Data/hora: 08/06/2024 02:37:38

Provedor de dados: | Brazilian Journal of Medical and Biological Research
País: | Brazil
Título: | CaV 3.1 and CaV 3.3 account for T-type Ca2+ current in GH3 cells
Autores: | Mudado,M.A.; Rodrigues,A.L.; Prado,V.F.; Beirão,P.S.L.; Cruz,J.S.
Data: | 2004-06-01
Ano: | 2004
Palavras-chave: | Calcium channel; T-type; Electrophysiology; RT-PCR; GH3 cells.
Resumo: | T-type Ca2+ channels are important for cell signaling by a variety of cells. We report here the electrophysiological and molecular characteristics of the whole-cell Ca2+ current in GH3 clonal pituitary cells. The current inactivation at 0 mV was described by a single exponential function with a time constant of 18.32 ± 1.87 ms (N = 16). The I-V relationship measured with Ca2+ as a charge carrier was shifted to the left when we applied a conditioning pre-pulse of up to -120 mV, indicating that a low voltage-activated current may be present in GH3 cells. Transient currents were first activated at -50 mV and peaked around -20 mV. The half-maximal voltage activation and the slope factors for the two conditions are -35.02 ± 2.4 and 6.7 ± 0.3 mV (pre-pulse of -120 mV, N = 15), and -27.0 ± 0.97 and 7.5 ± 0.7 mV (pre-pulse of -40 mV, N = 9). The 8-mV shift in the activation mid-point was statistically significant (P &lt; 0.05). The tail currents decayed bi-exponentially suggesting two different T-type Ca2+ channel populations. RT-PCR revealed the presence of a1G (CaV3.1) and a1I (CaV3.3) T-type Ca2+ channel mRNA transcripts.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000600020
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2004000600020
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.37 n.6 2004
Fonte: | info:eu-repo/semantics/openAccess