2+ pool. Ca T , [Ca 2+ ] i , and 45 Ca accumulations were directly related to the Ca 2+ concentration in the buffer, suggesting that [Ca 2+ ] i is not highly conserved but is maintained by simple equilibria between the various pools. Clonidine reduced 45 Ca accumulation in a time‐ and dose‐dependent manner. Maximum inhibition (40% at 100 μM ) occurred at 2 min and the IC 50 was 80 n M The reduction caused by clonidine (1 μM ) reached equilibrium after 5 min, but this equilibrium value was lower than in controls, suggesting that clonidine changes the exchangeable Ca 2+ pool size. The effects of clonidine (1 μM ) on [Ca 2+ ] i (26% reduction) and on 45 Ca accumulation (24% reduction) were most apparent under physiological conditions. However, while it was not dependent on depolarisation, it did not occur in physiological buffer containing low K + concentration (0.1–1 m M ). The inhibitory effect of clonidine on 45 Ca accumulation is receptor mediated as it was antagonised by idazoxan (1 μM ). Under nondepolarised conditions (5 m M K + ), ω ‐conotoxin fraction GVIA ( ω ‐CgTx; 0.5 μM ) caused a 35% reduction in 45 Ca accumulation in a 2‐min incubation, whereas nifedipine (1 μM ) had no significant effect. In contrast, both ω ‐CgTx and nifedipine effectively blocked 45 Ca entry into depolarised synaptosomes. However, the effect of ω ‐CgTx was not additive with that of clonidine, whereas that of nifedipine was. Finally, idazoxan (1 μM ) did not alter the effect caused by nifedipine. These data show (a) that clonidine decreases 45 Ca accumulation by inhibiting N‐ but not L‐type voltage‐sensitive Ca 2+ channels, (b) that specific Ca 2+ channels on synaptosomes display a range of voltage sensitivities, and (c) that L‐type Ca 2+ channels are operational under depolarising conditions." @default.
• W1992194033 created "2016-06-24" @default.
• W1992194033 creator A5016843344 @default.
• W1992194033 creator A5018273546 @default.
• W1992194033 creator A5039137589 @default.
• W1992194033 creator A5089543470 @default.
• W1992194033 date "1990-07-01" @default.
• W1992194033 modified "2023-10-17" @default.
• W1992194033 title "Regulation of Calcium Concentrations in Synaptosomes: <i>α</i>₂‐Adrenoceptors Reduce Free Ca²⁺ by Closure of N‐Type Ca²⁺ Channels" @default.
• W1992194033 cites W1969275677 @default.
• W1992194033 cites W1970415139 @default.
• W1992194033 cites W1978223897 @default.
• W1992194033 cites W1980280188 @default.
• W1992194033 cites W1982807202 @default.
• W1992194033 cites W1985087389 @default.
• W1992194033 cites W1987238214 @default.
• W1992194033 cites W1992169439 @default.
• W1992194033 cites W2005378562 @default.
• W1992194033 cites W2006370215 @default.
• W1992194033 cites W2016609732 @default.
• W1992194033 cites W2020420593 @default.
• W1992194033 cites W2027029852 @default.
• W1992194033 cites W2040501521 @default.
• W1992194033 cites W2050890071 @default.
• W1992194033 cites W2053559739 @default.
• W1992194033 cites W2056660986 @default.
• W1992194033 cites W2057395617 @default.
• W1992194033 cites W2060533392 @default.
• W1992194033 cites W2061056399 @default.
• W1992194033 cites W2064748241 @default.
• W1992194033 cites W2064998787 @default.
• W1992194033 cites W2068617048 @default.
• W1992194033 cites W2071378425 @default.
• W1992194033 cites W2074730021 @default.
• W1992194033 cites W2078494459 @default.
• W1992194033 cites W2082299946 @default.
• W1992194033 cites W2083335870 @default.
• W1992194033 cites W2094772184 @default.
• W1992194033 cites W2102131116 @default.
• W1992194033 cites W2117288347 @default.
• W1992194033 cites W2118309627 @default.
• W1992194033 cites W2122262212 @default.
• W1992194033 cites W2134782212 @default.
• W1992194033 cites W2226364488 @default.
• W1992194033 cites W2414216645 @default.
• W1992194033 doi "https://doi.org/10.1111/j.1471-4159.1990.tb08852.x" @default.
• W1992194033 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/2162379" @default.
• W1992194033 hasPublicationYear "1990" @default.
• W1992194033 type Work @default.
• W1992194033 sameAs 1992194033 @default.
• W1992194033 citedByCount "23" @default.
• W1992194033 crossrefType "journal-article" @default.
• W1992194033 hasAuthorship W1992194033A5016843344 @default.
• W1992194033 hasAuthorship W1992194033A5018273546 @default.
• W1992194033 hasAuthorship W1992194033A5039137589 @default.
• W1992194033 hasAuthorship W1992194033A5089543470 @default.
• W1992194033 hasConcept C12554922 @default.
• W1992194033 hasConcept C178790620 @default.
• W1992194033 hasConcept C185592680 @default.
• W1992194033 hasConcept C2778921374 @default.
• W1992194033 hasConcept C4141045 @default.
• W1992194033 hasConcept C519063684 @default.
• W1992194033 hasConcept C86803240 @default.
• W1992194033 hasConceptScore W1992194033C12554922 @default.
• W1992194033 hasConceptScore W1992194033C178790620 @default.
• W1992194033 hasConceptScore W1992194033C185592680 @default.
• W1992194033 hasConceptScore W1992194033C2778921374 @default.
• W1992194033 hasConceptScore W1992194033C4141045 @default.
• W1992194033 hasConceptScore W1992194033C519063684 @default.
• W1992194033 hasConceptScore W1992194033C86803240 @default.
• W1992194033 hasIssue "1" @default.
• W1992194033 hasLocation W19921940331 @default.
• W1992194033 hasLocation W19921940332 @default.
• W1992194033 hasOpenAccess W1992194033 @default.
• W1992194033 hasPrimaryLocation W19921940331 @default.
• W1992194033 hasRelatedWork W1963552271 @default.
• W1992194033 hasRelatedWork W1968193679 @default.
• W1992194033 hasRelatedWork W1973993210 @default.
• W1992194033 hasRelatedWork W1992493594 @default.
• W1992194033 hasRelatedWork W1998904547 @default.
• W1992194033 hasRelatedWork W2003019209 @default.
• W1992194033 hasRelatedWork W2025940399 @default.
• W1992194033 hasRelatedWork W2096436698 @default.
• W1992194033 hasRelatedWork W2208741647 @default.
• W1992194033 hasRelatedWork W2401640372 @default.
• W1992194033 hasVolume "55" @default.
• W1992194033 isParatext "false" @default.
• W1992194033 isRetracted "false" @default.
• W1992194033 magId "1992194033" @default.
• W1992194033 workType "article" @default.