P. Dominiak

Cefotaxime and desacetyl cefotaxime in human bile

SummaryTen patients were injected with 2 g cefotaxime i. v. The antibacterial activity in the bile was measured by the agar diffusion test and the concentrations of cefotaxime and desacetyl cefotaxime were determined by high performance liquid chromatography. The values found allow the use of cefotaxime in infectious biliary diseases.ZusammenfassungZehn Patienten wurden je 2 g Cefotaxim i. v. injiziert. In der Galleflüssigkeit wurden die antibakterielle Aktivität mittels Agardiffusionstest und die Konzentrationen von Cefotaxim und Desacetyl-Cefotaxim mit Hochdruckflüssigkeitschromatographie bestimmt, Die gefundenen Werte erlauben den Einsatz von Cefotaxim bei infektiösen Gallenwegserkrankungen.

Effect of ketanserin on hemodynamics, plasma-catecholamine concentrations, and serotonin uptake by platelets in volunteers and patients with congestive heart failure

Ketanserin, which preferentially blocks 5-HT2-serotonergic receptors, was injected intravenously (i.v.) to patients with congestive heart failure in a bolus dose of 10 mg, followed by an i.v. infusion of 3 mg/h over a period of 4 h. The drug caused a decrease in total peripheral resistance and, conversely, an increase in stroke volume. Right atrial and pulmonary artery pressures were decreased. Plasma noradrenaline rose twofold over the basal levels shortly after injection, but showed a distinct fall 2 h after beginning of the treatment. The concentrations of ketanserin in plasma after bolus injection approximated 100-150 ng/ml. The sympathoneuronal and sympathoadrenal reaction during tilting were increased after i.v. injection of 10 mg ketanserin in volunteers. The noradrenaline and adrenaline levels in plasma rose significantly more when compared with values before the injection of the drug. In vitro as well as in vivo ketanserin exerts a concentration-dependent inhibitory effect on the active transport of serotonin and catecholamines (dopamine, noradrenaline, adrenaline) into human platelets. Considering platelets as a model of the sympathetic neurons, the inhibition of reuptake of catecholamines by ketanserin could contribute to the observed increase in circulating catecholamines after injection of the drug.

Sympathoadrenal dysfunction in rats with chronic neurogenic hypertension

Compared to sham-operated controls 5 weeks after surgery neurogenic hypertensive rats with sino-aortic baroreceptor deafferentation had higher blood pressure, higher plasma noradrenaline and adrenaline levels, lower heart noradrenaline concentrations, higher adrenomedullary adrenaline levels and increased cardiac intraventricular pressure (dp/dtmax).

Circulating and tissue catecholamines in rats with chronic neurogenic hypertension

SummaryTo study the role of peripheral catecholamines in plasma and different tissues in neurogenic hypertension we measured directly blood pressure, maximum rate of left ventricular pressure rise (dp/dtmax) and heart rate through an aortic catheter 5 weeks after total sino-aortic baroreceptor deafferentation in male Sprague-Dawley rats. Blood samples were collected through the same catheter to determine plasma catecholamine concentrations. Blood pressure and dp/dtmax were significantly higher in neurogenic-hypertensive rats when compared with sham operated rats. Plasma noradrenaline concentrations and plasma adrenaline concentrations reached significantly higher levels in neurogenic-hypertensive rats. In the heart noradrenaline content was lower (when calculated per g wet weight) and in the adrenal medulla adrenaline content was higher in neurogenic-hypertensive rats, when compared with sham operated controls. A significant positive correlation was found between dp/dtmax and plasma noradrenaline concentrations.It is concluded that sino-aortic baroreceptor deafferentation produces a significant chronic hypertension, probably supported by elevated plasma catecholamine concentrations and enhanced synthesis and release of adrenaline from adrenal medulla.