A histochemical study of leucine amino peptidase activity in the testes of immature and mature guinea-pigs.
TL;DR: A direct relationship between the activity of the enzyme LAP and sexual maturation is indicated and is associated with immature and mature guinea-pig testes.
Abstract: The distribution of the enzyme leucine amino peptidase (LAP) has been studied histochemically in immature and mature guinea-pig testes. Immature guinea-pig testis showed a very feeble LAP activity, while in mature ones strong LAP activity was noted. The present communication indicates a direct relationship between the activity of the enzyme LAP and sexual maturation.
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TL;DR: The zinc containing peptidases angiotensin‐converting enzyme (ACE), neutral metalloendopeptidase (NEP), and leucine aminopeptidsase (LAP) occur in bull ejaculates in high activities, in close correlation with some routineously determined semen parameters.
Abstract: Summary: The zinc containing peptidases angiotensin-converting enzyme (ACE), neutral metalloendopeptidase (NEP), and leucine aminopeptidase (LAP) occur in bull ejaculates in high activities. These enzyme activities are in close correlation with some routineously determined semen parameters. These ejaculat parameters are used for quality classification and selection of ejaculates and are according to long term experience in good correlation to the male fertility. Semen quality related correlations could not be found for the dipeptidyl aminopeptidase (DPIV) and the aminopeptidase A (APA). Origin and possible function of the zinc containing peptidases in the semen are examined and discussed.
Zusammenfassung: Die Zink enthaltenden Peptidasen Angiotensin-Converting-Enzym (ACE), Neutrale Metalloendopeptidase (NEP) und Leucin-Aminopeptidase (LAP) sind mit auffalligen Aktivitaten in den Ejakulaten von Bullen enthalten. Sie zeigen enge Korrelationen zu einigen routinemasig bestimmten Spermaparametern, die in Beziehung zur Befruchtungsfahigkeit des Spermas stehen und bei der kunstlichen Besamung beim Rind zur Ejakulatklassifizierung und -selektion genutzt werden. Derartige Beziehungen lassen sich fur die Dipeptidylaminopeptidase IV (DPIV) und die Aminopeptidase A (APA) nicht nachweisen. Ursprung und mogliche Funktionen der Metalloproteasen im Sperma werden untersucht und diskutiert.
15 citations
01 Jan 2010
TL;DR: En esta revision se estudia la influencia de una dieta enriquecida en aceite de oliva sobre the actividad aminopeptidasica serica and of tejidos perifericos, analizando su influencia en the regulacion del sistema renina-angiotensina para el control of the presion arterial and el balance of liquidos y electrolitos.
Abstract: Numerosos estudios realizados en los ultimos anos, han puesto de manifiesto
que los niveles elevados de grasa en la dieta estan directamente relacionados con
el desarrollo de diversas patologias, entre las que destacan enfermedades cardiovasculares,
diabetes o incluso diversos tipos de canceres. Estudios epidemiologicos
tambien han demostrado que no solo es importante la cantidad, sino tambien el tipo
de grasa de la dieta.
Son especialmente conocidos los efectos beneficiosos de la dieta mediterranea,
caracterizada entre otros aspectos, por un consumo elevado de acidos grasos
monoinsaturados como el oleico. En cualquier caso, no se conoce con exactitud las
relaciones existentes entre el tipo de grasa de la dieta y el desarrollo de las distintas
patologias.
Las aminopeptidasas son enzimas proteoliticos implicados en una amplia variedad
de procesos biologicos, destacando su papel en el control de la presion arterial a traves del sistema renina-angiotensina. En esta revision se estudia la influencia
de una dieta enriquecida en aceite de oliva sobre la actividad aminopeptidasica
serica y de tejidos perifericos, analizando su influencia en la regulacion del sistema
renina-angiotensina para el control de la presion arterial y el balance de liquidos y
electrolitos.
2 citations
Cites background from "A histochemical study of leucine am..."
...Estos resultados indicaron una correlación directa entre la actividad del enzima LeuAP y la maduración sexual (57)....
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References
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TL;DR: A new method for the histochemical demonstration of leucine aminopeptidase in fresh frozen sections was developed with the substrate L-leucyl-4-methoxy-2-naphthylamide, and a description is given of the localization of leukines in the tissues of the rat and man.
Abstract: A new method for the histochemical demonstration of leucine aminopeptidase in fresh frozen sections was developed with the substrate L-leucyl-4-methoxy-2-naphthylamide. The superior enzyme localization is due to the more rapid rate of coupling of the hydrolysis product, 4-methoxy-2-naphthylamine as compared to 2-naphthylamine itself, and to the low lipid solubility and high substantivity for protein of the copper chelate of the dye formed on coupling with tetrazotized diorthoanisidine. A comparison of the old and the new method is illustrated, and a description is given of the localization of leucine aminopeptidase in the tissues of the rat and man.
302 citations
TL;DR: The demonstration of the leucine aminopeptidase enzyme in rat parathyroid and of alterations in its activity during various functional states are demonstrated.
Abstract: ALTHOUGH leucine aminopeptidase is widely distributed in mammalian tissues1 its physiological importance remains obscure. This communication concerns the demonstration of the enzyme in rat parathyroid and of alterations in its activity during various functional states.
41 citations
7 citations
TL;DR: The activity pattern and functional significance of leucine aminopeptidase (LAP) have been studied in the testes of oestrogen\x=req-\ treated, cryptorchid and HCG-treated guinea-pigs and showed marked fluctuations in its activity pattern, which correlated closely with alterations in the functional activities of the Leydig cells.
Abstract: The activity pattern and functional significance of leucine aminopeptidase (LAP) have been studied in the testes of oestrogen\x=req-\ treated, cryptorchid and HCG-treated guinea-pigs. The enzyme was present only in the Leydig cells and showed marked fluctuations in its activity pattern, which correlated closely with alterations in the functional activities of the Leydig cells. Hyperfunctioning Leydig cells exhibited enhanced LAP activity, whereas hypofunctioning of these intertubular cells resulted in a diminution in the enzyme activity. The LAP activity in the intertubular Leydig cells may be regarded as a cytochemical marker enzyme in the assessment of Leydig cell function in the guinea-pig testes under varying experimental conditions.
6 citations