## 3 Results
### Tissue RAS-Regulating Enzyme Activities
#### 3.7.4 Hypothalamus  
Figure 14 presents the effects of the various beverage treatments on the RAS-regulating specific enzymatic activities in the hypothalamus of WKY and SHRs. In Figure 14A, the ACE activity shows significant differences between WKY and SHRs across several treatments. The ACE activity is significantly elevated in WKY animals treated with TW/NAB and AB compared to TW and NAB (\(p\) < 0.05 and 0.01), but decreased in WKY animals treated with TW/AB (\(p\) < 0.01). On the contrary, no significant differences appear in SHRs.  
For APA, no significant differences are observed either in the soluble or membrane-bound fractions either in WKY or SHRs (Figure 14B,C).  
Only soluble ASAP activities showed significant differences between groups. Thus, WKY animals receiving NAB or TW/NAB had significantly decreased soluble ASAP specific activities (\(p\) < 0.05), whereas SHRs receiving NAB or AB also showed a significant decrease (\(p\) < 0.01 and 0.05) (Figure 14D).  
Regarding soluble APN (Figure 14F), its specific activity was significantly increased or decreased in both rat strains depending on the beverage received. In WKY animals, NAB and TW/AB decrease the activity, whereas in SHRs, NAB increases it (\(p\)< 0.05 in all cases). In the membrane-bound fraction, the specific APN activity was only modified in WKY animals, where a significant decrease (\(p\) < 0.05 or 0.01) occurs with NAB, AB, and TW/AB (Figure 14G).  
Figure 13: (**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 lung 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-ß-naphthyl hydrolyzed per minute per milligram of protein (mean \(\pm\) SEM; n = 8; * \(p<\) 0.05; ** \(p<\) 0.01).  
Figure 14: (**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 hypothalamus 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; \({}^{*}p<0.05\); \({}^{**}p<0.01\)).  
Finally, soluble APB also exhibits significant changes in its specific activity, in a way similar to APN (Figure 14H). In the membrane-bound fraction, only WKY animals receiving NAB had a significantly decreased (\(p\) < 0.05) APB-specific activity (Figure 14I).