The herbicide 3-amino-1, 2, 4-triazole induces complete chlorosis without any morphogenetic effect on Canna edulis leaves. Comparative analyses of the mineral and biochemical composition and also of the physiological properties of normal and bleached leaf cells establish a high specificity of this herbicide for inhibition of formation of chloroplast membranes. The synthesis of membrane lipids a...

AIM The examination of the possibility of ethanol oxidation in the brain in vivo and the evaluation of the enzyme catalase in this process. METHODS We anesthetized rats and perfused the brain with ethanol solutions through the lateral ventricle and collected the perfusate from the Cisterna magna. We determined ethanol and acetaldehyde in the perfusate by gas chromatography. RESULTS It was f...

Endogenous peroxidase activity in rat thyroid follicular cells is demonstrated cytochemically. Following perfusion fixation of the thyroid gland, small blocks of tissue are incubated in a medium containing substrate for peroxidase, before being postfixed in osmium tetroxide, and processed for electron microscopy. Peroxidase activity is found in thyroid follicular cells in the following sites: (...

Different light microscopical procedures for the histochemical demonstration of catalase were tested in cryostat sections of mussel digestive gland tissue by using both benzidine and diaminobenzidine (DAB) as hydrogen donors. The selected procedure, which was also applied to mouse liver for comparative purposes, consisted of incubation in media containing 0.2% DAB and 0.3% H2O2 at pH 10.4 for 3...

The pathogen Candida albicans responds to amino acid starvation by activating pseudohyphal development and the expression of amino acid biosynthetic genes (GCN response). In Saccharomyces cerevisiae, the GCN response is dependent on Gcn2, which regulates the translation of the transcription factor Gcn4. Therefore, we examined the role of Gcn2 in C. albicans by using molecular, cellular, and gen...

The early labeled bilirubin consists of two primary components. The more rapidly synthesized of the two is independent of erythropoiesis (nonerythropoietic), whereas the second fraction is related to red cell production (erythyropoietic). The present studies concern the origin of the nonerythropoietic component. The nonerythropoietic, early labeled bilirubin was studied in bile fistula rats wit...