TCAS 02. The role of bilateral major pelvic ganglia in the neural pathway of electrical stimulation of lesser splanchnic nerve-induced seminal vesical pressure increase in the rat

The results of our previous study suggested that electrical stimulation of the lesser splanchnic nerve (LSN) or major pelvic ganglion (MPG) may elicit a simultaneous significant similar increase of seminal vesical pressures (SVP) on each side seminal vesicle in the rat. The aim of this study was to investigate the role of bilateral major pelvic ganglia (MPG) in the neural pathway of electrical stimulation of LSN-induced SVP increase in the rat.

Male adult Sprague-Dawley rats were used. A PE50 tube was inserted into each side seminal vesicle to simultaneously monitor each side SVP. The MPG and LSN were electrically stimulated with stimulus parameters (10 V, 40 Hz, 1 ms, 60 seconds), respectively. Then the right MPG was resected and the LSN was electrically stimulated. Following resection of right MPG, the left MPG was also resected and the LSN was electrically stimulated again. The amount of SVP increase was calculated by subtracting resting SVP from peak SVP. The amount of SVP increase between left and right side was compared with Mann-Whitney U test.

There was a comparable amount of SVP increase at left and right side after electrical stimulation of right MPG (left 60.3± 8.2 mmHg and right 61.1± 6.3 mmHg, respectively, P=0.818) and LSN (56.4±9.8 mmHg and 44.7±8.5 mmHg, respectively, P=0.310), respectively. After resection of right MPG followed by electrical stimulation of LSN, again there was a comparable amount of SVP increase at left and right side. However, there was no change of SVP at each side of seminal vesicle (resting SVP 3.3± 0.7 mmHg vs. peak SVP 3.3±0.7 mmHg at left side; resting SVP 7.7±2.1 mmHg vs. peak SVP 7.7±2.1 mmHg at right side, respectively) after resection of bilateral MPG followed by electrical stimulation of LSN.

The results suggest that electrical stimulation of the MPG and LSN may induce a simultaneous significant, comparable amount of SVP increase on the left and right side seminal vesicle in the rat. This electrical stimulation of LSN-induced bilateral SVP increase is eliminated after resection of bilateral MPG. This implies that the neural pathway of electrical stimulation of LSNinduced SVP increase is through at least one side MPG in the rat.