Original Article The expression and functional evidence for voltage-dependent potassium channel Kv1.3 in lymphocytes during aging in spontaneously hypertensive rats

* Equal contributors and co-first authors. Received December 2, 2014; Accepted January 29, 2015; Epub February 15, 2015; Published February 28, 2015 Abstract: Aims: Our previous studies showed that expression and functional profile of voltage-dependent potassium channels Kv1.3 were increased in lymphocytes of spontaneously hypertensive rats (SHR) compared to normoten- sive rats, suggesting a crucial role for lymphocyte Kv1.3 in the development of hypertension. Here, we further inves- tigated whether the expression and functional profile of Kv1.3 was related to increased blood pressure in SHR with age of 4, 8, 16 and 24 wk. Methods: Systolic blood pressure was measured through pressure device around the tail. mRNA and protein expression were assessed by real-time PCR and western blot in lymphocytes of SHR. Current density of Kv channels in lymphocytes was measured by patch-clamp. Results: Systolic blood pressure was elevated in an age-dependent manner (ANOVA P < 0.05). mRNA and protein level of Kv1.3 were significantly increased in an age-dependent manner in lymphocyte of SHR (ANOVA P < 0.05). Moreover, the current density of Kv was dramati- cally enhanced in an age-dependent manner (ANOVA P < 0.05). Conclusion: The systolic blood pressure positively correlated with expression as well as current density of potassium channels in lymphocytes of SHR at age of 8, 16 and 24 wk. In conclusion, Kv1.3 channels were upregulated in an age-dependent manner in SHR and correlates with systolic blood pressure during aging. The present study implies that Kv1.3 blockers may be applied as a thera- peutic treatment for the development of hypertension during aging.