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

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

DISCUSSION

We found significant changes of AP activities in specific tissues, although in serum no changes were described. Previous preliminary in vitro studies using water-soluble complexes with cyclodextrines as carried showed that steroids hormones influence AP activities (Gandarias et al., 1989; Ramírez et al., 1993).

In addition, aminopeptidase B like activity (ArgAP) has been isolated from rat testes and has been implicated in several steps of spermatogenesis (Cadel et al., 1995). Therefore, the present results represent additional suport of a steroid influence on AP activities. We observed changes in AlaAP and ArgAP activities. Enkephalins, which play a neuromodulatory role in brain, have been described as substrates for both activities (Johnson and Hersh, 1990). Futhermore, AP activity plays a major role in the regulation of several biologically active peptides in circulation and tissues. AlaAP may hydrolise bradykinins (Sanderik et al., 1988) and enkephalins (Hersh, 1985) and may also act as an angiotensinase (Ahmad and Ward;1990). ArgAP activity specifically hydrolises basic N-terminal residues from peptides and arylamide derivaties (McDonald and Rarret, 1986). Because of its exopeptidase activity, it has been implicated in the metabolism of Met-enkephalin ((Johnson and Hersh, 1990) and angiotensin III (Ahmad and Ward, 1990); its endopeptidase activity is also thought to be involved inneurotensin metabolism ((McDermott et al., 1988). CysAP activity has been reeported to hydrolise oxytocin and vasopressin (Itoh and Nagamutsu, 1995), Therefore, the present results demonstrate that orchiectomy and testosterone influence aminopeptidase activities in specific locations in mice. These effects may induce functional modifications in the action of aminopeptidases on susceptible substrates; altermatively, they may reflect concomitant modifications in susceptible endogenous substrates.

Discussion Board

Any Comment to this presentation?

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

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

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
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Last update: 15/01/00