QUANTITATIVE MEASUREMENT OF UTERINE RESPONSES USING THE STRAIN GAGE DYNAMOMETER, WITH NOTES ON THE EFFECT OF ANTI-HISTAMINIC DRUGS ON THE RABBIT MYOMETRIUM

¹ Department of Embryology, Carnegie Institution of Washington, Baltimore 5, Md.
² Sinai Hospital, Baltimore 5, Maryland

1. The method of using a strain gage dynamometer for quantitative study of pharmacological responses of the myometrium is described.

2. The method permits determination of the effect on tone and rhythmic contractility.

3. Results are obtained either as, (a) the percentage increase in activity (tone, contractility, total work), or (b) as dynes per gram of myometrium per minute (for tone, contractility, and total work).

4. Quantitative effects of Pitocin, Pyribenzamine, and Benadryl are cited.

5. The effect of the anti-histaminic drugs administered intravenously is oxytocic, the effect being greater with increased doses. With low doses, a period of diminished activity may follow the initial oxytocic response.

6. Tone and rhythmic contractility are equally affected by the anti-histaminic drugs.

7. The uterus distended by the products of conception is affected in a manner similar to the non-distended portion of the uterus of the same animal.

8. The hormonal status (pregnancy, non-pregnancy) of the rabbit does not affect the responsiveness of the uterus to Pyribenzamine.