5'-deiodinase activity in cultured glial and fibroblastic cells from the cerebella of newborn rats.
The cerebellum of young rats contains significant 5'-deiodinase (5'-D) activity, but technical difficulties have made it impossible to identify the enzyme in cultured cerebellar astrocytes. We have developed a culture method which allows cerebellar astrocytes from 6-day-old rats to grow and develop 5'-D activity. Astrocytes cultured for 2 weeks in medium containing 3.25 microM reduced glutathione (GSH) and 0.21 microM vitamin E (VitE) as alpha-tocopherol had 5'-D activity which was stimulated by 1 mM dibutyryl cyclic adenosine monophosphate (dBcAMP) given 16 hours before measuring enzyme activity. Cells cultured without GSH and VitE showed little 5'-D activity, which was not stimulated by dBcAMP Primary cultures of cerebellar astrocytes were cultured for four weeks with or without GSH+VitE, and stimulated by dBcAMP had high 5'-D activity, but were also sometimes contaminated with fibroblasts. The effect of such contamination on the astrocyte 5'-D activity was assessed by preparing primary cultures of fibroblasts from the meninges surrounding 6-day-old rat cerebella. They were grown in the same media and under the same conditions as the astrocytes. The cultured fibroblasts had 5'-D activity independent of GSH+VitE or culture time. The 5'-D activity of both cell populations could be type II 5'-deiodinase (5'-DII) because it was not inhibited by 6-n-propylthiouracil (PTU). Thus, cerebellar astrocytes cultured for 2 weeks in medium containing GSH and VitE have 5'-DII activity. Prolonged cultures favor enzyme activity, but also enhance contamination with fibroblasts, which may also show 5'-DII activity.
Pruvost
V
V
Université de Montpellier II, Laboratoire de Physiologie Comparée II, France.
Valentin
S
S
Cheynel
I
I
Vigouroux
E
E
Bézine
M F
MF
D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000737:chemistry / Q000166:cytology / Q000201:enzymology*; D003994:Bucladesine / Q000494:pharmacology; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology*; D002540:Cerebral Cortex / Q000166:cytology; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D005260:Female; D005347:Fibroblasts / Q000737:chemistry / Q000166:cytology / Q000201:enzymology; D005353:Fibronectins / Q000032:analysis; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D005978:Glutathione / Q000494:pharmacology; D007453:Iodide Peroxidase / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000201:enzymology; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D014810:Vitamin E / Q000494:pharmacology
D005353:Fibronectins; D005904:Glial Fibrillary Acidic Protein; D014810:Vitamin E; D003994:Bucladesine; D007453:Iodide Peroxidase; D005978:Glutathione