Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of the male contraceptive, alpha-chlorohydrin, on in situ pH in seminiferous tubules and epididymal duct of the rat has been studied employing in vivo microelectrode techniques. After eight days of low-dose alpha-chlorohydrin administration (15mg/kg/day), a significant increase in acidity of luminal fluid in seminiferous tubules, proximal caput, middle caput, and proximal cauda epididymidis was observed. Increased acidity in the testis and epididymis may play an important role in the antifertility effect of alpha-chlorohydrin.
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PMID:Effect of alpha-chlorohydrin on in situ pH in rat testis and epididymis. 231 6

This study has investigated blood flow from the testicular artery to the pampiniform plexus in the spermatic cord of pigs. Testosterone levels, oxygen tension and the degree of acidity were measured in arterial and venous blood vessels of scrotally and abdominally located testes. Haemoglobin oxygen saturation was derived from the oxygen dissociation curve. Blood flow to abdominal and scrotal testes and epididymides was measured using the radioactive microsphere technique. Average blood flow to the scrotal testes and epididymides was 21 and 8 ml/min, respectively, in normal pigs. In unilaterally cryptorchid pigs average blood flow to the scrotal testis and epididymis was 23 and 6 ml/min, respectively, and to the abdominal testis and epididymis 4.2 and 1 ml/min. In pigs with bilateral scrotal testes oxygen consumption was 16 mumol O2/min/100 g. In unilaterally cryptorchid pigs oxygen consumption by the scrotal testis was 18 mumol O2/min/100 g, compared with 10 mumol O2/min/100 g by cryptorchid testes. From the percentage oxygen saturation in the various blood vessels it was calculated that 29-42% of testicular arterial blood was flowing through arteriovenous anastomoses between the testicular artery and the pampiniform plexus in the spermatic cord, thus bypassing the capillary net of the abdominal testes of unilaterally and bilaterally cryptorchid pigs. These results were supported by the testosterone measurements. In the spermatic cord of scrotal testes no blood bypassed the capillary net of the testes.
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PMID:Investigations of arterio-venous anastomoses in the spermatic cords and blood supply, oxygen consumption and testosterone production of scrotal and abdominal testes in the pig. 290 95

Previous studies (Carr and Acott , 1984) indicate that bovine sperm are maintained in a quiescent state in the caudal epididymis (CE) by a pH-dependent inhibitory factor. Here, we have determined that the pH of bovine CE fluid and of CE semen is approximately 5.8, and that the motility of CE sperm in undiluted CE fluid increases as the pH is elevated. Therefore, the acidity of CE fluid may play a physiological role in the maintenance of sperm quiescence. The changes in sperm motility, in response to changes in the pH of CE fluid, are reversible and rapid. Dilution of CE fluid with buffers at either pH 5.5 or 7.6 produces a much slower initiation of motility. In buffer a significantly lower pH is required to inhibit sperm motility than is required in CE fluid. The apparent pKs for inhibition are 5.3 in buffer and 6.6 in CE fluid. However, the motility of sperm in buffers that contain lactate, shows a pH dependence similar to sperm in CE fluid. That is, lactate inactivates sperm in buffer at pH 5.5 but not at pH 7.6. Lactate, and several other permeant weak acids, have previously been shown to reduce the intracellular pH of bovine sperm and many other types of cells. We show that these permeant weak acids, but not impermeant weak acids, reversibly reduce CE sperm motility in buffer at pH 5.5 but not at pH 7.6. Weak bases, which have previously been shown to elevate intracellular pH, initiate sperm motility in CE fluid. These results suggest that intracellular pH can regulate CE sperm motility and may be the intracellular messenger for the pH-dependent quiescence factor. Although sperm cyclic AMP levels have been previously correlated with motility stimulation, cyclic AMP levels do not change when the pH of CE fluid is elevated, even though full motility is initiated.
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PMID:Inhibition of bovine spermatozoa by caudal epididymal fluid: II. Interaction of pH and a quiescence factor. 632 37

In the epididymis, spermatozoa acquire their ability to become motile and to fertilize an egg. A luminal acidic pH and a low bicarbonate concentration help keep spermatozoa in a quiescent state during their maturation and storage in this organ. Net proton secretion is crucial to maintain the acidity of the luminal fluid in the epididymis. A sub-population of epithelial cells, the clear cells, express high levels of the proton-pumping V-ATPase in their apical membrane and are important contributors to luminal acidification. This review describes selected aspects of V-ATPase regulation in clear cells. The assembly of a particular set of V-ATPase subunit isoforms governs the targeting of the pump to the apical plasma membrane. Regulation of V-ATPase-dependent proton secretion occurs via recycling mechanisms. The bicarbonate-activated adenylyl cyclase is involved in the non-hormonal regulation of V-ATPase recycling, following activation of bicarbonate secretion by principal cells. The V-ATPase is also regulated in a paracrine manner by luminal angiotensin II by activation of the angiotensin II type 2 receptor (AGTR2), which is located in basal cells. Basal cells have the remarkable property of extending long and slender cytoplasmic projections that cross the tight junction barrier to monitor the luminal environment. Clear cells are activated by a nitric oxide signal that originates from basal cells. Thus, a complex interplay between the different cell types present in the epithelium leads to activation of the luminal acidifying capacity of the epididymis, a process that is crucial for sperm maturation and storage.
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PMID:Regulation of luminal acidification in the male reproductive tract via cell-cell crosstalk. 1944 84