Voltage-operated Ca(2) (+) currents and Ca(2) (+) -activated Cl(-) currents in single interstitial cells of the guinea-pig prostate.
BJU Int
; 114(3): 436-46, 2014 Sep.
Article
en En
| MEDLINE
| ID: mdl-24467706
ABSTRACT
OBJECTIVE:
To investigate the expression of 'T-type' and 'L-type' voltage-operated Ca(2) (+) channels in single interstitial cells of the guinea-pig prostate. MATERIAL ANDMETHODS:
Whole-cell and perforated patch-clamp techniques were applied to prostatic interstitial cells (PICs) dispersed using collagenase.RESULTS:
In contrast to prostatic myocytes, PICs under voltage clamp and filled with K(+) (130 mm) were distinguished by the absence of a voltage-operated transient outward K(+) current or spike discharge upon membrane depolarisation when under current clamp. Depolarisation of Cs(+) -filled PICs evoked an inward current at potentials positive to -60 mV, which peaked in amplitude near 0 mV. This inward current increased when Ba(2+) (5 mm) replaced the external Ca(2) (+) (1.5 mm) and displayed a variable sensitivity to the inhibitory actions of conditioning depolarisations to -40 mV applied before the test depolarisation or to 1 µm nifedipine, the 'L-type' Ca(2) (+) channel blocker. A residual inward current recorded in nifedipine was blocked by 10 µm Ni(2) (+) . Cs(+) -filled PICs also displayed a slowly inactivating outward current that was little affected by nifedipine, reduced by the Cl(-) channel blocker, niflumic acid (10 µm) and blocked by Ba(2) (+) or a conditioning depolarisation.CONCLUSION:
PICs express both a small 'T-type' Ca(2) (+) channel current (ICa ) and a large 'L-type' ICa . Ca(2) (+) influx through 'T-type' ICa was an essential trigger for the activation of a Ca(2) (+) -activated Cl(-) -selective current. The dependence of PIC Ca(2) (+) signalling on 'T-type' and 'L-type' ICa is unique compared with other interstitial cells of the urogenital tract and may well be pharmaceutically exploitable.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Próstata
/
Bloqueadores de los Canales de Calcio
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Nifedipino
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Canales de Calcio
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Canales de Cloruro
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Miocitos del Músculo Liso
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Células Intersticiales de Cajal
Límite:
Animals
Idioma:
En
Revista:
BJU Int
Asunto de la revista:
UROLOGIA
Año:
2014
Tipo del documento:
Article
País de afiliación:
Australia