Lipolytic Activity of Ribonucleotide and Deoxyribonucleotide-3′,5′-Cyclic Monophosphates in Isolated Rat Fat Cells

Summary

The lipolytic activity of a series of ribonucleotide and deoxyribonucleo-tide-3′,5′-cyclic monophosphates was investigated in fat cells incubated in a saline-phosphate medium, from which Ca²+, Mg²+, and K⁺ was omitted. It was found that the effect of 3′,5′-AMP to stimulate lipolysis is not specific; 3′,5′-UMP, 3′,5′-IMP, 3′,5′-CMP, 3′,5′-GMP, and 3′,5′-dAMP also exhibit lipolytic activity. Quantitatively, however, the lipolytic potency of 3′,5′-AMP is considerably greater than all of the other nucleotides tested. The results indicate the importance of the nucleotide base and the 2′-hydroxyl group of the ribose moiety for lipolytic activity.

We wish to thank Miss Sheila Rosenfield for her skillful technical assistance. One of us (HPB) wishes to thank Dr. Michael Smith (University of British Columbia, Vancouver, Canada) for his kindness in permitting the use of his laboratory for synthesis of part of the cyclic nucleotides used, and for a supply of reference nucleotides.