A dual 5α-reductase inhibitor dutasteride caused reductions in vascular density and area in benign prostatic hyperplasia

Abstract

Objectives. Dutasteride, a dual 5α-reductase inhibitor, is used to treat benign prostatic hyperplasia. Nevertheless, its histopathological effects on the morphometrics of blood vessels and glands are still controversial. The aim here was to assess the histopathological effects of dutasteride in cases of benign prostatic hyperplasia in a retrospective study. Methods. Patients with benign prostatic hyperplasia more than 40 cm(3) in prostatic volume were administered 0.5 mg of dutasteride daily or left untreated prior to receiving a transurethral resection of the prostate. Images of sections stained with hematoxylin/eosin and with anti-CD31 antibody were analyzed. Results. In the dutasteride-treated group, the duration of administration was 16.3 ± 8.1 weeks. Artery/arteriole density and vein/venule density in benign prostatic tissue were both lower in the dutasteride-treated group than in the control group. The vein/venule area as a percentage of the whole area was also lower in the dutasteride-treated group, while the artery/arteriole area did not show a significant difference. Glandular/CD31-expressing vessel densities as well as glandular/CD31-expressing vessel areas were comparable between the two groups. Conclusions. Dutasteride reduced the artery/arteriole and vein/venule densities and the proportion of vein/venule area in the tissue of patients with benign prostatic hyperplasia.

Figure 1

Histogram of calculated diameters of vascular vessels. Horizontal line: diameters of lumens, blue bars: CD31-expressing vessels, and red bars: artery/arteriole and vein/venule. The difference in the number of vessels detected either with hematoxylin/eosin staining or with CD31 staining was more in vessels whose diameters were less than 100 μm compared with larger vessels.

Figure 2

Upper panels: a representative light micrograph of a resected prostatic chip. Upper panels: hematoxylin and eosin staining; Lower panels: Elastica Van Gieson staining. A: artery/arteriole, V: vein/venule, G: gland, and bar = 1000 μm.

Figure 3

A representative image of a resected prostatic chip stained with the anti-CD31 monoclonal antibody, bar = 1000 μm.

Figure 4

(a) The correlation between AD and the duration of administration of dutasteride. AD: artery/arteriole density, P = 0.099. (b) The correlation between AA and the duration of administration of dutasteride. AA: artery/arteriole area as a proportion of the whole area. P = 0.089. (c) The correlation between VD and the duration of administration of dutasteride. VD: vein/venule density, P = 0.002. (d) The correlation between VA and the duration of administration of dutasteride. VA: vein/venule area as a proportion of the whole area. P = 0.003. Data for BPH tissues in the control group are plotted as duration 0. P values are for the Spearman's rank correlation test. A least squares regression line was drawn for each panel.