Hypertension and pathologic cardiovascular remodeling: a potential therapeutic role for T-type calcium antagonists

A model for the regulation of T-type Ca(2+) channels in proliferation: roles in stem cells and cancer

Ca(2+) influx at critical points in the cell cycle is required for proliferation. This requirement is so ubiquitous that its occurrence is often treated as background noise. Yet without it, cells stop dividing, suggesting an obvious and potentially effective way to treat cancer. To control proliferation by controlling Ca(2+) influx requires that the mechanism be elucidated, but this field of study has been filled with controversy and devoid of therapeutic utility. In this study, the authors present a model for the regulation of Ca(2+) influx at the G1/S restriction point in cancer and stem cells that is simple, cohesive and, we believe, reasonably complete. The model illustrates the essential role of T-type Ca(2+) channels in mediating influx and points clearly to the therapeutic strategies that have recently entered clinical trials.

Ion channels and the control of blood pressure

Ion channels exist in all cells and are enormously varied in structure, function and regulation. Some progress has been made in understanding the role that ion channels play in the control of blood pressure, but the discipline is still in its infancy. Ion channels provide many different targets for intervention in disorders of blood pressure and exciting advances have been made in this field. It is possible that new drugs, as well as antisense nucleotide technology or gene therapy directed towards ion channels, may form a new class of treatments for high and low blood pressure in the future.

Systemic availability of budesonide after nasal administration of three different formulations: pressurized aerosol, aqueous pump spray, and powder

AIMS

The present study was undertaken to determine the absolute systemic availability of budesonide from three different devices for nasal administration: pressurized aerosol, aqueous pump spray, and powder.

METHODS

Sixteen healthy, non-smoking, volunteers participated in this open, randomized, and crossover study. All subjects received budesonide as an intravenous dose of 400 microg, and as three, single-dose, intranasal administrations: pressurized aerosol 800 microg, aqueous pump spray 400 microg, and powder 800 microg. Blood was sampled for 10 h after each administration and budesonide was assayed in plasma by liquid chromatography plus mass spectrometry.

RESULTS

The mean [95% CI] systemic availability of budesonide with reference to the metered dose was: 13 [10; 15]%, 29 [23; 37]%, and 20 [16; 23]%, and the maximum plasma concentration (Cmax) was attained at (tmax) 2.0, 0.7, and 0.4 h after administration for the pressurized aerosol, aqueous pump spray, and powder, respectively.

CONCLUSIONS

The uptake of budesonide was more rapid and more complete, and the systemic availability of the drug was significantly higher from the aqueous pump spray and powder than from the pressurized aerosol.