Inotropic and anti-fatigue effects of the physiological molecules carnitine (C) and acetylcarnitine (AcC) have been widely described. We have here studied the effects of C and AcC on an in vitro smooth muscle preparation (urinary bladder strip of the rat) in which detrusor responses were measured as muscle tone and isometric contractions under electrical or cholinomimetic (muscarinic) stimulation. The results show that: (a) neither C nor AcC (up to 1 mM) have a direct mechanical effect on the detrusor; (b) the substances enhance the phasic responses to the electrical stimulation, given either with high (20-40 Hz) or with low frequency (2-5 Hz) pulse trains; (c) C and AcC enhance the phasic and also the tonic effect of the muscarinic agonist bethanechol. These biological actions - eliminated by TTX addition - seem to indicate that C and AcC increase the detrusor muscle responsiveness to cholinomimetic but also non-cholinomimetic activation. This inotropic effect can be explained by a metabolic action within the smooth muscle cell, while no evidence of a direct cholinomimetic effect has been found. These results could be of clinical relevance in cases of bladder voiding difficulties as seen after lesions of the CNS.
Effects of carnitine on detrusor muscle of urinary bladder / G. Monticelli, L. Provini. ((Intervento presentato al 11. convegno European winter conference on brain research tenutosi a Crans-Montana nel 1991.
Effects of carnitine on detrusor muscle of urinary bladder
G. MonticelliPrimo
;L. ProviniUltimo
1991
Abstract
Inotropic and anti-fatigue effects of the physiological molecules carnitine (C) and acetylcarnitine (AcC) have been widely described. We have here studied the effects of C and AcC on an in vitro smooth muscle preparation (urinary bladder strip of the rat) in which detrusor responses were measured as muscle tone and isometric contractions under electrical or cholinomimetic (muscarinic) stimulation. The results show that: (a) neither C nor AcC (up to 1 mM) have a direct mechanical effect on the detrusor; (b) the substances enhance the phasic responses to the electrical stimulation, given either with high (20-40 Hz) or with low frequency (2-5 Hz) pulse trains; (c) C and AcC enhance the phasic and also the tonic effect of the muscarinic agonist bethanechol. These biological actions - eliminated by TTX addition - seem to indicate that C and AcC increase the detrusor muscle responsiveness to cholinomimetic but also non-cholinomimetic activation. This inotropic effect can be explained by a metabolic action within the smooth muscle cell, while no evidence of a direct cholinomimetic effect has been found. These results could be of clinical relevance in cases of bladder voiding difficulties as seen after lesions of the CNS.Pubblicazioni consigliate
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