The formation of lymph in the ovary

The lymphatics of the ovaries of pregnant and non-pregnant ewes were outlined either by direct or retrograde injection of indian ink or Berlin blue and the distribution of these vessels within the ovary was determined. In active ovaries the mature follicles and corpora lutea contained a profuse network of lymphatics. In inactive ovaries the lymphatics were very small and poorly developed. Lymph was collected from the ovaries of conscious ewes for periods of several days. The flow of lymph from ovaries with corpora lutea averaged 4.15 ml./h; a maximum rate of flow of 14.9 ml./h was recorded in one ewe. The protein concentration of ovarian lymph was 73 % of the plasma concentration. When 131 I labelled albumin was injected intravenously into ewes it entered the ovarian lymph very rapidly and the specific activities of albumin in the plasma and lymph equilibrated within 10 to 20 min of injection. The structure of the ovarian blood capillaries provided an explanation for the very high rate of lymph flow and protein leakage in the ovary. The endothelium of the blood capillaries was discontinuous with gaps up to 1 to 2 μm in diameter through which red cells, indian ink particles and ferritin passed into the interstitial spaces. Where the basement membrane of the capillaries was deficient over gaps the surfaces of the luteal cells came into direct contact with the circulating plasma, and occasionally cytoplasmic extensions from the luteal cells projected into the lumen of the blood capillaries. The lymphatics which were associated with many of the blood capillaries had open intercellular junctions and material could enter these vessels readily from the interstitial spaces. The blood capillaries in the ovarian stroma and those around immature follicles appeared less permeable than the capillaries of the corpus luteum. The association between the development of the corpus and an increase in lymph production in the ovary suggests the possibility that the changes in capillary permeability may be related to the synthesis and secretion of steroid hormones.

1985 ◽  
Vol 248 (6) ◽  
pp. G670-G675
Author(s):  
J. S. Lee

Lymph flow (JL), lymph protein concentration (CL), and protein output (JP) from the main intestinal lymph duct were determined. The basal JL from the mesenteric pedicle alone was the same as that from the mesenteric pedicle attached with a segment of the nonabsorbing intestine, indicating that the basal JL does not originate from the intestine but is totally from the region of the mesenteric pedicle. The basal CL was 3.5-3.8 g/100 ml. When the intestine was absorbing water, JL increased and CL decreased, but JP increased above the basal JP in the initial 20 min of water absorption and then decreased progressively with time. Furthermore, it was estimated that CL in the "excess lymph" (formed during water absorption) was 1.4 +/- 0.2 g/100 ml in the initial 10 min of water absorption and was zero or nearly so in the later periods. From this and other evidence, it is concluded that under various conditions without net water absorption rat small intestine does not produce lymph and that during water absorption there is no significant increase in capillary permeability or capillary filtration. Therefore, the excess lymph could be mostly derived from the fluid absorbed from the lumen of the intestine.


1988 ◽  
Vol 65 (3) ◽  
pp. 1140-1146 ◽  
Author(s):  
F. Royer ◽  
D. J. Martin ◽  
G. Benchetrit ◽  
F. A. Grimbert

Changes in pulmonary capillary filtration induced by hyperoxia were investigated in 15 dogs. After 12 h of normobaric hyperoxic exposure, animals were anesthetized and artificially ventilated with 100% O2. A pulmonary lymphatic vessel was cannulated, and lymph flow and protein content were measured together with pulmonary and systemic hemodynamics. An increase in pulmonary capillary filtration was found when compared with reference data (normoxic dogs in similar conditions) gathered from available literature: lymph flow increased from 21.8 +/- 13.4 to 125.2 +/- 131.6 microliter/min, and the lymph-to-plasma protein concentration ratio increased from 0.67 +/- 0.08 to 0.78 +/- 0.08. To characterize the mechanisms involved, left atrial pressure was increased in two stages (approximately 10 and approximately 25 mmHg). The results clearly indicated an increase in pulmonary capillary permeability as evidenced by a decrease of the minimal estimate of the protein reflection coefficient from 0.62 +/- 0.05 to 0.42 +/- 0.05.


1985 ◽  
Vol 249 (4) ◽  
pp. H777-H782 ◽  
Author(s):  
T. H. Adair ◽  
A. C. Guyton

Previous studies have shown that lymph nodes function as fluid exchange chambers in which the protein concentration of lymph is changed in the direction required to establish equilibrium of the Starling forces acting across the nodal blood-lymph barrier. We examined the effect of increased lymph hydrostatic pressure on efferent lymph by use of an isolated dog popliteal node preparation in which lymph having a protein concentration averaging 27.6 +/- 1.2% (SD) of that of plasma was infused into the node at a flow rate averaging 45.6 +/- 0.2 (SD) microliter/min. We compared steady-state values of prenodal and postnodal lymph flow and protein concentration following step increases in efferent lymph pressure from 0 to over 15 mmHg. Increasing efferent lymph pressure to values less than about 8 mmHg caused the efferent lymph protein concentration to increase; however, further increases in lymph pressure caused the lymph protein concentration to decrease to values approaching those attained at very low lymph pressures. We suggest that the failure of high lymph pressure to increase lymph protein concentration might be caused by blood vessel collapse within the node, a condition believed to increase nodal blood capillary pressure and to decrease blood-lymph barrier filtration coefficient. An important finding was that increasing efferent lymph pressure caused significant amounts of lymph proteins to be lost during nodal transit. Therefore, it appears that increasing efferent lymph pressure to very high values has little effect on lymph protein concentration but has great effect on postnodal lymph protein flux.


1994 ◽  
Vol 143 (3) ◽  
pp. 423-431 ◽  
Author(s):  
P L Keyes ◽  
J L Kostyo ◽  
R Towns

Abstract The rabbit corpus luteum possesses LH receptors that are coupled to adenylyl cyclase, but paradoxically it does not require LH as a luteotrophic factor for the maintenance of progesterone secretion. This suggests that rabbit luteal cells may not respond physiologically to LH. Therefore, the present study was undertaken to investigate the responsiveness of the rabbit corpus luteum of pseudopregnancy to human chorionic gonadotrophin (hCG) which acts on the same receptor as LH. Pseudopregnancy was induced by injection of 40 IU pregnant mare serum gonadotrophin followed 50 h later by an injection of 40 IU hCG (day 0). On days 7 and 11 of pseudopregnancy, corpora lutea were obtained and incubated for 2 or 5 h in the presence of either 0·1 or 1 μg/ml hCG or 1 mm monobutyryl cyclic AMP (bcAMP). Neither hCG nor bcAMP stimulated progesterone production by the isolated corpus luteum, despite a sustained high rate of progesterone production by the tissue throughout the incubation period. By contrast, Graafian follicles removed from the same ovaries and incubated under the same conditions responded both to hCG and bcAMP with large increases in progesterone production. To determine whether the cyclic AMP content of the corpus luteum was altered by in vitro exposure to hCG, day 7 and day 11 corpora lutea were incubated for 5 or 15 min with various concentrations of hCG, and cyclic AMP in the tissue was then measured. Even at the highest concentration of hCG tested (10 μg/ml), the cyclic AMP content of the corpus luteum was unaltered. Given this result, the acute effects of various concentrations of hCG on the adenylyl cyclase activity of homogenates of day 11 corpora lutea were examined. Consistent with previous reports of others, adenylyl cyclase activity was stimulated, but only at a high concentration of hCG (1 μg/ml), and the degree of stimulation of the enzyme (∼75%) was quite modest. By contrast, the adenylyl cyclase activity of homogenates of rabbit Graafian follicles was stimulated by even the lowest concentration of hCG tested (0·01 μg/ml). Thus, the adenylyl cyclase of the rabbit follicle is much more sensitive to hCG stimulation than the luteal form of the enzyme. Given the poor responsiveness of luteal adenylyl cyclase to hCG, the possibility was considered that cyclic AMP production in response to hCG might be obscured by luteal cell phosphodiesterase. When day 11 corpora lutea were incubated with hCG in the presence of the phosphodiesterase inhibitor, isobutyl methylxanthine (5 mm), there was a marked increase in the cyclic AMP content of the tissue. Despite this large increase in endogenous cyclic AMP, progesterone production by the corpora lutea was again unaffected. Thus, the rabbit corpus luteum is insensitive to stimulation in at least two major respects. The adenylyl cyclase coupled to the LH receptor is resistant to stimulation by LH (hCG), and steroidogenesis, as reflected by progesterone production in vitro, is not stimulated acutely by cyclic AMP. These results suggest that progesterone biosynthesis in the rabbit corpus luteum is not a regulated process, but rather a process that becomes autonomous as a result of the differentiation of granulosa cells into luteal cells. Therefore, the role of a luteotrophin, such as oestrogen in the rabbit, is to maintain the health and viability of the luteal cells, which have, as an intrinsic property, the capacity to produce progesterone at a high rate. Journal of Endocrinology (1994) 143, 423–431


1961 ◽  
Vol 201 (1) ◽  
pp. 81-84 ◽  
Author(s):  
Walton K. T. Shim ◽  
Eugene L. Pollack ◽  
Theodore Drapanas

Serial studies of thoracic duct lymph flow rates and lymph proteins including albumin, globulin and fibrinogen were performed in 22 fasting unanesthetized dogs following intrathoracic cannulation of the thoracic duct with a polyethylene catheter. Serotonin given intravenously (20 µg/kg/min) produced a marked increase in lymph flow (115%) with a 20% decrease in total protein concentration. A single intravenous injection of epinephrine (1 mg) produced a 92% increase in lymph flow accompanied by a 12% increase in protein concentration. Histamine (1 mg) given intravenously also produced a significant increase in lymph flow (127%) but protein concentration remained constant. Hexamethonium chloride (2.5 mg/kg iv) markedly depressed lymph flow rate (50%) without significantly altering lymph protein concentrations. The possible mechanisms of action of each of these agents is discussed. Results indicate that serotonin markedly influences lymph production and lymph protein concentration by a probable selective alteration of capillary permeability rather than by increasing intestinal motility.


1988 ◽  
Vol 59 (01) ◽  
pp. 029-033 ◽  
Author(s):  
K G Chamberlain ◽  
D G Penington

SummaryNormal human platelets have been separated according to density on continuous Percoll gradients and the platelet distribution divided into five fractions containing approximately equal numbers of platelets. The mean volumes and protein contents of the platelets in each fraction were found to correlate positively with density while the protein concentration did not differ significantly between the fractions. Four mitochondrial enzymes (monoamine oxidase, glutamate dehydrogenase, cytochrome oxidase and NADP-dependent isocitrate dehydrogenase) were assayed and their activities per unit volume were found to increase in a very similar monotonie fashion with platelet density. When MAO and GDH were assayed on the same set of density fractions the correlation between the two activities was very high (r = 0.94–1.00, p <0.001) and a similar close correlation was found between MAO and ICDH. The results support the hypothesis that high density platelets either have a higher concentration of mitochondria or have larger mitochondria than low density platelets.


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.


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.


1996 ◽  
Vol 24 (4) ◽  
pp. 358-362 ◽  
Author(s):  
K Kanayama ◽  
H Osada ◽  
K Nariai ◽  
T Endo

The dose-response relationship for the inhibitory effect of indomethacin on implantation and continuance of pregnancy was examined in four groups of rabbits administered with indomethacin (2.5, 5.0, 7.5 and 10.0 mg/kg) during the implantation period and compared with a control group. Implanted fetuses and corpora lutea were counted by laparotomy, and the number of offspring born was noted. The inhibitory effect of indomethacin on implantation was found to be dose–dependent, and the birth rate decreased in the indomethacin groups compared with the control group. As a result, even where implantation had been achieved, death of the implanted fetuses occurred at a high rate in rabbits administered with indomethacin during the implantation period.


Sign in / Sign up

Export Citation Format

Share Document