HYPERTROPHIC NEURONS INNERVATING THE URINARY-BLADDER AND COLON OF THESTREPTOZOTOCIN-DIABETIC RAT

Female rats were made diabetic with an intravenous injection of strept ozotocin (STZ) producing bladder hypertrophy. Using fluorescent dyes i njected into the bladder or the colon, we have measured the size of ne urons in various ganglia associated with these organs in control and S TZ-diabetic rats. These include (1) postganglionic neurons in the pelv ic ganglion, (2) postganglionic neurons in the inferior mesenteric gan glion, (3) dorsal root ganglion neurons, (4) sympathetic chain ganglio n neurons, (5) preganglionic neurons in the sacral parasympathetic nuc leus, (6) motor neurons in Onuf's nucleus innervating the external ure thral sphincter. In addition we have measured neurons in some of these groups for rats which have been maintained on a 5% sucrose in water a nd restricted food diet. In the STZ-diabetic animals only those neuron s which make direct contact with the bladder or the colon were found t o be hypertrophied (15-70%). In the diuretic animals, only neurons dir ectly innervating the bladder exhibited hypertrophy. We speculate that a trophic factor transported from the organ to the neuron is responsi ble for this effect.