ABSTRACT
The effect of non-esterified myristate (C14:0) or dodecyl sulfate was studied on passive swelling of rat liver mitochondria suspended in hypotonic alkaline KCl medium in the absence of the potassium ionophore valinomycin. Both compounds rapidly initiated large-amplitude swelling. However, they failed to initiate swelling when the mitochondria were suspended in hypotonic alkaline sucrose medium. In contrast to myristate or dodecyl sulfate, the non-ionic detergent Triton X-100 initiated swelling of mitochondria in both of the media. The following findings indicate that the inner mitochondrial membrane (IMM) is permeabilized by myristate to K+ and Cl- in a specific manner. (i) Swelling initiated by myristate did not respond to cyclosporin A, (ii) the protonophoric uncoupler FCCP was unable to mimic the myristate effect on swelling, and (iii) myristate-induced Cl- -permeation (measured with KCl medium plus valinomycin) was inhibited by N,N'-dicyclohexylcarbodiimide, quinine or ATP. Myristate- or dodecyl sulfate-initiated swelling was paralleled by the lowering of endogenous Mg2+ content. Both effects, stimulation of swelling and depletion of endogenous Mg2+ are correlated with each other. Similar effects have been reported previously for the carboxylic divalent cation ionophore calcimycin (A23187). The A23187-induced swelling has identical inhibiting characteristics on Cl- -permeation with respect to N,N'-dicyclohexylcarbodiimide, quinine and ATP as the myristate-stimulated swelling. Therefore, we conclude that non-esterified fatty acids increase the permeability of mitochondria to K+ and Cl- at alkaline pH by activating Mg2+-dependent ion-conducting pathways in IMM.
Subject(s)
Fatty Acids, Nonesterified/metabolism , Intracellular Membranes/physiology , Mitochondria, Liver/physiology , Animals , Calcimycin/pharmacology , Cell Membrane Permeability , Detergents/pharmacology , Female , Hydrogen-Ion Concentration , In Vitro Techniques , Ionophores/pharmacology , Magnesium/metabolism , Mitochondrial Swelling , Myristates/metabolism , Octoxynol/pharmacology , Potassium Chloride/pharmacology , Rats , Rats, Wistar , Sodium Dodecyl Sulfate/pharmacology , Surface-Active Agents/pharmacology , Valinomycin/pharmacologyABSTRACT
A case of a lethal manganese-cadmium (Mn-Cd) intoxication is reported. The postmortem examination revealed a noticeable reddish-violet discolouration of the serous cutes of all body cavities, but there was no indication of any corrosive burns of the mucous membranes of the gastrointestinal tract. An Mn concentration of 899 micro g/l blood and a Cd concentration of 238 micro g/l blood were found in the deceased woman. These concentrations are higher than normal levels by a factor of about 100. A subacute or chronic manganese-cadmium absorption must be assumed.
Subject(s)
Cadmium Poisoning/complications , Manganese Poisoning/complications , Adult , Autopsy , Cadmium/pharmacokinetics , Cadmium Poisoning/metabolism , Fatal Outcome , Female , Humans , Manganese/pharmacokinetics , Manganese Poisoning/metabolism , Tissue DistributionABSTRACT
In a psychophysiological experiment with 18 patients with cardiovascular disorders but without infarction we proved the influence of habituallized cognitive structures on reactivity under mental load. We used the concepts of different causal attribution (Explanatory style: Peterson and Seligman) and psychic regulation of activity and action (Activity style: Günther). It can be shown that patients with pessimistic explanatory style as well as with diffuse psychic activity control show coronary-prone reaction patterns under load (indicators: cortisol and triglycerids in serum).