Characterization of a soluble LHRH-degrading activity in the rat ventral prostate
| Autor: | Roberta M. Moretti, Federica Pimpinelli, Donatella Dondi, Patrizia Limonta, Marcella Motta, Marina Montagnani, Roberto Maggi |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Enkephalin Urology Peptide hormone Biology Dithiothreitol Gonadotropin-Releasing Hormone Rats Sprague-Dawley chemistry.chemical_compound Prostate Internal medicine medicine Animals Dose-Response Relationship Drug Hydrolysis Metalloendopeptidases Biological activity Prolactin Rats Endocrinology medicine.anatomical_structure Somatostatin Oncology chemistry Hypothalamus Female Orchiectomy hormones hormone substitutes and hormone antagonists |
| Zdroj: | The Prostate. 23:315-328 |
| ISSN: | 1097-0045 0270-4137 |
| DOI: | 10.1002/pros.2990230405 |
| Popis: | Recent evidence supports the hypothesis of a direct action of LHRH at the level of the prostate. Since peptidases able to degrade the hormone are present in several LHRH target structures, it was deemed of interest to investigate whether the prostate of adult normal male rats might possess LHRH degrading activities (LHRH-DA). Through the use of RP-HPLC, it has been observed that LHRH-DA is present in the soluble fraction of the rat ventral prostate homogenate, and is able to hydrolyze synthetic LHRH and to generate fragments 1–3 and 1–5 of the decapeptide. The degradation of [pGlu-3H]LHRH is inhibited by LHRH itself, and affected by several LHRH agonists and antagonists with different kinetics and potencies. TRH, the enkephalin analog [D-Ala2-D-Leu5]enkephalin and rat prolactin do not inhibit the degradation of [pGlu-3H]LHRH by the soluble fraction of prostate homogenate; on the contrary, this is inhibited by graded doses of somatostatin. The prostatic LHRH-DA is also inhibited, in a dose dependent manner, by bacitracin, serine protease inhibitors (diisopropylfluorophosphate and phenylmethansulfonylfluoride), the metal chelating agent EDTA, HgCl2, and dithiothreitol. No inhibitory effect on [pGlu-3H]LHRH hydrolysis was observed after incubation of the prostatic extract in the presence of captopril. The prostatic LHRH-DA seems to be different from that present in other tissues of the rat (e.g., hypothalamus, pituitary, gonads), and to be decreased by castration performed 3 weeks before. These results suggest that (1) an LHRH-DA is found in the soluble fraction of rat prostate homogenate; (2) this enzymatic activity exhibits the characteristics of a metallo- and thioldependent neutral endopeptidase; (3) it appears to be different from similar hydrolytic activities found in other tissues; and (4) it is influenced by the hormonal milieu, since castration causes a significant decrease of its activity. © 1993 Wiley-Liss, Inc. |
| Databáze: | OpenAIRE |
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