Some reptiles are known to possess sperm storage in the female genital tract. Examination of the oviduct of the lizard Calotes versicolor shows the presence of sperm in storage pockets of the uterovaginal region throughout the reproductive cycle. Histochemical studies indicate that the epithelium of these pockets resembles the local oviductal epithelium and that a considerable amount of activity of steroidogenic and metabolic enzymes exists.
This study provides the first description of the ultrastructural features of sperm storage tubules (SSTs) in the uterovaginal region of the oviduct of the Indian garden lizard, Calotes versicolor. Abundant spermatozoa along with copious secretory material were found in the lumen of the SSTs. These secretory granules appeared similar in electron density to those found in the epithelial cells lining the SSTs indicating their similar origin. The close physical proximity of sperm with these granules suggests an intimate association between the two. The present study is also the first report of recovery of motile sperm from the flushings of SSTs in C. versicolor. The density of sperm found in the flushings varied, being most abundant during the reproductive phase and minimum/absent during the regressive phase. Understanding the microenvironment of the SSTs, the nature of the secretory granules and their interaction with sperm can guide us in unraveling the biology of oviductal sperm storage. Anat Rec, 298:1932Rec, 298: -1937Rec, 298: , 2015. V C 2015 Wiley Periodicals, Inc.Key words: uterovaginal junction; sperm storage tubules; secretory materialAbbreviations used: PAS 5 periodic acid-Schiff; SST 5 sperm storage tubule; TEM 5 transmission electron microscopy This article includes an AR WOW Video, which can be viewed at
Lipopolysaccharide (LPS) signaling through Toll-like receptor-4 (TLR-4) has been implicated in the pathogenesis of many infectious diseases. Some believe that TLR-mediated pathogenicity is due, in part, to the lipid pro-inflammatory mediator platelet-activating factor (PAF), but this has been questioned. To test the direct contribution of PAF in endotoxemia in murine models, we injected PAF intraperitoneally into Swiss albino mice in the presence and absence of LPS. PAF alone (5 μg/mouse) caused death within 15–20 min, but this could be prevented by pretreating mice with PAF-receptor (PAF-R) antagonists or PAF-acetylhydrolase (PAF-AH). A low dose of LPS (5 mg/kg body wt) did not impair PAF-induced death, whereas higher doses (10 or 20 mg/kg body wt) delayed death, probably via LPS cross-tolerance. Cross-tolerance occurred only when PAF was injected simultaneously with LPS or within 30 min of LPS injection. Tolerance does not appear to be due to an abundant soluble mediator. Histologic examination of lungs and liver and measurement of circulating TNF-α and IL-10 levels suggested that the inflammatory response is not diminished during cross-tolerance. Interestingly, aspirin, a non-specific cyclooxygenase (COX) inhibitor, partially blocked PAF-induced sudden death, whereas NS-398, a specific COX-2 inhibitor, completely protected mice from the lethal effects of PAF. Both COX inhibitors (at 20 mg/kg body wt) independently amplified the cross-tolerance exerted by higher dose of LPS, suggesting that COX-derived eicosanoids may be involved in these events. Thus, PAF does not seem to have a protective role in endotoxemia, but its effects are delayed by LPS in a COX-sensitive way. These findings are likely to shed light on basic aspects of the endotoxin cross-tolerance occurring in many disease conditions and may offer new opportunities for clinical intervention.
Long‐term sperm storage by females in various regions of the oviduct is documented across many invertebrate and vertebrate species. Although, many reports emphasize on the histology, histochemistry and ultrastructural features of sperm storage, very little is known about the mechanisms underlying the sperm storage. The current review documents the occurrence of sperm storage by females in a wide array of invertebrate and vertebrate species. This review also provides an insight on the presence of various molecular factors of the sperm storage tubules presumably responsible for the prolonged sperm storage with an emphasis on a model reptile, the Indian garden lizard, Calotes versicolor which contains a unique approximately 55‐kDa protein in its utero‐vaginal lavage and found to inhibit washed epididymal sperm motility in a concentration and time‐dependent manner in a reversible fashion.
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