+ Translate

Trh and gtp activate inositol trisphosphate formation in membranes isolated from rat pituitary cells

, : Trh and gtp activate inositol trisphosphate formation in membranes isolated from rat pituitary cells. Journal of Biological Chemistry 261(6): 2712-2717

Stimulation of the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) by a phospholipase C to produce inositol trisphosphate (InsP3) and 1,2-diacylglycerol appears to be the initial step in signal transduction for a number of cell-surface interacting stimuli, including thyrotropin-releasing hormone (TRH). In suspensions of membranes isolated from rat pituitary (GH3) cells that were prelabeled to isotopic steady state with [3H]inositol and incubated with ATP, [3H]PtdIns(4,5)P2, and [3H]phosphatidylinositol 4-phosphate, the polyphosphoinositides, and [3H]InsP3 and [3H]inositol bisphosphate, the inositol polyphosphates, accumulated. TRH and GTP stimulated the accumulation of [3H]inositol polyphosphates in time- and concentration-dependent manners; half-maximal effects occurred with 10-30 nM TRH and with 3 .mu.M GTP. A nonhydrolyzable analog of GTP also stimulated [3H]inositol polyphosphate accumulation. Moreover, when TRH and GTP were added together their effects were more than additive. Fixing the free Ca2+ concentration in the incubation buffer at 20 nM, a value below that present in the cytoplasm in vivo did not inhibit stimulation by TRH and GTP of [3H]inositol polyphosphate accumulation. ATP was necessary for basal and stimulated accumulation of [3H]inositol polyphosphates, and a nonhydrolyzable analog of ATP could not substitute for ATP. These data demonstrate that TRH and GTP act synergistically to stimulate the accumulation of InsP3 in suspensions of pituitary membranes and that ATP, most likely acting as substrate for polyphosphoinositide synthesis, was necessary for this effect. These findings suggest that a guanine nucleotide-binding regulatory protein is involved in coupling the TRH receptor to a phospholipase C that hydrolyzes PtdIns(4,5)P2.

(PDF 0-2 workdays service)

Order PDF Full Text


Click here to order any other PDF Full Text

Accession: 006839677

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

Moroni, M.; Cavalli, G.; Lodola, E., 1978: Viminol analgesic activity in elderly patients with chronic pain a controlled evaluation using self rating questionnaires. The analgesic effects of single oral doses of viminol (70 mg), of viminol (70 mg) combined with chlordiazepoxide (10 mg) and of chlordiazepoxide (10 mg) were compared in 41 outpatients with chronic pain mostly due to neoplasms. Alone, or combined...

Lepartre, L., 1973: Novel bactericidal composition. A disinfectant for use in dairies, breweries etc., is obtained by mixing a 3.6% aqueous formol solution with a 1.5% aqueous solution of a dimethyl alkyl benzyl ammonium chloride in which the alkyl group is a C8H17 to C16H33 straight chain. Test re...

Mishra, S. K.; Melinkeri, S. R.; Dabadghao, S., 2001: Benign thymic hyperplasia after chemotherapy for acute myeloid leukemia. Thymic hyperplasia can occur after cytotoxic therapy for various malignancies. The possible cause could be rebound enlargement after initial atrophy caused by these drugs. During the treatment of hematological malignancies this could be a cause of...

Galuzo, I. G., 1956: Osnovnye pereno-schiki zaraznykh boleznel sel'skok-hoziaistvennykh zhivotnykhi bor'ba s nimi.. Unknown

Sloan K.B.; Beall H.D.; Weimar W.R.; Villanueva R., 1991: The effect of receptor phase composition on the permeability of hairless mouse skin in diffusion cell experiments. The effect of different antimicrobial agents (0.1% and 0.04% formaldehyde and 0.002% NaN3) in the receptor phase of diffusion cells and the influence of the length of time of exposure of hairless mouse skins in the diffusion cells to the receptor...

Zusser, S. G., 1961: Daily vertical migrations of plankton feeding fishes. Trudy VNIRO: 44: 177-186

Moyer, J. R., 1980: Weed control in seedling stands of cicer milkvetch. The tolerance of cicer milkvetch to 27 herbicides or herbicide combinations was evaluated in growth chamber experiments; 2 herbicides and 2 herbicide combinations were selected for evaluations in the field. Cicer milkvetch was tolerant to triflura...

Anonymous, 2012: What Predicts Long-Term Survival After Heart Transplantation? An Analysis of 9,4 Ten-Year Survivors. This case-control study was conducted to identify factors predictive of 1-year survival after orthotopic heart transplantation (OHT). Prospectively collected data from the United Network for Organ Sharing registry were reviewed to identify adult p...

Prussin, Aaron, J. Ii; Zigler, David, F.; Jain, Avijita; Brown, Jared, R.; Winkel, Brenda, S. J.; Brewer, Karen, J., 2008: Photochemical methods to assay DNA photocleavage using supercoiled pUC18 DNA and LED or xenon arc lamp excitation. Methods for the study of DNA photocleavage are illustrated using a mixed-metal supramolecular complex [{(bpy)(2)Ru(dpp)}(2)RhCl2]Cl-5. The methods use supercoiled pUC18 plasmid as a DNA probe and either filtered light from a xenon arc lamp source...

Wahlberg, B.; Mietzner, T. A., 1993: Iron and oxygen-related environmental stresses produce opposite supercoiling responses in Neisseria gonorrhoeae. Abstracts of the General Meeting of the American Society for Microbiology 93(0): 74