1. Continuous infusion of adrenaline in the cat
produces over a wide range of doses a plateau
response both in the nictitating membrane and
2. This indicates that enzyme saturation does not
occur even with large doses (correction of conclusion
of Clark and Raventos, 19394).
3. The relation between the continuous and equivalent quick dosage shored that the amount cleared
per minute varied as (concentration present)²/³.
4. Such a form of clearance was also found by
dosage- duration relation as it showed a linear
relation between (dose)¹/³ and the duration of
5. The mathematical calculations of the course of
cumulation and clearance of adrenaline made by
means of the formulae derived from the above
relation approximate with the observed results.
6. Mathematical methods calculating the clearance
of adrenaline from its pharmacological effects on
the blood pressure and nictitating membrane of cat
have been used to study the effects of drugs which
inhibit its destruction.
7. The rate of clearance of adrenaline calculated
was diminished to about 40 per cent. by pyrogallol
and to 55 per cent. by cocaine, but was not
affected by ascorbic acid.
8. Large doses of cocaine inhibited the effect of
large doses of adrenaline on the nictitating
9. None of the enzyme inhibitors tested altered
the relation found, i.e. continuous dose of
adrenaline varies as (quick dose)¹/³.
10. The failure of ascorbic acid to prolong the
action of adrenaline was not due to its destruction,
since its presence in the tissues in adequate
concentration (0.15 per cent.) was demonstrated