NEURAL INPUT REGULATES TISSUE NGF AND GROWTH OF THE ADULT-RAT URINARY-BLADDER

To gain insight into the effect of innervation on neurotrophin product ion, NGF levels in the urinary bladder were measured following unilate ral ganglionectomy (bladder denervation)or separation of the post-gang lionic bladder neurons from the central nervous system of the adult ra t (bladder and ganglion decentralization). These interruptions of the neural input to half of the bladder caused histological evidence of sm ooth muscle growth, increased bladder weight (denervation-3 weeks: 98. 6 +/- 6 mg; decentralization-3 weeks: 94.0 +/- 7 mg vs. control: 79.6 +/- 4 mg, P < 0.05), transient increases in tissue NGF up to 10-fold ( 1.99 +/- 0.65 pg NGF/bladder control vs. 20.24 +/- 0.53 (P < 0.05) den ervated, ipsilateral, 1 week) and hypertrophy of the neurons in the pe lvic ganglia supplying the bladder (control: 340 +/- 4.4 mu m(2); dene rvated-3 weeks: 530 +/- 6.8 mu m(2), P < 0.05; decentralized-3 weeks: 463 +/- 6.8 mu m(2), P < 0.05). These data suggest that neural input h as a significant role in regulating growth of the bladder. Furthermore , the findings show that innervation influences tissue levels of NGF i n the bladder.