Investigations on myelinogenesis in vitro: Regulation of 5′-nucleotidase activity by thyroid hormone in cultures of dissociated cells from embryonic mouse brain

✍ Scribed by G. Shanker; G. S. Rao; R. A. Pieringer

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 512 KB
• Volume: 11
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490110306

✦ Synopsis

The developmental pattern of the myelin-associated 5'-nucleotidase and its regulation by L-3,3',5,-triiodothyronine (T,) have been demonstrated in a culture system of cells dissociated from embryonic mouse brain. Hypothyroid calf serum containing low levels of T3 (31 ng/100 ml), and thyroxine, T4 (< I pg/ml), was used in the culture medium in place of normal calf serum (T,, 103 ng/100mI; T4, 5.7 pg/ml) to render the cultures responsive to exogenously added T3. By means of T3 supplementation, the lower levels of enzyme activity observed in the cultures grown in the presence of hypothyroid calf-serum containing medium could be restored to a considerable extent although not completely to normal values. Halfmaximal stimulatory effect was obtained at 3.9 x lo-* M T, concentration. Among the various substrates tested, 5'-AMP, 5'-UMP and 5'-CMP were equally good, while 5'-GMP yielded approximately half the activity.