Evidence for recurrent laryngeal nerve contribution in motor innervation of the human cricopharyngeal muscle.

Objective: To study the functional motor nerve supply of the upper esophageal sphincter in humans.

Study Design: Intraoperative electromyographic study.

Methods: The contribution of the recurrent laryngeal nerve and the pharyngeal plexus in the motor nerve innervation of the cricopharyngeal muscle and the inferior pharyngeal constrictor muscle was examined intraoperatively.

Xanthine oxidoreductase activity in perfused hearts of various species, including humans.

Oxygen free radicals generated by xanthine oxidase have been implicated in cardiac damage. The activity of xanthine oxidase/reductase in adult rat heart is considerable. Its assay gives controversial results for other species, for example, rabbits and humans.

Myocardial adenosine cycling rates during normoxia and under conditions of stimulated purine release.

Formation and rephosphorylation of adenosine (adenosine cycling) was studied in isolated rat hearts during normoxia and under conditions of stimulated purine formation. Hearts were infused with an inhibitor of adenosine kinase (5-iodotubercidin, 2 microM). In addition, perfusions were carried out with or without acetate, which is converted into acetyl-CoA, with simultaneous breakdown of ATP to AMP and purines.