Search results for "STRAINS"

Evaluation of alprazolam-induced behavioural effects: differences with chlordiazepoxide after interaction with desipramine and rolipram, a cAMP phosp…

1989

Head-twitch and forepaw-shake responses after single and repeated treatment with rolipram: interaction with noradrenergic and dopaminergic agonists a…

1988

Temperature dependence of the toxic effects of phenytoin on peripheral neuromuscular function of the rat tail.

1990

We studied the acute effects of a single dose of phenytoin (250 mg/kg) on peripheral neuromuscular function. The evoked muscle action potentials of the dorsal segmental muscles in the rat tail, and the conduction velocity of the dorsal nerve trunk which innervates them, were measured before and after the intraperitoneal injection of phenytoin. The experiments were performed at different temperatures, 27 (physiological tail temperature), 36 and 37 degrees C (physiological central temperature) in different groups of animals. The amplitudes of the evoked muscle action potentials in the treated groups showed no significant modifications at 27 degrees C, at 36 degrees C a small nonsignificant de…

Growth-related changes of oxygen consumption rates of tumor cells grown in vitro and in vivo

1989

Growth-related changes of oxygen consumption rates of tumor cells, grown in vitro or in vivo, were investigated. For in vitro investigations, L929 and DS-carcinosarcoma cells were cultured in artificial media. For in vivo studies, DS-carcinosarcoma cells were implanted into the abdominal cavity of Sprague-Dawley rats (ascites tumor, containing malignant cells, leukocytes, lymphocytes, and macrophages). Oxygen uptake was measured photometrically. Parameters of the extracellular medium judged to possibly influence the respiratory activity of tumor cells were monitored at different growth stages (glucose, lactate, and amino acid levels, oxygen and carbon dioxide partial pressures, and pH value…

Hemodilution in isolated tumor perfusion.

1984

Experiments are performed to study the influence of local hemodilution on tumor blood flow, oxygen availability in tumor tissue and O2 consumption of cancer cells. The results obtained clearly show that hemodilution in isolated tumor perfusion can distinctly improve nutritive blood flow through solid tumors. This can be utilized to enhance pharmacokinetics of antitumor drugs. Due to the improved metabolic status, the pharmacodynamics of some antitumor drugs should also be enhanced. To achieve a maximum improvement of the O2 supply to the tumor, hematocrit values should not be decreased below 0.20.

Defense Responses of Fusarium oxysporum to 2,4-Diacetylphloroglucinol, a Broad-Spectrum Antibiotic Produced by Pseudomonas fluorescens

2004

A collection of 76 plant-pathogenic and 41 saprophytic Fusarium oxysporum strains was screened for sensitivity to 2,4-diacetylphloroglucinol (2,4-DAPG), a broad-spectrum antibiotic produced by multiple strains of antagonistic Pseudomonas fluorescens. Approximately 17% of the F. oxysporum strains were relatively tolerant to high 2,4-DAPG concentrations. Tolerance to 2,4-DAPG did not correlate with the geographic origin of the strains, formae speciales, intergenic spacer (IGS) group, or fusaric acid production levels. Biochemical analysis showed that 18 of 20 tolerant F. oxysporum strains were capable of metabolizing 2,4-DAPG. For two tolerant strains, analysis by mass spectrometry indicated…

Presynaptic regulation of the electrically evoked release of endogenous dopamine from the isolated neurointermediate lobe or isolated neural lobe of …

1988

Isolated neurointermediate lobes (NILs) or isolated neural lobes (NLs) of the rat pituitary gland were incubated in Krebs-HEPES solution which contained pargyline and the dopamine uptake inhibitor GBR 12921. The release of endogenous dopamine was determined by HPLC with electrochemical detection. Electrical stimulation of the pituitary stalk induced a frequency-dependent release of dopamine. The release of dopamine from the combined NIL evoked by stimulation at 15 Hz was increased by 130% in the presence of the dopamine D2 receptor antagonist, (-)-sulpiride; the (+)-enantiomer of sulpiride had virtually no effect. When the stimulation frequency was 3 Hz (-)-sulpiride caused an increase in d…

The role of cytoplasmic (newly synthesized) dopamine for the spontaneous and electrically evoked release of dopamine and its metabolites from the iso…

1987

Isolated rat NILs were incubated in Krebs-HEPES solution. The release of dopamine and its metabolites (DOPAC, HVA and MOPET) was determined by HPLC with electrochemical detection. The spontaneous release of the sum of metabolites was about 40 times that of dopamine. The spontaneous outflow of dopamine metabolites was unaffected after inhibition of dopamine uptake (by GBR 12921) or after pretreatment with reserpine (5 mg/kg, 12 h before the experiments), but it was reduced by 50% after preincubation with the irreversible DOPA decarboxylase inhibitor, (MFMD, 10 microM, for 10 min). The combination of pretreatment with reserpine and preincubation with MFMD resulted in an 80% inhibition of the …

BODY GROWTH AND POLYCYTHAEMIA IN HYPOXIC ALBINO RATS OF FIRST AND SECOND GENERATION

1990

SUMMARY 1. In our study we followed the growth rate and the haematologic changes occurring in albino rats of Wistar strain when living in a hypoxic environment. Two generations of hypoxic rats were observed for changes in their erythrocytes (RBC), haematocrit (Hct) and haemoglobin (Hb): the first generation (H1) and the second generation (H2). A few hours after birth, the H1 rats were placed and raised in a normobaric hypoxic environment (10% O2 in N2). The H2 rats were born and raised in the environment previously described. The control group had a normoxic environment. The H1 and H2 rats had inferior growth rates in respect to their controls, but H2 were found to have a larger growth rate…

Differentiation-regulated loss of the polysialylated embryonic form and expression of the different polypeptides of the neural cell adhesion molecule…

1989

The expression of the neural cell adhesion molecule (N-CAM) on cultured murine oligodendrocytes, their precursors, and myelin was examined by indirect immunofluorescence, biosynthetic radiolabeling followed by immunoprecipitation and Western blot analysis, using antibodies specific for various forms of the molecule. In all culture systems studied, whether the oligodendrocytes were cultured as an enriched fraction containing precursor cells or in the presence of astrocytes and neurons, a similar differentiation-stage-related expression of N-CAM was seen. At early developmental stages many tetanus toxin receptor- and A2B5 antigen-positive putative oligodendrocyte precursors with bipolar morph…