What is the clinical evidence from this study?

Study design: Other. Intervention: Captopril. Primary outcome: in vitro fertilization rate.

What question did this study set out to answer?

To purify and characterize the soluble form of germinal angiotensin I-converting enzyme from ram epididymal fluid and determine its physiological role in ram fertility and fertilization.

November 1, 2001Biology of ReproductionOpen Access

Physiological and Enzymatic Properties of the Ram Epididymal Soluble Form of Germinal Angiotensin I-Converting Enzyme1

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Key result

There was no statistically significant correlation between seminal ACE activity and ram fertility, and the addition of 10(-4) M captopril did not affect the in vitro fertilization rate.

Population

Ram epididymal fluid form of the sperm membrane-derived germinal angiotensin I-converting enzyme and young…

Design

Preclinical

Authors

SMSonia MétayerInstitut National de la Recherche Agronomique FDFrançoise DacheuxUniversité de Tours JDJean‐Louis DacheuxUniversité de Tours

Discussion

Member takes

Implication

No effect of ACE inhibition on ram IVF; leaves open any role in other species or human fertility.

Key Points

To purify and characterize the soluble form of germinal angiotensin I-converting enzyme from ram epididymal fluid and determine its physiological role in ram fertility and fertilization.
Purified the 94-kDa germinal ACE from ram epididymal fluid using chromatography to assess substrate kinetics with FAPGG and hippuryl-L-histidyl-L-leucine under varied pH, ion concentrations, and inhibitor conditions.
Tested competitive inhibition against natural peptides including bradykinin, angiotensin I, angiotensin II, and LHRH.
Analyzed the relationship between seminal plasma ACE carboxypeptidase activity, sperm concentration, and young ram fertility, and measured in vitro fertilization rates with and without 10^-4 M captopril.
Purified ACE displayed a Km of 0.18 mM and Vmax of 34 µmol/(min·mg) for FAPGG, with FAPGG hydrolysis inhibited 82.5% by EDTA, 67.5% by dithioerythritol, and 100% by captopril, lisinopril, and related inhibitors.
Bradykinin and angiotensin I acted as the most potent competitive substrates for FAPGG, with the enzyme cleaving angiotensin I to angiotensin II optimally at pH 7.5 and 300 mM chloride.
ACE activity correlated with semen sperm concentration but showed no statistically significant correlation with fertility, and in vitro fertilization rates showed no difference in the presence of 10^-4 M captopril.

Structured PICO

Population

Ram epididymal fluid form of the sperm membrane-derived germinal angiotensin I-converting enzyme (ACE) and young rams

Intervention

Enzymatic characterization under various conditions and inhibition with captopril (10(-4) M) during in vitro fertilization

Outcome

Enzymatic properties (Km, Vmax) and in vitro fertilization ratesurrogate

Ram germinal ACE exhibits specific enzymatic properties and correlates with sperm concentration, but its inhibition does not affect in vitro fertilization rates.

Cite This Study

Métayer et al. (2001) studied this question. Captopril was evaluated on in vitro fertilization rate. There was no statistically significant correlation between seminal ACE activity and ram fertility, and the addition of 10(-4) M captopril did not affect the in vitro fertilization rate.

synapsesocial.com/papers/6a843896002ab1506fb2a3e8 https://doi.org/10.1095/biolreprod65.5.1332

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Physiological and Enzymatic Properties of the Ram Epididymal Soluble Form of Germinal Angiotensin I-Converting Enzyme1

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Physiological and Enzymatic Properties of the Ram Epididymal Soluble Form of Germinal Angiotensin I-Converting Enzyme1

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider