Quinpirole (QNP) sensitization is one of the commonly used animal models of obsessive-compulsive disorder (OCD). We have previously shown that QNP-sensitized animals display a robust cognitive flexibility deficit in an active place avoidance task with reversal in Carousel maze. This is in line with numerous human studies showing deficits in cognitive flexibility in OCD patients. Here we explored the effect of clomipramine, an effective OCD drug that attenuates compulsive checking in QNP, on sensitized rats in acquisition and reversal performances in an active place avoidance task. We found that the addition of clomipramine to QNP-sensitization impairs acquisition learning to a degree that reversal learning could not be tested. In a hippocampal-independent two-way active avoidance task clomipramine did not have an effect on acquisition learning in QNP-treated rats; suggesting that the detrimental effect of clomipramine is hippocampus based. We also tested the effect of risperidone in QNP-sensitized animals, which is not effective in OCD treatment. Risperidone also marginally impaired acquisition learning of QNP-sensitized animals, but not reversal. Moreover, we explored the effect of the augmentation of clomipramine treatment with risperidone in QNP-sensitized rats- a common step in treating SRI-unresponsive OCD patients. Only under this treatment regime animals were unimpaired in both acquisition and reversal learning. Augmentation of SRI with neuroleptics therefore could be beneficial for improving cognitive flexibility, and possibly be considered a first line of treatment in patients with reduced cognitive flexibility.
- MeSH
- agonisté dopaminu toxicita MeSH
- analýza rozptylu MeSH
- antagonisté serotoninu farmakologie MeSH
- bludiště - učení účinky léků MeSH
- chinpyrol toxicita MeSH
- elektrický šok MeSH
- hipokampus účinky léků fyziologie MeSH
- klomipramin terapeutické užití MeSH
- krysa rodu rattus MeSH
- lokomoce účinky léků MeSH
- modely nemocí na zvířatech MeSH
- obsedantně kompulzivní porucha chemicky indukované farmakoterapie MeSH
- potkani Long-Evans MeSH
- risperidon farmakologie MeSH
- selektivní inhibitory zpětného vychytávání serotoninu terapeutické užití MeSH
- učení vyhýbat se účinky léků MeSH
- úniková reakce účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Cardiac sensitivity to oxygen deprivation changes significantly during ontogenetic development. However, the mechanisms for the higher tolerance of the immature heart, possibilities of protection, and the potential impact of perinatal hypoxia on cardiac tolerance to oxygen deprivation in adults have not yet been satisfactorily clarified. The hypoxic tolerance of an isolated rat heart showed a triphasic pattern: significant decrease from postnatal day 1 to 7, followed by increase to the weaning period, and final decline to adulthood. We have observed significant ontogenetic changes in mitochondrial oxidative phosphorylation and mitochondrial membrane potential, as well as in the role of the mitochondrial permeability transition pores in myocardial injury. These results support the hypothesis that cardiac mitochondria are deeply involved in the regulation of cardiac tolerance to oxygen deprivation during ontogenetic development. Ischemic preconditioning failed to increase tolerance to oxygen deprivation in the highly tolerant hearts of newborn rats. Chronic hypoxic exposure during early development may cause in-utero or neonatal programming of several genes that can change the susceptibility of the adult heart to ischemia-reperfusion injury; this effect is sex dependent. These results would have important clinical implications, since cardiac sensitivity in adult patients may be significantly affected by perinatal hypoxia in a sex-dependent manner.
- MeSH
- hypoxie buňky MeSH
- hypoxie embryologie metabolismus MeSH
- ischemická choroba srdeční embryologie etiologie metabolismus MeSH
- kardiovaskulární komplikace v těhotenství metabolismus MeSH
- lidé MeSH
- myokard metabolismus MeSH
- reperfuzní poškození myokardu etiologie metabolismus MeSH
- srdce embryologie růst a vývoj MeSH
- srdeční mitochondrie metabolismus MeSH
- těhotenství MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
The purpose of the present study was to assess the impact of brief daily reoxygenation during adaptation to chronic continuous hypoxia (CCH) on protective cardiac phenotype. Adult male Wistar rats were kept at CCH (10% oxygen) for 5, 15 or 30 days; a subgroup of animals was exposed to room air daily for a single 60-min period. While 5 days of CCH did not affect myocardial infarction induced by 20-min coronary artery occlusion and 3-h reperfusion, 15 days reduced infarct size from 62% of the area at risk in normoxic controls to 52%, and this protective effect was more pronounced after 30 days (41%). Susceptibility to ischemic ventricular arrhythmias exhibited reciprocal development. CCH increased myocardial abundance of mitochondrial superoxide dismutase (MnSOD) without affecting malondialdehyde concentration. Daily reoxygenation abolished both the infarct size-limiting effect of CCH and MnSOD upregulation, and increased malondialdehyde (by 53%). Ventricular cardiomyocytes isolated from CCH rats exhibited better survival and lower lactate dehydrogenase release caused by simulated ischemia/reperfusion than cells from normoxic and daily reoxygenated groups. The cytoprotective effects of CCH were attenuated by the large-conductance Ca2+-activated K+ (BKCa) channel blocker paxilline, while the opener NS1619 reduced cell injury in the normoxic group but not in the CCH group. Daily reoxygenation restored the NS1619- induced protection, whereas paxilline had no effect, resembling the pattern observed in the normoxic group. The results suggest that CCH is cardioprotective and brief daily reoxygenation blunts its salutary effects, possibly by a mechanism involving oxidative stress and attenuation of the activation of mitochondrial BKCa channels.
- MeSH
- draslíkové kanály metabolismus MeSH
- glykosylace MeSH
- hypoxie metabolismus MeSH
- kardiotonika farmakologie MeSH
- krysa rodu rattus MeSH
- kyslík metabolismus MeSH
- malondialdehyd metabolismus MeSH
- oxidační stres * MeSH
- potkani Wistar MeSH
- superoxiddismutasa metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Transient receptor potential melastatin 3 ion channel (TRPM3) belongs to the TRP family of cation-permeable ion channels involved in many important biological functions such as pain transduction, thermosensation, and mechanoregulation. The channel was reported to play an important role in Ca(2+) homeostasis, but its gating mechanisms, functions, and regulation are still under research. Utilizing biophysical and biochemical methods, we characterized two independent domains, Ala-35-Lys-124 and His-291-Gly-382, on the TRPM3 N terminus, responsible for interactions with the Ca(2+)-binding proteins calmodulin (CaM) and S100A1. We identified several positively charged residues within these domains as having a crucial impact on CaM/S100A1 binding. The data also suggest that the interaction is calcium-dependent. We also performed competition assays, which suggested that CaM and S100A1 are able to compete for the same binding sites within the TRPM3 N terminus. This is the first time that such an interaction has been shown for TRP family members.
- MeSH
- kalmodulin chemie genetika metabolismus MeSH
- kationtové kanály TRPM chemie genetika metabolismus MeSH
- lidé MeSH
- missense mutace MeSH
- proteiny S100 chemie genetika metabolismus MeSH
- substituce aminokyselin MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Physostigmine (Phy), a reversible inhibitor of acetylcholine (ACh) esterase (AChE), may also act as a low potency agonist and a modulator of the nicotinic receptor. The actions of Phy on mouse muscle nicotinic receptors in the COS-7 cell line were studied by the patch-clamp technique. Currents were recorded in the whole-cell mode 3-7 days after cell transfection by plasmids coding alphabetagammadelta combination of receptor subunits. The application of ACh to cells clamped at -10 mV produced inward currents which displayed desensitization. The application of Phy in concentrations up to 1 x 10(-3) M did not give reliable specific whole-cell membrane responses. The application of Phy in concentrations of 10(-6)-10(-4) M together with ACh modulated the amplitude; accelerated desensitization of currents induced by ACh and increased the final extent of desensitization in a concentration-dependent manner. This finding is in contrast to the suppression and slowing down of desensitization by Phy and 1-methyl-galanthamine observed in Torpedo receptors.
- MeSH
- acetylcholin farmakologie metabolismus MeSH
- buněčná membrána genetika metabolismus účinky léků MeSH
- Cercopithecus aethiops MeSH
- cholinesterasové inhibitory farmakologie MeSH
- COS buňky MeSH
- financování organizované MeSH
- fysostigmin farmakologie MeSH
- genetické vektory chemická syntéza MeSH
- iontové kanály chemická syntéza metabolismus účinky záření MeSH
- kosterní svaly inervace metabolismus MeSH
- membránové potenciály genetika účinky léků MeSH
- metoda terčíkového zámku MeSH
- myši MeSH
- nervosvalové spojení mikrobiologie účinky léků MeSH
- nervový přenos imunologie účinky záření MeSH
- nikotinové receptory genetika nedostatek účinky léků MeSH
- synergismus léků MeSH
- transfekce MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
