Studies on Pituitary Adrenocortical Function in Asthmatics : II. Experimental Research

Abstract

For the purpose of clarifying the etiological factor of pituitary adrenocortical hypofunction in asthmatics, plasma cortisol levels were measured in 109 male guinea pigs treated with inhalation of histamine solution and/or administration of dexamethasone for 1, 4 and 7 months. The experiments gave the following results. 1) In the three groups with experimentaly induced asthma provoked by inhalation of histamine solution every day for 1, 4 and 7 months, no differences of cortisol levels in the plasma were observed. 2) In the three groups treated with inhalation of histamine solution once a week for 1, 4 and 7 months, no differences of cortisol levels in the plasma were observed. 3) In the three groups treated with the subcutaneous administration of dexamethasone every day for 1, 4 and 7 months, a significant decrease of cortisol levels in the plasma was observed in the group treated for 1 month, but cortisol levels of the other two groups were within normal range. 4) In the groups treated with both inhalation of histamine solution and subcutaneous administration of dexamethasone every day for 1 and 4 months, plasma cortisol levels were within normal range, but a significant decrease of plasma cortisol levels was observed in cases with treatment for 7 months. From these results, it seemed that pituitary adrenocortical function in asthmatics was suppressed due to cumulative actions of both recurrence of the respiratory distress of asthmatic attack and administration of a small dosage of steroids during a long suffering time.