Levodopa-mediated alteration in the activity of pyridoxal kinase in rat basal ganglia.
The acute intraperitoneal administration of 400 mg/kg of levodopa reduced the concentration of pyridoxal phosphate and increased the activity of pyridoxal kinase. The chronic oral administration of 100 mg/kg/day of levodopa did not alter the concentration of pyridoxal phosphate, but increased the activity of pyridoxal kinase in 7 days. This initial elevation in kinase activity returned to normal levels in 2 weeks, became reduced in 3 weeks and then fluctuated back to normal levels in 4 weeks. These results are interpreted to indicate that chronic intake of levodopa results in adaptive alteration in the activity of pyridoxal kinase. This maintains the steady-state concentration of pyridoxal phosphate in order to meet the levodopa-induced enhancement in decarboxylation reaction.
D000818:Animals; D001479:Basal Ganglia / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D007980:Levodopa / Q000494:pharmacology*; D008297:Male; D010770:Phosphotransferases / Q000378:metabolism*; D011731:Pyridoxal Kinase / Q000378:metabolism*; D011732:Pyridoxal Phosphate / Q000378:metabolism; D011736:Pyridoxine / Q000378:metabolism; D051381:Rats; D013997:Time Factors
D007980:Levodopa; D011732:Pyridoxal Phosphate; D010770:Phosphotransferases; D011731:Pyridoxal Kinase; D011736:Pyridoxine; D004298:Dopamine