Tag Archives: Sperm

Developmental Profile of a Caltrin-Like: DISCUSSION(3)


Thus, no acrosin but proacrosin exists in spermatozoa before their passage to the oviduct. Since proacrosin is not exposed on the sperm surface but is located in the acrosomal matrix of intact sperm, P12 is unlikely to interact with the zymogen unless P12 penetrates into the acrosomal region. In fact, there is one protein component, which is distinct from acrosin/proacrosin but is capable of binding a PI of seminal vesicle origin, in the supernatant of frozen-thawed murine epididymal sperm suspension. proventil inhaler

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Developmental Profile of a Caltrin-Like: DISCUSSION(2)

The P12-binding sites are on the anterior region of the acrosome of mouse sperm. Corresponding to the histological localization of the cells developed during spermatogenesis and spermiogenesis in the testis, they are present in the cell layers closely restricted to the lumen of seminiferous tubules. Their absence in the spermatogenic cells such as spermatogonia and spermatocytes indicates that the P12-binding sites are synthesized predominantly in the postmeiotic cells such as spermatids and spermatozoa. Thus, the biosynthesis of P12-binding sites is likely to start in the early haploid spermatids during sperm generation.

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Developmental Profile of a Caltrin-Like: DISCUSSION(1)


Protease inhibitors are ubiquitous in the genital tracts of mammals. Previously, Nicholson et al. identified a 6.4-kDa PI from mouse seminal vesicle by SDS-PAGE. Since its amino acid sequences have not been reported yet, it is assumed to be identical to P12 for the time being, considering that they are secreted from the same organ and have similar molecular size. Among the male and female genital tracts, P12 was found only in the seminal vesicle, coagulating gland, and prostate of male adults. In each of the accessory sexual glands, P12 is predominantly secreted from the luminal epithelium of mucosa folds to the lumen, where the secretion is accumulated. Apparently, P12-sperm binding to affect sperm activity should take place after ejaculation, and the removal of P12 from the cells may proceed in the uterus, according to the study of Irwin et al.. Buy Advair Diskus Online

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Developmental Profile of a Caltrin-Like: RESULTS(6)

The apparent dissociation constant (Kd) was determined to be 70.15 ± 5.25 nM, and 1.49 ± 0.06 X 106 binding sites/ cell was estimated from the maximum binding capacity (Bmax). The latter is comparable to that estimated from the isotherm saturation.

We examined the development of P-12 binding sites during sperm generation in the testis. In contrast to the cell morphology in the tissue (Fig. 9A), no P12 appeared in the seminiferous tubules or Leydig cells (Fig. 9C). P12 could be immunolocalized (Fig. 9B) in spermatids and spermatozoa but remained undetectable in Leydig cells, Sertoli cells, and precursor cells such as spermatogonia and spermatocytes in the tissue slices preincubated with P12 (Fig. 9B).

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Developmental Profile of a Caltrin-Like: RESULTS(5)


125I-P12 was used for the quantitative characterization of sperm-P12 binding. To minimize the nonspecific binding of P12 to the glass microfiber filters used in the binding assay, the filters had been blocked with 1.0% skim milk for 30 min. This resulted in low background binding of the radiolabeled P12 to the filters. Consequently, the nonspecific binding of ligand to the cells was sufficiently low to allow the measurement of specific binding. Figure 7 displays the data from one representative determination from the cell incubation (1.0 X 107 cells/ml) in 50 mM Tris-1.0% skim milk (pH 7.4) in the presence of 100 nM 125I-P12. antibiotics levaquin

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Developmental Profile of a Caltrin-Like: RESULTS(4)

No fluorescence appeared on the epididymal spermatozoa after they had been immunoreacted successively with the P12 antiserum and the fluorescein-conjugated anti-rabbit IgG, manifesting the lack of P12 on the cell surface. When the cells were preincubated with P12 before cyto-chemical staining, a crescent fluorescence zone on the anterior region of the sperm acrosome was visible (Fig. 6), indicating P12-binding sites on the acrosomal region. antibiotic levaquin

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Developmental Profile of a Caltrin-Like: RESULTS(3)


Apparently, P12 is synthesized by the translation at a constant level of P12 mRNA in the epithelium of mucosa folds, and the successive secretion from the epithelial cell results in its accumulation in the lumen. The positive correlation of P12 and its RNA message with the development of the seminal vesicle prompted us to assess the effect of androgen on P12 expression in the accessory sexual gland. Figure 5 displays the Western blot analyses of P12 in the tissue homogenates of seminal vesicles from mice (14 wk) treated in several ways. The protein disappeared in the tissue of mice that had been castrated 3 wk earlier (Fig. 5, lane 2). The protein was not detectable in the tissues of castrated mice that had received a daily injection of corn oil only (Fig. 5, lane 3). buy cheap antibiotics

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Developmental Profile of a Caltrin-Like: RESULTS(2)

Abundant P12 appeared in the concretion of the glandular alveolar in the prostate and in the fluid in the lumen of both the seminal vesicle and coagulating gland. In the seminal vesicle, P12 was immunolocalized on the luminal epithelium of primary and secondary mucosa folds, but it was absent in smooth muscle cells, indicative of the secretion of P12 from the epithelium of mucosa folds to lumen. The secretion of P12 from the epithelium of mucosa folds was also noted in the coagulating gland. In the prostate, the secretion of P12 from the fold projecting into the lumen of glandular alveolus was obvious. birth control yasmin

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Developmental Profile of a Caltrin-Like: RESULTS(1)

RESULTS(1)Distribution of P12 in Mouse Reproductive Tracts

Hypodermic injection of P12 to rabbits poorly induced the production of P12 antibody. Instead, we immunized the animals by intrasplenic injection of P12. The antiserum prepared from this method showed strong immunoaffinity to P12 as well as to GST-P12 but did not cross-react with GST (cf. lanes 1-3 of Fig. 1). Among the protein components of SVS, which contained a trace amount of P12 (Fig. 1A, lane 4), the antiserum immunoreacted only with P12 (Fig. 1B, lane 4), showing the high specificity of the P12 antibody in the antiserum. Therefore, we used the antiserum for the immunodetection of P12 throughout this study. antibiotic levaquin

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Developmental Profile of a Caltrin-Like: MATERIALS AND METHODS(5)

45Ca2+ Uptake by Spermatozoa

Ca2+ uptake by epididymal spermatozoa was measured according to the method of Coronel and Lardy. Before this measurement, the spermatozoa in the modified Tyrode’s solution (1.0 X 107 cells/ml) were preincubated with 1.5 ^M P12 or recombinant P12 at 37°C for 10 or 60 min. Then they were incubated in the presence of 200 ^M CaCl2 labeled with 45Ca2+ (10-40 ^Ci/mg calcium; Amersham, Arlington Heights, IL) at 37°C for 10 min, and the cells were collected by vacuum filtration under 0.16 atm through a cellulose acetate filter. The cells on the filters were washed with six volumes of modified Tyrode’s solution. The filters were dried and transferred into scintillation vials containing 5.0 ml of scintillation counting cocktail (Merck, Darmstadt, Germany). Radioactivity was counted by a liquid scintillation counter (Parker; LKB, Stockholm, Sweden). buy cheap antibiotics

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