Related Experiment Videos
A time correlation study between reflectance spectroscopic cutaneous vasoconstriction and plasma corticosteroid
1Department of Dermatology, University of California, School of Medicine, San Francisco 94143-0989, USA.
The British Journal of Dermatology
|January 1, 1995
Summary
Corticosteroid skin blanching shows a dual vascular reaction. Initially, vasoconstriction occurs, followed by paradoxical vasodilation as exposure time increases, impacting drug delivery assessments.
Area of Science:
- Dermatology
- Pharmacology
- Biophysics
Background:
- Cutaneous vasoconstriction assays are standard for evaluating corticosteroid efficacy and drug delivery.
- The relationship between skin blanching response and corticosteroid concentrations in plasma or tissue is poorly understood.
Purpose of the Study:
- To investigate the correlation between skin blanching reactions and plasma betamethasone concentrations.
- To explore the dual vascular effects of corticosteroids on dermal vessels over time.
Main Methods:
- Utilized an improved reflectance spectroscopic method to measure cutaneous vascular reactions in five volunteers.
- Employed radioimmunoassay to quantify plasma betamethasone concentrations.
- Used a specially developed betamethasone-17-valerate patch for constant corticosteroid release.
Main Results:
- Maximal skin blanching occurred at 12 hours post-application, while plasma concentrations peaked later at 32 hours.
- A paradoxical telangiectatic vasodilatation was observed, peaking at 72 hours, concurrent with rising plasma corticosteroid levels.
- Both vasoconstriction and vasodilatation were linked to changes in arterial hemoglobin (Oxy Haem).
Conclusions:
- Corticosteroids exhibit a dual vascular effect on dermal vessels, dependent on time and concentration.
- Lower concentrations/shorter exposure (6-12h) induce vasoconstriction.
- Prolonged exposure (> or = 24h) leads to paradoxical vasodilatation, even as plasma levels continue to rise.