Age-related changes in cholinergic and purinergic neurotransmission in human isolated bladder smooth muscles

We evaluated the correlation among age, cholinergic and purinergic neurotra nsmissions in the electrical field stimulation-induced contractions in huma n isolated urinary bladder smooth muscles, using the muscle bath technique. Human bladder specimens were divided into three groups (G1, under 50 years ; G2, 51-70 years; G3, over 70 years old), and each muscle strip was suspen ded in a thermostatically controlled organ bath filled with oxygenated Kreb s-Henseleit solution, connected to an isometric force displacement transduc er, and an isometric tension development was recorded. The contractile resp onses induced by KCl, carbachol, adenosine triphosphate (ATP) and electrica l field stimulation, and the effects of atropine and alpha, beta methylene ATP on electrical field stimulation-induced contractions were observed. The contractile response to KCl and concentration-response curves for carbacho l and ATP, and frequency-response curves for electrical field stimulation w ere not significantly different among the three groups. The atropine sensit ive and resistant parts of contraction induced by electrical held stimulati on were decreased and increased with age, respectively. There are significa nt positive and negative correlations between age and the purinergic, and a ge and the cholinergic neurotransmissions in human isolated bladder smooth muscles, respectively. The age-related changes in neurotransmissions may co ntribute to the changes in bladder function in the elderly. (C) 2001 Elsevi er Science Inc. All rights reserved.