Action of Theelol (Tri-Hydroxy-Oestrin) on Uterine Fistulae in the Unanesthetized Rabbit

Abstract

The present paper presents observations relating to the effect of theelol (tri-hydroxy-oestrin) on the quiescent non-gravid uterine fistula of the castrated adult rabbit. The method of recording such contractions has been described. 1 , 2 The data embody observations following the intravenous and subcutaneous administration of theelol (Parke, Davis and Co.) totalling 19 times in 8 rabbits. The uterine response to theelol was as follows:

Intravenous Administration. Three castrated rabbits with quiescent uteri were treated with theelol as follows: Four divided doses covering 8 hours were given and records of motility obtained before, during, and from 24 to 48 hours following the injections. The amount injected was comparable to the threshold amounts of theelin (keto-hydroxy-oestrin) similarly administered as reported before. 3 In each of the records of the present series, a beginning of rhythmical motility by 10 hours following the first injection occurred and by 24 hours the contractions were of duration, amplitude and frequency which was entirely comparable to and indistinguishable from those which follow intravenous administration of theelin. Moreover, they were similar to the contractions one usually sees in “oestral” rabbits. 3 The waning of the action of theelol was likewise similar to that following administration of theelin, occupying a second 24 hours or more.

Subcutaneous Administration. The rabbits used in this work were intended primarily for drug studies on the effects of certain calcium salts on the uterus. It was desired, therefore, to have “standard” animals which were easily procurable and ready for use within a day or so. Inasmuch as one cannot safely predict the sexual state of intact rabbits unless they happen to be post partum and so possibly in heat, we decided to employ recently castrated (3 days to a week or 2) rabbits with uterine fistulae already prepared.