María Jesús García-López⁽¹⁾, María Jesús Ramírez-Expósito⁽²⁾, José Manuel Martínez-Martos⁽³⁾, María Dolores Mayas-Torres⁽⁴⁾, Isabel Prieto-Gómez⁽⁵⁾, Garbiñe Arechaga-Maza⁽⁶⁾, Manuel Ramírez-Sánchez^{(7)
(1)(3)(4)(5)(6)(7)}Unit of Physiology. University of Jaén - Jaén. Spain
⁽²⁾Unit of Physiology. University of Jaen - Jaén. Spain

	[Biochemistry]	[Endocrinology]	[Neuroscience]	[Physiology]	[Reproduction Sciences]

DISCUSSION

We found significant differences in AP A activity in serum and different periferic tissues. Moreover, our results also demonstrate an influence of orchiectomy and testosterone on AP A activity. These enzymes responded in a different way in the analized situations. Testosterone increases AspAP and GluAP activities in serum, but in the other tissues the behaviour of these enzymes was quite different. Soluble AspAP only decreased in FC, the rest of tissues did not change with orchiectomy or testosterone. However, Sol GluAP activity suffered more modifications. These results may indicate that Asp- and GluAP are different enzymes although their action may be very simillar.

By other hand, AP activity plays a major role in the regulation of circulating biologically active peptides (Sanderik et al., 1988). Aminopeptidase A Appears to be a membrane-bound ectoenzime especially abundant in the kidney (Lodja and Gossrau, 1980) and is also found in the vascular circulation, where it appears to originate from the autolysis of membrane-bound AP A (Wilk and Healy, 1993). This is analogous to angiotensin-converting enzyme, which is originally membrane-bound but becomes soluble in plasma with autolysis (Williams, 1988). In any case, it is unlikely that the major mechanism of regulation of AP activity performs through active synthesis or release. Passive regulation of circulating and tissullar AP is plausible, depending on the biochemical enviroment, under specific cphysiological or pathological conditions. Our results are in accordance with that theory, because indicate the existence of an hormonal influence on AP activity. However, due to the role of AP A on the systemic and local renin-angiotensin systems, hormonal modifications during physiological and/or pathological conditions could modify blood pressure regulation through these systems.

Discussion Board

Any Comment to this presentation?

[ABSTRACT] [INTRODUCTION] [MATERIAL & METHODS] [RESULTS] [IMAGES] [DISCUSSION] [REFERENCES] [Discussion Board]

---

	[Biochemistry]	[Endocrinology]	[Neuroscience]	[Physiology]	[Reproduction Sciences]

María Jesús García-López, María Jesús Ramírez-Expósito, José Manuel Martínez-Martos, María Dolores Mayas-Torres, Isabel Prieto-Gómez, Garbiñe Arechaga-Maza, Manuel Ramírez-Sánchez
Copyright © 1999-2000. All rights reserved.

Last update: 15/01/00