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)

In a first series of experiments, the effects of uridine and inosine on glucose metabolism in rat diaphragm muscle incubated in Krebs-bicarbonate buffer were studied. Uridine in concentrations of 10(-4) to 10(-6) M stimulated the uptake of glucose and increased the content of glycogen, but had no effect on the production of lactate. When diaphragm muscles were incubated in the buffer without glucose, uridine (10(-4)-10(-6) M) had no effects on the content of glycogen and on the production of lactate. On the other hand, inosine in concentrations of 10(-4) to 10(-6) M stimulated the uptake of glucose and the production of lactate, but had no effect on the content of glycogen in the muscle. In a second series of experiments, uridine (10(-4)-10(-5) M) and inosine (10(-4)-10(-7) M) inhibited the relase of glycerol from isolated rat epididymal adipose tissue in Krebs-bicarbonate buffer. Uridine and inosine in concentrations of 10(-4) M inhibited the epinephrine (10(-5) M)-, the norepinephrine (10(-5) M)- and the theophylline (10(-3) M)-stimulated lipolysis. Dibutyryl 3',5'-adenosine monophosphate-stimulated lipolysis was further activated in the presence of 10(-4) M uridine or inosine. Dose-response curves studies suggested that inosine, but not uridine, has a common receptor site with epinephrine in adipose tissue. These results demonstrated that both nucleosides stimulated the glucose uptake, but only uridine increased the synthesis of glycogen in the muscle. Both nucleosides also inhibited lipolysis in adipose tissue. The mechanism of antilipolytic action of these nucleosides is unknown, but one of the receptor sites for inosine might be adenylate cyclase.
 ...
PMID:Effects of uridine and inosine on glucose metabolism in skeletal muscle and activated lipolysis in adipose tissue. 18 86

The de novo pyrimidine synthetic enzyme, aspartate carbamyltransferase, and the two pyrimidine salvage enzymes, uridine and thymidine kinases, of the rat testis and epididymis were measured 1, 2, 4, 6, 8, and 10 wk following unilateral vasectomy. Vasectomy had no effect on organ wet weights and on testicular and epididymal asparate carbamyltransferase and thymidine kinase activities. Increases in the uridine kinase activity of the caput epididymidis at 2 wk and of the cauda epididymidis from the second to the sixth weeks were the only significant enzymatic changes observed.
 ...
PMID:Pyrimidine synthetic enzymes of the rat testis and epididymis following unilateral vasectomy. 22 15

Earlier reports have suggested that the epididymis secretes RNA, and that the amount of these secretions varies among T/t6, T/t12 and C57BR mice. In this report, the epididymal perfusate, the total uptake and incorporation of 5-3H-uridine into the epididymis and testicle were examined. Mice examined were T/t6 and +/+ (B6D2F1) and their F1 hybrids, and T/t12 and +/+ (Swiss Webster) and their F1 hybrids. No t-related or age-related effect was seen. However, the F1 hybrids of T/t6 and +/+ (B6D2F1) were significantly lower than the parents at the 4-hour interval.
 ...
PMID:Absence of an effect of t-alleles on epididymal and testicular metabolism of 5-3H-uridine in mice. 101 Sep 34

Rat epididymal tubules maintained in organ culture for 3 or 7 days in media containing androgen showed a marked increase in the incorporation of radioactive amino acids and uridine into acid insoluble material. When the tubules were exposed to these hormones for brief periods, the incorporation of precursors was inhibited initially. In studying the time course of binding of 3H testosterone to the cytoplasmic receptor, a significant amount of radioactivity bound to the receptor was detected only after 12 hr of exposure to the hormone which increased three-fold after 24 hr. The time lag in the binding corresponded closely to the shortest times of observed hormone action wherein a significant increase in the incoporation of uridine (16 hr) and amino acids (24 hr) was produced. Evidence is presented demonstrating that testosterone is bound with high affinity by components of the fetal calf serum present in the culture medium.
 ...
PMID:Studies on the correlation between androgen binding and activation of rat epididymal tubules in culture. 447 76

Cells isolated enzymically from seminal vesicles and epididymides of normal and castrated rats were shown by electron microscopy to be intact and representative of the tissue. The cells synthesize and secrete tissue-specific proteins. Short-term incorporation of [3H]uridine and [35S]methionine was measured to determine the effects of castration on RNA and protein synthesis. Epididymal cells and tissue incorporated uridine at similar rates which were unaltered by castration. Similarly castration failed to diminish uridine incorporation by seminal vesicle cells and tissue. Therefore, androgens may principally control RNA degradation. A similar situation pertained to methionine incorporation by epididymal cells and tissue so here too control may be via protein degradation. In contrast, castration greatly decreased methionine incorporation by seminal vesicle tissue but not by isolated cells. Isolated cells were more active than in tissue, particularly those from castrated rats, and may be released from stromal-epithelial interactions and controls.
 ...
PMID:Isolation of cells from rat seminal vesicles and epididymis and their use in studying androgen action. 616

In vitro studies suggested that increased flux of glucose through the hexosamine biosynthesis pathway (HexNSP) contributes to glucose-induced insulin resistance. Glutamine:fructose-6- phosphate amidotransferase (GFAT) catalyzes glucose flux via HexSNP; its major products are uridine diphosphate (UDP)-N-acetyl hexosamines (UDP-HexNAc). We examined whether streptozotocin (STZ)-induced diabetes (4-10 days) or sustained hyperglycemia (1-2 h) in normal rats alters absolute or relative concentrations of nucleotide-linked sugars in skeletal muscle and liver in vivo. UDP-HexNAc and UDP-hexoses (UDP-Hex) were increased and decreased, respectively, in muscles of diabetic rats, resulting in an approximately 50% increase in the UDP-HexNAc:UDPHex ratio (P < 0.01). No significant changes in nucleotide sugars were observed in livers of diabetic rats. In muscles of normal rats, UDP-HexNAc concentrations increased (P < 0.01) and UDP-Hex decreased (P < 0.01) during hyperglycemia. The UDP-HexNAc:UDP-Hex ratio increased approximately 40% (P < 0.01) and correlated strongly with plasma glucose concentrations. Changes in liver were similar to muscle but were less marked. GFAT activity in muscle and liver was unaffected by 1-2 h of hyperglycemia. GFAT activity decreased 30-50% in muscle, liver, and epididymal fat of diabetic rats, and this was reversible with insulin therapy. No significant change in GFAT mRNA expression was detected, suggesting post-transcriptional regulation. The data suggest that glucose flux via HexNSP increases in muscle during hyperglycemic hyperinsulinemia and that the relative flux of glucose via HexNSP is increased in muscle in STZ-induced diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effects of diabetes and hyperglycemia on the hexosamine synthesis pathway in rat muscle and liver. 758 52

In mammalian cells the requirement for pyrimidines is met by uridine phosphate (UMP) de novo synthesis and, to a greater or lesser extent, by salvage of free nucleosides. The fourth enzyme of the de novo synthesis, the mitochondrially bound dihydroorotate dehydrogenase (DHODH) was the focus of the present study. Rabbit anti-DHODH IgG, which was generated using an immunization protocol with truncated recombinant human DHODH protein and purified by an immunosorbent method, was used for immunocytochemical detection and localization of this enzyme in ejaculated human spermatozoa. The presence of DHODH protein was demonstrated by Western blotting of solubilized membrane fractions with peroxidase conjugated anti-rabbit IgG in combination with chemiluminescence detection. Indirect immunofluorescence microscopy, using Cy3-conjugated anti-rabbit IgG, revealed specific binding in the midpiece of spermatozoa. As these cells no longer have a demand for de novo biosynthesis of pyrimidines, we hypothesize that the pathway could serve a specialized function in nitrogen or zinc metabolism during the process of spermiogenesis and/or epididymal maturation.
 ...
PMID:Immunocytochemical detection of mitochondrial dihydroorotate dehydrogenase in human spermatozoa. 1101 87

The nucleoside transport systems in cultured epididymal epithelium were characterized and found to be similar between the proximal (caput and corpus) and distal (cauda) regions of the epididymis. Functional studies revealed that 70% of the total nucleoside uptake was Na(+) dependent, while 30% was Na(+) independent. The Na(+)-independent nucleoside transport was mediated by both the equilibrative nitrobenzylthioinosine (NBMPR)-sensitive system (40%) and the NBMPR-insensitive system (60%), which was supported by a biphasic dose response to NBMPR inhibition. The Na(+)-dependent [(3)H]uridine uptake was selectively inhibited 80% by purine nucleosides, indicating that the purine nucleoside-selective N1 system is predominant. Since Na(+)-dependent [(3)H]guanosine uptake was inhibited by thymidine by 20% and Na(+)-dependent [(3)H]thymidine uptake was broadly inhibited by purine and pyrimidine nucleosides, this suggested the presence of the broadly selective N3 system accounting for 20% of Na(+)-dependent nucleoside uptake. Results of RT-PCR confirmed the presence of mRNA for equilibrative nucleoside transporter (ENT) 1, ENT2, and concentrative nucleoside transporter (CNT) 2 and the absence of CNT1. It is suggested that the nucleoside transporters in epididymis may be important for sperm maturation by regulating the extracellular concentration of adenosine in epididymal plasma.
 ...
PMID:Characterization of nucleoside transport systems in cultured rat epididymal epithelium. 1128 19

Nucleic acids have been known to have biological effects on the digestive and immune systems, although less attention has been paid to the action on metabolism. In the present study, in order to investigate the effects of oral ingestion of uridylic acid (5'-uridine monophosphate, 5'-UMP) on hormonal and metabolic levels, we measured changes in the plasma concentrations of leptin, insulin, glucose, non-esterified fatty acids (NEFA), weights of the liver and abdominal fat and fat accumulation in the liver and M. gastrocnemius in male rats. Intragastric administration of 5'-UMP via a stomach tube at a dose of 44 mg/day for 7 days slightly (P=0.098) blunted the body weight gain without causing a significant change in food intake. The administration significantly reduced the plasma concentrations of glucose (P=0.004) and NEFA (P=0.004), whereas it significantly increased (P=0.03) plasma leptin concentration. The weights of perirenal (but not epididymal) fat (P=0.083) and the liver (P=0.061) were slightly increased. The triacylglyceride concentration in M. gastrocnemius was slightly increased (P=0.097), although the muscle weight was not significantly changed (P=0.197). In summary, acute oral administration of 5'-UMP was effective in the rat in reducing plasma concentrations of glucose and NEFA, an effect that was accompanied by an elevated plasma leptin concentration.
 ...
PMID:Oral administration of uridylic acid increases plasma leptin, but suppresses glucose and non-esterified fatty acid concentrations in rats. 1649 Feb 18