Effect of anoxia-glucopenia and re-superfusion on intrinsic nerves of mammalian detrusor smooth muscle: importance of glucose metabolism.

AIMS

To investigate the effect of anoxia/glucopenia and re-superfusion on intrinsic nerves in the mammalian urinary bladder.

METHODS

Strips of detrusor smooth muscle were dissected from monkey and human urinary bladder and mounted for tension recording in organ baths superfused with Krebs solution. Human, monkey, and guinea-pig urinary bladders were treated to evaluate glycogen contents by a biochemical method.

RESULTS

Detrusor strips from both monkeys and humans had to be exposed to anoxia-glucopenia for up to 2-2.5 hr to observe a progressive decline in the response to electrical field stimulation (EFS) of the intrinsic nerves, at variance with guinea-pig detrusor strips. In contrast, the response to direct activation of the smooth muscle with carbachol remained almost unaltered. Incubation of human and monkey detrusor strips with 2-deoxyglucose (2-DG) during 1 hr anoxia-glucopenia, however, caused a marked damage to the intrinsic nerves. The glycogen contents of both human detrusor specimens and monkey urinary bladders were 2.0- and 1.4-fold higher, respectively, than that found in guinea-pig urinary bladder; furthermore, untreated monkey detrusor sections showed a greater number of glycogen granules as compared to those subjected to anoxia-glucopenia and re-superfusion. In guinea-pig and in monkey detrusor sections glycogen granules were found in smooth muscle cells but not in neurons of intramural ganglia.

CONCLUSIONS

A higher susceptibility of guinea-pig as compared to monkey and human nerves has been demonstrated; it is suggested that anaerobic glucose metabolism during anoxia-glucopenia is crucial for the functional recovery of detrusor intrinsic nerves from damage caused by anoxia-glucopenia and re-superfusion.