H-Tyr-His-OH

Samples Preparation

Calibration samples were prepared by spiking lung homogenate (1 : 3, w/v, in PBS) with each working solution.

Preparation Method

Samples (plasma or tissue homogenates from male rats) were prepared by protein precipitation with HClO(4) (1 : 1, v/v) containing H-Tyr-His-OH as internal standard.

Reaction Conditions

Using 0.1% HFBA as ion-pairing agent: the histidine-containing dipeptides eluted at 4.54 min (CAR), 4.64 min (ANS, HCAR) and 5.06 min (BAL), with an excellent bell shape. H-Tyr-His-OH was chosen as IS for quantitative analysis.

Applications

The mapping profile( H-Tyr-His-OH as internal standard) in rat tissue gave the following results: the highest concentrations of CAR and ANS were found in skeletal muscles (soleus, gastrocnemius, tibialis), followed by the heart, cerebellum and brain (ANS below the LOQ). HCAR was found only in the brain and cerebellum. No histidine-containing dipeptides were detectable in plasma, liver, kidney and lung.

References:
[1]. Aldini G, Orioli M,et,al. Profiling histidine-containing dipeptides in rat tissues by liquid chromatography/electrospray ionization tandem mass spectrometry. J Mass Spectrom. 2004 Dec;39(12):1417-28. doi: 10.1002/jms.696. PMID: 15578740.