• A confluent layer of cells (approximately 1.5 X 10' cells, 15 mg of cell protein per flask) was obtained on the 6th or 7th day of incubation. (nih.gov)
  • Activation of alpha 1-adrenoceptors appears to amplify beta-adrenergic stimulation of cyclic AMP (cAMP) accumulation in rat pinealocytes severalfold by a mechanism involving activation of a Ca2+-, phospholipid-dependent protein kinase (protein kinase C). The mechanism of action of protein kinase C was investigated in this report using intact cells. (nih.gov)
  • The amplification of the beta-adrenergic cAMP response by these agents also occurred in the presence of isobutylmethylxanthine (10(-3) M) and Ro 20-1724 (10(-4) M), an observation suggesting that inhibition of cAMP phosphodiesterase activity is not the mechanism of action. (nih.gov)
  • Withdrawal of the inhibitory ligand unmasks the elevated enzyme activity and results in a prolonged 4- to 10-fold increase in cellular cyclic AMP levels. (nih.gov)
  • Cells thus develop an apparent toler- ance to and dependence upon morphine, carbamylcho- line, or norepinephrine with respect to maintenance of cellular cyclic AMP levels. (nih.gov)
  • Inhibition of PGI2 signaling by miconazole in vascular smooth muscle cells. (harvard.edu)
  • The cells were centrifuged for 4 min at 1000 x g, and the cell pellets were frozen in Dry Ice and stored over liquid nitrogen. (nih.gov)
  • In contrast, exposure of NG108-15 cells to 2-chloroadenosine resulted in the rapid loss of response to 2-chloroadenosine with a half- life of 1.8 hr, but prostaglandin E,-stimulated and basal enzyme activities decreased only slightly. (nih.gov)
  • The cAMP response following cholera toxin pretreatment (60-120 min) was rapidly and markedly enhanced by alpha 1-adrenergic agonists (cirazoline greater than PE greater than methoxamine), by phorbol esters (PMA greater than 4 beta-phorbol 12,13,-dibutyrate much greater than 4 alpha-phorbol 12,13-didecanoate), and by synthetic diacylglycerols (1,2-dioctanoylglycerol greater than 1-oleoyl 2-acetylglycerol much greater than diolein). (nih.gov)
  • however, exposure of cells to the receptor ligand for 10-24 hr gradually results in an increase in adenylate cyclase specific activity. (nih.gov)
  • showed that treatment of NG108-15 cells with PGE,' for several days resulted in decreases in A preliminary report of this work has been published [Fed. (nih.gov)