Effects of L-DOPA on the concentrations of free and sulfoconjugated catecholamines in plasma, cerebrospinal fluid, urine, and central and peripheral nervous system tissues of the rat.
The effects of subcutaneous injection of L-beta-3,4-dihydroxyphenylalamine (L-DOPA) on the concentrations of the catecholamines and catecholamine sulfates in the central and peripheral nervous systems of the rat were studied. The results showed that free 3,4-dihydroxyphenylethylamine (DA, dopamine) increased rapidly and markedly in the hypothalamus and striatum after L-DOPA but DA sulfate did not change. Increased concentrations of DA sulfate were detected in the CSF and in the plasma, where it reached a concentration of 130.8 +/- 12.8 ng/ml at 2 h, seven times the level of free DA (19.1 +/- 2.9 ng/ml). In the kidney the ratio of DA sulfate to free DA was reversed in favor of free DA. Urine samples of L-DOPA-treated rats showed a higher increase of free DA than DA sulfate, but free norepinephrine (NE) and NE sulfate remained unchanged. Concentrations of free DA and free NE in the adrenal glands of L-DOPA-treated rats showed no change. Adrenal DA sulfate and NE sulfate were not detectable in the control and L-DOPA-treated rats, suggesting that the adrenal glands lack the capacity to take up or store catecholamines and their sulfate counterparts from the plasma.
D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D002395:Catecholamines / Q000378:metabolism*; D004298:Dopamine / Q000031:analogs & derivatives / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D007980:Levodopa / Q000494:pharmacology*; D008297:Male; D009420:Nervous System / Q000378:metabolism*; D009638:Norepinephrine / Q000031:analogs & derivatives / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013464:Sulfuric Acids / Q000378:metabolism
D002395:Catecholamines; D013464:Sulfuric Acids; C022807:dopamine 4-O-sulfate; D007980:Levodopa; C017574:noradrenaline sulfate; D004298:Dopamine; D009638:Norepinephrine