Stroke: Just a Chemistry

Stroke is a significant health issue with its neuropathological mechanisms requiring better understanding. Within the course of ischemic stroke, obstruction of a major brain artery results in an abrupt blood flow limitation below a critical threshold and focal ischemic brain insult arises. Chemical shift imaging using magnetic resonance spectroscopy and more advanced imaging methods have recently provided some novel insights into the chemistry of stroke. Given the fact that stroke disturbs the normal brain chemistry, assessing and perhaps targeting the metabolic pathways ought to be a practical and useful approach to better understand the neurobiochemical aspects of stroke. This perspective paper focuses on the evolving dimensions of neurochemical research in stroke.[GMJ.2016;5(2):49-55]

Lower Leg High-Intensity Resistance Training and Peripheral Hemodynamic Adaptations

High-intensity resistance (HIR) training has been associated with muscle hypertrophy and decreased microvascular density that might produce a blood flow limitation. The effect of HIR training on lower leg maximal blood flow and minimum vascular resistance (Rmin) during reactive hyperemia were investigated in 7 healthy males. The gastrocnemius-soleus muscles of one leg were trained using maximal isokinetic concentric contractions for 4 weeks; the nontrained leg was the control. Lower leg blood flow was measured by venous occlusion plethysmography. Lower leg muscle volume was determined using magnetic resonance imaging. Peak isokinetic torque increased in both the trained (T) and nontrained (NT) legs (p <.05). Lower leg muscle volume increased by 2% in the T leg only (p <.05). In the T leg, maximal blood flow decreased and Rmin increased (p <.05); no hemodynamic change was detected in the NT leg. It is concluded that HIR training of the calf muscles is associated with a decrease in hyperemia-induced blood flow; thereby, indicating a blood flow limitation to the calf muscles. Key words: Isokinetic strength training, reactive hyperemia