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]

DISCUSSION

We report here the influence of orchiectomy and testosterone on pyroglutamyl- -naphthylamide hydrolising activity levels in serum and different tissues in mice. pGluAP is an omega peptidase which removes pyroglutamyl N-terminal residues from peptides and arylamide derivatives. This enzime is widely distributed in fluids and tissues. To date, three distint types of this enzime have been described and called serum thyroliberinase , cytosolic pyroglutamil aminopeptidase type I and membrane bound pyroglutamyl aminopeptidase type II. The activity of all of them is thought to be implicated in the regulation, more or less restricted in their substrate specificity, of various susceptible endogenous substrates such as TRH, GnRH, neurotensin and bombesin (Bauer, 1994; Browne and O´Cuinn,1983; Cummins and O´Connor, 1996; Taylor and Dixon, 1978).

Our results suggest that orchiectomy and posterior injection of testosterone modified the pGluAP activity not only in serun but also in different periferic tissues. These results also suggest that the hormonal status in the animal may modificate the action of pGluAP, so it is possible that the metabolism of endogenous substrates as TRH may be affected by the hormonal microenviroment exists in the animals. However, the existence of changes in adrenal status affect TRH in parallel with corticopropin releasing hormone (Kakucska et al., 1995). Moreover, the potential pyroglutamyl aminopeptidase activity on N-terminal pGlu residues other than TRH should be taken into accounts as well.

Discussion Board

Any Comment to this presentation?

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

---

	[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
Copyright © 1999-2000. All rights reserved.

Last update: 15/01/00