A Study On Morphology Of Normal Male Canine Prostatic Duct And Acinus System

Objective To investigate the three-dimensional structure of normal male canine prostatic duct and acinus system and to study the anatomic mechanism of intraprostatic urinary reflux(IPUR) resulting from high pressure of the posterior urethra by experiment. To offer intuitionistic steric mold for anatomy. Then imaginarily reconstruct computerized the three-dimensional mold image of male canine prostatic duct and acinus system based on the resin casting of normal male canine prostatic duct and to further study the relationship of prostatitis with threedimensional structure of prostatic duct.Methods Using scanning electron microscopy(SEM) and corrosion casting methods, high pressure of the prostatic urethra was produced based upon IPUR in normal male canines. Acrylonitrile-butadiene-styrene(ABS) casting solution was injected into 8 Beagle canines' normal prostates to induce intraprostatic resin solution reflux. General samples were observed with anatomic megaloscope and taken pictures with high-resolution digital camera. Partial duct specimens were collected and mounted on cuprum stubs and studied by SEM. Observation and measurement were carried out and photographs were taken with an JSM-6700 Field Emission. According to the three-dimensional structure of casting duct and acinus system, drew the cross-section images of prostatic duct and reconstructed the three-dimensional mold images of male canine prostatic duct and acinus system by using Photoshop7.0 and 3DDOCTOR software.Result Six casting molds of normal canine prostate specimens were obtained,and the casting failed in 2. By corrosin and casting treatment, the prostate appeared to consist of several glandular lobes. The columnar apophyses of glandular surface were observed. The most glandular ducts point outward from urethral peristome. Each glandular duct system was made up of many bifurcated branches from the bough as a duct tree. More than 90% of the bifurcations were Y-shaped,and 6 bifurcated branches were rarely seen.The tip of the duct was vesicular.The diameter and length of the bough were (0.37±0.14)㎜ and (1.14±0.04)㎜,respectively. The intersectional angle of urethra and peripheral glandular duct was the biggest. Peripheral glandular duct was perpendicular or converse to urinary flow. Peripheral glandular acinus appeared elliptic and velvet. The mesh-like and crater-like depression were shown on the surface of central glandular acinus. Ejaculatory duct independently and branchlessly entered the urethra. The diameter of peripheral glandular terminal duct was (70.28±14.05)μm. The diameter and area of peripheral glandular acinus were (97.32±13.43)μm and (7.60±2.10)×103μm2 respectively. The diameter of central glandular terminal duct was (131.85±14.88)μm. The diameter and area of central glandular acinus were (115.98±15.73)μm and (10.73±2.81)×103μm2 respectively.160 cross-sectional pictures and one three-dimensional reconstructional mold of canine prostatic duct were obtained. 20 different rotated directional mold pictures were saved. The three dimensional reconstructional mold image can clearly show the three-dimensional structure of canine prostatic duct and anatomical relation of urethra and duct including ejaculatory duct. The threedimensional mold image can rotate in different direction.Conclusion The resin corrosion casting methods combined with SEM can clearly show the three-dimensional structure of normal male canine prostatic duct and acinus system.According to the three-dimensional structure of casting duct and acinus system, the anatomical relation of urethra and prostatic duct was reconstructed. Peripheral glandular duct was perpendicular or converse to urinary flow. IPUR may easily occur in the peripheral gland from the prostatic duct anatomic morphological view. It is suggested that prostatitis occurs more commonly in peripheral gland,confirming a fact that high pressure of the posterior urethra can induce IPUR.