title: Similar enhancement of BK(Ca) channel function despite different aerobic exercise frequency in aging cerebrovascular myocytes.
abstract: Aerobic exercise showed beneficial influence on cardiovascular systems in aging, and mechanisms underlying vascular adaption remain unclear. Large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels play critical roles in regulating cellular excitability and vascular tone. This study determined the effects of aerobic exercise on aging-associated functional changes in BK(Ca) channels in cerebrovascular myocytes, Male Wistar rats aged 20-22 months were randomly assigned to sedentary (O-SED), low training frequency (O-EXL), and high training frequency group (O-EXH). Young rats were used as control. Compared to young rats, whole-cell BK(Ca) current was decreased, and amplitude of spontaneous transient outward currents were reduced. The open probability and Ca(2+)/voltage sensitivity of single BK(Ca) channel were declined in O-SED, accompanied with a reduction of tamoxifen-induced BK(Ca) activation; the mean open time of BK(Ca) channels was shortened whereas close time was prolonged. Aerobic exercise training markedly alleviated the aging-associated decline independent of training frequency. Exercise three times rather than five times weekly may be a time and cost-saving training volume required to offer beneficial effects to offset the functional declines of BK(Ca) during aging.
authors.affiliation: Institute for Fetology, First Hospital of Soochow University, Suzhou, China, Department of Exercise Physiology, Beijing Sport University, Beijing, China. l_j_shi72@163.com.
authors.forename: N
authors.initials: N
authors.lastname: Li
authors.forename: B
authors.initials: B
authors.lastname: Liu
authors.forename: S
authors.initials: S
authors.lastname: Xiang
authors.forename: L
authors.initials: L
authors.lastname: Shi
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure; D001835:Body Weight; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000378:metabolism*; D008297:Male; D020768:Middle Cerebral Artery / Q000378:metabolism*; D032342:Muscle Cells / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D017208:Rats, Wistar
chemical_list: D051036:Large-Conductance Calcium-Activated Potassium Channels