Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Histamine synthesis in male reproductive tissues remains largely unknown. The interaction between stem cell factor and its receptor, c-Kit, has been found to be essential for the maturation of male germ cells and peripheral mast cells. Based on this analogy, we investigated the expression of histidine decarboxylase (HDC), the rate-limiting enzyme of histamine synthesis, in mouse male germ cells. Immunohistochemical analyses revealed that HDC is localized in the acrosomes of spermatids and spermatozoa. In the testis, epididymis, and spermatozoa, a significant amount of histamine and HDC activity were detected. W/W(V) mice, known to lack most of their germ cells in the seminiferous tubules, were found to lack HDC protein expression as well as HDC activity in the testis. An in vitro acrosome reaction induced by a calcium ionophore, caused the release of histamine from epididymal spermatozoa. Our observations indicate that histamine is produced in and released from the acrosomes.
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PMID:Expression of L-histidine decarboxylase in mouse male germ cells. 1182 77

The tyrosine kinase receptor c-kit and its interaction with the ligand, stem cell factor (SCF), play an essential role in the developing testis. C-kit is important for the development of the Leydig cells and for the migration, proliferation and survival of spermatogonia. Platelet-derived growth factor (PDGF) and its tyrosine kinase receptor (PDGFR) are important for the development of Leydig cells and myoid cells. The chemotherapeutic agent, imatinib mesylate (STI571, Glivec; Novartis) inhibits both of these tyrosine kinase receptors. Three-day treatment of immature male rats (SD) with imatinib (150 mg/kg) on postnatal days 5-7 delayed the formation of germ-line stem cell pool, reduced proliferation of type A spermatogonia and induced germ cell apoptosis. PDGFR-mediated proliferation of mesenchymal myoid precursors was also decreased and the length of the seminiferous cord was reduced. However, at the age of 11 weeks the exposed animals had normal epididymal sperm counts, whereas plasma levels of luteinizing hormone and follicle stimulating hormone were significantly increased. Imatinib serves as a good tool to study postnatal formation of the male germ-line stem cell pool and factors determining the final testicular size. As development of the human testis is controlled by the same mechanisms, further studies with primate and human models are needed to explore whether imatinib affects the testis in children as well.
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PMID:Inhibition of tyrosine kinases PDGFR and C-Kit by imatinib mesylate interferes with postnatal testicular development in the rat. 1770 9

Age-related changes, namely the increase in oxidative stress (OS) with the consequent sperm damage, result in decreased male fertility. Regucalcin (RGN) is a Ca2+-binding protein that has been shown to have beneficial effects on spermatogenesis by suppressing OS and chemical/radiation-induced damage. This work aims to evaluate whether RGN overexpression reduces the ageing-associated decline of male reproductive function. Sperm and testicular function analysis were performed in young-adult and senescent transgenic rats overexpressing RGN (Tg-RGN) comparatively with their wild-type (Wt) littermates. The gonadosomatic index (GI), tubular differentiation index and the expression levels of RGN and other proliferation regulators were evaluated. Moreover, the sperm parameters, OS analysis and immunolocalization of RGN were assessed, as well as morphometric evaluation of epididymal tubules. Both GI and sperm counts were reduced in the senescent Wt rats, but maintained in the Tg-RGN. Also, the levels of stem cell factor (SCF), c-Kit, and Akt were maintained in the testis of aged Tg-RGN rats, suggesting that the normal spermatogenic output was preserved over time in these animals, an effect not observed in Wt. Senescent Tg-RGN rats also presented lower sperm lipid peroxidation and total oxidant status relative to the Wt. Furthermore, aged Tg-RGN rats displayed higher sperm viability, higher frequency of sperm with normal morphology, and reduced incidence of head and neck/midpiece defects when compared with Wt, which may be a consequence of the lower OS levels found in the sperm of these animals. Interestingly, RGN expression increased with ageing in sperm, being mainly localized in the acrosome. Altogether, these findings indicate that the modulation of RGN levels may alleviate the age-related decline in sperm quality and testicular function.
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PMID:Overexpression of regucalcin mitigates the ageing-related changes in oxidative stress and sperm quality. 3289 22