Yc. Tong et al., EVIDENCE OF NONADRENERGIC, NONCHOLINERGIC CONTRACTION IN RAT URINARY-BLADDER BY 1,1-DIMETHYLPHENYLPIPERAZINIUM STIMULATION IN-VIVO, European urology, 29(3), 1996, pp. 362-365
Nonadrenergic, noncholinergic (NANC) contraction has been demonstrated
in animal urinary bladder. However, the exact nature of the NANC inne
rvation is still unclear. 1,1-Dimethylphenylpiperazinium (DMPP), which
generates action potentials in the cell body of the postganglionic ne
uron and causes neurotransmitter release (both acetylcholine and norad
renaline), was given intravenously (0.1-0.7 mg/kg) to 3-month-old fema
le Wistar rats under anesthesia (n = 20). Intravesical pressure, heart
rate and blood pressure of the rats were monitored on Gould polygraph
. Monophasic dose-dependent contractile response was observed upon adm
inistration of DMPP in 12 of 20 rats. After total adrenergic and choli
nergic blockade with atropine, guanethidine, phentolamine and proprano
lol, the contractile response was reduced, not completely, in the anim
als. At the dose of 0.7 mg/kg, the contraction was reduced to about 48
% of the original response. The study provides in vivo evidence for NA
NC contraction in the rat urinary bladder; moreover, the neurotransmit
ter is released from the postganglionic neurons.