Histochemical demonstration of the presence of serotonin in the hen (Gallus domesticus) reproductive tract

The purpose of the present study was to demonstrate visually and localize the presence of serotonin (5-HT) in the ovary and oviduct of the domestic hen using a histochemical Falck-Hillarp method. Experiments were carried out on White Leghorn laying hens with no egg in the shell gland. The specific yellow fluorescence, indicating the presence of 5-HT, was found both in the ovary and all examined oviductal parts. The strongest fluorescence was present in the ovarian stroma containing small follicles with a diameter under 4 mm. In the wall of the largest preovulatory follicle a very strong fluorescence was located mainly in the theca layer. In the oviductal parts, the intensity of 5-HT fluorescence in the infundibulum and magnum was fairly strong, whereas in the isthmus and shell gland it was weak. Fluorescence seen in the infundibulum, magnum, and isthmus was primarily localized along the luminal borders of the fold surface epithelium. In the shell gland 5-HT fluorescence was found within the uterine folds, especially in the tubular glands. Moreover, the presence of an egg in the definite oviductal segment (infundibulum or isthmus) increased the intensity of yellow fluorescence in this part.     

Immunohistochemical localization of a calcium pump and calbindin-D28k in the oviduct of the laying hen.

The localization of a plasma membrane calcium pump in the oviduct of the laying hen was investigated by immunohistochemical techniques, utilizing a monoclonal antibody (5F10) produced against the human erythrocyte calcium pump. This antibody was shown to react with an epitope of the pump in oviductal tissue, and prominent staining was observed on the microvilli of the tubular gland cells of the hen shell gland (uterus) and the isthmus. The Ca2+ pump was not detectable in the infundibulum or the magnum. Calbindin-D28k, also localized by immunohistochemical means, was observed to be present in the tubular gland cells of the shell gland and the distal isthmus (adjacent to shell gland) but not in either the proximal isthmus (adjacent to the magnum), the magnum or the infundibulum. The localization of the Ca2+ pump in the oviduct corresponds to known sites of mineral deposition during egg shell formation. The distribution of calbindin-D28k differed, co-localizing with the Ca2+ pump in the shell gland and distal isthmus but not in the proximal isthmus. This might reflect a greater rate of active Ca2+ secretion in the distal isthmus and shell gland as compared to the proximal isthmus.     

Histomorphological changes in the oviduct of the mallard (Aves: Anatidae)

Studies on histomorphometrical changes in different segments (infundibulum, magnum, isthmus, shell gland and vagina) of oviduct of mallard, Anas platyrhynchos during active and quiescent phases of the reproductive cycle have been made. The absolute and per cent length and width of each segment showed a marked change. The magnum showed an increase of 280 per cent. Of all the histological parameters studied the number and height of mucosal folds and mucosal epithelium showed more marked increase in all segments of oviduct. The size of tubular glands and frequency of ciliated and secretory cells were studied in relation to oviductal activity.     

Acid glycosidases in the isthmus of the hen oviduct and egg shell membranes

Specific activities of seven acid glycosidases: beta-hexosaminidase, alpha- and beta-galactosidase, alpha- and beta-mannosidase, alpha-glucosidase and alpha-fucosidase were determined in various parts of the domestic hen oviduct (infundibulum, isthmus, shell gland and vagina). The activity of most enzymes was the highest in the isthmus. Multiple forms of all acid glycosidases from the isthmus were separated by strong anion exchange chromatography at pH 6.0. The isoelectric points of the isthmus forms of beta-hexosaminidase, beta-galactosidase and alpha- and beta-mannosidase were determined by chromatofocusing. For the first time the high beta-galactosidase activity was found in hen egg shell membranes.     

Immunohistochemical localization of a calcium pump and calbindin-D28k in the oviduct of the laying hen

Summary The localization of a plasma membrane calcium pump in the oviduct of the laying hen was investigated by immunohistochemical techniques, utilizing a monoclonal antibody (5F10) produced against the human erythrocyte calcium pump. This antibody was shown to react with an epitope of the pump in oviductal tissue, and prominent staining was observed on the microvilli of the tubular gland cells of the hen shell gland (uterus) and the isthmus. The Ca²⁺ pump was not detectable in the infundibulum or the magnum. Calbindin-D_28k, also localized by immunohistochemical means, was observed to be present in the tubular gland cells of the shell gland and the distal isthmus (adjacent to shell gland) but not in either the proximal isthmus (adjacent to the magnum), the magnum or the infundibulum. The localization of the Ca²⁺ pump in the oviduct corresponds to known sites of mineral deposition during egg shell formation. The distribution of calbindin-D_28k differed, co-localizing with the Ca²⁺ pump in the shell gland and distal isthmus but not in the proximal isthmus. This might reflect a greater rate of active Ca²⁺ secretion in the distal isthmus and shell gland as compared to the proximal isthmus.     

Ultrastructural changes in the oviduct of the laying hen during the laying cycle

The ultrastructural changes occurring in the fully functional oviduct of Isa Brown laying hens were studied during various stages of the laying cycle. Hens were killed at different positions of the egg in the oviduct. The oviduct was lined by ciliated and non-ciliated cells (also referred to as granular cells). The granular cells in the infundibulum contributed to secretion during egg formation, whereas ciliated cells showed little evidence of secretion. Ultrastructural changes were recorded in the granular and glandular cells of the distal infundibulum. In the magnum, the surface ultrastructure revealed glandular openings associated with the ciliated and granular cells. Cyclic changes were recorded in the glandular cells of the magnum. With respect to the three observed types of glands, the structure of gland type A and C cells varied at different egg positions in the oviduct, whereas type B cells represented a different type of gland cell containing amorphous secretory granules. The surface epithelium of the isthmus was also lined by mitochondrial cells. Two types of glandular cell (types 1 and 2) were recorded in the isthmus during the laying cycle. Intracisternal granules were found in type 2 cells of the isthmus. A predominance of glycogen particles occurred in the tubular shell gland. The granular cells in the shell gland contain many vacuoles. During egg formation, these vacuoles regressed following the formation of extensive rough endoplasmic reticulum; the reverse also occurred. The disintegrated material found in the vacuoles may have been derived from the disintegrating granules. The Physiology Teaching Unit, University of New England, provided financial support to K. Chousalkar for this study.     

Presence of histamine and mast cells in chicken oviduct

The purpose of the present study was: (1) to demonstrate immunocytochemically the localization of histamine in the wall of four chicken oviductal parts, i.e. infundibulum, magnum, isthmus, and shell gland, (2) to identify the presence of mast cells in chicken oviduct, and (3) to determine histamine concentration in oviductal tissue by the spectrofluorometric method. Experiments were carried out on Isa Brown laying hens decapitated just after oviposition. The specific immuno-reactivity for histamine and the presence of mast cells were found in the wall of all the examined oviductal parts. The immuno-reactive histamine was localized in epithelium, tubular glands, connective tissue layer, circular and longitudinal muscles, and endothelium and muscles of blood vessels. The intensity of immuno-positive reaction was as follows: infundibulum > shell gland > magnum = isthmus and correlated with quantitatively determined histamine level and tissue density of mast cells. It is suggested that mast cells are the main source of histamine in the chicken oviduct.     

Histology and functional morphology of the female reproductive tract of the tortoise Gopherus polyphemus

The oviducts of 25 tortoises (Gopherus polyphemus) were examined by using histology and scanning electron microscopy to determine oviductal functional morphology. Oviductal formation of albumen and eggshell was of particular interest. The oviduct is composed of 5 morphologically distinct regions; infundibulum, uterine tube, isthmus, uterus, and vagina. The epithelium consists of ciliated cells and microvillous secretory cells throughout the oviduct, whereas bleb secretory cells are unique to the infundibulum. The epithelium and endometrial glands of the uterine tube histologically resemble those of the avian magnum which produce egg albumen and may be functionally homologous. The isthmus is a short, nonglandular region of the oviduct and appears to contribute little to either albumen or eggshell formation. The uterus retains the eggs until oviposition and may form both the fibrous and calcareous eggshell. The endometrial glands are histologically similar to the endometrial glands of the isthmus of birds, which are known to secrete the fibers of the eggshell. These glands hypertrophy during vitellogenesis but become depleted during gravidity. The uterine epithelium may supply "plumping water" to the egg albumen as well as transport calcium ions for eggshell formation. The vagina is extremely muscular and serves as a sphincter to retain the eggs until oviposition. Sperm are found within the oviductal lumen and endometrial glands from the posterior tube to the anterior uterus throughout the reproductive cycle. This indicates sperm storage within the female tract, although the viability and reproductive significance of these sperm are unknown.     

Cell-specific and temporal aspects of gene expression in the chicken oviduct at different stages of the laying cycle

Egg formation and embryonic development occur as the yolk passes through the magnum, isthmus, and shell gland of the oviduct before oviposition in hens. The present study identified candidate genes associated with secretory function of the chicken oviduct after ovulation and contributing to egg formation and oviposition. Hens (n = 5 per time point) were euthanized to recover the reproductive tract when the egg was in the magnum (3 h after ovulation) and the shell gland (20 h after ovulation). Total RNA was extracted from each segment of the oviducts and subjected to Affymetrix chicken GeneChip analysis. Quantitative PCR and in situ hybridization analyses of selected genes confirmed the validity of the gene expression patterns detected using microarray analysis. In particular, ACP1, CALB1, CYP26A1, PENK, RCAN1 and SPP1 expression increased significantly in the shell gland between 3 h and 20 h postovulation, whereas only RCNA1 expression increased significantly in the magnum between 3 h and 20 h postovulation. Results of the high-throughput analysis revealed cell-specific and temporal changes in gene expression in the oviduct at 3 h and 20 h postovulation in laying hens provide novel insight into changes at the molecular and cellular levels of candidate genes related to formation of the egg and oviposition.     

Involvement of alpha 1- and alpha 2-adrenergic receptors in the hypothalamo-pituitary-ovarian axis of the domestic fowl, Gallus domesticus

The alpha 1-adrenergic receptor ligand, 3H-WB4101, and the alpha 2-adrenergic receptor ligand, 3H-para-aminoclonidine, were utilized at a 1.0 nM incubation concentration to determine relative alpha 1-and alpha 2-adrenergic receptor binding by cell membranes from selected tissues within the brain, ovary and oviduct of the domestic fowl. Significant specific alpha 1-adrenergic binding was observed in the hypothalamus, anterior pituitary, pineal, cerebrum and cerebellum but only the cerebrum had significant alpha 2-receptor binding. Significant levels of alpha 1-adrenergic binding were observed in the granulosa cells of the three largest ovarian follicles and in the postovulatory follicle. Significant specific alpha 2-adrenergic binding was measured in the infundibulum, magnum, isthmus and shell gland of the oviduct. The physiological implications of alpha-adrenergic receptors in these tissues are discussed.     

北京鸭产卵期输卵管管状腺细胞超微结构研究

用电子显徽镜对北京鸭输卵管管状腺细胞进行观察。鸭输卵管由五部分组成:漏斗、蛋白分泌部、峡部、壳腺和阴道。蛋白分泌部的管状腺细胞有四种类型。A型细胞有电子密度深色颗粒;B型细胞充满了无定型低电子密度物质;C型细胞具有非常明显的粗面内质网和高尔基复合体;D型细胞是由致密的颗粒和低电子密度的颗粒所组成,腔内充满分泌颗粒。我们在这篇文章中分析了蛋白分泌周期的四个不同阶段。     

Effect of prostaglandins on oviduct tone in the domestic hen in vivo

The effect of i.v. injected prostaglandins (PG) F₂α and E₂ on intraluminal pressure of the different oviductal parts (infundibulum, magnum, isthmus, uterus and vagina) was investigated in the domestic hen. PGF₂α induced only a pressure rise in all oviduct segments. Administration of PGE₂ resulted in variable changes in oviductal tone: pressure rise in the infundibulum; pressure increase often preceded by a small decrease in the magnum, isthmus and uterus; pressure decrease in the vagina and sometimes in the uterus. Simultaneous i.v. injection of both PG's induced mostly a decrease in vaginal tone. Intraluminal administration of PGF₂α or E₂ resulted only in an increase in uterine pressure.The observed effects on oviduct tone are discussed and a possible in intervention of both PG's in the mechanism of ovum transport and oviposition in the domestic hen is proposed.     

Seasonal changes in the oviduct of the pied myna (Aves: Sturnidae)

Study of the oviduct of the pied myna (Sturnus contra contra) throughout the year reveals that oviductal weight, length, surface epithelial height and glycogen content are low during August to January (nonbreeding phase), partially increase during February to April (pre-breeding phase), maximally increase in May (breeding phase) and decrease in June and July (post-breeding phase). In the nesting cycle, there is greatest growth in all the regions of the oviduct from early nest-building to the egg-laying period and this is followed by rapid involution during incubation and nestling periods. Some notable features in the oviduct of the pied myna are described: 1) All five regions of the oviduct (infundibulum, magnum, isthmus, uterus, and vagina) are clearly distinguishable when studied from serial sections of the oviduct even during the nonbreeding phase of the annual ovarian cycle. 2) There is a strong correlation between initiation of tubular gland formation and the onset of nestbuilding activity. 3) The distal part of the magnum is differentiated into a 'mucous region' having well developed basal nonciliated cells. 4) A sixth zone can be identified between the magnum and isthmus. Sperm hostlike glands exist at the cranial end of the zone. 5) Several circular epithelial invaginations are evident in the intermucosal folds and their size decreases in centripetal order in the vagina. 6) The pattern and degree of regression are different in various regions of the oviduct. A close synchrony between ovarian and oviducal cycles is indicated in the pied myna (Sturnus contra contra).     

The occurrence of neutral and acidic mucins in the reproductive tract of the laying hen

Summary The tissues of the domestic hen's reproductive tract have been shown to contain both acidic and neutral mucins. The presence of an egg in the isthmus was always accompanied with an increase in the concentration in the isthmus secretory epithelium of PAS-positive mucins without free acidic groups. Staining of uterine tissue for strongly acidic groups with basic dyes was greater when an egg had been present in the shell gland at the time of death and the same was true for tissues of the upper oviduct. The results are discussed with special reference to the periodic secretion of organic mammillary core and egg shell mucins.     

Involvement of osteopontin in egg shell formation in the laying chicken

Expression of the osteopontin (OPN) gene in the oviduct of the laying hen was studied. It was detected only in the egg shell gland (ESG), where massive calcification occurs. No OPN gene expression was detected in any other part of the oviduct, such as the magnum and isthmus. The OPN gene was expressed in a circadian fashion during the daily egg cycle only during the period of egg shell calcification. No OPN gene expression was detected in the ESG of a pre-laying hen before the onset of reproduction, or after forced removal of the egg close to its entrance into the ESG. OPN was found to be synthesized by the epithelial cells of the ESG lining the lumen. Upon synthesis, OPN is immediately secreted out of cells and accumulates in the egg shell. These findings demonstrate for the first time temporal and spatial association of OPN with egg shell calcification. OPN, which was found to be part of the organic matrix of the egg shell, may play an important role in egg shell calcification.     

Zinc Secretion in the Oviduct of the Coturnix Quail

The oviduct from laying quail were used to investigate mechanisms of trace mineral secretion and the possible role of metallothionein in this process. Secretion of zinc occurred maximally at pH 5.4, which is close to the normal pH of the oviduct. Secretion occurred to a much greater extent in the isthmus and shell gland than in the magnum, the major protein-secretory section of the oviduct. Intraperitoneal administration of cadmium resulted in a marked reduction in Zn secretion from the oviduct of laying quail. This effect could not be correlated with metallothionein since metallothionein could not be detected in any section of the oviduct in control or Cd-induced quail. Small-molecular-weight metal-binding ligands were present in the isthmus and shell gland, which may play a role in trace mineral mobilization. Histological evaluation by light and elelctron microscopy show that Zn is transported from the smooth muscle cells through the connective tissue matrix in the extracellular space to the epithelial goblet cells. Presumably, Zn and other trace minerals are secreted from the secretory goblet cells into the egg.     

Role of hydroxyl radical scavengers dimethyl sulfoxide,alcohols and methional in the inhibition of prostaglandin biosynthesis

Prostaglandin (PG) F_2α provoked a contraction of longitudinal tissue strips from the uterine, vaginal and isthmus regions of the chicken oviduct; no response was induced in longitudinal tissue strips from the magnum and infundibulum.PGE₂ induced a contraction of circular and longitudinal uterine strips and of circular strips from the isthmus and infundibulum. With both circular and longitudinal vaginal strips a relaxation was obtained. A dose-dependent response was observed with circular magnum strips: contraction with low doses and relaxation at higher doses. No response was obtained with longitudinal tissue strips from the isthmus, magnum and infundibulum.The possible influence of both prostaglandins in the mechanism of ovum transport and oviposition in the domestic hen is discussed.     

Expression of TLR2/4 in the sperm‐storing oviduct of the Chinese soft‐shelled turtle Pelodiscus sinensis during hibernation season

The initiation of innate immunology system could play an important role in the aspect of protection for sperms long‐term storage when the sperms got into oviduct of turtles and come into contact with epithelium. The exploration of TLR2/4 distribution and expression in oviduct during hibernation could help make the storage mechanism understandable. The objective of this study was to examine the gene and protein expression profiles in Chinese soft‐shelled turtle during hibernation from November to April in the next year. The protein distribution of TLR2/4 was investigated in the magnum, isthmus, uterus, and vagina of the turtle oviduct using immunohistochemistry, and the gene expression of TLR2/4 was analyzed using quantitative real‐time PCR (qRT‐PCR). The results showed positive TLR2 protein expression primarily in the epithelium of the oviduct. TLR4 immunoreactivity was widely observed in almost every part of the oviduct, particularly in the epithelium and secretory gland membrane. Analysis of protein, mRNA expression revealed the decreased expression of TLR2/4 in the magnum compared with the isthmus, uterus, and vagina during hibernation. The protein and mRNA expression of TLR2 in the magnum, isthmus, uterus, and vagina was decreased in April compared with that in November. TLR4 protein and mRNA expression in the magnum, isthmus, uterus and vagina was decreased in November compared with that in April. These results indicated that TLR2/4 expression might protect the sperm from microbial infections. In contrast to the function of TLR2, which protects sperm during the early stages of hibernation, TLR4 might play a role in later stages of storage. The present study is the first to report the functions of TLR2/4 in reptiles.