Inhibitory effect of A 23187 on protein synthesis in isolated murine hepatocytes.
The effect of the Ca ionophore A 23187 on amino acid incorporation into protein, on gluconeogenesis and on synthesis of some eicosanoids was investigated in isolated mouse hepatocytes (i) in the presence of 2.5 mM Ca2+, (ii) in the absence of Ca2+ and in the presence of 0.2 mM EGTA, (iii) after calcium depletion. A 23187 inhibited amino acid incorporation into protein both in the presence and in the absence of Ca2+ in a concentration dependent manner, whereas in the absence of Ca2+ the known stimulating effects of A 23187 on eicosanoid synthesis could not be detected. In hepatocytes prepared from 24 h starved mice A 23187 increased the rate of gluconeogenesis and similarly to eicosanoid synthesis this stimulation in the absence of Ca2+ could not be observed. On the other hand, after calcium depletion the inhibition of protein synthesis by A 23187 was markedly moderated. It is concluded that the effect of A 23187 on protein synthesis is also related to its ionophoretic effect but calcium sensitivity in this effect is smaller than in gluconeogenesis or eicosanoid synthesis.
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology*; D002118:Calcium / Q000502:physiology*; D015237:Dinoprost; D011464:Epoprostenol / Q000096:biosynthesis; D005943:Gluconeogenesis / Q000187:drug effects; D066298:In Vitro Techniques; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D011460:Prostaglandins F / Q000096:biosynthesis; D011500:Protein Synthesis Inhibitors; D013931:Thromboxanes / Q000096:biosynthesis
D011460:Prostaglandins F; D011500:Protein Synthesis Inhibitors; D013931:Thromboxanes; D000001:Calcimycin; D015237:Dinoprost; D011464:Epoprostenol; D002118:Calcium