Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1970-1974  (3)
  • 1910-1914
  • 1870-1879
  • Life and Medical Sciences  (2)
  • Glucocorticoids  (1)
  • 1
    ISSN: 1432-1912
    Keywords: Lipolysis ; Adenyl Cyclase ; Phosphodiesterase ; Glucocorticoids ; Cyclic AMP ; Cortisone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of adrenalectomy and cortisone replacement in rats on the activities of adenyl cyclase and phosphodiesterase in homogenates of isolated fat cells and on the accumulation of cyclic 3′,5′-AMP in intact cells were studied. 1. Adrenalectomy caused a decrease in the activity of norepinephrine- and fluoride-stimulated adenyl cyclase in homogenates of isolated fat cells. This decrease was not significantly reversed by pretreatment of the animals with cortisone in vivo. 2. Adrenalectomy caused an increase in the activity of phosphodiesterase. This increase was not reversed by pretreatment of the animals with cortisone for 4 h in vivo but was reversed after 18 h. Incubation of cells from adrenalectomized animals with cortisone in vitro caused no change in phosphodiesterase activity. 3. The incorporation of prelabelled nucleotides into cyclic 3′,5′-AMP was significantly reduced in intact cells from adrenalectomized rats. Pretreatment of the animals with cortisone in vivo for 4 h completely restored the ability of the cells to accumulate radiolabelled cyclic 3′,5′-AMP upon stimulation by norepinephrine. The experiments underline the difficulties in comparing activation patterns of enzymes under optimal conditions with those occurring in the intact cell. The nature of the lesion in lipolysis caused by adrenalectomy and the reversal of this lesion by cortisone replacement can be demonstrated in the intact cell only.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A flow-system multiparameter cell analyzer that simultaneously measures and processes fluorescence and cell volume signals from single cells was used to study the binding of fluorescein-conjugated Concanavalin A (Con A-F) to the cell surface. Cells reacted with Con A-F were passed through a flow chamber where sensors measured both cell volume and fluorescence of each individual cell. Sensor signals were electronically processed by first converting the cell volume signals to two-thirds power (proportional to surface area) and then forming the fluorescence-to-surface area ratio. These ratios, which were considered as estimates of the surface density of binding sites, were displayed as frequency distribution histograms using a multichannel pulse-height analyzer for various cell populations differing in cell size. Comparisons between cell lines showed characteristic differences in binding site density. Cell cycle dependent changes were not found for CHO cells synchronized by mitotic selection. An important benefit of this analysis method was the ability to quantitate very weak cell surface fluorescence.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Flow microfluorometry has been used to quantitate cell-surface binding of fluorescein-conjugated lectins. Frequency distributions of total surface binding of Concanavalin A per cell were prepared for a variety of cultured cell populations, including established cell lines, virus-transformed lines and non-transformed parental lines. In the case of growing Chinese hamster cells (line CHO), much of the variability of Con A binding per cell could be related to variability of cell size. Experiments with cells synchronized by mitotic selection indicated that the modal surface density of binding sites was almost constant throughout the cell cycle. However, as indicated by inhibition of binding with α-methyl mannopyranoside and by the effect of trypsin, the sites on each cell were heterogeneous in chemical structure and/or exposure. Agglutinability of virus-transformed cell lines or trypsin-treated parental lines was demonstrated but could not be correlated closely with binding.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...