PubMed HealthSearch

Biomedical subjects

J S Sobel

Publications and source records attributed to J S Sobel.

4 recordsLinked to original sources

Differences in concanavalin A-FITC binding to rat spermatozoa during epididymal maturation and capacitation.

Rat spermatozoa from the caput epididymis and cauda epididymis, but not from the testis, demonstrated a crescent of greenish fluorescence on the convex surface of the sperm head, as observed by fluorescence microscopy after staining with concanavalin A-fluorescein isothiocyanate. The percentage of spermatozoa displaying this fluorescent zone decreased during incubation under capacitating conditions, both in vivo and in vitro, suggesting that a glycoprotein zone that is capable of binding concanavalin A was removed or altered during the capacitation period.

Animals

Changes in concanavalin A agglutinability during development of the inner cell mass and trophoblast of mouse blastocysts in vitro.

Mouse blastocyst cultures were analysed for Concanavalin A (Con A) agglutinability by microhaemadsorption methods and for Con A binding capacity with Rhodamine-Con A stain. The inner cell mass, which was not agglutinable in the early culture stages, became agglutinable when it started to develop. The trophoblast, which was initially agglutinable, lost this property as the cells matured. There was no apparent correlation between changes in agglutinability and capacity to bind Rhodamine-Con A. The pattern of change in Con A agglutinability which characterized development of the inner cell mass and trophoblast is consistent with an interpretation that agglutinability was related to the migratory activities of these cells. The loss of agglutinability associated with trophoblast maturation may have been due to alterations in Con A receptor accessibility.

Agglutination

Inhibitory effect of hydroxyurea on [3-H]leucine incorporation in human peripheral lymphocytes.

Hydroxyurea (HU), generally considered to be a specific inhibiter of DNA synthesis, has an inhibitory effect on the incorporation of TCA-precipitable [3-H]leucine in peripheral lymphocytes. This action is not secondary to the inhibition of DNA synthesis since incorporation of [3-H]leucine is unaffected when DNA synthesis is inhibited by 5-fluorodeoxyuridine (FUdR); it does not appear to be directly related to inhibition of RNA synthesis; and it is not mediated at the level of translation since HU has no effect on protein synthesis in rabbit reticulocytes. The relevance of these findings to the use of HU as a DNA inhibitor is discussed.

Animals