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Long-term treatment of isolated rat soleus muscle with phorbol ester leads to loss of contraction-induced glucose transport.

ABSTRACT: Muscle contraction involves mobilization of intracellular Ca2+ and is associated with several metabolic adjustments, including increased glucose transport. In the present study isolated rat soleus muscles were exposed to 12-O-tetradecanoylphorbol 13-acetate, and responses to both insulin and contraction in terms of glucose transport were assessed. Muscles treated with this phorbol ester for 12 h showed an increased basal rate of 3-O-methylglucose uptake, and responded partially to insulin but did not respond to contraction. Phorbol-ester-treated and non-treated (vehicle-only) muscles were indistinguishable in terms of pre-contraction content of adenine nucleotide, phosphocreatine, lactate and glycogen, as well as contractile performance and contraction-induced glycogenolysis. Phorbol ester treatment of isolated solei for 12 h resulted in the loss of 90% of protein kinase C activity as determined with histone IIIs as substrate, and 70% as determined by using phorbol ester binding. It is concluded that treatment of solei with phorbol ester gives rise to a marked loss of contraction-induced glucose transport.

SUBMITTER: Cleland PJ

PROVIDER: S-EPMC1131348 | biostudies-other | 1990 May

REPOSITORIES: biostudies-other

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Phorbol ester only partially mimics the effects of insulin on glucose transport and glucose-transporter distribution in 3T3-L1 adipocytes.

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The PMA Phorbol Ester Tumor Promoter Increases Canonical Wnt Signaling Via Macropinocytosis.

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