scholarly journals The immunohistochemical presence and distribution of ghrelin, apelin and their receptors in dog ovaries

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Carolina Pirino ◽  
Margherita Maranesi ◽  
Angela Polisca ◽  
Alessandro Troisi ◽  
Cecilia Dall'Aglio

The activity of ghrelin, apelin and their receptors has been correlated to the control of some infectious diseases, besides the hypothesis of their role in the control of some peripheral organs, among which ovaries. The aim of the present work was to highlight the presence and distribution of ghrelin, apelin and cognate receptors in the ovaries of pregnant bitches, by means of immunohistochemical techniques. Apelin, its receptor and the receptor of ghrelin were highlighted in the corpora lutea, with a particular localization in the cytoplasm of some luteal cells. Instead, a positive reaction for ghrelin was evident in the walls of small arteries in the connective tissue. These results allowed us to hypothesize that these molecules intervene in the control of ovaries in pregnant bitches, suggesting autocrine/paracrine mechanisms of regulation.

1973 ◽  
Vol 21 (3) ◽  
pp. 321 ◽  
Author(s):  
MJ Smith ◽  
RA How

Reproduction was studied in eight female T. caninus held in captivity in Armidale, N.S.W., for up to 5 yr. Oestrus was diagnosed from the vast increase in epithelial cells in the vaginal smear, post-oestrus being detected by the appearance of many leucocytes and of some elongate epithelial cells. The mean of 17 oestrous cycles was 26.4+- 1.0 days and the mean of 10 gestation periods was 16.2+-0.2 days. The teats evert and the female first ovulates at the end of her 2nd year, but no captive female gave birth till near the end of her 3rd year. In the anatomy of the uteri and vaginae, T. caninus resembles T. vulpecula but the ovaries of T. caninus are markedly distinguished by the presence of up to seven large corpora lutea. Although the weight of the luteal tissue may contribute as much as 83.9 % of the total ovarian weight, there is no evidence from the uteri that these large corpora lutea are functional in hormone secretion. The luteal cells are large but vacuolated and are separated by a well developed network of connective tissue. As the corpora lutea persist throughout the life of the animal, it is suggested that their number be used to indicate the maximum age of the animal.


1979 ◽  
Vol 27 (5) ◽  
pp. 881 ◽  
Author(s):  
AG Lyne ◽  
DE Hollis

Ovaries from the bandicoots I. macrourus and P. nasuta, collected during pregnancy and lactation, were examined macroscopically and with the light microscope. The mean number of corpora lutea (CL) was greater in I. macrourus (5.13) than in P. nasuta (3.31). This difference in ovulation rate was reflected in the mean number of embryos and the mean number of pouch young respectively (I. macrourus 4.05, 3.07; P. nasuta 2.63, 2.65). During the first few days of pregnancy, the transformation of follicle granulosa cells into luteal cells was accompanied by the intrusion of the theca, which produced a network of blood vessels and connective tissue. A conspicuous feature of the developing CL was the presence of pools of blood between the luteal cells. By 5-6 days of pregnancy, the CL was a fully formed structure, the central cavity having been filled in by hypertrophy of the luteal cells and an increase in the connective tissue which formed a central core. The luteal cells had almost reached their maximum size and they contained numerous lipid droplets. Mitoses of luteal cells were not evident at any stage in the formation of the CL or later, though some of the luteal cells had two or more nuclei. The structure of the CL and the diameter of the luteal cells and their nuclei remained almost constant until regression occurred after the 45th day of the 60-day lactation period. Regression of the CL was characterized by a marked reduction in the size of the luteal cells and their nuclei as well as an increase in the connective tissue component. Diameters and volumes of the CL were similar in the two species, reaching maxima during the second half of pregnancy and changing very little until the 45th day of lactation, after which they decreased rapidly. This decline occurred whether or not the animals subsequently ovulated during the last quarter of the lactation period.


1968 ◽  
Vol 59 (2_Suppl) ◽  
pp. S35-S51 ◽  
Author(s):  
B. L. Lobel ◽  
E. Levy

ABSTRACT Activities of various hydrolases and dehydrogenases were studied during the formation, development and involution of cyclic corpora lutea and in the corpora lutea of early pregnancy. At 24 hours postovulation the luteal cells, whether of granulosal or thecal origin, contained demonstrable levels of Δ5-3β-hydroxysteroid dehydrogenase and the NADP and NADPH2 diaphorases. During the period of proliferation and cellular growth, enzymic activities in the luteal cells were moderate at first, and then increased. In the mature corpus luteum, activities of the dehydrogenases occurred in all luteal cells but were most intense in the large polymorphic luteal cells. Activities of hydrolytic enzymes, low in the immediate postovulatory period, increased with the development of the vascular system. Enzymic characteristics of corpora lutea of gestation were similar to those of cyclic corpora, except for phosphorylase activity which was observed in luteal cells in gestational corpora, but confined to the vascular walls in cyclic corpora. No increase in activities of 17β- and 20β-hydroxysteroid dehydrogenases (above those seen in pre-ovulatory follicles) were observed after incubation of sections of either mature cyclic or gestational corpora. Involution of cyclic corpora lutea began with degenerative changes in the blood vessels: pyknosis of the endothelial cell nuclei and a sudden decline in activities of hydrolytic enzymes in the vascular walls. Subsequently, the luteal cells showed a sharp decrease in activities of the dehydrogenases as well as other signs of regressive change. The cytochemical findings are discussed in relation to biochemical observations on steroid synthesis by the bovine corpus luteum.


1986 ◽  
Vol 113 (4) ◽  
pp. 570-575 ◽  
Author(s):  
Firyal S. Khan-Dawood

Abstract. Immunoreactive oxytocin is detectable in the corpora lutea of women and cynomolgus monkeys by radioimmunoassay. To localize the presence of oxytocin and neurophysin I in ovarian tissues of subhuman primates, three corpora lutea and ovarian stromal tissues and two Fallopian tubes obtained during the menstrual cycle of the baboon and decidua from two pregnant baboons were examined using highly specific antisera against either oxytocin or neurophysin I and preoxidase-antiperoxidase light microscopy immunohistochemistry. Oxytocin-like as well as neurophysin I-like immunoreactivities were found in some cells of all the corpora lutea only, but could not be demonstrated in ovarian stromal tissues, Fallopian tubes and decidua. Specificity of the immunocytochemical reaction was further confirmed by immunoabsorption of the antiserum with excess oxytocin or neurophysin, after which the immunoreactivities for both oxytocin and neurophysin in the luteal tissue were negative. Similar controls using normal rabbit serum gave no positive staining for either oxytocin or neurophysin. Counterstaining of the positive immunoreactivities for oxytocin and neurophysin I with Mayer's haematoxylin and eosin demonstrated clearly that the oxytocin and neurophysin I appeared as granular material mainly within the cytoplasm of the luteal cells. The localization of immunoreactive oxytocin and neurophysin I in the corpus luteum of the baboon demonstrates directly the presence of these two neurohypophysial peptides within primate luteal cells and suggests their local production.


1997 ◽  
Vol 45 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Firyal S. Khan-Dawood ◽  
Jun Yang ◽  
M. Yusoff Dawood

We have recently shown the presence of E-cadherin and of α- and γ-catenins in human and baboon corpora lutea. These are components of adherens junctions between cells. The cytoplasmic catenins link the cell membrane-associated cadherins to the actin-based cytoskeleton. This interaction is necessary for the functional activity of the E-cad-herins. Our aim therefore was to determine the presence of α-actin in the baboon corpus luteum, to further establish whether the necessary components for E-cadherin activity are present in this tissue. An antibody specific for the smooth muscle isoform of actin, α-actin, was used for these studies. The results using immunohistochemistry show that (a) α-actin is present in steroidogenic cells of the active corpus luteum, theca externa of the corpus luteum, cells of the vasculature, and the tunica albuginea surrounding the ovary. The intensity of immunoreactivity for α-actin varied, with the cells of the vasculature reacting more intensely than the luteal cells. A difference in intensity of immunoreactivity was also observed among the luteal cells, with the inner granulosa cells showing stronger immunoreactivity than the peripheral theca lutein cells. There was no detectable immunoreactivity in the steroidogenic cells of the atretic corpus luteum. However, in both the active and atretic corpora lutea, α-actin-positive vascular cells were dispersed within the tissue. (b) Total α-actin (luteal and non-luteal), as determined by Western blot analyses, does not change during the luteal phase and subsequent corpus luteum demise (atretic corpora lutea). (c) hCG stimulated the expression of α-actin and progesterone secretion by the early luteal phase (LH surge + 1–5 days) and midluteal phase (LH surge + 6–10 days) cells in culture, but only progesterone in the late luteal phase (LH surge + 11–15 days). The data show that α-actin is present in luteal cells and that its expression is regulated by hCG, thus suggesting that E-cadherin may form functional adherens junctions in the corpus luteum.


Reproduction ◽  
2001 ◽  
pp. 587-594 ◽  
Author(s):  
T Tsubota ◽  
S Taki ◽  
K Nakayama ◽  
JI Mason ◽  
S Kominami ◽  
...  

The Japanese black bear, Ursus thibetanus japonicus, is a seasonal breeder and shows delayed implantation for several months during pregnancy. The objective of this study was to clarify the steroidogenic capability of the corpus luteum and placenta during pregnancy, including both delayed implantation and fetal development, by immunolocalization of steroidogenic enzymes in these organs of the Japanese black bear. Ovaries and placentae from 15 wild Japanese black bears, which had been killed legally by hunters and were thought to be pregnant, were used in an immunocytochemical study to localize the cholesterol side chain cleavage cytochrome P450 (P450scc), 3beta-hydroxysteroid dehydrogenase (3betaHSD), 17alpha-hydroxylase cytochrome P450 (P450c17) and aromatase cytochrome P450 (P450arom) by the avidin-biotin-peroxidase complex method using polyclonal antisera raised in mammals against P450scc, 3betaHSD, P450c17 and P450arom. P450scc and 3betaHSD were localized in all luteal cells throughout pregnancy. P450c17 was present in a few luteal cells, especially in the outer area of the corpus luteum throughout pregnancy, but the number of positively immunostained cells decreased during the post-implantation period. Cells positively immunostained for P450c17 were significantly smaller than negatively immunostained cells (P < 0.01). P450arom was present sporadically in a few luteal cells throughout pregnancy, but the number of positively immunostained cells decreased during the post-implantation period. The size of cells positively immunostained for P450arom was not significantly different from that of negatively immunostained cells. The whole placenta was negatively immunostained for P450scc, 3betaHSD and P450c17, but P450arom was present in the syncytiotrophoblasts and endothelial cells of maternal blood vessels. These results indicate that, in the Japanese black bear, corpora lutea are a source of progesterone which may play an important role in the maintenance of delayed implantation and fetal development during pregnancy. Corpora lutea have a minimum capability to synthesize androgen in small luteal cells and oestrogen in normal-sized luteal cells during pregnancy, and placentae have the ability to synthesize oestrogen during late pregnancy.


Author(s):  
Andrea C. Adams

Many immune-mediated diseases and infections affect the central and peripheral nervous systems. The common feature that characterizes both immune-mediated diseases and infections is a subacute temporal profile. Immune-mediated disease can affect only the nervous system or involve the nervous system as part of a systemic illness, as in vasculitis and connective tissue disease. Multiple sclerosis (MS), the most common disabling neurologic illness of young people, is the prototypical immune-mediated disease of the central nervous system (CNS).


1996 ◽  
Vol 1996 ◽  
pp. 69-69
Author(s):  
AJ Holt ◽  
RG Rodway ◽  
JBC Findlay ◽  
HS Sands ◽  
DN Batchelder

The role of β-carotene in the fertility of ruminant animals has long been acknowledged (Friesecke, 1978). Initially this was thought to be due to its action as a vitamin A precursor but recently β-carotene itself has been considered responsible for improving reproductive performance (Hurley & Doane, 1989). The mechanism by which β-carotcne acts is unclear, but as its concentration in the corpus luteum was typically found to be 70μg per gram of tissue, its biological action is probably exerted in this area.β-Carotene has been studied in the bovine corpus luteum using Raman spectroscopy, high performance liquid chromatography (HPLC) and gel filtration chromatography. The structure of β-carotene produces a characteristic Raman spectrum and by utilising an imaging technique, photographs of isolated luteal cells were obtained indicating the regions of β-carotene within them. Differential centrifugation was used to obtain pure subcellular fractions of luteal cells.


1982 ◽  
Vol 95 (1) ◽  
pp. 65-70 ◽  
Author(s):  
G. J. S. Tan ◽  
R. Tweedale ◽  
J. S. G. Biggs

The effects of oxytocin on dispersed luteal cells from human corpora lutea of the menstrual cycle were studied. Oxytocin at a concentration of 4 mi.u./ml produced a slight increase in basal progesterone production. However, higher oxytocin concentrations (400 and 800 mi.u./ml) markedly inhibited both basal and human chorionic gonadotrophin-induced progesterone production. These data provide evidence for an effect of oxytocin on the human corpus luteum. In view of the inhibitory action of oxytocin, increased secretion of this hormone may be important in the demise of the corpus luteum at the end of the menstrual cycle.


1978 ◽  
Vol 56 (8) ◽  
pp. 1684-1696 ◽  
Author(s):  
T. Charles Dauphiné Jr.

Reproductive tracts were collected from 532 female caribou (Rangifer tarandus groenlandicus) in northern Canada over a [Formula: see text]-year period. Ovaries were weighed and scrutinized by gross and histological techniques. Ovaries of nulliparous and nongravid, parous cows responded to follicular fluctuations by increasing in weight in summer and declining in winter. Weights of ovaries from calves, yearlings, and 2 year olds overlapped extensively. Formation of corpora lutea of pregnancy more than doubled ovary weight. During gestation ovary weight declined and then partially recovered; it increased with age in pregnant cows. The number and size of follicles [Formula: see text] diameter increased with age until puberty, reaching greatest development just before the autumn rut. After puberty the seasonal incidence of such follicles remained stable except during gestation, when it declined. Corpora lutea of pregnancy regressed to form apparently permanent scars composed of vascular and connective tissue remnants. Secondary corpora lutea developed in 35% of the cows at or before conception and upon regression produced scars which were not permanent. Regressing corpora lutea of estrus also disappeared into the ovarian stroma, apparently within 1 year. In individual cows one ovary, selected at random, dominated in the production of ova and corpora lutea.


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