Endurance exercise training restores atrophy-induced decreases of myogenic response and ionic currents in rat skeletal muscle artery

Inter-arm blood pressure difference in post-stroke patients with hemiparesis

The aim of this study was to investigate that inter-arm blood pressure (BP) difference (IAD) and reference arm in 420 post-stroke patients with hemiparesis. Synchronous bilateral-arm BP was measured with two automatic BP devices, and the systolic BP difference of ≥10 mm Hg was recorded as increased sIAD. The arm with higher systolic BP (SBP) was assigned as the reference arm. Our results showed that the prevalence of sIAD was 18.1% in the total group. The paretic arms had similar mean SBP levels (133.6±18.4 vs. 133.8±18.4 mm Hg, NS) and DBP (77.8±11.5 vs. 77.2±10.9 mm Hg, NS) as compared with the unaffected arms. The detection rate of hypertension or uncontrolled hypertension on the SBP values of the reference arm was higher than that on the unaffected arm (41.8% vs. 36.3%). It is concluded that in the post-stroke patients with hemiparesis in the rehabilitation period, the prevalence of sIAD ≥10 mmHg was relatively higher, and using the unaffected arm, rather than the unaffected arm, for BP measurement could induce correctly detection of hypertension.

Is the blood pressure different between the paralyzed and unaffected arms or legs?

OBJECTIVES

To investigate whether the blood pressure (BP) levels are similar between the paralyzed and unaffected arms or legs.

METHODS

This study enrolled 236 post-stroke patients with hemiplegic paralysis. Simultaneous four-limb BP was measured using four automatic BP devices for three times, and the average was used as final value. The inter-arm difference (IAD) and inter-ankle difference (IAND) were the BP difference between the arms or ankles, respectively. The difference between maximal BP reading and minimal BP reading was calculated as △BP to reflect the variation of three BP readings.

RESULTS

The paralyzed arm had similar mean SBP (134.8 ± 18.7 vs. 135.1 ± 19.0 mmHg, NS) and DBP (79.5 ± 11.3 vs 78.1 ± 10.4 mmHg, NS) levels as compared with the unaffected arm. Similarly, the mean ankle SBP (143.6 ± 19.1 vs. 143.7 ± 18.6 mmHg, NS) and DBP (77.9 ± 17.7 vs. 75.8 ± 11.1 mmHg, NS) in the paralyzed legs were also similar to those in the unaffected legs. The detection rate of systolic IAD ≥10 mmHg was 5.9% and that for systolic IAND ≥15 mmHg was 20.3%. Meanwhile, △SBP levels were similar between two arms or ankles.

CONCLUSION

In the post-stroke patients with hemiplegic paralysis, the SBP and DBP levels of the paralyzed and unaffected arms or ankles were similar.

Increased inward rectifier K+ current of coronary artery smooth muscle cells in spontaneously hypertensive rats; partial compensation of the attenuated endothelium-dependent relaxation via Ca2+ -activated K+ channels

Endothelium-dependent vasorelaxation is partly mediated by small-conductance (SK3) and intermediate-conductance Ca²⁺ -activated K⁺ channels (SK4) in the endothelium that results in endothelium-dependent hyperpolarization (EDH). Apart from the electrical propagation through myoendothelial gap junctions, the K⁺ released from the endothelium facilitates EDH by increasing inward rectifier K⁺ channel (Kir) conductance in smooth muscle cells. The EDH-dependent relaxation of coronary artery (CA) and Kir current in smooth muscle cells (CASMCs) of hypertensive animals are poorly understood despite the critical role of coronary flow in the hypertrophic heart. In spontaneously hypertensive (SHR) and control (WKY) rats, we found attenuation of the CA relaxation by activators of SK3 and SK4 (NS309 and 1-EBIO) in SHR. In isolated CASMCs, whole-cell patch-clamp study revealed larger I_Kir in SHR than WKY, whereas the myocytes of skeletal and cerebral arteries showed smaller I_Kir in SHR than WKY. While the treatment with I_Kir inhibitor (0.1 mmol/L Ba²⁺ ) alone did not affect the WKY-CA, the SHR-CA showed significant contractile response, suggesting relaxing influence of the higher I_{K ir} in the CASMCs of SHR. Furthermore, the attenuation of NS309-induced relaxation of CA by the combined treatment with 0.1 mmol/L Ba²⁺ was more prominent in SHR than WKY. Our study firstly shows a distinct increase of I_{K ir} in the CASMCs of SHR, which could partly compensate for the attenuated relaxation via endothelial SK3 and SK4.