Die Differenzierung isolierter Herzzellen in einem chemisch definierten N�hrmedium

In vitro study on the transfer of volatile oil components

The following volatile oils were tested in vitro: chamomile (Matricaria recutica L.), peppermint (Mentha piperita L.) and sage (Salvia officinalis L.) to obtain information on which components of volatile oils or minerals are able to pass through the membranes under different conditions. The transfer of chamomile and peppermint oil from aqueous volatile oil to the stomach (pH=1.1) and then to the plasma (pH=7.5) was studied, and the transfer of sage oil through the skin (from pH=5.5 to pH=7.5) was examined. The transfer of some components was more favorable than that of others. The transfer of chamomile oil was faster to buffer pH=1.1 than from buffer pH=1.1 to buffer pH=7.5 and most of the components, except for chamazulene, passed through the membranes. In the case of peppermint the components went through the membranes in the first 15 min although the main components mostly remained in the initial solution. The sage oil transferred showed the same characteristics as the starting oil. A small amount of metal present in the volatile oils also passed through the membranes. The transfer of metals varied, depending on the time, type of the oil, metal quality and the conditions applied.

Open chain crown-type polyethers and pyridinophane cryptands act as ionophores upon frog motor nerve and isolated rat heart cells

Frog motor nerves and isolated heart cells from neonatal rats were incubated with solutions of open chain crown-type polyether or pyridinophane cryptand. The following alterations in membrane excitability and energy consumption were found: 1. The non-cyclic ligand stabilizes the resting potential of the frog nerve and reduces the pulsation rate of heart muscle cells. It is reversibly bound at the cell surface and does not affect the energy metabolism of the heart cells. (formula: see text) 2. The cryptand 1,12-dioxo-2,11-diaza-5,8,21,24-tetraoxa[12-8(2,11)] (2,6)-pyridinophane) ([2.2.1py]-diamide) is irreversibly bound by the tissues. It facilitates the depolarization of the nerve and shows a positively chronotropic effect upon the heart muscle cells. Single treatment of the cell cultures with 10 microgram [2.2.1py]-diamide per ml medium increased the activities of lactate dehydrogenase and of creatine kinase. When the cell cultures were treated three times at 24 h intervals with 10 microgram complexone/ml, the creatine kinase activity of the heart muscle cells decreased by about 40%. The physiological properties of the ligands are correlated with the stability of their alkali metal ion complexes and with the rate constants of complex formation. It is concluded that [2.2.1py]-diamide can act as a passive carrier for Na+ K+.