Avian Oviduct Research Articles

Support for chromatin acidic proteins as acceptors for progesterone in the chick oviduct

Studies in this laboratory have supported the role of chromosomal protein-DNA complexes as the nuclear acceptor sites for progesterone in the avian oviduct. The protein coacceptor appears to be a low molecular weight acidic protein(s) which when removed from the DNA results in a marked loss of binding by the activated progesterone-receptor complex. When the protein is reannealed back to the pure DNA, the binding capacity is restored. During studies on these nuclear binding sites for progesterone in the hen oviduct, a seasonal variation in the level and function of the progesterone receptor (P-R) was detected. Cytosol preparations obtained from the chick oviducts during the winter/ spring period between January and May display reduced receptor levels as well as a loss of the capacity of the receptor to bind to nuclear “acceptor” sites in vitro. The binding of [ 3H]-P-R to whole chromatin or purified acceptor proteins reannealed to DNA display the same rhythm. No such rhythm is detected for the binding of P-R to pure DNA. The nuclear binding in vivo, achieved by injecting [ 3H]-progester-one into the wing vein and analyzing the radioactivity localized in the oviduct nuclei, also displays a similar rhythm. These results indicate that the native nuclear acceptor sites for progesterone in the chick oviduct are protein-DNA complexes and not pure DNA. The failure of P-R to bind the nuclear acceptor sites in vivo and in vitro during this period can be explained by the two subunit hypothesis of Schrader and O'Malley, whereby one of the two subunits is absent or inactive during this period.

Study of the motility of the avian oviduct with chronically implanted electrodes.

Electrical activity was recorded in conscious hens from chronically implanted electrodes in the smooth muscle layers of the oviduct. Transport of the egg through the magnum resulted from an inhibition of the electrical activity in the oviduct cranial to the egg and an increased spiking activity caudally. During an ovulatory cycle the progression of the egg was related to four different patterns of the uterine motility: within a sequence, the ovulatory cycles varied according to the duration of Phases 3 and 4.

Nuclear Binding Sites (“Acceptors”) for Progesterone in Avian Oviduct: Characterization of the Highest‐Affinity Sites*

Nuclear Binding Sites (“Acceptors”) for Progesterone in Avian Oviduct: Characterization of the Highest‐Affinity Sites^*

Role of nuclear proteins as high affinity sites (“acceptors”) for progesterone in the avian oviduct

Administering multiple doses of progesterone to immature chicks results in the detection of several classes of oviduct nuclear binding sites. Comparisons of serum progesterone levels and responses to RNA polymerase I and II activities with the nuclear binding, indicate that the highest affinity classes of sites are the biologically important ones. In vitro binding studies using isolated progesterone receptor complex also reveal the presence of these multiple classes of sites. The highest affinity class of nuclear sites in the oviduct, representing 6000 to 10,000 sites per cell with a K D ~ 10 −9 M, appear to be tissue specific. These sites are present but completely masked in the chromatin of non-target organs (spleen and erythrocyte), while 70% are masked in the target tissue (oviduct). Further fractionation studies involving DNA affinity chromatography using chromatin-cellulose resins and molecular sieve-chromatography using Agarose-GuHCl resins reveal that the “acceptor” activity is associated with two molecular weight-proteins between 12,000 and 17,000. These proteins are bound with very high affinity to DNA. The “acceptor-proteins” must be reannealed to DNA to achieve binding activity. These results support that acidic proteins determine the high affinity nuclear binding sites for steroids.

PARATHYROID HORMONE AND EGGSHELL CALCIFICATION IN JAPANESE QUAIL

The effect of parathyroid hormone (PTH) on egg-shell calcification has been investigated in egg-laying Japanese quail. Lilly parathyroid extract (PTE) when injected into quail within 2-6 h of oviposition caused a significantly increased deposition of a chronic 45Ca label into the sequential egg-shell compared with the previous egg in the clutch, indicating increased mobilization of bone Ca and its subsequent incorporation into the egg-shell. At the same time egg-shell weight/unit area and egg-shell Ca/unit area were significantly decreased. Parathyroid extract injected 12-16 after oviposition had none of these effects. Purified PTH also caused a significant decrease in egg-shell weight/unit area if injected within 2-6 h of oviposition. This result indicated an action of PTH either directly or indirectly on the avian oviduct limiting egg-shell calcification. The loss of responses in the 12-16 h treated birds may reflect high endogenous PTH levels with subsequent saturation of target organ receptors.

ATP-PPi exchange activity of progesterone receptor.

Progesterone receptor preparations from avian oviduct catalyze a pyrophosphate (PPi)-exchange reaction between ATP and 32P-labeled PPi. The reaction requires ATP exclusively and is Mn++-dependent. This enzyme activity is detectable in receptor preparations that have been purified extensively by chromatography on ATP-Sepharose and DEAE-Sephadex columns. Polyacrylamide gel electrophoresis of purified preparations reveals a comigration of [3H]progesterone-receptor complex and the enzyme activity. The PPi-exchange reaction is inhibited by both o-phenanthroline and rifamycin AF/013, which also block the nuclear binding of progesterone receptor. These findings indicate that progesterone receptor may be an enzyme or a subunit of an enzyme that is active in nucleotide metabolism.

Avian oviduct motility induced by prostaglandin E 1

Oviduct segments from infundibulum, magnum, uterus, uterovaginal junction and vagina of actively laying hens at preoviposition time were tested for their contractile reaction to prostaglandin E 1 by in vitro or in vivo methods. Maximum stimulatory response was observed from the muscular strips of the proximal oviduct segment (infundibulum) and a complete relaxation was recorded from the distal part (vagina) at molar concentrations of 1.4 × 10 −7, 3.4 × 10 −7 and 7.0 × 10 −7. The uterine strips reacted with a stimulatory response at higher concentrations (1.4 × 10 −6 and 2.8 × 10 −6 moles), but lacked any significant change at lower concentrations. The uterovaginal muscular strips showed a mild but prolonged inhibitory response, while the magnum responded with a significant increase in the luminal pressure when tested in vivo . It is concluded that PGE 1 exerts a stimulatory effect on the uterus to initiate transport of the egg to subsequent segments (uterovaginal junction and vagina), which relax under PGE 1 influence and allow passage of the egg by pressure differences.

Observations on the ultrastructure of the oviduct of the Costa Rican green turtle ( Chelonia mydas L.)

Unpublished investigations have shown that at the light microscope level the oviduct of the green turtle ( Chelonia mydas L.) has two glandular subdivisions each of which appears to be structurally homogeneous. Histochemical studies suggest that the function of the more cranial of these is albumen secretion and that this is its sole function; in its ultrastructural features also it resembles the albumen secreting subdivision (magnum) of the avian oviduct except that it lacks the terminal mucous region to which the formation of the thick layer of egg albumen has been attributed. Layering of albumen (thick and thin layers) is not a characteristic of turtle eggs. The more caudal glandular segment presents ultrastructural features which tend to support the hypothesis that this is the site of shell-membrane formation but the presence of eggs undergoing calcareous shell formation in this subdivision shows that despite its structural homogeneity it is functionally dualistic, secreting both shell membranes and calcareous shell. In the available material ultrastructural features indicative of the latter function could not be demonstrated and further work is required in relation to calcium localization and acid phosphatase which may play a significant rôle in calcium transportation. The glands of the avian uterus in which calcareous shell deposition occurs are believed to be concerned with the addition to the albumen of plumping water. There is evidence that this addition is not a feature of turtle eggs and this may explain the absence of comparable glands in turtle.

Some physiological characteristics of motility in the in vivo avian oviduct.

Some physiological characteristics of motility in the in vivo avian oviduct.

Adrenergic activity of the avian oviduct in vivo

The effect of noradrenaline or isoproterenol, alone or in the presence of an alpha (phenoxybenzamine) or beta (propranolol) adrenergic blocking drugs on the oviducts of anesthetized laying hens was investigated. The results show that both alpha and beta adrenergic activity is present in the avian oviduct with the exception of the uterus which does not appear to have alpha excitatory activity. Norepinephrine induced a strong contraction followed by a brief relaxation period in the infundibulum, magnum and is thmus; administration of phenoxybenzamine blocked this response in all the three segments, indicating the presence of alpha adrenergic receptors. The uterus, however, exhibited an inhibitory response in the majority of the hens and this response was not affected by the administration of phenoxybenzamine. Isoproterenol always induced relaxation in all the four segments of the oviduct. This response was blocked by propranolol, a beta adrenergic blocker, indicating the presence of beta adrenergic receptors. The role of autonomic nerves innervating the reproductive tract in the regulation of reproduction is discussed.

Biochemical, Electron Microscopic, and Cytochemical Studies of ATPase Localization in Avian, Murine, and Human Oviducts

Human mouse and avian oviduct mucosa was studied histochemically and with light and electron microscope for the presence and localization of adenosine triphosphatases (ATPases); peritoneal fluid and serum were also studied. ATPase activity was found in oviductal fluid in all 3 species; no ATPase activity was found in sera and only very small amounts in peritoneal fluid. Light microscopy revealed ATPase-secreting cells most heavily concentrated in the lower preampulla of hens oviducts. ATPase secreting cells in human and mouse oviducts varied with age and hormonal states. Infant postmenopausal and follicular phase oviducts showed few active sites; oviducts from secretory phase oviducts had very high activity along the preampullar mucosal surface. Highest ATPase activity was demonstrated in and on the surface of secretory cells bordering the lumen.

Rapid inactivation of ovalbumin messenger ribonucleic acid after acute withdrawal of estrogen.

Synthesis of ovalbumin mRNA is induced and maintained in the avian oviduct by estrogen. When estrogen is rapidly removed from circulation, there is a general involution of the oviduct and an unusually rapid decay of ovalbumin mRNA activity. The kinetics of ovalbumin mRNA decay were not first order; instead, the rate of degradation increased about 10-fold over a 20-hr period after removal of estrogen. These results are in contrast with first-order decay kinetics observed for ovalbumin mRNA in estrogen-stimulated chicks (t(1/2) = about 24 hr) and in cell-free extracts. The degradative response triggered by hormonal withdrawal becomes more rapid between 1 and 4 days of estrogen-stimulated growth. We conclude that in the process of inducing egg-white protein synthesis, estrogen produces a cellular environment in which the egg-white protein mRNAs are relatively stable; removal of estrogen initiates cellular catabolism in a manner that is not understood.

The effect of progesterone on activities of δ-aminolevulinic acid synthetase and δ-aminolevulinic acid dehydratase in estrogen-primed avian oviduct

The effect of a single dose of progesterone, administered to estradiol-primed chicks, on the activities in oviduct and liver of the first two enzymes of the porphyrin-heme biosynthetic pathway, δ-aminolevulinic acid synthetase (ALAS) and δ-aminolevulinic acid dehydratase (ALAD), has been investigated. The specific activity of ALAS in pooled glandular tissue of uterus and isthmus became significantly elevated at 18–24 hr after hormone injection. ALAD activity in uterine glandular tissue was not significantly increased after such treatment. Progesterone had no effect on hepatic activities of these two enzymes.

Development, cellular growth, and function of the avian oviduct. Studies on the magnum during a reproductive cycle of the domestic fowl (Gallus domesticus).

Development, cellular growth, and function of the avian oviduct. Studies on the magnum during a reproductive cycle of the domestic fowl (Gallus domesticus).

Secretion granules in the ciliated cells of the avian oviduct.

The avian oviduct is subdivided into five regions according to its function in egg formation and histological features. They are the infundibulum, albumen secreting region (magnum), isthmus, shell gland (uterus), and vagina. The epithelium of these regions consists of ciliated and nonciliated cells. In addition to secretion granules, specific to each region, in the non-ciliated cells, considerable numbers of granules in the ciliated cell are characteristic to this organ. In the infundibulum a small number of moderately dense granules are seen both in laying and non-laying birds. The ciliated cells in the magnum have mucous type globules which appear to increase in number in non-laying birds suggesting that they may represent reabsorbed mucous. The isthmus ciliated cell contains complex-type granules composed of a dense cortex and a less dense core. This type of granules are increased in laying birds. Large dense granules are located in the uterus and in the adjacent areas. This type also increases in laying birds. Discharged gramule content was found in the lumen keeping its continuity with the apical granules. These findings were evident in the hen, duck, quail and pigeon. ACPase was not detected and ATPase activity was weak in the dense granule. TPPase appeared to be localized in some of the granules. Electron probe microanalysis of the dense granules did not prove a significant concentration of Ca, indicating that the uterine ciliated cell may not be involved in shell formarion in the uterus gland.

Development, cellular growth and function of the avian oviduct—III. Electrophoretic and immunological patterns of soluble proteins from each region of domestic fowl ( Gallus domesticus) oviduct during a reproductive cycle

1. 1. The soluble proteins, obtained from each region of the domestic fowl ( Gallus domesticus) oviduct in the developing, laying and regressing stages, were analyzed. 2. 2. The electrophoretic pattern of the soluble proteins in the laying-hen magnum is similar to that of egg white protein. The other four regions of the laying-hen oviduct and all regions of developing and regressing oviducts have patterns that are similar to each other but are different to that of egg white protein. 3. 3. Immunological techniques revealed the presence of ovoconalbumin in all regions of the oviduct throughout the entire reproductive cycle. It is also found in the blood of immature chicks and mature hens. Ovomucoid is only found in the magnum and isthmus of the laying hen. Ovalbumin, in contrast, is only found in the magnum. 4. 4. The major portion of ovalbumin is the A1-form (60–70 per cent) while the A3-form is the least. A shift in the proportion of A1-, A2- and A3- ovalbumins may occur during the laying period.

Development, Cellular Growth, and Function of the Avian Oviduct. II. A Comparative Study on the Changes of Cellular Components in each Region of the Domestic Fow1 (Gallus domesticus) Oviduct during a Reproductive Cycle

The levels of cellular components in each region of the domestic fowl (Gallus domesticus) oviduct at various stages of a reproductive cycle (developing, laying, and regressing) were compared. There were differential growth patterns in each region of the oviduct (infundibulum, magnum, isthmus, uterus, and vagina) during a reproductive cycle. The magnum weight, relative to other regions of the oviduct, increased most rapidly during development and growth, and decreased in a similar manner during regression of the oviduct. Development and growth of the oviduct were primarily associated with hyperplasia (increase in total DNA), and to a lesser extent with cellular hypertrophy (dry matter/DNA). Regression of the oviduct was essentially a reversal of the developing oviduct: both total DNA and ratios of dry matter/DNA decreased.The highest ratios of RNA/DNA and protein/DNA were found in the laying-hen oviduct, particularly in the magnum and isthmus. The magnum and isthmus of the laying hen, being actively involved with the formation of secretory soluble and insoluble proteins, respectively, also had the highest respective ratios of soluble protein/DNA and insoluble protein/DNA. The infundibulum, uterus, and vagina, consisting mainly of connective tissue and musculature, are not actively involved in the formation of secretory proteins. These regions of the laying-hen oviduct had low ratios of RNA/DNA and protein/DNA. All regions of the functionally quiescent developing and regressing oviducts had similar and low ratios of RNA/DNA and protein/DNA.The levels of soluble nonprotein nitrogen, when expressed on a cell unit basis, also tended to parallel those of protein while lipid levels remained relatively constant for all regions of the oviduct throughout the various stages of the reproductive cycle.

Autoradiographic localization of calcium in the mucosal cells of the avian oviduct.

The cellular location of calcium in the mucosa of the avian oviduct has been studied by45Ca autoradiography in tissue prepared either by incubation with45Ca or by intravenous injection of45Ca. Freeze-substitution was used to retain easily diffusible calcium in the tissue.In vitro, columnar epithelium of the shell gland acquired significantly more45Ca as the length of incubation time was increased from one to ten minutes and/or when the temperature was raised from 0° to 42°. These effects were diminished by the addition of dinitrophenol to the incubation medium. The tubular glands of this tissue responded minimally. Genrally, after intravenous injection of45Ca, the shell gland sequestered, more radionuclide than the other regions of the oviduct. When an egg shell was being calcified, the columnar epithelium of the shell gland revealed a higher grain count than the tubular glands, but when a shell was not forming, grain counts were similar over the two types of cells.

Sex hormone control mechanisms. I. Effect of estrogen and progesterone on major cellular components in chicken (Gallus domesticus) oviducts.

The role and mode of action of sex hormones in the regulation of avian oviduct metabolism have been investigated. The oviducts of chicks treated with repeated injections of various sex hormones and of untreated hens have been analyzed for their contents of DNA, RNA, protein, lipids, glucose, and glycogen.Estrogen induces a profound growth of chick oviduct primarily by hyperplasia (increased amount of DNA). Cellular hypertrophy (indicated by the ratio dry matter/DNA) accounts for a smaller proportion of the total oviduct growth. Progesterone alone seems to have little or no effect on oviduct growth. Progesterone, in combination with estrogen, however, antagonizes the estrogen-induced hyperplasia of oviduct, but synergizes with estrogen in eliciting cellular hypertrophy. The increase of oviduct growth as influenced by the hormones is mainly contributed to by relatively proportional increases of both protein and lipids. In all cases the changes in total protein parallel the changes in total RNA, thus suggesting RNA formation as a prerequisite for hormonal induction of protein synthesis. Electrophoresis of the soluble oviduct proteins shows that there are qualitative differences among the various treatment groups. Estrogen or estrogen with low level of progesterone is needed for ovalbumin formation. Estrogen or progesterone induces significant increases in glycogen concentrations; combinations of the two hormones exhibit a synergistic effect. The hormone-stimulated synthesis of glycogen seems to depend on accelerated uptake of glucose by oviduct cells.The levels of various cellular components in the hormone-treated chicks are interpreted partially in terms of data obtained from mature hens. The results are discussed in terms of hormone control mechanisms and estrogen–progesterone interactions.

Genital Tract Motility in the Domestic Hen

THE role of the avian oviduct in egg formation has received attention for many years. More recently, the oviduct’s role in the storage and transport of sperm cells has been investigated (see reviews by Hafez, 1968; and Van Teinhoven, 1968). While the spontaneous motility of the oviduct is necessary for both the transport of ovum and of spermatozoa, there has been a minimum of work in the area of oviduct motility.The spontaneous motility pattern of avian vaginal and uterine muscle strips was studied in vitro by Sykes (1955). He demonstrated that contractions of the vagina differed from those of the uterus, being of smaller amplitude and greater frequency. No spontaneous motility was found in the vagina of a non-laying hen and the amplitude of uterine contractions was much lower than those of a laying hen. Sykes was unable to demonstrate differences between regions within the same part of the…