876 DECREASED POLVAMIHE CONTENT IN CON A STIMULATED LYMPHOCYTES FROM DOWN'S SYNDROME

Abstract

The present study was done to determine if polyamine content of Concanavolin A (Con A) stimulated lymphocytes was decreased in cells from D.S. patients. Increased polyamine content or synthesis has been associated with increased rates of growth in a number of tissues in many animal species. Down's syndrome fibroblasts have a lengthened doubling time and PHA stimulated lymphocytes have decreased DNA polymerase activity and 3H thymidine uptake. Lymphocytes were isolated and cultured in RPMI-16 media with 15% v/v autologous plasma for 4 or 5 days in presence or absence of Con A. Polyamines were extracted, quantitated with an amino acid analyzer and the net increase between non-Con A and Con A stimulated lymphocytes compared in D.S. and control subjects. The net spermidine content of cells stimulated 4 days was 814.4±115.5 nM/10⁹ cells in controls compared to 410.8±107.9 nM/10⁹ cells in D.S. (p.<.025). The spermine content was 858.9±150.4 nM/10⁹ cells in controls compared to 329.4±78.8 nM/10⁹ cells in D.S. (p.<.01). In cells stimulated 5 days by Con A net spermidine content was 700.8±77.8 nM/10⁹ cells in controls and 379.2±67.1 nM/10⁹ cells in D.S. (p.<.01). Spermine content was 825.3±131.5 in control cells compared to 372.3±68.5 nM/10⁹ cells in D.S. (p.<.01). The decreased content was not due to increased leak of polyamines into the medium or to differences in time of peak content of polyamines in the D.S. cells. Decreased polyamine content in D.S. tissues may be a factor in the slow growth rates seen in D.S, subjects.

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account

Continue with Google

Continue with ORCiD