+ Site Statistics
+ Resolve Accession
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
Submit PDF Full TextSubmit PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Trh induced spike and plateau in cytosolic free calcium concentrations in pituitary cells relation to prolactin release

, : Trh induced spike and plateau in cytosolic free calcium concentrations in pituitary cells relation to prolactin release. Journal of Biological Chemistry 259(9): 5827-5832

Using the acetoxymethyl ester of Quin 2 a fluorescent CA2+-indicator, prolactin (PRL)-producing rat pituitary cells were loaded with non-toxic concentrations of Quin 2 and quantitated changes in cytosolic free calcium concentration ([Ca2+]i) during stimulation of PRL release by TRH and 40 mM K+. TRH induced a biphasic response, with an immediate (< 1 s) spike in [Ca2+]i from basal levels (350 .+-. 80 nM) to a peak of 1-3 .mu.M, which decayed rapidly (t1/2 = 8s) to a near basal nadir, then rising to a plateau in [Ca2+]i of 500-800 nM. The TRH-induced spike phase was attenuated but not abolished by prior addition of EGTA [ethylene glycol bis(.beta.-aminoethyl ether)-N,N,N',N'-tetraacetic acid], while the plateau phase was eliminated by EGTA. Addition of 40 mM K+ caused an immediate spike in [Ca2+]i to 1-3 .mu.M which equilibrated slowly (t1/2 = 1 min) directly to a plateau of 600-800 nM. The K+-induced spike and plateau phases were both abolished by prior addition of EGTA. The biphasic nature of TRH action on [Ca2+]i parallels the biphasic actions of TRH on 45Ca2+ fluxes and the biphasic release of PRL by GH [growth hormone] cells in suspension. Ca2+-dependent agonist-mediated increases in [Ca2+]i and hormone release are linked, and may generally have 2 modes: an acute spike mode, dependent primarily on redistribution of intracellular Ca2+ stores; and a sustained plateau mode, dependent on influx of extracellular Ca2+.

(PDF 0-2 workdays service)

Order PDF Full Text


Click here to order any other PDF Full Text

Accession: 006839754

PDF Full Text: Submit

Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:

Other references

Kawada, Norifumi; Seki, Shuichi; Asahina, Kinji; Kristensen, Dan Bach; Yoshizato, Katsutoshi, 2000: The molecular profiles of stellate cell activation by proteomics. Hepatology 32(4 Pt 2): 385A, October

Zheng DaWei; Wang YanTian; Pan XueBiao; Lin QiMei, 2005: Progresses on integrated management and dryland farming technical system for ecological protection in ecotone of the North China. The northern ecotone is one of the ecological fragile and poor regions in China. It becomes the main source of sand and dust storm which deteriorated the environment of inland China. Aiming at the main ecological obstacles, e.g. water erosion, win...

Kleiman, A. M.; Senyuta, N. B.; Tryakin, A. A.; Vinogradova, T. V.; Karseladze, A. I.; Sauter, M.; Muller Lanch, N.; Tyulyandin, A. S.; Gurtsevich, V. E., 2001: Expression of HERV-K/HTDV endogenous retroviruses in patients with germinogenic testicular tumours. RT-PCR was used with specific primers discriminating type 1 proviruses from type 2 ones to study transcription of HERV-K/HTDV in various morphological forms of GCTs and in normal testicular parenchyma and placenta. The results indicated that trans...

Kamal, Robin N.; Chehata, Ash; Rainbow, Michael J.; Llusá, Manuel; Garcia-Elias, Marc, 2012: The Effect of the Dorsal Intercarpal Ligament on Lunate Extension After Distal Scaphoid Excision. After a distal scaphoid excision, most wrists develop a mild form of carpal instability nondissociative with dorsal intercalated segment instability. Substantial dysfunctional malalignment is only occasionally seen. We hypothesized that distal sca...

Alfa C.E.; Reakes C.F.L.; Rowbury R.J., 1987: Increased sensitivity to erythromycin in escherichia coli associated with the presence of the col v i k94 virulence plasmid. Introduction of the virulence plasmid, ColV,I-K94, into Escherichia coli strains led to increased sensitivity to erythromycin. This was the result of increased passage of antibiotic into ColV,I-K94+ organisms because the plasmid effect was abolish...

Pinheiro Machado, L. C.; Hurnik, J. F.; Burton, J. H., 1996: Effect of amniotic fluid ingestion on the nociception in parturient cows. Journal of Animal Science 74(SUPPL 1): 129

Menon Shanti, 1996: Insects of the oxygeniferous.; 3. Pages 220-221 1996

Heringer, I.; Carvalho, P. C. de F., 2002: Stocking rate adjustment in grazing experiments: a new approach. A new method was proposed to adjust stocking rate and for better forage mass control, based on forage mass and forage allowance, dry matter (DM) accumulation rate, herbage intake rate, and forage susceptible to refusal and lost parameters. This me...

Rosillo Calle, F.; Hall, D. O., 1992: Biomass energy, forests and global warming. The importance of biomass energy is discussed in the context of the rate of deforestation, climatic changes and environmental effects, biomass sinks to sequester CO2, and socioeconomic and political aspects. Possible measures to alleviate global w...

Kofler, W., 1977: The determination of resort and stress areas by air pollution part 2 the evaluation of air pollution in spreadout areas classification into stress categories. To qualify the air pollution by SO2 and particulate matter in widespread areas a method for complex terrain was used in the Austrian Alps. The working model was previously described. It is possible to classify the investigated area according to st...