Modulation of cyclic AMP accumulation in GH3 cells by a phorbol ester and thyroliberin.
4 beta phorbol-12, 13-dibutyrate (PDBu) stimulated cyclic AMP accumulation in GH3 pituitary tumour cells in the presence of isobutylmethylxanthine. This effect persisted after preincubation of cells with cholera or pertussis toxins. In contrast, vasoactive intestinal polypeptide (VIP)-stimulated cyclic AMP accumulation was inhibited by PDBu in a dose dependent fashion (IC50 = 5.1 nM). Thyroliberin (TRH) had a similar, but non-additive, stimulatory effect on cyclic AMP accumulation with PDBu, however it did not inhibit VIP stimulation. These results suggest that TRH may stimulate cyclic AMP accumulation through protein kinase C and that stimulation of adenylate cyclase by PDBu and TRH may occur distal to the guanine nucleotide binding regulatory proteins, Ns and Ni.
L A
LA
Quilliam
P R
PR
Dobson
B L
BL
Brown
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D037361:Adenylate Cyclase Toxin; D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology; D002460:Cell Line; D002772:Cholera Toxin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000037:antagonists & inhibitors; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000494:pharmacology*; D010704:Phorbols / Q000494:pharmacology*; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism; D010911:Pituitary Neoplasms / Q000378:metabolism*; D051381:Rats; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*; D013997:Time Factors; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology; D010566:Virulence Factors, Bordetella
D037361:Adenylate Cyclase Toxin; D001427:Bacterial Toxins; D010703:Phorbol Esters; D010704:Phorbols; D010566:Virulence Factors, Bordetella; D000246:Adenosine Diphosphate Ribose; D014660:Vasoactive Intestinal Peptide; D015240:Phorbol 12,13-Dibutyrate; D013973:Thyrotropin-Releasing Hormone; D002772:Cholera Toxin; D000242:Cyclic AMP; D019204:GTP-Binding Proteins; D015056:1-Methyl-3-isobutylxanthine; C033085:phorbol