Data/hora: 11/06/2024 16:01:53

Provedor de dados: | Brazilian Journal of Medical and Biological Research
País: | Brazil
Título: | Erythrocyte phosphoglucomutase activity of bipolar I patients currently using lithium or carbamazepine
Autores: | Montero-Lomelí,M.; Galvão,D.; Morais,B.B.; Nardi,A.E.
Data: | 2007-01-01
Ano: | 2007
Palavras-chave: | Phosphoglucomutase; Lithium; Carbamazepine; Bipolar disorder.
Resumo: | Lithium has been used for the last five decades to treat bipolar disorder, but the molecular basis of its therapeutic effect is unknown. Phosphoglucomutase is a key enzyme in the metabolism of glycogen. In yeast, rabbit and human HEK293 cells, it is inhibited by lithium in the therapeutic concentration range. We measured the phosphoglucomutase activity in erythrocytes and the inhibitor constant for lithium in a population of healthy subjects and compared them to those of bipolar patients treated with lithium or carbamazepine. The specific activity of phosphoglucomutase measured in vitro in erythrocytes from control subjects presented a normal distribution, with the difference between the lowest and the highest activity being approximately 2-fold (0.53-1.10 nmol mg Hb-1 min-1). Comparison of phosphoglucomutase activity in untreated bipolar patients and control subjects showed no significant difference, whereas comparison between bipolar patients treated with carbamazepine or lithium revealed significantly lower mean values in patients treated with carbamazepine (747.3 ± 27.6 vs 879.5 ± 35.9 pmol mg Hb-1 min-1, respectively). When we studied the concentration of lithium needed to inhibit phosphoglucomutase activity by 50%, a bimodal distribution among the population tested was obtained. The concentration of LiCl needed to inhibit phosphoglucomutase activity by 50% was 0.35 to 1.8 mM in one group of subjects and in the other it was 3 to 4 mM. These results suggest that phosphoglucomutase activity may be significant in patients with bipolar disorder treated with lithium and carbamazepine.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007000100003
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2006005000059
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.40 n.1 2007
Fonte: | info:eu-repo/semantics/openAccess