Isolated longitudinal smooth muscle from guinea pig ileum exposed to a high potassium depolarizing medium exhibited a sustained increase in muscle tone and an increase in potassium efflux. When the concentration of calcium ion in the medium was elevated the increase in muscle tone was enhanced, but the change in potassium efflux was reduced slightly. Lowering the calcium concentration diminishe...

This study concerns the effects of ions on the shell-secreting membrane of clam mantles. The average resting potentials were --47 mV for freshwater mantles and --60 mV for marine mantles. Elevation of potassium in the absence of chloride gave a maximal slope of depolarization equivalent to 59 mV for a 10-fold change in the marine form but much less in the freshwater form. In normal potassium, a...

To determine whether or not the previously reported association between alcohol intake and high blood pressure is influenced by differential intake of calcium and potassium in drinkers compared with nondrinkers and to assess the magnitude of the independent contributions of alcohol, calcium, and potassium to blood pressure, these associations were evaluated in 7,011 men of Japanese descent. Cat...

The purpose of this study was to determine the mechanisms by which organic calcium channel blockers inhibit cerebral vasoconstriction. Isolated bovine middle cerebral arteries were cut into rings to measure contractility or into strips to measure radioactive calcium (45Ca) influx and efflux. Calcium channel blockers (10(-5) M verapamil or 3.3 X 10(-7) M nifedipine) and calcium-deficient solutio...

Cerebellar Purkinje neurons fire spontaneously in the absence of synaptic transmission. P/Q-type voltage-gated calcium channels and calcium-activated potassium channels are required for normal spontaneous activity. Blocking P/Q-type calcium channels paradoxically mimics the effects of blocking calcium-activated potassium channels. Thus, an important function of the P/Q-type calcium channels is ...

background: stroke is one of the leading causes of death and certainly the major cause of disability in the world. diet and nutrient has an effective role in prevention and control of the risk of stroke. the aim of this study was to review the studies on the relationship between dietary intake and stroke incidence. methods: in this study, the terms of “fat”, “cholesterol”, “antioxidant”, “vitam...

ATP-sensitive potassium (KATP) channel openers have a relaxation effect due to the lower cellular membrane potential and inhibit calcium influx. There has been considerable interest in exploring KATP channel openers in the treatment of various diseases such as cardiovascular, cerebrovascular, and urinary system disease and premature labor. The purpose of this study was to synthesize 3,3,6,6-tet...