Matches in SemOpenAlex for { <https://semopenalex.org/work/W2015233872> ?p ?o ?g. }
Showing items 1 to 79 of
79
with 100 items per page.
- W2015233872 endingPage "495" @default.
- W2015233872 startingPage "484" @default.
- W2015233872 abstract "The purpose of this study was to characterize the adenylate cyclase system in a purified population of normal somatotrophs derived from rat pituitary and to determine the responses of this system to GRF, somatostatin, guanine nucleotides, and cations. Additionally, experiments were performed to evaluate the interrelationships among changes in adenylate cyclase activity, cellular cAMP levels, and GH release induced by GRF and somatostatin. The results obtained using homogenates and membrane preparations from somatotrophs included the following. 1) GRF caused guanine nucleotide-dependent concentration- related (Ka, -10-8 M) stimulation of adenylate cyclase activity. 2) Guanine nucleotides were effective in stimulating cyclase in the absence of GRF; the concentration of guanine nucleotide required for half-maximal stimulation was decreased more than 10-fold in the presence of GRF. 3) Adenylate cyclase activity increased with increasing concentrations of free Mg2+ (0.25–20 mM); activation by GRF and guanine nucleotide resulted in an approximately 7-fold increase in the enzyme’s affinity for free Mg2+. 4) Somatostatin, up to 10-6 M, did not alter basal or GRF-stimulated adenylate cyclase activity. 5) Ca2+ (0.5μ11.9 μM) produced concentration-dependent inhibition of basal (up to 28%) and GRF-stimulated (up to 47%) cyclase activities; the inhibitory effect of Ca2+ was accompanied by a decrement (2- to 3-fold) in the apparent affinities of the enzyme for both GRF and guanine nucleotide. In intact somatotrophs, GRF produced concentration-dependent stimulation of GH release (Ka, -6 x 10-11 M), preceded by a marked elevation of cAMP levels. While somatostatin blocked GRF-induced GH release, the augmented cAMP levels were only slightly reduced. The above results indicate that in somatotrophs, 1) adenylate cyclase is coupled to the GRF receptor via a stimulatory guanine nucleotide regulatory protein, Ns; 2) the mechanistic events underlying GRF stimulation of the cyclase are similar to those recognized for other hormone receptor-coupled adenylate cyclase systems; 3) the response characteristics of adenylate cyclase to GRF are consistent with an essential role for cAMP in GRFmediated GH release; 4) the increase in intracellular Ca2+ resulting from activation of the adenylate cyclase-cAMP system by GRF will not only promote GH release, but may trigger inhibition of cAMP formation to attenuate the secretory response; and 5) a fractional population of the GRF-sensitive adenylate cyclase units may be coupled to somatostatin receptors in an inhibitory manner, and the primary action of somatostatin in blocking GRF-induced GH release occurs at a step(s) distal to cAMP formation, or independent of changes in cAMP levels. (Endocrinology124: 484–495,1989)" @default.
- W2015233872 created "2016-06-24" @default.
- W2015233872 creator A5020922662 @default.
- W2015233872 creator A5051570811 @default.
- W2015233872 creator A5068222095 @default.
- W2015233872 creator A5075065545 @default.
- W2015233872 creator A5076249354 @default.
- W2015233872 date "1989-01-01" @default.
- W2015233872 modified "2023-10-15" @default.
- W2015233872 title "Growth Hormone-Releasing Factor-Sensitive Adenylate Cyclase System of Purified Somatotrophs: Effects of Guanine Nucleotides, Somatostatin, Calcium, and Magnesium*" @default.
- W2015233872 doi "https://doi.org/10.1210/endo-124-1-484" @default.
- W2015233872 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/2562826" @default.
- W2015233872 hasPublicationYear "1989" @default.
- W2015233872 type Work @default.
- W2015233872 sameAs 2015233872 @default.
- W2015233872 citedByCount "51" @default.
- W2015233872 countsByYear W20152338722021 @default.
- W2015233872 crossrefType "journal-article" @default.
- W2015233872 hasAuthorship W2015233872A5020922662 @default.
- W2015233872 hasAuthorship W2015233872A5051570811 @default.
- W2015233872 hasAuthorship W2015233872A5068222095 @default.
- W2015233872 hasAuthorship W2015233872A5075065545 @default.
- W2015233872 hasAuthorship W2015233872A5076249354 @default.
- W2015233872 hasConcept C104317684 @default.
- W2015233872 hasConcept C126322002 @default.
- W2015233872 hasConcept C134018914 @default.
- W2015233872 hasConcept C180526460 @default.
- W2015233872 hasConcept C181199279 @default.
- W2015233872 hasConcept C185592680 @default.
- W2015233872 hasConcept C24998067 @default.
- W2015233872 hasConcept C2776297358 @default.
- W2015233872 hasConcept C2777658017 @default.
- W2015233872 hasConcept C2778301229 @default.
- W2015233872 hasConcept C2780069284 @default.
- W2015233872 hasConcept C512185932 @default.
- W2015233872 hasConcept C55493867 @default.
- W2015233872 hasConcept C71315377 @default.
- W2015233872 hasConcept C71924100 @default.
- W2015233872 hasConcept C86803240 @default.
- W2015233872 hasConcept C94984642 @default.
- W2015233872 hasConceptScore W2015233872C104317684 @default.
- W2015233872 hasConceptScore W2015233872C126322002 @default.
- W2015233872 hasConceptScore W2015233872C134018914 @default.
- W2015233872 hasConceptScore W2015233872C180526460 @default.
- W2015233872 hasConceptScore W2015233872C181199279 @default.
- W2015233872 hasConceptScore W2015233872C185592680 @default.
- W2015233872 hasConceptScore W2015233872C24998067 @default.
- W2015233872 hasConceptScore W2015233872C2776297358 @default.
- W2015233872 hasConceptScore W2015233872C2777658017 @default.
- W2015233872 hasConceptScore W2015233872C2778301229 @default.
- W2015233872 hasConceptScore W2015233872C2780069284 @default.
- W2015233872 hasConceptScore W2015233872C512185932 @default.
- W2015233872 hasConceptScore W2015233872C55493867 @default.
- W2015233872 hasConceptScore W2015233872C71315377 @default.
- W2015233872 hasConceptScore W2015233872C71924100 @default.
- W2015233872 hasConceptScore W2015233872C86803240 @default.
- W2015233872 hasConceptScore W2015233872C94984642 @default.
- W2015233872 hasIssue "1" @default.
- W2015233872 hasLocation W20152338721 @default.
- W2015233872 hasLocation W20152338722 @default.
- W2015233872 hasOpenAccess W2015233872 @default.
- W2015233872 hasPrimaryLocation W20152338721 @default.
- W2015233872 hasRelatedWork W124728163 @default.
- W2015233872 hasRelatedWork W1578076358 @default.
- W2015233872 hasRelatedWork W180243494 @default.
- W2015233872 hasRelatedWork W1964888906 @default.
- W2015233872 hasRelatedWork W1983113419 @default.
- W2015233872 hasRelatedWork W2053922838 @default.
- W2015233872 hasRelatedWork W2159620470 @default.
- W2015233872 hasRelatedWork W2406327875 @default.
- W2015233872 hasRelatedWork W2419940757 @default.
- W2015233872 hasRelatedWork W3103481565 @default.
- W2015233872 hasVolume "124" @default.
- W2015233872 isParatext "false" @default.
- W2015233872 isRetracted "false" @default.
- W2015233872 magId "2015233872" @default.
- W2015233872 workType "article" @default.