Antibodies against gonadotropin-releasing hormone (GnRH) and destruction of enteric neurons in 3 patients suffering from gastrointestinal dysfunction

Background: Antibodies against gonadotropin-releasing hormone (GnRH) and gastrointestinal dysmotility have been found after treatment with GnRH analogues. The aim of this study was to examine the presence of such antibodies in patients with dysmotility not subjected to GnRH treatment and study the anti-GnRH antibody effect on enteric neurons viability in vitro. Methods: Plasma and sera from 3 patients suffering from either enteric dysmotility, irritable bowel syndrome (IBS) or gastroparesis were analysed for C-reactive protein (CRP), and for GnRH antibodies and soluble CD40 by ELISA methods. Primary cultures of small intestinal myenteric neurons were prepared from rats. Neuronal survival was determined after the addition of sera either from the patients with dysmotility, from healthy blood donors, antiserum raised against GnRH or the GnRH analogue buserelin. Only for case 1 a full-thickness bowel wall biopsy was available for immunohistochemical analysis. Results: All 3 patients expressed antibodies against GnRH. The antibody titer correlated to the levels of CD40 (r(s) = 1.000, p < 0.01), but not to CRP. Serum from case 3 with highest anti-GnRH antibody titer, and serum concentrations of sCD40 and CRP, when added to cultured rat myenteric neurons caused remarkable cell death. In contrast, serum from cases 1 and 2 having lower anti-GnRH antibody titer and lower sCD40 levels had no significant effect. Importantly, commercial antibodies against GnRH showed no effect on neuron viability whereas buserelin exerted a protective effect. The full-thickness biopsy from the bowel wall of case 1 showed ganglioneuritis and decrease of GnRH and GnRH receptor. Conclusion: Autoantibodies against GnRH can be detected independently on treatment of GnRH analogue. Whether the generation of the antibody is directly linked to neuron degeneration and chronic gastrointestinal symptoms in patients with intestinal dysmotility, remains to be answered

Neurotoksičnost trimetilnog olova u štakora: promjene u glijalnom fibrilarnom kiselom proteinu (GFKP)

The literature on the toxicology of lead provides little evidence of the neurotoxicity of organic lead compounds. Toxicant-induced changes in the concentration of glial fibrillary acidic protein (GFAP) in the brain may help clarify at which stage of neurotoxicity astrocytes are affected and whether GFAP may provide an index of toxicity. Male F344 rats (>42 days old) were exposed to 0 (control), 8 or 16 ppm lead as trimethyl lead (TMPb) in drinking water for up to 14 days. Weight gain was significantly reduced in both exposed groups. Control rats had the expected brain regional pattern of GFAP concentration with the highest in the hippocampus and cerebellum and lowest in the cerebral cortex. The hippocampus was the region very sensitive to TMPb, with increased GFAP in rats exposed to 8 and 16 ppm TMPb for 14 days. There was a significant time-response in rats exposed to 8 ppm TMPb with decreases in GFAP on day 7 and increases on day 14. A hypothesis concerning this biphasic change in GFAP concentrations is discussed. The results indicate that GFAP may be used to indicate the role of the astrocyte in the neurotoxicity of TMPb. GFAP concentration, as biomarker of TMPb effect, was as sensitive to TMPb as body weight and thus may provide a marker of neurotoxicity.Medu literaturnim podacima o toksičnosti olova ima malo podataka o neurotoksičnosti organskih spojeva olova. Otrovom izazvane promjene u koncentraciji glijalnog fibrilarnog kiselog proteina (GFKP) u mozgu mogu pokazati u kojoj fazi neurotoksičnosti dolazi do oštećivanja astrocita te da li GFKP može služiti kao praktični pokazatelj otrovnog djelovanja. U ovom radu procjenjivano je izaziva li izloženost štakora organskom olovu promjene u koncentraciji GFKP te kako promjene ovise o dozi i o trajanju izloženosti. Mužjaci F344 štakora u dobi iznad 42 dana izlagani su dozi od 0 (kontrola), 8 ili 16 ppm olova u obliku trimetilnog olova (TMPb) u pitkoj vodi do ukupno 14 dana. U svakoj skupini bilo je osam životinja. Prirast tjelesne težine bio je značajno smanjen u obje izložene skupine. U kontrolnih štakora izmjerene su očekivane koncentracije GFKP u ispitivanim područjima mozga, s najvišim vrijednostima u hipokampusu i u malom mozgu i s najnižim vrijednostima u moždanoj kori. Područje hipokampusa bilo je veoma osjetljivo na TMPb, s porastom GFKP u štakora izloženih 8 i 15 ppm TMPb tijekom 14 dana. U štakora izloženih B ppm TMPb opažena je značajna ovisnost učinka o vremenu, tako da su koncentracije TMPb nakon sedam dana bile snižene, a nakon 14 dana povišene. U radu se raspravlja o hipotezi o ovim bifazičnim promjenama u koncentracijama GFKP. Rezultati pokazuju da GFKP može poslužiti kao pokazatelj mogućih staničnih mehanizama i uloge astrocita u neurotoksičnom djelovanju TMPb. Pokazano je također da je GFKP, kao biološki pokazatelj učinaka TMPb, jednako osjetljiv kao i tjelesna težina, pa stoga može poslužiti kao praktični pokazatelj neurotoksičnosti

Neurotoksičnost trimetilnog olova u štakora: promjene u glijalnom fibrilarnom kiselom proteinu (GFKP)

The literature on the toxicology of lead provides little evidence of the neurotoxicity of organic lead compounds. Toxicant-induced changes in the concentration of glial fibrillary acidic protein (GFAP) in the brain may help clarify at which stage of neurotoxicity astrocytes are affected and whether GFAP may provide an index of toxicity. Male F344 rats (>42 days old) were exposed to 0 (control), 8 or 16 ppm lead as trimethyl lead (TMPb) in drinking water for up to 14 days. Weight gain was significantly reduced in both exposed groups. Control rats had the expected brain regional pattern of GFAP concentration with the highest in the hippocampus and cerebellum and lowest in the cerebral cortex. The hippocampus was the region very sensitive to TMPb, with increased GFAP in rats exposed to 8 and 16 ppm TMPb for 14 days. There was a significant time-response in rats exposed to 8 ppm TMPb with decreases in GFAP on day 7 and increases on day 14. A hypothesis concerning this biphasic change in GFAP concentrations is discussed. The results indicate that GFAP may be used to indicate the role of the astrocyte in the neurotoxicity of TMPb. GFAP concentration, as biomarker of TMPb effect, was as sensitive to TMPb as body weight and thus may provide a marker of neurotoxicity.Medu literaturnim podacima o toksičnosti olova ima malo podataka o neurotoksičnosti organskih spojeva olova. Otrovom izazvane promjene u koncentraciji glijalnog fibrilarnog kiselog proteina (GFKP) u mozgu mogu pokazati u kojoj fazi neurotoksičnosti dolazi do oštećivanja astrocita te da li GFKP može služiti kao praktični pokazatelj otrovnog djelovanja. U ovom radu procjenjivano je izaziva li izloženost štakora organskom olovu promjene u koncentraciji GFKP te kako promjene ovise o dozi i o trajanju izloženosti. Mužjaci F344 štakora u dobi iznad 42 dana izlagani su dozi od 0 (kontrola), 8 ili 16 ppm olova u obliku trimetilnog olova (TMPb) u pitkoj vodi do ukupno 14 dana. U svakoj skupini bilo je osam životinja. Prirast tjelesne težine bio je značajno smanjen u obje izložene skupine. U kontrolnih štakora izmjerene su očekivane koncentracije GFKP u ispitivanim područjima mozga, s najvišim vrijednostima u hipokampusu i u malom mozgu i s najnižim vrijednostima u moždanoj kori. Područje hipokampusa bilo je veoma osjetljivo na TMPb, s porastom GFKP u štakora izloženih 8 i 15 ppm TMPb tijekom 14 dana. U štakora izloženih B ppm TMPb opažena je značajna ovisnost učinka o vremenu, tako da su koncentracije TMPb nakon sedam dana bile snižene, a nakon 14 dana povišene. U radu se raspravlja o hipotezi o ovim bifazičnim promjenama u koncentracijama GFKP. Rezultati pokazuju da GFKP može poslužiti kao pokazatelj mogućih staničnih mehanizama i uloge astrocita u neurotoksičnom djelovanju TMPb. Pokazano je također da je GFKP, kao biološki pokazatelj učinaka TMPb, jednako osjetljiv kao i tjelesna težina, pa stoga može poslužiti kao praktični pokazatelj neurotoksičnosti

Enhancement of nitric oxide production by methylecgonidine in cultured neonatal rat cardiomyocytes

1. In the present experiments, we investigated the effects of methylecgonidine (MEG) on nitric oxide (NO) production in cultured neonatal rat cardiomyocytes. Incubation of cultured cardiomyocytes with carbachol or MEG for 48 h significantly enhanced NO production. No release was increased from 1.48±0.13 μM (mg protein)(−1) for control to 5.73±0.19 μM (mg protein)(−1) for 1 μM carbachol treated cells (P<0.001). In addition, incubation with 1 μM MEG enhanced NO production to 5.55±0.28 μM (mg protein)(−1). The effects of MEG on NO production were concentration-dependent. The muscarinic antagonist atropine prevented the enhancement of NO production induced by carbachol or MEG. Compared to MEG-induced NO production, cocaine was much less potent. 2. The enhancement of NO production by carbachol or MEG was even greater in cultured cardiomyocytes transfected with the M(2) cDNA. After 48-h incubation with 1 μM carbachol or 1 μM MEG, NO production was increased by 6.5 and 6.7 fold, respectively, in cardiomyocytes overexpressing M(2) receptors. Coincubation with atropine or N(G)-nitro-L-arginine methyl ester abolished the enhancement of NO production. In contrast, NO production enhanced by carbachol or MEG in M(1)- or M(3)-transfected cardiomyocytes was similar to the level in non-transfected cells. 3. Western blot analysis showed that the protein levels of M(1), M(2), and M(3) were significantly increased in cardiomyocytes transfected with the receptor cDNAs, but MEG had no effect on the expressions. It is interesting that both carbachol and MEG caused a significant increase in constitutive endothelial NO synthase (eNOS) only in M(2)-transfected cardiomyocytes, not in non-transfected, M(1)- or M(3)-transfected cells. Again, atropine blocked the MEG-produced induction of eNOS. 4. Our data demonstrate that MEG significantly enhanced NO production in cultured cardiomyocytes and that the enhancement of NO production may result from MEG stimulation of muscarinic M(2) receptors

An immunocytochemical study of calpain II in the hippocampus of rats injected with kainate

10.1007/BF02454147Experimental Brain Research1131117-129EXBR