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

Gamma-aminobutyric acid (GABA) is found in the gonads and accessory reproductive organs, and a direct effect on steroidogenesis and sperm viability and motility has been described. The golden (Syrian) hamster is a seasonal breeder, and a pattern of regression-recrudescence in their reproductive organs is observed when adult animals are exposed to less than 12.5 h daylight for an extended period of time. The purpose of this study was to investigate: (1) the presence of GABA in the testis and epididymis of golden hamsters undergoing regression and spontaneous recrudescence; (2) glutamic acid levels and glutamate decarboxylase (GAD) activity in both tissues, and (3) testicular and epididymal testosterone, dihydrotestosterone and 5 alpha-androstane-3 alpha, 17 beta-diol concentrations. Adult golden hamsters were exposed to long (LP 14L:10D) or short (SP 6L:18D) photoperiods for 9, 12, 14, 16, 18 or 22 weeks. When animals were exposed to SP for 14-16 weeks, the testis and epididymis reached maximal involution. Testicular and epididymal androgen levels showed a marked decrease (p < 0.05) during the regression period, and after 18-22 weeks, values began to recover. Between 12 and 18 weeks in SP, the testicular and epididymal content of GABA and glutamic acid was reduced significantly. The concentration of GABA in both tissues showed a sharp rise (p < 0.05), while the concentration of glutamic acid diminished during the period of maximal involution (p < 0.05). In the testis, GAD activity was increased (p < 0.001) after 14 weeks in SP, with no change in the epididymis. In conclusion, glutamic acid via GAD activity could be the main source of GABA in the testis, but not in the epididymis. Furthermore, the presence of GABA in testicular cells and its subsequent photoperiodic variations might act as an important autocrine and/or paracrine modulatory signal in gonadal processes.
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PMID:Influence of photoinhibition on GABA and glutamic acid levels, and on glutamate decarboxylase activity in the testis and epididymis of the golden hamster. 887 67

The adipocyte does not only serve as fuel storage but produces and secretes compounds with modulating effects on food intake and energy homeostasis. Although there is firm evidence for a centrally mediated regulation of adipocyte function via the autonomous nervous system, little is known about signaling between adipocytes. Amino acid neurotransmitters are candidates for such paracrine signaling. Here, we applied immunohistochemistry to detect components required for amino acid transmitter signaling in rat fat depots. In interscapular brown adipose tissue as well as in interscapular, mesenteric, perirenal, and epididymal white adipose tissues, we demonstrate robust immunosignals for the excitatory neurotransmitter glutamate, the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), and the GABA-synthesizing enzyme glutamate decarboxylase (GAD) isoforms GAD65 and GAD67. Moreover, all adipose tissues stained for the vesicular glutamate transporter VGLUT1 and the vesicular GABA transporter VGAT in addition to the vesicle marker synaptophysin. Electron microscopic immunocytochemistry showed that VGLUT1 and VGAT, but not VGLUT2 or VGLUT3, are localized in vesicular organelles in adipocytes. The receptors for glutamate (subunits GluR2/3 and NR1 but not mGluR2) and for GABA (GABA(A)Ralpha2) were present in the adipocytes. The presence of glutamate, GABA, their vesicular transporters, and their receptors indicates a paracrine signaling role for amino acids in adipose tissues.
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PMID:The components required for amino acid neurotransmitter signaling are present in adipose tissues. 1760 Mar 3

In mammals, ejaculated sperm acquire their fertilizing ability during migration through the female reproductive tract, which secretes several factors that contribute to sperm capacitation. Gamma-aminobutyric acid (GABA) is a well-known neurotransmitter in the central nervous system, but additionally enhances the sperm acrosome reaction in the rat and cow. However, the detailed effects of GABA concentration on sperm function remain unclear. In this study, we detected the presence of the GABA type A receptor (GABA A) in mouse epididymal sperm by western blot analysis and in the sperm acrosome by immunocytochemistry. We also investigated the effects of GABA on sperm fertilizing ability. We found that GABA facilitated the tyrosine phosphorylation of sperm proteins, which is an index of sperm capacitation. GABA also promoted the acrosome reaction, which was suppressed by a selective GABA A receptor antagonist. We then found that the effective GABA concentration for the acrosome reaction corresponds to sperm concentration, but we did not detect any marked effect of GABA on sperm motility using a computer-assisted sperm analysis system. Using immunohistochemistry, we also detected GABA expression in the epithelia of the mouse uterus and oviduct. Furthermore, we found that the mRNA levels of glutamate decarboxylase (Gad), which generates GABA from L-glutamate, were higher in the oviduct than in the uterus, and that Gad mRNA levels were higher at estrus than at the diestrus stage. These results indicate that the GABA concentration can act as a modulator of the acrosome reaction and sperm capacitation in the female reproductive tract.
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PMID:Capacitation of mouse sperm is modulated by gamma-aminobutyric acid (GABA) concentration. 3117 51