Exercise training increases inwardly rectifying K(+) current and augments K(+)-mediated vasodilatation in deep femoral artery of rats
| Autor: | Yang Sook Chun, Yin Hua Zhang, Kyung Sun Park, Eun Yeong Seo, Hyang Sun Kim, Sung Joon Kim, Chun Zi Jin, Dong Hoon Shin |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Male
medicine.medical_specialty Time Factors Physiology Cerebral arteries Myocytes Smooth Muscle Physical Exertion Vasodilation Hyperemia Muscle Smooth Vascular Membrane Potentials Rats Sprague-Dawley Hyperaemia Physiology (medical) Internal medicine otorhinolaryngologic diseases medicine Myocyte Animals Splanchnic Circulation Potassium Channels Inwardly Rectifying Muscle Skeletal Mesenteric arteries Membrane potential Microscopy Video business.industry Sodium Skeletal muscle Cerebral Arteries Potassium channel Mesenteric Arteries Rats Up-Regulation Femoral Artery medicine.anatomical_structure Endocrinology Regional Blood Flow Anesthesia Cerebrovascular Circulation Potassium medicine.symptom Cardiology and Cardiovascular Medicine business Ion Channel Gating |
| Zdroj: | Cardiovascular research. 91(1) |
| ISSN: | 1755-3245 |
| Popis: | A moderate increase in extracellular [K(+)] ([K(+)](e)) induces relaxation of small arteries by activating inwardly rectifying K(+) current (I(Kir)). The K(+)-induced vasodilatation is an important mechanism for exercise-induced hyperaemia in skeletal muscle. We investigated whether I(Kir) and K(+)-induced vasodilatation are enhanced in deep femoral arteries (DFAs) from exercise-trained rats (ET rats; treadmill running for 20 min at 20 m/min, 3 days/week for 2 weeks). The effects of exercise training on K(+)-induced vasodilatation and I(Kir) were also investigated in cerebral (CA) and mesenteric arteries.The K(+)-induced vasodilatation of DFAs and the density of I(Kir) and voltage-gated K(+) current (I(Kv)) were increased in DFA myocytes of ET rats. The myogenic tone of the DFA was unchanged by exercise. Although similar functional up-regulations of I(Kir) and I(Kv) were observed in CA myocytes, the K(+)-induced vasodilatation was not increased in the CA of ET rats. Interestingly, concomitant to the increases in I(Kir) and I(Kv), background Na(+) conductance was also increased in the CA myocytes. However, such an effect was not observed in DFA myocytes from ET rats. Neither I(Kir) nor K(+)-induced vasodilatation was observed in mesenteric arteries of ET rats.The present study provides evidence that regular exercise up-regulates I(Kir) in DFA and CA myocytes. Although the increase in I(Kir) was observed in two types of arteries, augmentation of K(+)-induced relaxation was observed only in the DFA of ET rats, possibly due to the increased Na(+) conductance in CA myocytes. The increases in I(Kir) and K(+)-induced vasodilatation of the arteries of skeletal muscle suggest novel mechanisms of improved exercise hyperaemia with physical training. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|