Accumulation of methylguanidine and changes in guanidino compound levels in plasma, urine, and kidneys of furosemide-treated rats

Simultaneous determination of guanidinosuccinic acid and guanidinoacetic acid in urine using high performance liquid chromatography/tandem mass spectrometry

“…They commented that the origin of GSA was unknown but suggested that it would be expected to arise from failure of transamidination and described that uremic patients excrete substantially more GSA than control subjects. In the previous study [22,26], GAA was decreased in 24-h urine samples from uremic patients, since urine production would be impaired in a substantial portion of the kidney. It was reported that GSA and GAA are localized in the inner medulla and cortex of the kidney, respectively [27].…”

“…A kinetic study of GCs and Args was reported by Eloot et al [21]. These compounds were found to be distributed in the plasma, urine, kidneys and cerebrospinal fluid and were taken up by the choroid plexus and distributed in the cerebrum [22][23][24][25]. Urine samples are useful biological samples for clinical diagnosis to detect patient diseases, and can be collected in a convenient, non-invasive and chronologic manner.…”

Improved Gas Chromatographic Determination of Guanidino Compounds Using Isovaleroylacetone and Ethyl Chloroformate as Derivatizing Reagents

“…They differ considerably in their metabolism, time distribution, biological properties and physiological functions. 1 They are generated in vivo as the result of protein and amino acid metabolism in the mammalian kidneys. 2 A number of them are labeled as uremic toxins because they have an ability to interact with reactive species.…”