sodium-oxybate and 4-hydroxy-2-butenoic-acid

Trans-gamma-hydroxycrotonate (THCA), a compound naturally present in rat brain, possesses high-affinity binding sites with a heterogeneous distribution which are superimposable with those for gamma-hydroxybutyrate (GHB). Binding studies of THCA on rat brain membranes revealed two binding components, one of high affinity (Kd1, 7 nM, Bmax1 42 fmol/mg protein) and the other of low affinity (Kd2, 2 microM, Bmax2 13 pmol/mg protein). Displacement curves of [3H]THCA by THCA and GHB or of [3H]GHB by THCA are in favour of the existence of a specific high affinity site for THCA. Quantitative autoradiography with image analysis of [3H]THCA binding in rat brain slices indicated that [3H]THCA high affinity binding was displaced at a lower potency by GHB. THCA showed also some selectivity in displacing [3H]GHB from its high affinity binding site (Kd = 95 nM). This mutual overlap favours a subpopulation of GHB receptors, which have THCA as a natural ligand, showing partial agonistic properties compared to GHB. The functional significance of this result remains unknown.

Topics: Animals; Brain; Hydroxybutyrates; Male; Rats; Rats, Inbred Strains; Receptors, Neurotransmitter; Sodium Oxybate

gamma-Hydroxybutyric acid (GHB) and trans-gamma-hydroxycrotonic acid (HCA) together with their respective internal standards were derivatized to give the pentafluorobenzyl esters of the N-tert-butyldimethylsilyl derivatives. These compounds give, under electron capture conditions, very simple negative ion mass spectra. A very sensitive and specific assay for GHB and HCA in brain tissue (detection limit of about 5 pg per injection) using gas chromatography/negative ion mass spectrometry is described. The average levels measured in the whole brain were 1.10 +/- 0.18 nmol GHB/g wet weight and 0.18 +/- 0.02 nmol HCA/g wet weight.

Topics: Animals; Brain Chemistry; Gas Chromatography-Mass Spectrometry; Hydroxybutyrates; Male; Rats; Rats, Inbred Strains; Sodium Oxybate

The organic acids in renal tissue biopsy (0.5-1 mg) obtained from chronic glomerulonephritis patients were analyzed capillary column gas chromatography--mass spectrometry. Some twenty compounds were identified in the renal tissue. The organic acid profile of renal tissue showed a marked difference from those of urine and serum. In particular, 4-hydroxybutyric acid and 4-hydroxy-2-butenoic acid, which are usually undetectable in urine and serum, were detected for the first time in renal tissue in considerably large amounts.

Topics: Biopsy; Gas Chromatography-Mass Spectrometry; Glomerulonephritis; Humans; Hydroxybutyrates; Kidney; Sodium Oxybate