[Effects of telmisartan on 4-Aminopyridine-sensitive voltage dependant potassium channel of lymphocyte derived from spontaneously hypertensive rat].
OBJECTIVE
To study the effects of telmisartan on voltage dependant potassium channel (Kv) expression in lymphocytes from spontaneously hypertensive rat (SHR).


METHODS
Peripheral blood was collected from male SHR aged 16 and 4 weeks. Peripheral lymphocytes were separated from heparinized whole blood by standard Ficoll-Hypaque density gradient centrifugation. The whole-cell Kv currents were recorded with patch-clamp technique in the absence and presence of telmisartan(10, 30, 100 µmol/L). Real-time PCR was used to determine Kv1.3 mRNA expression in lymphocytes.


RESULTS
(1) The currents density of Kv was higher in lymphocytes from 16 weeks-old SHR [ (119.0 ± 9.6) pA/pF] than from 4 weeks-old SHR [(59.0 ± 7.2) pA/pF, P < 0.05]. (2) Currents density was positively correlated with systolic blood pressure in 16 weeks-old SHR (r = 0.837, P < 0.05). (3) The lymphocytes Kv 1.3 mRNA expression was significantly higher in 16-weeks-old SHR than in 4-weeks-old SHR (P < 0.05). (4) Telmisartan reduced the whole-cell Kv currents in a concentration-dependent manner (10.5 ± 3.4)% at 10 µmol/L, (45.8 ± 3.7)% at 30 µmol/L and (81.6 ± 4.2)% at 100 µmol/L, P < 0.01.


CONCLUSIONS
The lymphocyte Kv channel is upregulated in 16 weeks-old SHR suggesting a role of Kv in the pathophysiology of hypertension. Kv current in lymphocyte could be significantly blocked by telmisartan in a concentration dependent manner.
Department of General Medicine, First Affiliated Hospital, Xin Jiang Medical University, Urumqi 830054, China.
Jian
J
Luo
Ke-Tao
KT
Ma
Yuan-Ming
YM
Zhang
Jun-Qiang
JQ
Si
Ping
P
Liang
Jing
J
Li
D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology*; D001565:Benzoates / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D018408:Patch-Clamp Techniques; D024642:Potassium Channels, Voltage-Gated / Q000187:drug effects*; D051381:Rats; D011918:Rats, Inbred SHR / Q000378:metabolism*; D000077333:Telmisartan
D001562:Benzimidazoles; D001565:Benzoates; D024642:Potassium Channels, Voltage-Gated; D015761:4-Aminopyridine; D000077333:Telmisartan