Reproducibility and consistency of the responses to supine bicycle ergometry; evaluation in conjunction with beta 1‐adrenoceptor occupancies.

Abstract

A protocol is presented for supine bicycle ergometry in healthy subjects, which aims for a target increase of heart rate (HR = 140 beats min‐1) after 4 min cycling under constant load. The required load is selected from a pre‐study ergometry with stepwise increasing load. Repeated testing with this protocol was shown to yield highly reproducible ergometric HR‐responses. Because of their high reliability, the ergometric endpoints and increments permit a highly sensitive comparison of beta 1‐adrenoceptor antagonism across dose and time within a given compound. The relationship between the changes of the ergometric rise of HR and the beta 1‐adrenoceptor occupancy (estimated from radioreceptor assay data) permits to evaluate the ergometric efficiency of different beta‐adrenoceptor antagonists across time and doses and to identify eventual differences that do not relate primarily to the extent of beta 1‐adrenoceptor antagonism itself. 1994 The British Pharmacological Society