Sergej Pirkmajer

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Astrocytes have a key role in the clearance and inactivation of histamine in the adult central nervous system, but transporters which mediate histamine uptake into astrocytes have not been fully characterized. We therefore investigated the kinetic and molecular characteristics of histamine uptake into cultured adult rat astrocytes. [(3)H]-histamine was(More)
BACKGROUND Replacement of proinsulin C-peptide in type 1 diabetes ameliorates nerve and kidney dysfunction, conditions which are associated with a decrease in Na,K-ATPase activity. We determined the molecular mechanism by which long term exposure to C-peptide stimulates Na,K-ATPase expression and activity in primary human renal tubular cells (HRTC) in(More)
Acetylcholinesterase (AChE) and agrin play unique functional roles in the neuromuscular junction (NMJ). AChE is a cholinergic and agrin a synaptogenetic component. In spite of their different functions, they share several common features: their targeting is determined by alternative splicing; unlike most other NMJ components they are expressed in both,(More)
Acetylcholinesterase (EC, AChE) is one of the components of the neuromuscular junction (NMJ). Its expression and targeting in the skeletal muscle fiber is therefore under the control of the mechanisms responsible for the formation of the highly complex structure of this synapse. Recently, it has been demonstrated that myotubes of the C2C12 mouse(More)
Epidemiological studies indicate that metformin, a widely used type 2 diabetes drug, might reduce breast cancer risk and mortality in patients with type 2 diabetes. Metformin might protect against breast cancer indirectly by ameliorating systemic glucose homeostasis. Alternatively, it might target breast cancer cells directly. However, experiments using(More)
Magnetic nanoparticles (NPs) are a special type of NP with a ferromagnetic, electron-dense core that enables several applications such as cell tracking, hyperthermia, and magnetic separation, as well as multimodality. So far, superparamagnetic iron oxide NPs (SPIONs) are the only clinically approved type of metal oxide NPs, but cobalt ferrite NPs have(More)
Proteins in living organisms have names that are usually derived from their function in the biochemical system their discoverer was investigating. Typical examples are acetylcholinesterase and agrin; however, for both of these, various other functions that are not related to the cholinergic system have been revealed. Our investigations have been focused on(More)
Histaminergic signalling constitutes an attractive target for treatment of neuropsychiatric disorders. One obstacle to developing new pharmacological options has been failure to identify putative specific histamine transporter responsible for histamine clearance. Although high-affinity histamine uptake was detected in neonatal cortical astrocytes, its(More)
Background The neurotransmitter histamine is synthesized from his-tidine in histaminergic neurons. Later on it is taken up into synaptic vesicles by the vesicular monoamine transporter 2 and released into the synaptic cleft upon depo-larization stimuli. The released neurotransmitter is metabolised by the enzyme histamine N-methyltransfer-ase (HNMT)(More)
Background Histamine is a double-protonated molecule with corresponding pK a values of 5.8 and 9.4. Therefore, at physiological pH, histamine exists as an equilibrium mixture of tautomeric cations: the monocation making up 96%, the dication only 3% and the rest being nonprotonated hista-mine. As a protonated molecule histamine most probably uses a carrier(More)
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