passages.id: BioInfer.d419.s0__text
passages.type: Sentence
passages.text: METHODS AND RESULTS: The frequency-dependent effects of iodotubercidin (ITU, an inhibitor of adenosine kinase), erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA, an inhibitor of adenosine deaminase), draflazine (a nucleoside transport blocker), and PD81,723 (an allosteric enhancer of the A1 adenosine receptor binding) on the stimulus-to-His bundle (SH) interval, a measure of AV nodal conduction, were determined in guinea pig hearts and compared with those of adenosine and diltiazem.