The effects of industrial whey on cell physiology were studied in a repeated fed-harvest mode using free-suspended murine hybridoma cells. After several days of culture in medium containing 9% whey and 1% fetal calf serum (FCS), cell growth and viability, carbohydrate, amino acid, energy metabolism, and antibody production rates were investigated. Differences were found between cells cultured in whey medium and those cultured in conventional FCS medium. The cell growth obtained in medium supplemented with fresh whey was similar to that obtained in FCS medium. The viability showed an increase for hybridoma cells cultured in whey medium. Glucose consumption rates were similar, whereas the lactate production rate was higher in whey medium. The metabolic uptake rates of glutamine and ammonia increased in whey medium. More alanine, glutamate, glycine, and proline were produced; their production partly came from glutamine and lactate. The consumption rates of branched amino acids changed little; their utilization was higher in whey medium. Finally, antibody productivity was increased about 20% for cells cultured in medium containing whey.

Animals↗

PubMedDate not supplied

Localization of S100 protein in the rat cerebellum: an immunoelectron microscope study.

Immunoelectron microscopy has shown that, in adult rat cerebellum, S100 protein is localized exclusively in the astroyctes of both the cortex and the white matter. The labelling pattern was unaffected by the inclusion of glutaraldehyde in the primary paraformaldehyde fixative. The immunoperoxidase reaction product is observed over both the perikaryal cytoplasm of astrocytes and their processes. S100 proteins was not found in neuronal structures nor in oligodendrocytes.

Animals↗

PubMedDate not supplied

Histochemical and biochemical studies of butyrylcholinesterase activity in adult and developing cerebellum. Effects of abnormal thyroid state and undernutrition.

The cellular and subcellular localization of BuchE activity (EC.3.1.1.8) was studied in the developing and adult rat cerebellum at light and electron microscope levels. In the adult cerebellum, BuchE activity was exclusively localized to glial cells, myelin and endothelial cells. In the immature cerebellum, BuchE activity was additionally found transiently localized to the neuroblasts of the external germinative layer and in Purkinje cells of the nodulus. In both the immature and the adult animals, the main part of the activity seemed to be membrane-bound. The developmental pattern of cerebellar BuchE activity was assayed in developing normal, hypothyroid, thyroxine-treated and undernourished rats. In normal newborn rats, the specific activity was higher than in adults and it showed one characteristic peak at 6 days (1.8 times the adult value reached at 30 days). At the age of 5 days, the ratio of BuchE-containing astrocytes (numbered in the ganglionic layer) to Purkinje cells was the same as the ratio of Bergmann astrocytes to Purkinje cells determined at 35 days in Nissl preparations; their nucleus size already represented 80% of the adult value and their processes were well developed. The three experimental conditions modified the timing of BuchE development. During the early post-natal period, it was accelerated in the thyroxine-treated and undernourished animals, while in the hypothyroid rats it was delayed. During the same period, the number of labelled astrocytes per Purkinje cell was modified only by hypothyroidism and undernourishment. On the basis of these histochemical and biochemical results, BuchE can be considered as a good marker for the study of Bergmann glia development in the early post-natal period.

Animals↗

PubMedDate not supplied

Effects of thyroid state and undernutrition on S100 protein and astroglia development in rat cerebellum.

The developmental pattern of S100 protein, a specific marker of astroglia, was studied by radioimmunoassay in the cerebellum of thyroid-deficient, thyroxine-treated and undernourished rats during development. In the control animals, the S100 protein content of the cerebellum increased maximally after the 3rd postnatal week, i.e., after cell multiplication had stopped and when the cerebellum had acquired more than 70% of its adult weight and protein content. This developmental pattern of S100 protein reflected essentially the maturation of astroglia. In the thyroxine-treated rats the total amount and the concentration of S100 protein were higher than in controls during the first 3 weeks of postnatal life and returned to normal values thereafter. In the thyroid-deficient rats both the amount and concentration were lower than in controls throughout development. In the undernourished animals the amount of S100 protein per organ was also lower than in controls during the whole experimental period studied; the S100 protein concentration was higher during the first 2 postnatal weeks and became lower thereafter. These results are discussed taking into consideration previous histological and ultrastructural observations on the effects of altered thyroid state and undernutrition on the formation and maturation of cerebellar astrocytes.

Animals↗

PubMedDate not supplied

Effects of hypothyroidism on the structural development of the organ of Corti in the rat.

The structural development of the organ of Corti was studied in 30 rat pups rendered hypothyroid by daily administration of propylthiouracil during the first 35 days after birth. Cochlear changes were observed by light microscopy and electronmicroscopy. Hypothyroid rat pups were found to have severe abnormalities in the organ of Corti. There was an abnormally prolonged persistence of Kölliker's organ and striking distortion of the tectorial membrane. The sensory epithelium exhibited marked signs of immaturity: the tunnel of Corti has not opened yet in animals 35 days old, sensory and supporting cells presented immature characteristics with abnormal persistence of the kinocilium. It is suggested that hypothyroidism results in an overall retardation of the maturation of cochlear structures and ultrastructural changes that appear to be significant enough to account for the hearing loss.

Animals↗

PubMedDate not supplied

[Steroidogenic function of the intra-arterial trophoblast in the rat. Ultrastructural, histoenzymologic and biochemical data].

The ultrastructural study of the intra-arterial trophoblast has revealed in the pregnant Rat a steroidogenic activity which has been confirmed by histoenzymologic observations (presence of delta 5-3 beta-HSDH and 17 beta-HSDH). At the 15th day postcoitum an in vitro investigation upon the metabolism of steroid hormone precursors suggests that the steroids (oestrogens, progestogens and androgens) secreted by the intra-arterial trophoblast have a local action upon the wall of the uterine placental arteries and are actively concerned with an important part upon the utero-placental hemodynamic as a whole.

Androstenedione↗

PubMedDate not supplied

[Influence of hypothyroidism on growth in length and histological differentiation of the femur of the rat fetus at the end of the pregnancy].

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Animals↗

PubMedDate not supplied

Effects of thyroid hormone on synaptogenesis in the molecular layer of the developing rat cerebellum.

In 14-day-old thyroid-deficient rats, qualitative and quantitative ultrastructural study of the cerebellar molecular layer shows that the retardation in synaptogenesis between Purkinje cell dendritic spines or excrescences and synaptic segments of parallel fibres is related to the marked hypoplasia of Purkinje cell dendritic arborizations and to the retarded development of parallel fibres rather than to the delay in the deposition of granule cells. Synaptogenesis inhibition is more marked in the inner parts of the molecular layer so that the normal "march" of synaptogenesis from the bottom of the layer upwards is distorted. This study also indicates that thyroid hormone deprivation affects synaptogenesis by interacting with growth and branching of neuronal processes and with the organization of their microtubular apparatus rather than with the differentiation of the structural specializations forming the synapses. The first corrective effect of a very low dose of thyroxine administered 24 h before sacrifice to the hypothyroid animal is observed at the level of parallel fibres and their varicosities. Purkinje cells take longer to respond to the hormone. However, their directing role in the histogenesis of the cerebellar cortex is strongly suggested. The significance of these observations with regard to the mechanisms underlying the effects of thyroid hormone on synaptogenesis and synaptic organization between Purkinje cells and parallel fibres as well as on histogenetic granule cell death is discussed.

Aging↗