Muscarinic Cholinergic Receptors in Bladder Exstrophy

Abstract

The surgical management of classical bladder exstrophy should be influenced by the inherent detrusor function of the exstrophied bladder. Up until the last decade, the biochemical and neurophysiological properties of the exstrophied bladder had never been studied. Our study using radioligand receptor binding techniques was the first investigation to compare the density and equilibrium dissociation constant of muscarinic cholinergic receptors in control and exstrophy bladders. The density of muscarinic cholinergic receptors in the control and exstrophy groups was 1.97 ± 0.29 and 1.44 ± 0.21 fmol. per.μg. DNA (mean ± S.E.M.), respectively. The dissociation constant of the control and exstrophy groups was 0.15 ± 0.02 and 0.14 ± 0.02 nM. (mean ± S.E.M.), respectively. The data show that the muscarinic receptor density and binding affinity in control and exstrophy bladders are similar. Therefore, the neurophysiological composition of the exstrophied bladder is not significantly altered during the anomalous development. Quantitative morphometric studies suggest that the closed bladder sxstrophy has a cellular composition that is similar to control bladders. Our findings together with these morphometric studies suggest that patients with bladder exstrophy should have normal detrusor contractility if successful bladder closure and subsequent bladder neck reconstruction are ultimately achieved.