The effect of carbonated soft drink components on isolated detrusor muscle contraction
thesisposted on 15.12.2014, 10:33 authored by Jaydip Dasgupta
The objective of our study was to investigate the hypothesis that carbonated soft drink components modulate detrusor muscle contraction. Strips of rat detrusor muscle were placed in an organ bath and stimulated with electrical field stimulation (EFS) in the absence and presence of atropine, and with alpha, beta methylene ATP, potassium, calcium and carbachol. The responses were repeated in the presence of carbonated soft drink components and the whole carbonated soft drink. The artificial sweeteners, ascorbic acid and critic acid (10-7 M to 10-2 M) enhanced the contractile response to 10 Hz EPS compared to control (p<0.01). The sweeteners (acesulfame K 10-6 M, aspartame 10-7M, sodium saccharin 10-7 M) increased the atropine resistant response to EFS marginally. Acesulfame K 10-6 M and sodium saccharin 10-7 M enhanced the maximum contractile response to alpha, beta methylene ATP, to KC1 and calcium significantly compared to control. Ascorbic acid significantly increased the atropine resistant response to EFS and inhibited contraction in response to carbachol. Both ascorbic acid and citric acid enhanced the contractile responses to alpha, beta methylene ATP, KC1 and calcium significantly compared to control. Whole carbonated soft drink (1:200) also enhanced the contractile responses to alpha,beta methylene ATP, KC1 and calcium. These results suggested that low concentrations of artificial sweeteners, ascorbic acid and critic acid, enhanced detrusor muscle contraction by augmenting Ca2+ influx by a mechanism yet to be defined. Western blot analysis suggested the presence of protein molecules in the rat bladder of similar size to the sweet taste receptor present in tongue. These data suggest that carbonated soft drink components may be acting via specific receptors to modulate the effects observed.