PubMed Health⌕ Search

Biomedical subjects

H Lohmann

Publications and source records attributed to H Lohmann.

48 records · Page 3Linked to original sources
PubMed1978

The pharmacokinetic profile of pyrazinobutazone in man.

The rate of absorption of phenylbutazone from pyrazinobutazone (Ranoroc/Carudol) capsules is distinctly lower than that from phenylbutazone capsules. The capsules are bioequivalent to an equimolar dose of Na-phenylbutazone in solution, as judged by both the area under the plasma level curves (AUC), and the sum of the unchanged phenylbutazone excreted in the urine. A single dose of 300 mg pyrazinobutazone produces maximum plasma levels of 35.2 +/- 1.1 micrograms/ml at 5.5 h after administration (+/- SEM, 70 kg bodyweight, N = 39). Two dosage schedules for long-term therapy were tested (2400 and 1500 mg/week). Both produced accumulation to saturation plasma levels within approximately three days. The concentration of phenylbutazone obtained with the lower dosage was about 110 micrograms/ml plasma. This corresponds with the recommendations for long-term therapy with phenylbutazone. With the higher dosage, the plasma levels were elevated by only 25%, however, the renal elimination of unchanged drug and the number of side-effects were remarkably increased. The recommended dosage scheme is specifically adapted to the pharmacokinetics of pyrazinobutazone.

Adult↗
PubMed1973

[Is the mind tabu?].

Explore the source record for details and available documents.

Adaptation, Psychological↗
PubMedDate not supplied

The action of thallium on the excitability of CA1 pyramidal cells in hippocampal slices.

The effect of thallium ions on central neuronal activity was investigated in hippocampal slice preparations from guinea pigs and rats using extra- and intracellular recording techniques. Thallium induced a reversible and concentration-dependent reduction of the orthodromically evoked compound action potential of CA1 pyramidal cells with only weak effects on either afferent fiber activity, postsynaptic potentials or antidromically evoked responses. The membrane potential and input resistance of the pyramidal cells were not impaired by thallium. In contrast, variations in the maintained spike activity and spontaneously occurring inhibitory postsynaptic potentials were observed. It is concluded, that in contrast to its presynaptic action in the peripheral nervous system, thallium has a predominant postsynaptic target site in the hippocampal slice preparation. It is suggested that the neurotoxic action of thallium is not mediated by an interaction with specific ion channels of the cell membrane, but rather by an unspecific influence on the intracellular metabolism of the CA1 pyramidal cell.

Action Potentials↗
PubMedDate not supplied

The action of cobalt, cadmium and thallium on presynaptic currents in mouse motor nerve endings.

The action of cobalt, cadmium and thallium on presynaptic currents was investigated by recording extracellular potentials from mouse motor nerve terminals. Recorded waveforms consisted of two negative deflections preceded by a small positivity. The second negative deflection could be blocked by the potassium channel blockers tetraethylammonium (TEA) and 3,4-diaminopyridine (3,4-DAP). Application of either divalent cations (cobalt, cadmium) or monovalent thallous ions to the bath, even in mM concentrations, did not change these waveforms significantly. After application of high TEA and 3,4-DAP concentrations (10 mM and 250 microM, respectively), a prolonged positive-going wave arose, which could be blocked reversibly by bath application of cobalt and cadmium, but not thallium. The concentration-inhibition curve for cadmium suggested two apparent dissociation constants, whereas cobalt seemed to have only one apparent dissociation constant. It was concluded that the long-lasting positive wave is driven by calcium influx, since it was competitively antagonized by the application of cobalt and cadmium. A different, short-lasting positive wave arose using lower concentrations of potassium channel blockers, and this wave could not be blocked by cobalt, cadmium, or thallium.

4-Aminopyridine↗