[Pathological changes of benign hyperplastic prostate after removal of innervation of cholinergic pelvic nerve: experiment with spontaneous hypertension rats].

ABSTRACT

OBJECTIVE: To study the pathological change of benign hyperplastic prostate after removal of the innervation of cholinergic parasympathetic pelvic nerve. METHODS: Sixty-five male spontaneous hypertension rats (SHRs) were randomly assigned into 3 groups operation group (n = 30) undergoing truncation of bilateral originating branches of parasympathetic pelvic nerve of major pelvic ganglion (MPG) followed by cystostomy, sham operation group (operation control group, n = 30) undergoing cystostomy, and normal control group (n = 5) not undergoing operation. 3, 7, 11, 15 and > or = 21 days after operation 6 rats from the 2 operation groups and 1 from the control group were sacrificed to observe the gross morphology and histological and cellular changes of the prostate glands. RESULTS: The prostate of the operation group on post-operational day 7 showed mild granular solidification and such change progressed gradually over time, the ratio of prostate wet weight/rat body weight was (0.4764 +/- 0.0125) mg/g on day 3, then gradually decreased, and became (0.2749 +/- 0.0197) mg/g > or = 21 days post-operationally; while the ratio of prostate tissue dry weight/wet weight on day 3 was (0.1966 +/- 0.0062), then gradually increased, and became (0.2596 +/- 0.0035) > or = 21 days post-operationally. HE staining showed that the glandular structure gradually became dilated and rounded, with accumulation of prostatic fluid. The glandular epithelial cells showed gradual degeneration, necrosis, and detachment. The glandular epithelium became progressively thinner, the smooth muscles elongated and thinned progressively, and the stromal components showed mild to moderate overgrowth. Electron microscopy showed that the glandular cells gradually underwent vacuolar degeneration and the structures of the basement membrane became fuzzy. The smooth muscle cells degenerated mildly, and the fibroblasts and collagenous fibers in the stroma overgrew slowly. All these histological changes were not found in the sham operation control and normal control groups. CONCLUSION: Remarkable atrophy occurs in benign hyperplastic prostatic gland after radical removal of the innervation of cholinergic parasympathetic pelvic nerve. Such operation may represent a novel therapy for BPH.