Endocrinology, Vol 106, 1532-1536, Copyright © 1980 by Endocrine Society

ARTICLES

Action of cholera toxin on hormone synthesis and release in GH cells: evidence that adenosine 3',5'-monophosphate does not mediate the decrease in growth hormone synthesis caused by thyrotropin-releasing hormone

PS Dannies and AH Tashjian Jr

We have examined the effects of cholera toxin, a specific probe for processes which are caused by an increase in cAMP, on clonal strains of rat pituitary cells (GH cells) in culture. We found that 5 ng/ml cholera toxin increased the amount of intracellular cAMP after a lag period of 30-60 min. After a similar lag period, cholera toxin increased the release of PRL into the medium by 50% and caused a decrease in intracellular PRL to 60% of control values at 90 min. PRL synthesis was increased to 100% above control after 1 week of treatment, and GH synthesis was elevated to 280% above control. TRH caused an increase in PRL release and synthesis but a decrease of GH synthesis. Depending on the dose, TRH prevented or reduced the cholera toxin-induced rise in GH synthesis. We conclude that the decrease in GH synthesis caused by TRH is not likely to be mediated through an increase of intracellular cAMP.

This article has been cited by other articles:

				T. Yonehara, H. Kanasaki, H. Yamamoto, K. Fukunaga, K. Miyazaki, and E. Miyamoto Involvement of Mitogen-Activated Protein Kinase in Cyclic Adenosine 3',5'-Monophosphate-Induced Hormone Gene Expression in Rat Pituitary GH3 Cells Endocrinology, July 1, 2001; 142(7): 2811 - 2819. [Abstract] [Full Text] [PDF]