Biomedical subjects

R Schwabe

Publications and source records attributed to R Schwabe.

4 recordsLinked to original sources

PubMed1992

Effects of a single haloperidol application to neonatal and early postnatal rats on the neurotransmitter content in the corpus striatum.

We investigated the influence of the dopamine antagonist haloperidol on the neurotransmitter content in the developing rat brain. Dopamine (DA), serotonin (5-HT) and the corresponding metabolites dopac, HVA and HIAA were determined in the corpus striatum of the rat between day 1 and day 21 pn by HPLC with electro-chemical detection. A consistent increase in the content of dopamine was found during postnatal development. The concentrations (ng/g wet tissue; mean +/- standard deviation) increased from 793 +/- 237 on day 1 pn to 4584 +/- 581 on day 21 pn, but remained still lower than in adult animals (9763 +/- 494). Similar results were found for the metabolites dopac and HVA. The content of dopac increased from 59 +/- 22 (day 1 pn) to 551 +/- 59 (day 21 pn) and the content of HVA from 53 +/- 18 (day 1 pn) to 419 +/- 41 (day 21 pn). Both metabolites were also about two times lower than in adult animals (dopac 1090 +/- 282, HVA 744 +/- 206). In contrast to dopamine and its metabolites we found no age-dependent changes in the content of 5-HT from day 1 pn (99 +/- 11) to day 14 pn (121 +/- 21). A remarkable increase in the content of 5-HT was seen from day 14 pn to day 21 pn (438 +/- 56), reaching almost adult levels (570 +/- 92). The metabolite HIAA was nearly three times higher on day 21 pn (610 +/- 123) than on day 14 pn (223 +/- 28) and two times higher than in adults (321 +/- 58).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Device for monitoring locomotor activity of 120 animals: motility of offspring of dams exposed to haloperidol.

A device using four infra-red light photocells per cage which monitor simultaneously the motility of 120 individual rodents, was developed at our institute. The measuring interval can be chosen freely, the starting time may be set freely and the test may last several weeks. The motility of the offspring (day 35-39) of dams exposed to the neuroleptic haloperidol during lactation was investigated, because of the important stage of the brain development in the neonatal age and of the relatively high concentration of haloperidol in the milk. Mice dams were treated sc. with a single dose (1.5 mg/kg) of haloperidol postnatally on day 3 to 6. Compared to the controls the body weight gain of treated (via milk) pups was reduced (controls = 72%, haloperidol = 30%) and the mortality was higher (controls = 10%, haloperidol = 77%) during the treatment period. The quantitative and qualitative analysis of the locomotor activity from day 35 to day 39 shows a distinct shift in the kind of motility: the locomotor activity of haloperidol offspring is significantly reduced while the number of activity phases is increased. It appears that there is a persistent alteration in the central nervous system that leads to a higher frequency but a lower efficacy of activity.

Animals↗

PubMed1989

[Changeable bridge-work prosthesis. Proposal for solution].

A newly developed solution is introduced, which makes it possible to design artificial bridges conditionally variable. Thus the frame is fixed on tangential bridges--departing from common techniques--by means of lateral assembled barriers.

Denture Design↗

PubMed1985

Enzyme cytochemistry combined with electron microscopy, pharmacokinetics, and clinical chemistry for the evaluation of the effects of steady-state valproic acid concentrations on the mouse.

A number of organs from adult female mice were investigated after continuous application of the anticonvulsant drug valproic acid (VPA) by enzyme cytochemistry, light and electron microscopy, pharmacokinetics and clinical chemistry. VPA plasma levels were maintained between 55 micrograms/ml and 67 micrograms/ml for three days following subcutaneous implantation of drug reservoirs. Effects detectable by enzyme cytochemical or electron microscopical means were mainly observed in liver, kidney, thymus and spleen. A strict concentration-dependency of drug effects could not be found. In the liver, the activities of some surface-membrane hydrolases were increased at the biliary pole; the activities of other hydrolases were decreased or unchanged. Electron microscopically, number and length of microvilli of hepatocytes were increased and many of them showed fat inclusions, mitochondrial swellings and autophagic vacuoles. In some of the proximal convoluted tubules of the kidney, the reaction product originating from microvillous and lysosomal hydrolases was diffusely distributed and its amount lowered. This was paralleled by tubular cells with an increased number of fat droplets and swollen mitochondria or destroyed tubular cells, as demonstrated by electron microscopy. Additionally, peritubular endothelial cells were arranged in a garland-like pattern. Alkaline phosphatase was activated in the straight portion of the proximal tubules. Increased glucose, creatinine and total protein concentrations and increased gamma-glutamyl transpeptidase and alkaline phosphatase activities in the urine reflected well the damage of the proximal renal tubules. Cortical and medullary morphology varied considerably in the thymus. In extreme cases, the cortical zone was either reduced in size or the medulla showed a cortex-like structure or vice versa (inverted type of thymus). The thymic cortical reticular cells showed increased aminopeptidase A activity accompanied by a generalized aminopeptidase M and alkaline phosphatase reaction. Our data indicate that--in addition to the liver--also the kidney, thymus and spleen are target organs of VPA-induced toxicity in the mouse.

Alkaline Phosphatase↗