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application/pdf, The oviduct is an active contractile tube that provides the proper environment for sperm transport, capacitation and survival. Oviductal contractions are regulated by autocrine/paracrine secretion of several factors, such as prostaglandins (PGs) and endothelin-1 (EDN-1). We have previously shown that during the preovulatory stage, sperm are exposed to polymorphonuclear neutrophils (PMNs) in the bovine oviduct, and the bovine oviduct epithelial cells (BOECs) secrete molecules including PGE2 that suppress sperm phagocytosis by PMNs in vitro. In this study, we investigated the possible effects of EDN-1 on the phagocytic activity of PMNs toward sperm. The local concentrations of EDN-1 in oviduct fluid and BOEC culture medium ranged from 10–10 to 10–11 M as determined by EIA. Phagocytosis and superoxide production were assayed by co-incubation of sperm pretreated to induce capacitation with PMNs exposed to EDN-1 (0, 10–11, 10–10, 10–9, and 10–8 M) for 2 h. EDN-1 suppressed dose dependently (10–11 to 10–8 M) the phagocytic activity for sperm and superoxide production of PMNs in response to capacitated sperm. Moreover, this suppression was eliminated by an ETB receptor antagonist (BQ-788). EDN-1 suppressed mRNA expression of EDN-1 and ETB but not ETA receptors in PMNs, suggesting the ETB receptor-mediated pathway. Scanning electron microscopic observation revealed that incubation of PMNs with EDN-1 (10–9 M) completely suppressed the formation of DNA-based neutrophil extracellular traps for sperm entanglement. The results provide evidence indicating that EDN-1 may be involved in the protection of sperm from phagocytosis by PMNs in the bovine oviduct, supporting sperm survival until fertilization.

application/pdf, In the testis of the Sunda porcupine (Hystrix javanica), the distribution pattern of cytoskeletal proteins was immunohistochemically examined to understand their functional roles in the testis. Immunoreactivity for α-smooth muscle actin (SMA) was found in the peritubular myoid cells of the seminiferous tubules and in the sub-tubular myoid cells of epididymal ducts. In intermediate filaments, desmin was exhibited in the sub-tubular myoid cells of the epididymal ducts, and vimentin immunoreactivity was detected in the Sertoli cells, Leydig cells, peritubular myoid cells, and sub-tubular myoid cells of the epididymal ducts. However, cytokeratin was not expressed in the testes or epididymides. Strong immunoreactivity for vimentin was demonstrated between the infranuclear part of the elevated nuclei and the basal membrane in the Sertoli cells. Furthermore, vimentin was extended from supranuclear to apical parts in some Sertoli cells. Immunoreactivity for α-tubulin was detected only in the Sertoli cells. It is concluded that, in the porcupine testes, desmin plays no role in the contractile function of peritubular myoid cells, vimentin may contribute to the anchoring and transition of the elevated nuclei in the Sertoli cells, and α-tubulin and vimentin in the Sertoli cells are likely involved in their structure and function as the main cytoskeleton. © The Mammal Society of Japan.

application/pdf, The structure and functions of placentas were examined in 3 species of rorqual whales, common minke (Balaenoptera acutorostrata), Bryde’s (B. brydei) and sei (B. borealis) whales, with the aim of confirming the structural characteristics of the chorion, including the presence of the areolar part, and clarifying steroidogenic activities and fetomaternal interactions in the placentas of these whales. Placentas were collected from the second phase of the Japanese Whale Research Program under Special Permit in the North Pacific (JARPN II). Histological and ultrastructural examinations revealed that these whale placentas were epitheliochorial placentas with the interdigitation of chorionic villi lined by monolayer uninucleate cells (trophoblast cells) and endometrial crypts as well as folded placentation by fold-like chorionic villi. Moreover, well-developed pouch-like areolae were observed in the placentas, and active absorption was suggested in the chorionic epithelial cells of the areolar part (areolar trophoblast cells). Berlin blue staining showed the presence of ferric ions (Fe3+) in the uterine glandular epithelial cells and within the stroma of chorionic villi in the areolar part. An immunohistochemical examination revealed tartrate-resistant acid phosphatase (TRAP; known as uteroferrin in uteri) in the cytoplasm of glandular cells and areolar trophoblast cells. This result suggested that, in cetaceans, uteroferrin is used to supply iron to the fetus. Furthermore, immunoreactivity for P450scc and P450arom was detected in trophoblast cells, but not in areolar trophoblast cells, suggesting that trophoblast cells synthesize estrogen in whale placentas. Therefore, we herein immunohistochemically revealed the localization of aromatase and uteroferrin in cetacean placentas during pregnancy for the first time.

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Schematic comparison of abdominal organs between calf presented herein (A) and general cattle (B and C), in association with Fig. 1. 1–22, corresponding to Fig. 1; 23, right kidney; 24, spleen; 25, Grooves of rumen. Figure S2. Comparison of computerized tomography (CT) images between calf presented herein (A and C) and general cattle (B and D), in association with Fig. 2. 1–6 and asterisks; corresponding to Fig. 2. Figure S3. Schematic comparison of digestive tracts between calf presented herein (A) and general cattle (B), in association with Fig. 3. Numbers are corresponding to Fig. 3. Figure S4. Schematic comparison of organs surrounding pancreas between calf presented herein (A) and general cattle (B), in association with Fig. 5. 1–13, corresponding to Fig. 3 (except 11, coalesced mesojejunum and mesocolon); 14–16, Body, right robe and left lobe of pancreas, respectively. (PDF 1156 kb)

application/pdf, In this study, we examined the existence and structure of areolae and the steroidogenesis of areolar trophoblast cells in the Antarctic minke whale placenta morphologically and immunohistochemically. Placentas were collected from the 15th, 16th and 18th Japanese Whale Research Program under Special Permit in the Antarctic (JARPA) and 1st JARPA II organized by the Institute of Cetacean Research in Tokyo, Japan. The opening and cavity of fetal areolae formed by taller columnar trophoblast cells (areolar trophoblast cells) with long microvilli and a bright cytoplasm, as compared with the trophoblast cells of the chorionic villi interdigitating with the endometrial crypts, were recognized in observations of serial sections. The opening of the areolar cavity was hidden by chorionic villi with areolar trophoblast cells. Furthermore, a closed pouch-like structure lined by tall columnar cells similar to areolar trophoblast cells within the stroma of chorionic villi was noticed and continued to the areolar cavity, with the opening seen on serial sections. In a surface investigation of the chorion and endometrium by SEM, maternal (endometrial) areolae irregularly surrounded by endometrial folds were obvious. Moreover, we distinguished areolar trophoblast cells with long microvilli attached with many blebs from trophoblast cells. In our immunohistochemical observations, a steroidogenic enzyme, cytochrome P450 side chain cleavage enzyme (P450scc), was detected with strong immunoreactivity in trophoblast cells. However, areolar trophoblast cells showed weak or no immunoreactivity for P450scc.

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application/pdf, There are few reports describing the structure and function of the whale placenta with the advance of pregnancy. In this study, therefore, the placenta and nonpregnant uterus of the Antarctic minke whale were observed morphologically and immunohistochemically. Placentas and nonpregnant uteri were collected from the 15th, 16th and 18th Japanese Whale Research Programme with Special Permit in the Antarctic (JARPA) and 1st JARPA II organized by the Institute of Cetacean Research in Tokyo, Japan. In the macro- and microscopic observations, the placenta of the Antarctic minke whale was a diffuse and epitheliochorial placenta. The chorion was interdigitated to the endometrium by primary, secondary and tertiary villi, which contained no specialized trophoblast cells such as binucleate cells, and the interdigitation became complicated with the progress of gestation. Furthermore, fetal and maternal blood vessels indented deeply into the trophoblast cells and endometrial epithelium respectively with fetal growth. The minke whale placenta showed a fold-like shape as opposed to a finger-like shape. In both nonpregnant and pregnant uteri, many uterine glands were distributed. The uterine glands in the superficial layer of the pregnant endometrium had a wide lumen and large epithelial cells as compared with those in the deep layer. On the other hand, in the nonpregnant endometrium, the uterine glands had a narrower lumen and smaller epithelial cells than in the pregnant endometrium. In immunohistochemical detection, immunoreactivity for P450scc was detected in most trophoblast cells, but not in nonpregnant uteri, suggesting that trophoblast epithelial cells synthesized and secreted the sex steroid hormones and/or their precursors to maintain the pregnancy in the Antarctic minke whale.

application/pdf, The lamination of the masseter muscle was gross anatomically examined in the water deer (Hydropotes inermis). We could distinguish several layers such as the M. masseter superficialis, M. masseter intermedius, M. masseter profundus, M. maxillo-mandibularis, and M. zygomaticomandibularis. The M. masseter superficialis was subdivided into lamina prima and lamina secunda. The lamina prima originated from the facial tuber, facial crest, and zygomatic arch with a broad tendinous sheet. The lamina secunda arose from the posterior facial crest and anterior area of the zygomatic arch and was inserted to the mandible by a broad tendinous sheet. The M. masseter intermedius arose from approximately same origin as the superficialis lamina secunda by a distinct tendinous sheet. Moreover, only one part was confirmed in the M. maxillo-mandibularis and the M. zygomatico-mandibularis and only two parts in the M. masseter profundus pars posterior. Moreover, the most rostral part of the M. maxillo-mandibularis was inserted to the mandible by a small weak tendon. This result suggests that this muscle layer may not restrict the mouth opening more remarkably than that of cervids which develop the tendon. In this study, we could confirm the lamination of the masseter muscle with the simplified layers in the water deer.

application/pdf, Peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) are produced in endocrine cells that show distal distribution in each of small and large intestine. They are colocalized in the same endocrine cells at different ratios depending on the animal species. The present study examined the possibility of plasticity in the colocalization pattern in the bovine rectum, which is known to contain endocrine cells at a high concentration. Consecutive sections from different pre- and postnatal stages were stained immunohistochemically. The immunoreactive (IR) cells were divided into three groups: 1) cells IR for both PYY and GLP-1 (PYY/GLP-1-IR cells), 2) cells IR only for PYY (PYY-IR cells), and 3) cells IR only for GLP-1 (GLP-1-IR cells). The percentage of PYY/GLP-1-IR cells was high in the prenatal (early, mid- and late fetuses) and suckling stages, whereas it decreased in the herbivorous (weaning, weaned and adult) stages. In contrast, percentages of PYYand GLP-1-IR single cells were low in the prenatal and suckling stages and increased after the suckling stage. PYY/GLP-1 endocrine cells may adapt to the change of digestion depending on feeding habits and/or specific developmental stages of cattle. The present results suggest the developmental plasticity of the colocalization pattern of gut hormones with nutritional transition.

application/pdf, Testicular steroidogenesis and spermatogenesis during developmental and seasonal changes were investigated in male sika deer (Cervus nippon), a short-day seasonal breeder, to clarify the physiological mechanisms for reproductive function. The immunohistochemical localization of steroidogenic enzymes (P450scc, P450c17, 3βHSD and P450arom), spermatogenesis and cell proliferation were analyzed in the testes of fetal (164 to 218 days of fetal age), fawn (0 years old), yearling (1 year old) and adult (more than 2 years old) male sika deer. Three kinds of steroidogenic enzymes, P450scc, P450c17 and 3βHSD, essential for the synthesis of testosterone were located only in the Leydig cells of the testes from the fetal period, and these localizations did not change during developmental or seasonal stages. Immunoreactivity for P450arom, a key enzyme converting testosterone to estradiol, was also localized only in the Leydig cells of testes but was also further limited to the testes of yearlings and adults. Seminiferous tubules had already formed in the fetal testes examined in the present study. Spermatogenesis started in yearlings and was more active in the breeding season. In the adult sika deer testes, the Leydig cells, which displayed immunoreactivities for steroidogenic enzymes, changed to have more cytoplasm in the breeding season than in the non-breeding season. Cell proliferation of Leydig cells was hardly observed in adult testes during seasonal changes. The present results suggested that sika deer testes start to synthesize testosterone from the fetal period, that seasonal changes in testosterone and estradiol syntheses are dependent on the quantitative variation of steroidogenic enzymes synchronized with the size of Leydig cells and that estradiol synthesized in yearling and adult testes makes a contribution to the initiation and recrudescence of spermatogenesis and spermiogenesis in the sika deer.

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