Sheep testicular and epididymal angiotensin converting enzyme: inhibitions by captopril, lisinopril and enalapril

Abstract

Inhibition of angiotensin converting enzyme(ACE) in presence of captopril(C), lisinopril(L) and enalapril(E) were investigated in testis and epididymis of sheep using Hip‐His‐Leu as substrate. Captopril, lisinopril and enalapril were competitive inhibitors of the enzyme from both tissues. Differences in the I50 and Ki values using these three inhibitors reflects the affinities of these inhibitors for the, ACE. In addition, the relative potencies of captopril, lisinopril and enalapril were different for testicular ACE(C > L > E) and epididymal ACE(L>C >E). This observation suggests differences between the active sites of the testicular and epididymal ACE which may reflect on their functions in vivo.

Antihypertensive activity of Rosa rugosa Thunb. flowers: Angiotensin I converting enzyme inhibitor

“…The obtained IC 50 value for captopril was found to be 69.8 nM (15.16 ng/ml). The data obtained is similar to that in literature where IC 50 values for captopril range from 2.27 nM to 0.58 mM (Inada et al, 1986;Carr et al, 1990;Udupa and Rao, 1997;Dyck et al, 2003). When 10 ml of 1.25 mg/ml HHL and 20 ml ACE (0.05 unit/ml) were added to the reaction mixture, the IC 50 value for captopril was 13 nM (Geng et al, 2010).…”

Angiotensin-converting enzyme inhibitors of Bothrops jararaca snake venom affect the structure of mice seminiferous epithelium

“…Considering the structural similarity between the C-terminal sites of sACE and tACE [] and the observation that male tACE “knockout” mice are hypofertile, ACE inhibitors may reduce male fertility [ 21 – 23 ]. Captopril, lisinopril and enalapril have been reported to act as tACE inhibitors in vitro [ 21 , 24 , 25 ]. Likewise, BPP-5a (<EKWAP) and BPP-9a (<EWPRPQIPP), which are natural sACE inhibitors, are also tACE inhibitors in vitro , acting at the nanomolar level [ 26 , 27 ].…”

An in Vitro Study of Cinnamomum Zeylanicum as Natural Inhibitor of Angiotensin-Converting Enzyme (Ace) on Sheep (Ovis Aries) Tissues

“…Tissue ACE activity was also measured similarly in the presence of well-known ACE-inhibitor, i.e., captopril as standard. Hence, the amount of enzyme catalyzing the release of 1 µmol of hippuric acid per minute at 37°C can be defined as one unit of ACE activity [20,27].…”