Abstract
The age-related changes in the density of alpha1-adrenoceptors in the dorsolateral lobe of the rat prostate were evaluated in Wistar rats at 8, 52, and 104 weeks of age. [3H]YM617, a newly senthesized alpha1-adrenergic blocker, was used as the ligand. The mean maximum number of binding sites, or alpha1-adrenoceptor density (Bmax)±SE of 104-week-old rats (11.0±1.2 fmol/mg protein) was significantly lower than that in the 8-week-old rats (37.0±4.3 fmol/mg protein) and 52-week-old rats (37.2±3.4 fmol/mg protein) respectively, P<0.01. In contrast, mean affinity (Kd) values±SE of these groups showed no significant differences (8-week-old rats, 115.8±9.1; 52-week-old rats, 100.5±5.8; and 104-week-old rats, 116.4±9.8 pM). Mean volumes±SE of muscle cells of the prostate were 3.7±1.1x103 μm3 at 8 weeks, 30.0±6.2x103 μm3 at 52 weeks, and 18.6±8.2x103 μm3 at 104 weeks. Volumes for 8-week-old rats were significantly smaller than those for 52-week-old (P<0.01) and 104-week-old rats (P<0.05). However, the mean area density of the muscle cells showed no difference among the three groups: 20.1±2.2% at 8 weeks, 27.3±2.9% at 52 weeks and 20.3±3.4% at 104 weeks. In conclusion, the density of YM617-binding sites (alpha1-adrenoceptors) in 104-week-old rats was lower than in 8- and 52-week-old rats. Muscle volume in the rat prostate was larger in rats aged 52 and 104 weeks than in 8-week-old rats, but no correlation was found between alpha1-adrenoceptor density and the muscle volume or muscle density in aging.
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Moriyama, N., Kurimoto, S., Nagase, Y. et al. Age-related changes in alpha1-adrenoceptors in rat prostate. Urol. Res. 22, 389–392 (1995). https://doi.org/10.1007/BF00296882
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DOI: https://doi.org/10.1007/BF00296882