Adrenocorticotropin stimulation of cyclic adenosine 3′,5′-monophosphate formation in isolated rat adrenal cells the role of membrane sialic acid

• Published in: Biochimica et biophysica acta Vol. 362; no. 2; pp. 356 - 365
• Main Authors: Haksar, Ajai, Maudsley, David V., Kimmel, Gary L., Péron, Fernand G.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.09.1974
• Subjects: Adenylyl Cyclases - metabolism; Adrenal Cortex; Adrenal Glands - cytology; Adrenal Glands - drug effects; Adrenal Glands - metabolism; Adrenocorticotropic Hormone - pharmacology; Animals; Binding Sites; Cattle; Cell Membrane - drug effects; Cell Membrane - metabolism; Clostridium perfringens - enzymology; Cyclic AMP - biosynthesis; Fluorides - pharmacology; In Vitro Techniques; Kinetics; Male; Microbial Collagenase; Neuraminidase; Protein Binding; Proteins - metabolism; Rats; Receptors, Cell Surface - drug effects; Sialic Acids - metabolism; Theophylline - pharmacology; Time Factors; Tritium; Trypsin; ACTH; adrenocorticotropin
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/0304-4165(74)90228-1

Neuraminidase treatment of isolated rat adrenal cells inhibited the cyclic AMP response to adrenocorticotropin stimulation. Greater percent inhibition was observed with the lower doses of adrenocorticotropin. Although the maximum amount of cyclic AMP produced by the neuraminidase-treated cells was similar to that obtained with untreated cells, the concentration of adrenocorticotropin required to produce it was greatly increased. The increase in adrenocorticotropin concentration to produce half-maximum amounts of cyclic AMP was 2-fold. Neuraminidase treatment caused a dose-related depletion of sialic acid from the cells with about 60% of the total sialic acid being released by 20 munits/ml of the enzyme. Stimulation of cyclic AMP formation by NaF in a particulate fraction obtained from homogenates of cells was unchanged after treatment of the cells with neuraminidase. The data implicate a role for sialic acid in the early events in the action of adrenocorticotropin on the cell membrane. Sialic acid may be involved in the interaction of the adrenocorticotropin molecule with the receptor or it may have a role in transmission of the signal arising from adrenocorticotropin-receptor interaction to the catalytic unit of adenyl cyclase.