Decreased blood sugar increases, glucagon which triggers cAMP and activates Protein Kinase. Protein Kinase phosphorylates L,PK and decreases its activit. Again, this decreases the liklihood that the liver will attempt to use the glucose it is producing from glycogenolysis and gluconeogenesis. More importantly, if you are going to carry out gluconeogenesis, you don't want to perform this step just so you can spend energy to reverse it. Lactate enters the blood and travels to the liver.
Glucose leaves liver and enters blood stream.
Glucose used by muscle in glycolysis. PDH has a phosphatase and a kinase subunit. If ATP is plentiful, you do want to be able to use pyruvate to reform glucose if you have to. Once pyruvate forms Acetyl CoA, glucose cannot be reformed. Acetyl CoA and high NADH levels also promotes PDH Kinase acitivity, causing self phosphorylation, and shuts off the reaction.