Pulmonary delivery of fluoroquinolones (FQs) is an interesting approach to treat lung infections as it may lead to high local concentrations while minimizing systemic exposure. However, FQs have a rapid diffusion through the lung epithelium giving the pulmonary route no advantage compared to the oral route. Interactions between FQs and metal cations form complexes which limit the diffusion thro...

1. Phosphatidate phosphohydrolase from the particle-free supernatant of rat liver was assayed by using emulsions of phosphatidate as substrate. 2. The inhibition of the phosphohydrolase by chlorpromazine was of a competitive type with respect to phosphatidate. The potency of various amphiphilic cationic drugs as inhibitors of this reaction was related to their partition coefficients into a phos...

We previously showed that gonadotropin increases the K+ activity in Xenopus oocytes and that this is a signal for increased translation. However, K+ need not act to control synthesis directly but may act through an unidentified downstream effector. Using microinjection to vary the salt content of oocytes and concomitantly measuring [3H]leucine incorporation, we found that small changes in Mg2+ ...

The activation of the avian liver phosphoenolpyruvate carboxykinase catalyzed reversible decarboxylation of oxalacetate by Mn2+ has been studied. The Mn2+ facilitates the interaction of oxalacetate to the enzyme. At saturating ITP and oxalacetate concentrations, Mn2+ has a Km = 2 microM. The cation Mg2+ can substitute for Mn2+ with 50% Vmax in the oxalacetate decarboxylation and 2% Vmax in the ...

We investigated in detail the permeation selectivity electro-dialysis of Na+, K+, Mg2+ and Ca2+ both binary quaternary mixtures using a supported liquid membrane (SLM). The SLM consisted organic 2-nitrophenyl octyl ether (NPOE) containing lipophilic anion, i.e. tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, as cation-exchanging site, which was used to fill pores supporting AccurelR. first dete...

Several divalent cations were studied as agonists of a Ca2+-activated K+ channel obtained from rat muscle membranes and incorporated into planar lipid bilayers. The effect of these agonists on single-channel currents was tested in the absence and in the presence of Ca2+. Among the divalent cations that activate the channel, Ca2+ is the most effective, followed by Cd2+, Sr2+, Mn2+, Fe2+, and Co2...

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author F. Vinberg and A. Koskelainen Name of the publication Cobalt (Co2+) can mediate dynamic feedback signals driven by calcium (Ca2+) sensor molecules in mouse rod photoreceptors Publisher School of Science Unit Biomedical Engineering and Computational Science (BECS) Series Aalto University publication series SCIENCE + TECHNOLOGY ...

The mechanism by which bi-and trivalent cations affect human liver phosphatidatephosphohydrolase (PAP) activity was investigated. Bivalent cations up to 1 mM increased PAP activity whereas at higher concentrations the activity of the enzyme decreased. The stimulatory concentration for trivalent cations such as Al3+ and Cr3+, however, was much lower being 2 m M and 1 m M, respectively. All catio...

Two new symmetrical bis-thiourea, 2,2'-[{(terephthaloylbis(azanediyl)bis(carbonothioyl) bis(azanediyl)}dipropanoic acid] (1A) and 3,3'-[{(terephthaloylbis(azanediyl)bis (carbonothioyl)bis(azanediyl)} dipropanoic acid] (1B) were synthesized by the reaction of terephthaloyl chloride with α- and β-alanine in good yields. Their binding properties were investigated with various metal cations using U...