## 3 Results
### Tissue RAS-Regulating Enzyme Activities
#### 3.7.9 Testis  
Figure 19 presents the enzymatic activities of the RAS in the testis of WKY and SHRs under the different experimental conditions, that is, receiving TW, NAB, TW/NAB, AB or TW/AB.  
In WKY animals, the ACE activity is significantly decreased in animals receiving NAB (\(p<0.05\)), TW/NAB (\(p<0.01\)) and TW/AB (\(p<0.05\)). In SHRs, significant ACE activity was found in animals receiving AB (\(p<0.05\)) or TW/AB (\(p<0.05\); Figure 19A).  
For APA-specific activities, both the soluble (Figure 19B) and membrane-bound (Figure 19C) forms showed no significant differences between WKY and SHRs across all groups.  
Figure 18: (**A**) Angiotensin-converting enzyme (ACE) activity, and specific activities of soluble (**B**) and membrane-bound (**C**) aminopeptidase A (APA), soluble (**D**) and membrane-bound (**E**) aspartyl aminopeptidase (ASAP), soluble (**F**) and membrane-bound (**G**) aminopeptidase N (APN), and soluble (**H**) and membrane-bound (**I**) aminopeptidase B (APB) in the adrenal medulla of Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHRs). Experimental groups included animals provided with tap water (TW), alcohol-free beer (NAB), tap water or alcohol-free beer at their discretion (TW/NAB), alcoholic beer (AB), or tap water and alcoholic beer at their discretion (TW/AB). Results are presented as ACE activity in IU/L, and for APA, ASAP, APN and APB, in picomoles of the corresponding aminoacyl-\(\beta\)-naphthyllamide hydrolyzed per minute per milligram of protein (mean \(\pm\) SEM; \(n\) = 8; \({}^{*}\)\(p<0.05\); \({}^{**}\)\(\ast\)\(p<0.01\)).  
Figure 19: (**A**) Angiotensin-converting enzyme (ACE) activity, and specific activities of soluble (**B**) and membrane-bound (**C**) aminopeptidase A (APA), soluble (**D**) and membrane-bound (**E**) aspartyl aminopeptidase (ASAP), soluble (**F**) and membrane-bound (**G**) aminopeptidase N (APN), and soluble (**H**) and membrane-bound (**I**) aminopeptidase B (APB) in the testis Wistar–Kyoto rats (WKY) and spontaneously hypertensive rats (SHRs). Experimental groups included animals provided with tap water (TW), alcohol-free beer (NAB), tap water or alcohol-free beer at their discretion (TW/NAB), alcoholic beer (AB), or tap water and alcoholic beer at their discretion (TW/AB). Results are presented as ACE activity in IU/L, and for APA, ASAP, APN and APB, in picomoles of the corresponding aminoacyl-\(\beta\)-naphthyl hydrolyzed per minute per milligram of protein (mean \(\pm\) SEM; n = 8; *_p_ \(<\) 0.05; **_p_ \(<\) 0.01).  
The soluble ASAP activity (Figure 19D) only showed significant differences in WKY animals receiving TW/NAB compared to animals receiving TW/AB (\(p<0.05\)), whereas SHRs did not show significant changes. On the contrary, the membrane-bound ASAP activity did not change in WKY animals, but significantly increased in SHRs receiving AB (\(p<0.05\); Figure 19E).  
APN only showed significant changes in its soluble form and in SHRs, but not in the membrane-bound form or WKY animals. Thus, a significant decrease in the soluble specific APN activity (\(p<0.05\)) was found in SHRs receiving TW/AB (Figure 19F).  
Similar results were found for APB activity. While no significant changes were observed in the membrane-bound specific activity either in WKY or SHRs (Figure 19I), a significant increase was found in WKY animals receiving TW/NAB (\(p<0.01\)) or AB compared to NAB (\(p<0.01\); Figure 19H). Regarding SHRs, a significant decrease in the soluble APB specific activity was also found after TW/AB intake (\(p<0.01\)).