Topical amiloride solution accelerates healing of mechanical skin ulcers in albino rats

The present investigation was undertaken to explore the ulcer healing properties of three dosage schedules of various concentrations of topically administered amiloride solution in mechanically produced skin ulcers in albino rats. Four skin ulcers (two on either side of the midline) were made 2.5 cm apart on the preshaved back of each anesthetized rat with a round body skin biopsy punch (7 mm diameter) through the dermis to the depth of subcutaneous tissue. The animals were randomly divided into groups of 5 rats each. Ulcers on one side of the midline were treated with normal saline and served as control, whereas those on the other side were treated with amiloride solutions. Each ulcer was observed for its size, slough formation and any sign of irritation on alternate days until healing was complete. Healing of ulcers was significantly accelerated with all the strengths of amiloride (0.01, 0.02 and 0.04%) in all the dosage schedules (o.d., b.i.d. and q.i.d.) in terms of days required for complete healing, ulcer size and area under the size-time curve. This acceleration was dose-dependent with maximum effect at b.i.d. administration of 0.04% solution. No irritation or suppression of immunity was noticeable. Thus topical amiloride may prove to be an inexpensive and better ulcer healing agent with no apparent side effects. Inhibition of u-PA by amiloride seems to be responsible for this effect.