Characterization and bioactivity of novel calcium antagonists - N-methoxy-benzyl haloperidol quaternary ammonium salt.

BACKGROUND AND PURPOSE: Calcium antagonists play an important role in clinical practice. However, most of them have serious side effects. We have synthesized a series of novel calcium antagonists, quaternary ammonium salt derivatives of haloperidol with N-p-methoxybenzyl (X1), N-m-methoxybenzyl (X2) and N-o-methoxybenzyl (X3) groups. The objective of this study was to investigate the bioactivity of these novel calcium antagonists, especially the vasodilation activity and cardiac side-effects. The possible working mechanisms of these haloperidol derivatives were also explored. EXPERIMENTAL APPROACH: Novel calcium antagonists were synthesized by amination. Compounds were screened for their activity of vasodilation on isolated thoracic aortic ring of rats. Their cardiac side effects were explored. The patch-clamp, confocal laser microscopy and the computer-fitting molecular docking experiments were employed to investigate the possible working mechanisms of these calcium antagonists. RESULTS: The novel calcium antagonists, X1, X2 and X3 showed stronger vasodilation effect and less cardiac side effect than that of classical calcium antagonists. They blocked L-type calcium channels with an potent effect order of X1 > X2 > X3. Consistently, X1, X2 and X3 interacted with different regions of Ca2+-CaM-CaV1.2 with an affinity order of X1 > X2 > X3. CONCLUSIONS: The new halopedidol derivatives X1, X2 and X3 are novel calcium antagonists with stronger vasodilation effect and less cardiac side effect. They could have wide clinical application.

N-n-butyl haloperidol iodide inhibits H2O2-induced Na+/Ca2+-exchanger activation via the Na+/H+ exchanger in rat ventricular myocytes.

N-n-butyl haloperidol iodide (F2), a novel compound, has shown palliative effects in myocardial ischemia/reperfusion (I/R) injury. In this study, we investigated the effects of F2 on the extracellular signal-regulated kinase kinase (MEK)/extracellular signal-regulated kinase (ERK)/Na(+)/H(+) exchanger (NHE)/Na(+)/Ca(2+) exchanger (NCX) signal-transduction pathway involved in H2O2-induced Ca(2+) overload, in order to probe the underlying molecular mechanism by which F2 antagonizes myocardial I/R injury. Acute exposure of rat cardiac myocytes to 100 µM H2O2 increased both NHE and NCX activities, as well as levels of phosphorylated MEK and ERK. The H2O2-induced increase in NCX current (I NCX) was nearly completely inhibited by the MEK inhibitor U0126 (1,4-diamino-2,3-dicyano-1,4-bis[o-aminophenylmercapto] butadiene), but only partly by the NHE inhibitor 5-(N,N-dimethyl)-amiloride (DMA), indicating the I NCX increase was primarily mediated by the MEK/mitogen-activated protein kinase (MAPK) pathway, and partially through activation of NHE. F2 attenuated the H2O2-induced I NCX increase in a concentration-dependent manner. To determine whether pathway inhibition was H2O2-specific, we examined the ability of F2 to inhibit MEK/ERK activation by epidermal growth factor (EGF), and NHE activation by angiotensin II. F2 not only inhibited H2O2-induced and EGF-induced MEK/ERK activation, but also completely blocked both H2O2-induced and angiotensin II-induced increases in NHE activity, suggesting that F2 directly inhibits MEK/ERK and NHE activation. These results show that F2 exerts multiple inhibitions on the signal-transduction pathway involved in H2O2-induced I NCX increase, providing an additional mechanism for F2 alleviating intracellular Ca(2+) overload to protect against myocardial I/R injury.

[Analysis of death causes of 345 cases with HIV/AIDS in Guangdong area].

OBJECTIVE: To analyze the death causes of 345 cases with HIV/AIDS in Guangdong area. METHODS: The situations of 345 hospitalized death cases with HIV/AIDS were conducted by retrospective analysis. RESULTS: (1)There were total 3406 hospitalized cases with HIV/AIDS in a hospital from January 2001 to December 2011 and 345 cases died, the fatality rate was 10. 13%. Since 2005 the introduction of free anti-viral treatment, the fatality rate of HIV/AIDS declined. The fatality rate of the patients whose CD4+ T lymphocyte counts <200 cells/microl was 14.61% (299/2046) and it was significantly higher than that of patients whose CD4 T lymphocyte counts >or=200 cells/microl (P <0.01). (2) 99.42% of the death cases had more than one kind of opportunistic infections (OI) and there were 924 cases of OI totally. 84. 64% of OI related to the death directly. Fungal infection was the most common in OI, followed by bacterial infection. Most OI occurred in the lungs, mouth, other systemic disseminated diseases, gastrointestine, central nerver system, septicemia, skin. The AIDS defining opportunistic infections such as several pneumonia, disseminated penicilliosis marneffei and CNS infections accounted for 29.65%. Other factors that caused HIV/AIDS death included opportunistic tumors, HIV related disease and non AIDS-related disease accounted for 15.36%. No accepted effective highly active antiretroviral therapy (HARRT) also constituted factors of death. Among cases which accepted HARRT treatment, only 6.96% had the period of treatment over three months. CONCLUSION: The fatality rate of end-stage AIDS patients was high and the opportunistic infections was the most important cause of death. Early diagnosis and treatment for opportunistic infections, timely effective HARRT were the key to improve the quality of life of AIDS patients.

Effects of N-n-butyl haloperidol iodide on the rat myocardial sarcoplasmic reticulum Ca(2+)-ATPase during ischemia/reperfusion.

We have previously shown that N-n-butyl haloperidol iodide (F(2)), a newly synthesized compound, reduces ischemia/reperfusion (I/R) injury by preventing intracellular Ca(2+) overload through inhibiting L-type calcium channels and outward current of Na(+)/Ca(2+) exchanger. This study was to investigate the effects of F(2) on activity and protein expression of the rat myocardial sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) during I/R to discover other molecular mechanisms by which F(2) maintains intracellular Ca(2+) homeostasis. In an in vivo rat model of myocardial I/R achieved by occluding coronary artery for 30-60 min followed by 0-120 min reperfusion, treatment with F(2) (0.25, 0.5, 1, 2 and 4 mg/kg, respectively) dose-dependently inhibited the I/R-induced decrease in SERCA activity. However, neither different durations of I/R nor different doses of F(2) altered the expression levels of myocardial SERCA2a protein. These results indicate that F(2) exerts cardioprotective effects against I/R injury by inhibiting I/R-mediated decrease in SERCA activity by a mechanism independent of SERCA2a protein levels modulation.