Effect of prostaglandins on cyclic nucleotide levels in cultured keratinocytes

Abstract

Guinea pig ear epidermal cells (keratinocytes) were established in primary cultures using trypsin, and treated in their proliferative phase of growth with prostaglandins E 1, D 1, F 1α, E 2, D 2, or F 2α. This phase is induced by the addition of retinoic acid during cell plating. Intracellular content of cAMP and cGMP was measured by radioimmunoassay at various times after treatment. Maximum stimulation of cAMP levels was observed with PGD 2, smaller increases with PGE 2 and relatively transient rises with PGF 2α which were of low significance, but confirm earlier data. Similar results were observed with PGD 1, PGE 1, and PGF 1α with smaller increases. The effects of D and E PGs were biphasic. Significant increases in cGMP were immediately observed with PGD 2 and PGE 2. With PGF 2α, maximum cGMP levels were noted after some delay. All PGs tested showed some effect in elevating cyclic nucleotides in keratinocytes. The most striking result was the increase in cAMP on PGD 2 treatment.