Journal of Reproduction and Development
Online ISSN : 1348-4400
Print ISSN : 0916-8818
ISSN-L : 0916-8818
Volume 38, Issue 2
Displaying 1-12 of 12 articles from this issue
  • Xinhua ZHOU, Hayato KAWAKAMI, Yoshiakira KANAI, Yoshihiro HAYASHI, Hir ...
    1992 Volume 38 Issue 2 Pages 99-106
    Published: 1992
    Released on J-STAGE: May 15, 2008
    JOURNAL FREE ACCESS
    Changes in lectin binding in rat testis and epididymis in association with experimental cryptorchidism, in which adult male Wistar rats were subjected to unilateral cryptorchid surgery, were examined by light and electron microscopy with 9 biotinylated-lectins (ConA, WGA, RCA, SBA, DBA, PNA, UEA-I, GS-I and GS-II). In the control testis, ConA, WGA, RCA and GS-I intensely stained every stage of germ cells. PNA, SBA and GS-II bound to all germ cells except spermatogonia. DBA and UEA-I reactions were identified only in spermatocytes and spermatids. Electron microscopically, reaction products were observed mainly along the plasma membrane and in the Golgi apparatus of each germ cell. In addition, the acrosome and/or acrosomal cap were strongly stained with PNA, SBA, WGA, and RCA. In the epididymis, lectin stainings were positive as follows: ConA, WGA, RCA and UEA-I; in all segments examined; PNA; in segments I and II; SBA, DBA, and GS-II; mainly in segments I, II, and V; GS-I; in segments II, III, and V. Electron microscopically, lectin binding sites were distributed mostly on the apical plasma membrane, microvilli, Golgi apparatus, and granules of the principal cells. Two weeks after the cryptorchid operation, stainings of all the lectins used were decreased in intensity and sometimes negative in the spermatogenic cells of the testis. In the epididymis, lectin staining was decreased primarily in segments I, II, and V. The present results indicate that certain glycoconjugates containing Gal, GaINAc, and GIcNAc residues are expressed in the acrosome. In cryptorchidism, the elevated environmental temperature caused the decrease in lectin stainings in testis, reflecting temperature-sensitive changes in cell-associated glycoconjugates during spermatogenesis. The decrease in lectin staining of segments I, II, and V in the epididymis under cryptorchid condition suggests that these segments may play a role for maturation of spermatozoa and that glycoconjugates in these segments are easily affected by an elevated environmental temperature.
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  • Midori YOSHIZAWA, Satoshi NAKAMOTO, Emiko FUKUI, Takashi MURAMATSU, Ak ...
    1992 Volume 38 Issue 2 Pages 107-113
    Published: 1992
    Released on J-STAGE: May 15, 2008
    JOURNAL FREE ACCESS
    Eggs derived from superovulated F1(BALB/c × C57BL/6) mice were fertilized in a modified Krebs-Ringer bicarbonate medium (TYH) containing 2-mM caffeine. Spermatozoa obtained from the cauda epididymis of ICR male mice were preincubated in the caffeine-containing for 2 h before the mixing of gametes. Gametes preincubated and inseminated in the caffeine-free medium served as controls. Chromosome analysis at the first cleavage showed a significantly (P<0.05) higher incidence of triploidy in eggs fertilized in the caffeine-containing medium (22.9%) than in the control (15.8%). The incidence of aneuploidy and the sex ratio were not significantly different between the two groups of eggs. Most of the triploid eggs observed were considered to be dispermic in origin.
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  • Sachiko SAITO, Shigemi MATSUYAMA, Keitaro YAMANOUCHI, Michio TAKAHASHI
    1992 Volume 38 Issue 2 Pages 115-120
    Published: 1992
    Released on J-STAGE: May 15, 2008
    JOURNAL FREE ACCESS
    We investigated changes in the ratio of phagocytotic cells (rPC) in splenic adherent cell population which were harvested from rats at different estrous cycle stages or during pseudopregnan-cy. rPC was assessed using the horse radish peroxidase intake as an index. Either the highest or lowest ratio was observed on the proestrous or the metestrous day during the course of estrous cycle. The highest ratio observed on the proestrous day decreased to 50% by ovariectomy on an antecedent diestrous day, and treatment with either 17β-estradiol or progesterone nullified this decrease. A decrease in rPC observed between the proestrous and estrous days was blocked by a dopamine agonist, CB-154 (150μg/rat), treatment on the proestrous day, and a simultaneous PRL treatment (25 μg/rat) counteracted this effect. The induction of pseudopregnancy by cervical stimulation on the proestrous day severely decreased rPC on 2 days later, and this decrease was completely inhibited by the treatment with CB-154. Thereafter rPC gradually increased toward the end of pseudopregnancy, but a high rPC observed at the end of pseudopregnancy (day 12) was significantly decreased by an ovariectomy one day before. These results indicate that rPC changes during estrous cycle and pseudopregnancy, and that this changes is induced at least by ovarian steroids and PRL.
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  • Sueo NIIMURA, Ikuko YOTSUTANI, Kazuo ISHIDA
    1992 Volume 38 Issue 2 Pages 121-124
    Published: 1992
    Released on J-STAGE: May 15, 2008
    JOURNAL FREE ACCESS
    The incidence of polyspermy and the number of Lens culinaris agglutinin reactive cortical granules were compared between the two groups of eggs; one group was from juvenile mice (30 days old) and the other from adult ones (60 to 90 days old). The incidence of polyspermy was 14.9% in juvenile mice while it was 1.2% in adult ones; the percentage from juvenile mice being significantly higher. On the other hand, the incidence of eggs containing a large number of the above mentioned cortical granules was 69.6% in juvenile mice while it was 92.9% in adult ones; the number of such eggs being significantly fewer in juvenile mice, These findings suggest that the higher incidence of polyspermy in juvenile mice is caused by an insufficient number of cortical granules in their eggs.
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  • Wei-Hua WANG, Masaki UCHIDA, Koji NIWA
    1992 Volume 38 Issue 2 Pages 125-131
    Published: 1992
    Released on J-STAGE: May 15, 2008
    JOURNAL FREE ACCESS
    Cumulus-enclosed or denuded pig oocytes before and after maturation were inseminated with cryopreserved ejaculated spermatozoa in modified TCM-199. High proportions (79-94%) of cumulus-enclosed mature oocytes, but none of immature oocytes, were penetrated regardless of the presence of extra granulosa cells. However, significantly (P<0.001) higher penetration rates were always obtained in denuded mature and immature oocytes in the presence than in the absence of granulosa cells. All of the penetrated immature oocytes had decondensed sperm nuclei and remained at the germinal vesicle (GV) or condensed GV stage. The ability of granulosa cells to induce sperm capacitation and/or acrosome reaction was acquired fully when they were cultured for 36h at 39C. Frozen-thawed granulosa cell masses could support penetration of denuded mature oocytes in spite of complete loss in cell viability indicating that intercellular matrix and possibly cytosolic components liberated from damaged cells rather than components secreted from living cells may play an important role for inducing sperm capacitation and/or acrosome reaction and penetration of oocytes. The activity of the granulosa cell masses was completely lost by treatment of them at 60C for 30 min.
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  • Tomohiro HAMADA, Takeo SHIMIZU, Masumi ICHIKAWA, Yuji MORI
    1992 Volume 38 Issue 2 Pages 133-142
    Published: 1992
    Released on J-STAGE: May 15, 2008
    JOURNAL FREE ACCESS
    Gonadotropin-releasing hormone (GnRH) neurons were examined immunohistochemical-ly in the brain of mature female Shiba goats with a monoclonal antibody to GnRH (LRH-13, Park and Wakabayashi, Endocrinol.Jpn. 33: 257-272, 1986). In all animals, GnRH immunoreactive neurons exhibited a complex morphology consisting of round (49.6%), multipolar (39.8%) or fusiform (10.6%) cell bodies and fibers with beaded varicosities. GnRH cell bodies were distributed rostrally from the diagonal band of Broca and medial septum, passing through the medial and lateral preoptic areas, and caudally ending within the ventromedial anterior hypothalamic areas. A majority (62.6%) of GnRH cells were found in the preoptic areas adjacent to the organum vasculosum of the lamina terminalis, and relatively few cells (7.1%) were distributed in the arcuate nucleus or its vicinity. Preoptic GnRH neurons project their fibers to the tubero-infundibular sulcus of the median eminence by at least 2 routes: (1) the majority of fibers were observed in the periventricular area and the arcuate neuclus (periventricular pathway), and (2) less prominent ones were found in the anterior and ventrolateral hypothalamus (ventrolateral pathway). In addition to these hypothalamic regions, GnRH immunoreac-tive fibers were also found in the neurohypophysis.
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  • Mitsuo YAMAGUCHI, Yasuhiro MANABE, Tomomi TANAKA, Yuji MORI, Kunio HOS ...
    1992 Volume 38 Issue 2 Pages 143-150
    Published: 1992
    Released on J-STAGE: May 15, 2008
    JOURNAL FREE ACCESS
    The microdialysis technique was applied to examine the pattern of gonadotropin-releasing hormone (GnRH) secretion in the mediobasal hypothalamus of the goat using a probe with a polycarbonate membrane. An in vitro recovery test showed that changes in the GnRH concentration in the microdialysis perfusate were highly correlated (r=0.996) with those in the external medium, and the relative recovery rate was 2.8% at a flow rate of 5μl/min. Then an in vivo study was carried out in ovariectomized goats which had been implanted stereotaxically with a microdialysis probe in the median eminence of the hypothalamus. Artificial cerebrospinal fluid was perfused and every 10 min fractions were collected under conscious and unrestrained conditions. Patterns of perfusate GnRH were pulsatile and closely associated with LH pulses in the peripheral circulation suggesting that the microdialysis technique can be successfully adopted for examining the neurosecretory activity of GnRH neurons in the conscious goat.
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  • Manami SHIMO, Eimei SATO, Yohei MIYAMOTO, Hajime MIYAMOTO
    1992 Volume 38 Issue 2 Pages 151-157
    Published: 1992
    Released on J-STAGE: May 15, 2008
    JOURNAL FREE ACCESS
    Dibutyryl cyclic adenosine 3', 5'-monophosphate (dbcAMP) and calmodulin antagonist (W7) inhibit the occurrence of spontaneous germinal vesicle breakdown (GVBD) of isolated mouse oocytes in culture. The effect on the morphological profile of germinal vesicle (GV) of cumulus-free mouse oocytes with dbcAMP and W7 was examined. Striking changes in the oocytes occurred when incubated with dbcAMP and W7. In oocytes incubated with dbcAMP at a concentration of 100μM for 3 h, the distinct Hoechst dye-derived fluorescence in the nucleolus disappeared while the nuclear envelope developed an undulatory contour. The chromosomes started to condense and a large vacuole appeared within the nucleolus. These results suggest that dbcAMP did not suppress the initial phase of GVBD of mouse oocytes. In oocyte treated with W7, the smooth nuclear envelope developed an undulatory contour with fragmentation of the nucleolus into one large segment and many small pieces. The nucleolus retained the Hoechst dye-derived fluorescent staining. The present findings suggest that dbcAMP and W7 act at different loci in inhibiting spontaneous induction of GVBD of mouse oocytes in culture.
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  • Hiroko TSUKAMURA, Satoshi OHKURA, Kei-ichiro MAEDA
    1992 Volume 38 Issue 2 Pages 159-164
    Published: 1992
    Released on J-STAGE: May 15, 2008
    JOURNAL FREE ACCESS
    The effect of intravenous injection of naloxone on the suppression of LH secretion during lactation was examined in intact, ovariectomized, and ovariectomized steroid-primed lactating rats at early and late lactation. The day of parturition was designated day 0. The litter size was adjusted to 8 on day 1, and ovariectomy was performed on day 2. Progesterone alone or progesterone and estradiol in silicone capsules were implanted subcutaneously immediately after the ovariectomy. Blood samples were collected every 6 min for 3 h on day 8 and 16 in intact and ovariectomized rats and on day 16 in ovariectomized steroid-primed rats. Naloxone (total amount=1.2 mg) was injected intravenously via the sampling catheter every 6 min for 2 h after the first hour of the sampling period. Intravenous injection of naloxone had no significant effect on plasma concentrations of LH on day 8 in intact or ovariectomized lactating rats. On day 16, naloxone treatment increased the plasma level of LH in intact lactating rats but not in ovariectomized or ovariectomized steroid-primed lactating rats. The present study clearly indicates that the endogenous opioid peptides do not mediate the suppression of the LH release by suckling stimulus, since intravenous injection of naloxone did not increase the LH secretion at early lactation when the suckling stimulus is the dominant factor suppressing LH release.
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  • Mitsuhiro MIZUMACHI, Josef K. VOGLMAYR
    1992 Volume 38 Issue 2 Pages 165-172
    Published: 1992
    Released on J-STAGE: May 15, 2008
    JOURNAL FREE ACCESS
    The effects of intravenously injected steroid-free rete testis fluid (RTF) on the testosterone concentrations of testicular lymph and its flow rates have been studied. Lymphatic ducts of 5 rams were cannulated at the top of the vascular cone and the total output of testicular lymph was collected in serial samples for 3 censecutive days. Peripheral blood was obtained through an indwelling catheter in the jugular vein. Ten ml of RTF was injected intravenously once or 3 times. Testicular lymph testosterone levels, peripheral blood follicle stimulating hormone (FSH) and leuteinizing hormone (LH) were determined by radioimmunoassay. Injection of RTF suppressed FSH levels, but its effect on LH was variable. Testosterone profiles during 24h preceding and subsequent to the treatment period (24h) were characterized by 3 to 4 distinct testosterone spikes per day. Administration of RTF suppressed the amplitude of these testosterone spikes and prolonged the intervals between the spikes by up to 24h. The flow of testicular lymph was significantly reduced following injection of RTF. These results indicate that a non-steroidal Sertoli cell factor(s) in RTF may possess both paracrine and long-loop feedback modes of action, affecting both the endocrine and exocrine functions of the testis.
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  • Kunihiko NAITO, Yutaka TOYODA
    1992 Volume 38 Issue 2 Pages 173-178
    Published: 1992
    Released on J-STAGE: May 15, 2008
    JOURNAL FREE ACCESS
    Porcine follicular oocytes matured in a modified Krebs-Ringer solution were microinjected with glutathione (GSH) and their male pronucleus (mPN) formation ability was examined after in vitro fertilization. While viability of the oocytes injected with 140 pl vehicle solution (91%) was comparable with non-injected control (93%), microinjections of 35 pl and 140 pl of GSH solution (240 mM) decreased oocyte viability dose dependently (76% and 47%, respectively), showing a toxicity of the highly concentrated GSH solution. Male PN formation rate was low in the control (23%) and was not affected by injection of vehicle solution (17%). In contrast, a microinjection of both 35 and 140 pl GSH solution increased the ability significantly (52% and 53%, respectively). These rates were, however, significantly lower than the rate (70%) of those matured in porcine follicular fluid, which have been suggested to be comparable with in vivo matured oocytes. These results suggest that the low mPN formation ability in the porcine oocytes matured in vitro might be attributed in part to their low intracellular GSH concentration.
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  • 1992 Volume 38 Issue 2 Pages e1
    Published: 1992
    Released on J-STAGE: August 14, 2009
    JOURNAL FREE ACCESS
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