Metabolikus transzformációk kromatográfiás vizsgálata = Chromatographic studies on metabolic biotransformations

Az OTKA T049492 sz. kutatási támogatás eredményeinek összefoglalása Vizsgáltuk az N-demetileződés során keletkező formaldehidet, és annak szervezetbeni sorsát. Az N-metil csoporton 14C-vel jelölt deprenilt alkalmaztunk, és rétegkromatográfiásan, HPLC-vel, HPLC-MS-sel és HPLC-MS-MS-sel bizonyítottuk a radiojelzett formaldehid keletkezését, annak kiürülését részben a vizelettel, részben pedig további metabolizmussal való átalakulását, azaz a 14C-N-E-monometil-lizin keletkezését. Az N-metileződés a nem kötött (szabad) lizinen következik be. A radiojelzett metabolitok és az anyavegyület aránya a következő volt: methamfetamin:p-hidroximetamfetamin:deprenil:formaldehid = 20:3:1:1. A formaldehidnek csupán töredéke lépett be a lizint metilező reakcióba, és adott 14C-N-E-monometil-lizint. Peptid- és/vagy fehérje láncban kötött lizin metileződését radiojelzett kisérletein során nem tapasztaltuk. Táplálék hatására vagy patológiás állapotban lévő érfalból 14C-N-E-monometil-lizin kimutatása nem járt sikerrel. Bizonyos gyógyszerek (prodrug-ok) szervezeten belüli aktiválódása O-dezetileződéssel megy végre. Ilyen esetet követünk a moexipril metabolizmusának vizsgálata során, lizinen N-etileződést nem tapasztaltunk. Aromás gyűrűkben lévő kvaterner nitrogéneket összekötő alkil láncok esetében N-dezalkiláldást nem találtunk. | Progress report (final) of the OTKA T049492 project N-methyl group of L-deprenyl was labeled using 14C. The 14C-labelled methyl group was used to trace its fate in the body. Generation of 14C-labelled formaldehyde was verified using TLC, HPLC, HPLC-MS and HPLC-MS-MS. One part of the generated formaldehyde was urinary eliminated, an another part took place in the methylation reaction of L-lysine giving 14C-labelled N-E-monomethyl lysine. The ratio of the 14C-labelled deprenil metabolites was: methamphetamine:p-hydroxy-methamphetamine:deprenylformaldehyde = 20:3:1:1. Only a minor part of formaldehyde was subjected to N-methylation of lysine. Free lysine molecules were solely methylated, lysine residues of either peptides or proteins were not methylated by formaldehyde originated from deprenyl. N-methylation of lysine was not found under the effect of regular daily food, nor N-E-monomethyl lysine was detected under pathological conditions of blood vessels. Special prodrugs are activated by O-deethylation. Metabolic O-ethyl to N-ethyl transfer was not indicated during our metabolic study of moexipril. Alkyl-bridged quaternary amines (e.g. bis-pyridinium aldoximes) did not show metabolic N-dealkylation or alkyl transfer to another compound

A diabetes mellitus immunológiája: a hő-shock proteinek, egyéb endogén anyagok és gyógyszerek kölcsönhatása kardiovaszkuláris szövődmények kialakulására = The immunological aspect of diabetes mellitus: the interactions between heat-shock proteins, endogeneous substances and drugs in cardiovascular complications of diabetes mellitus

Autoimmun diabetes mellitust (DM) váltottunk ki streptozotocin (STZ) kis dózisával (3x30 mg/kg, 40mg/kg) patkányon és histidin dekarboxiláz knock-out (KO) egéren és vizsgáltuk a hőshock fehérjék(hsp) szerepét a DM kialakulásában. Vizsgálatainkat kiterjesztettük az endogén nociceptinerg és a hisztamin rendszer valamint a DM kapcsolatának kutatására. Patkányon a hsp65-el történő immunizálás (mind 1x, mind 2x) nem befolyásolta a magas vércukor értéket , de jelentősen növelte a túlélési százalékot . A hsp-vel történő kezelés hatása a DM-os állatok túlélésére szignifikánsnak bizonyult, azonban a hsp65 ellenanyag szint nem változott, továbbá nem befolyásolta a diabeteszes szívfunkció változást. A KO és vad egerek esetén a STZ kevésbé volt hatékony. A hsp-vel immunizált állatokban a vércukorérték csökkent, de az immunizálás csak a vad egerekben okozott szignifikáns hsp elleni antitest szint növekedést. Humán vizsgálatainkban az IDDM-ban szignifikáns eltolódás találtunk Th1 immunválasz irányába p277 esetén. A patkányokban a nociceptin (NC) a liquorban(CSF) a vizsgált agy részekben jelentős hisztamin szint növekedést okozott. A NC plazma koncentrációja életkorfüggő, a 14. hétre stabilizálódik. A CSF magasabb NC szintet mutat, mint a plazma, viszont a nocistatin (NS) a plazmában található magasabb koncentrációban, mint a CSF-ben. A STZ indukálta DM a NC szintre nincs hatással, viszont a NS koncentrációját mind a három vizsgált szövetben (plazma, CSF, májszövet) jelentősen megemelte. | Diabetes mellitus (DM) considered as autoimmune disease was induced by low dose of streptozotocin (STZ) in rats and histidine decarboxylase knock out (KO) mice. The role of different heat shock proteins (hsp65, p277) in the pathophysiology of DM was investigated. The aim was also to study the relationship between histaminergic and nociceptinegic systems and DM. In the rats STZ (3x30 mg/kg) was able to cause diabetes and the hsp65 treatment significantly increased the survival of the diabetic animals. However, the vaccination with hsp65 cause any significant change in the antibody level. In the case of KO and WT mice the STZ dose (3x 40 mg/kg) was not so effective, a less massive diabetes was observed. Vaccination with both hsp65 and p277 caused a significant decrease of glucose level, but the antibody level increased only in WT animals. Determining Th1 and Th2 cytokine levels in Type 1 diabetic patients we found a shift towards Th1 immun response in the case of p277. Nociceptin (NC) significantly increased the histamine levels in various brain region. In DM in rats NC and nocistatin (NS) levels in plasma and liquor(CSF) were measured. Age dependence of both plasma and CSF NC levels reached the adult level in 14 weeks old rats. NC level was higher in CSF than in plasma, while the NS level showed a contrary tendency. Neither plasma nor CSF NC levels showed significant difference from control in DM, while in the case of NS increased levels were observed in DM

Increased nociceptin/orphanin FQ plasma levels in hepatocellular carcinoma

AIM: The heptadecapeptide nociceptin alias orphanin FQ is the endogenous agonist of opioid receptor-like1 receptor. It is involved in modulation of pain and cognition. High blood level was reported in patients with acute and chronic pain, and in Wilson disease. An accidental observation led us to investigate nociceptin in hepatocellular carcinoma. METHODS: Plasma nociceptin level was measured by radioimmunoassay, aprotinin was used as protease inhibitor. Hepatocellular carcinoma was diagnosed by laboratory, ultrasound, other imaging, and confirmed by fine needle biopsy. Results were compared to healthy controls and patients with other chronic liver diseases. RESULTS: Although nociceptin levels were elevated in patients with Wilson disease (14.0 +/- 2.7 pg/mL, n = 26), primary biliary cirrhosis (12.1 +/- 3.2 pg/mL, n = 21) and liver cirrhosis (12.8 +/- 4.0 pg/mL, n = 15) compared to the healthy controls (9.2 +/- 1.8 pg/mL, n = 29, P < 0.001 for each), in patients with hepatocellular carcinoma a ten-fold increase was found (105.9 &PLUSMN; 14.4 pg/mL, n = 29, P < 0.0001). High plasma levels were found in each hepatocellular carcinoma patient including those with normal alpha fetoprotein and those with pain (104.9 +/- 14.9 pg/mL, n = 12) and without (107.7 +/- 14.5 pg/mL, n = 6). CONCLUSION: A very high nociceptin plasma level seems to be an indicator for hepatocellular carcinoma. Further research is needed to clarify the mechanism and clinical significance of this novel finding

Rising plasma nociceptin level during development of HCC: A case report

AIM: Although liver cirrhosis is a predisposing factor for hepatocellular carcinoma (HCC), relatively few reports are available on HCC in primary biliary cirrhosis. High plasma nociceptin (N/OFQ) level has been shown in Wilson disease and in patients with acute and chronic pain. METHODS: We report a follow-up case of HCC, which developed in a patient with primary biliary cirrhosis. The tumor appeared 18 years after the diagnosis of PBC and led to death within two years. Alfa fetoprotein and serum nociceptin levels were monitored before and during the development of HCC. Nociceptin content was also measured in the tumor tissue. RESULTS: The importance and the curiosity of the presented case was the novel finding of the progressive elevation of plasma nociceptin level up to 17-fold (172 pg/mL) above the baseline (9.2 +/- 1.8 pg/mL) parallel with the elevation of alpha fetoprotein (from 13 ng/mL up to 3 480 ng/mL) during tumor development. Nociceptin content was more than 15-fold higher in the neoplastic tissue (0.16 pg/mg) than that in the tumor-free liver tissue samples (0.01 pg/mg) taken during the autopsy. CONCLUSION: Results are in concordance with our previous observation that a very high plasma nociceptin level may be considered as an indicator for hepatocellular carcinoma

Monitoring by HPLC of chamomile flavonoids exposed to rat liver microsomal metabolism

Three major flavonoid chamomile components (quercetin, apigenin-7-O- glucoside and rutin) were subjected to oxidative metabolism by cytochrome P-450 of rat liver microsomal preparations. Changes over time in their respective concentrations were followed using reversed-phase HPLC with UV detection. No clean-up had to be applied as only the specific flavonoid had to be separated from the background components originating from the rat liver microsome. Neither the concentration of apigenin-7-O-glucoside nor that of the diglycoside rutin decreased during one hour of exposure to rat microsomal treatment. In contrast, the concentration of quercetin, a lipophilic aglycon, decreased. Our analytical HPLC results complement the in silico calculated lipophilicity (logP) of these compounds; the relatively high lipophilicity of quercetin appears to predispose it to oxidative metabolism in order to decrease its fat solubility. In contrast the much less lipophilic compounds apigenin-7-O-glucoside and rutin were resistant in vitro to microsomal treatment. © A.A. El Maghraby; Licensee Bentham Open