STEROID METABOLIC PATHWAYS IN THE OVARY OF THE CHINCHILLA (CHINCHILLA LANIGER)

1972 ◽  
Vol 52 (1) ◽  
pp. 37-50 ◽  
Author(s):  
W. H. TAM
Keyword(s):  
Corpus Luteum ◽  
Metabolic Pathways ◽  
Ovarian Tissue ◽  
Controlling Factor ◽  
Steroid Metabolism ◽  
Interstitial Tissue ◽  
Corpora Lutea ◽  
Luteal Tissue ◽  
Kinetic Investigations ◽  
High Yields

SUMMARY The ovarian tissue components of the pregnant chinchilla were incubated with equimolar amounts of [7α-3H]pregnenolone and [4-14C]progesterone. The greater contribution by [7α-3H]pregnenolone than by [4-14C]progesterone towards the formation of 17α-hydroxyprogesterone and androstenedione, and the relatively high yields of 17α-hydroxypregnenolone and dehydroepiandrosterone showed that both the 4-ene and 5-ene pathways of steroid metabolism were used in the interstitial tissue. No significant amount of 17α-hydroxylation was observed in the primary and accessory corpora lutea. The results of kinetic investigations using [7α-3H]pregnenolone as substrate also demonstrated a precursor—product relationship between dehydroepiandrosterone and androstenedione in the interstitial tissue, but this was not apparent in the luteal tissue. The results indicated that the interstitial tissue was capable of synthesizing progesterone and oestrogens as major products, and that the lack of 17α-hydroxylation in the luteal tissue was a controlling factor ensuring the synthesis of progesterone as its principal hormonal product. A small amount of [4-14C]dehydroepiandrosterone was always isolated with a much larger amount of the tritiated compound. This implied the conversion of 14C-labelled 4-en-3-oxosteroids into 5-ene-3β-hydroxysteroids which has generally been regarded as impossible. The isolation of this product, which may be an artifact, and the possibility that progesterone and oestrogens may be synthesized by different cells (granulosa and theca lutein cells) in the corpus luteum, or that there may be a third pathway for oestrogen synthesis, as suggested by the results of the kinetic experiments, are discussed.

Ovarian steroid metabolism and oestrogens in the corpus luteum of the tammar wallaby

1984 ◽  
Vol 101 (2) ◽  
pp. 231-NP ◽  
Author(s):  
M. B. Renfree ◽  
A. P. F. Flint ◽  
S. W. Green ◽  
R. B. Heap
Keyword(s):  
Corpus Luteum ◽  
Follicular Development ◽  
Hydroxysteroid Dehydrogenase ◽  
Tammar Wallaby ◽  
Steroid Metabolism ◽  
Interstitial Tissue ◽  
Corpora Lutea ◽  
Embryonic Diapause ◽  
Probable Source

ABSTRACT Ovaries were obtained from tammar wallabies at various stages of the reproductive cycle to examine the occurrence of oestrogens in corpora lutea, and the synthesis and metabolism of steroids in the corpus luteum and ovarian cortical and interstitial tissues. Corpora lutea contained oestradiol-17β and oestrone during embryonic diapause and at all stages of pregnancy studied after blastocyst activation. Aryl sulphatase, 3β-hydroxysteroid dehydrogenase and 17β-oxidoreductase were shown to be present in luteal and other ovarian tissues by incubation in vitro with labelled substrates. Aromatase was undetectable in corpora lutea or in interstitial tissue, but was present in the ovarian tissues (including follicles) which remained after removal of corpora lutea. The probable source of the oestrogens detected in the corpus luteum is discussed in relation to their role in the inhibition of follicular development during embryonic diapause. J. Endocr. (1984) 101, 231–240

Localization of oxytocin and neurophysin in baboon (Papio anubis) corpus luteum by immunocytochemistry

1986 ◽  
Vol 113 (4) ◽  
pp. 570-575 ◽  
Author(s):  
Firyal S. Khan-Dawood
Keyword(s):  
Corpus Luteum ◽  
Rabbit Serum ◽  
Corpora Lutea ◽  
Positive Staining ◽  
Normal Rabbit Serum ◽  
Fallopian Tubes ◽  
Papio Anubis ◽  
Luteal Cells ◽  
Luteal Tissue ◽  
Immunocytochemical Reaction

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.

scholarly journals Effects of increased ambient temperature and supplemental altrenogest prior to pregnancy establishment in gilts

2022 ◽  
Author(s):  
Matthew R Romoser ◽  
Katie L Bidne ◽  
Lance H Baumgard ◽  
Aileen F Keating ◽  
Jason W Ross
Keyword(s):  
Heat Stress ◽  
Ovarian Tissue ◽  
Economic Effects ◽  
Mitigation Strategies ◽  
Delayed Puberty ◽  
Corpora Lutea ◽  
Estrous Synchronization ◽  
Conceptus Development ◽  
Luteal Tissue ◽  
Uterine Flushing

Abstract Heat stress (HS) mitigation strategies are critically needed to combat the substantial economic effects on animal agriculture. The manifestations of seasonal infertility include delayed puberty onset, reduced conception rates, decreased litter size, and increased wean to estrus interval. To assess the effects of HS during early gestation and evaluate a benefit of supplemental altrenogest (ALT) as a mitigation strategy, thirty crossbred post-pubertal gilts (157 ± 11 kg) were subjected to estrous synchronization via 14 d oral administration of ALT. Artificial insemination during estrus was performed and gilts were then placed into one of four treatment groups; heat stress (HS; 35 ± 1 οC for 12h/31.60 ± 1 οC for 12h) with (HSALT, n = 7) or without (HSCON, n = 7) 15 mg/d ALT supplementation or thermal neutral (TN; 20 ± 1 οC) conditions with (TNALT, n = 8) or without (TNCON, n = 8) 15 mg/d ALT supplementation until 12 d post-estrus (dpe). Administrating ALT occurred at 0600 h from 3-12 dpe and rectal temperatures (TR) and respiration rates (RR) were recorded. Blood was collected via jugular venipuncture on 0, 4, 8 and 12 dpe. Gilts were euthanized humanely at 12 dpe followed by collection of ovarian tissue, and uterine flushing for conceptus collection. In HS compared to TN gilts, RR and TR were increased (P < 0.01) but unaffected by ALT supplementation. Feed intake (FI) was reduced (P < 0.01) by HS but unaltered by ALT treatment. Corpora lutea (CL) weight was reduced (P < 0.01) in HSCON gilts when compared to TNCON and HSALT gilts despite progesterone (P4) concentrations in serum and luteal tissue not being affected by treatment (P ≥ 0.10). CL diameter was reduced (P ≤ 0.05) in HSALT gilts compared to other treatments. Interleukin-1β (IL1B) uterine flush concentration was not affected (P > 0.20) by environment or ALT supplementation, although moderate (P = 0.06) interaction between environment and ALT existed, as IL1B concentration in TNALT was increased (P = 0.03) compared to TNCON gilts. While environment did not affect conceptus development (P = 0.90), ALT supplementation advanced conceptus elongation (P < 0.01). Collectively, these data demonstrate that HS may affect luteal development prior to pregnancy establishment, and ALT increases conceptus elongation by12 dpe.

CHANGES IN THE DENSITY AND PROGESTERONE CONTENT OF LUTEAL TISSUE IN THE EGYPTIAN BUFFALO DURING THE OESTROUS CYCLE

1967 ◽  
Vol 39 (2) ◽  
pp. 163-171 ◽  
Author(s):  
A. S. EL-SHEIKH ◽  
FRANÇOIS B. SAKLA ◽  
SAFAA O. AMIN
Keyword(s):  
Corpus Luteum ◽  
Cell Volume ◽  
Distribution System ◽  
Oestrous Cycle ◽  
Luteal Cell ◽  
Corpora Lutea ◽  
Luteal Cells ◽  
Functional Changes ◽  
Parallel Increase ◽  
Luteal Tissue

SUMMARY The histological and functional changes of 31 corpora lutea of Egyptian buffaloes during the various phases of the oestrous cycle were studied. The volumes of the corpora lutea were calculated, the volume per cell, the cell volume and the volume of the intercellular spaces were estimated from transverse serial sections stained with haematoxylin and eosin, Mallory's triple stain or van Gieson's stain. The nuclear volumes were also determined and the cytoplasmic volume was calculated. The progesterone content was estimated using column absorption chromatography and a counter-current distribution system. It was concluded that the luteal cells increase both in volume and in number due to mitosis. The luteal cells decrease in volume after the 15th day after ovulation, the cells lose their distinct outlines in the regressive stage and disappear completely in the corpus albicans. There was a parallel increase in luteal cell volume and progesterone content until the 15th post-ovulatory day followed by a decrease in the regressive phase and disappearance of the hormone in the corpus albicans. A highly significant correlation (r = +0·875) was found between the progesterone content and the cytoplasmic volume. Progesterone concentration/g. luteal tissue increased from the corpus haemorrhagicum to the mature corpus luteum, decreased in the regressive corpus luteum and completely disappeared in the corpus albicans.

scholarly journals The suppression of oestrus in the rat during pregnancy and lactation

1938 ◽  
Vol 124 (837) ◽  
pp. 464-475 ◽  
Keyword(s):  
Corpus Luteum ◽  
Corpora Lutea ◽  
Luteal Tissue ◽  
Pregnancy And Lactation ◽  
Made In

It is well known that one function of the corpus luteum is the inhibition of oestrus. This fact has been established by experiments in which corpora lutea are removed and by experiments in which the functional life of corpora is prolonged. More recently it has been shown that the corpora exercise this inhibiting influence by means of their internal secretion. The exact part they play in the suppression of oestrus during pregnancy and in lactation in the rat is, however, still obscure. An attempt was therefore made in the following investigation to study the influence of destruction of luteal tissue on the return of oestrus and on the ripening of follicles, a technique which to our knowledge has not before been applied to the rat.

103 Effects of administration of human chorionic gonadotrophin at Day 5 post-ovulation on development of the original corpus luteum depend on the locational relationship between the original and accessory corpora lutea

2020 ◽  
Vol 32 (2) ◽  
pp. 177
Author(s):  
K. Hazano ◽  
S. Haneda ◽  
M. Matsui
Keyword(s):  
Corpus Luteum ◽  
Repeated Measures ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Corpora Lutea ◽  
Intrauterine Environment ◽  
Prostaglandin F2a ◽  
Tissue Area ◽  
Luteal Tissue ◽  
Relationship Of

In cattle, human chorionic gonadotrophin (hCG) is administered at Day 5 post-ovulation to improve fertility. This treatment can induce ovulation of the first-wave dominant follicle (W1DF), from which an accessory corpus luteum (CL) is generated. In addition, hCG has the effect of promoting CL development. It is possible that the locational relationship between the original and accessary CLs influences the effect of hCG on CL development, because the locational relationship of the CLs affects intraovarian blood flow. The present study aimed to clarify whether the locational relationship between the original and accessory CLs influences the effect of hCG on their development. Cross-bred beef heifers (Holstein×Japanese Black, n=56) were used for the present study. The oestrus cycle was synchronized using oestradiol benzoate (EB) and a controlled internal drug release (CIDR)-based program. Briefly, an administration of EB (2mg) with 9-day CIDR insertion was followed by administration of prostaglandin F2a analogue (PGF2a) on the day of CIDR removal, EB (1mg) 1 day after a PGF2a injection, and GnRH 12h after the second EB injection. At Day 5 post-ovulation, the locational relationship between the original CL and the W1DF was confirmed using transrectal ultrasonography (USG), and two groups were defined: ipsilateral group (IG; n=30), in which the CL and the W1DF are in the same ovary, and contralateral group (CG; n=26), in which the CL and the W1DF are in separate ovaries. Moreover, IG and CG were respectively subdivided into two groups, with or without hCG (1500IU) treatment (IG/hCG, n=15; IG without hCG, n=15, and CG/hCG, n=14; CG without hCG, n=12). The diameter and luteal tissue area (i.e. minus the cavity area) of the original CL and the accessory CL were examined at Days 5, 7, and 14, using USG. Two-way repeated-measures ANOVA was used to compare the diameter and luteal tissue area between IG/hCG and IG without hCG, and between CG/hCG and CG without hCG. In CG, the diameter (P<0.01) and luteal tissue area of the original CL (P<0.001) at Day 7 was increased by receiving hCG, while it did not change in IG. The diameter and luteal tissue area of the original CL at Day 14 were not affected by the administration of hCG in either CG or IG. Moreover, for the accessory CL, no difference of the diameter and luteal tissue area was observed between CG and IG. The present study showed that hCG treatment at Day 5 post-ovulation stimulate the growth of the original CL at Day 7, when the original CL and accessory CL are on contralateral sides. Our results suggest that the effect of administration of the hCG at Day 5 post-ovulation on the original CL development depends on the locational relationship between the original and accessory CL (IG or CG). The function of the CL affects the intrauterine environment for embryonic development. Therefore, it is necessary to investigate the effect of the hCG injection at Day 5 on the function of CL (i.e. plasma P4 concentration) in IG and CG, respectively.

PROGESTATIONAL STEROIDS DURING PSEUDOPREGNANCY IN THE RABBIT

1972 ◽  
Vol 55 (1) ◽  
pp. 89-96 ◽  
Author(s):  
ELISABETH HORRELL ◽  
PATRICIA W. MAJOR ◽  
R. KILPATRICK ◽  
BRENDA M. SMITH
Keyword(s):  
Corpus Luteum ◽  
Significant Alteration ◽  
Interstitial Tissue ◽  
Corpora Lutea ◽  
Steroid Synthesis ◽  
Progesterone Secretion ◽  
Pregnant Rabbit

SUMMARY The secretion of progestational steroids by the rabbit ovary was examined during pseudopregnancy. Progesterone secretion rose up to the mid-period but exceeded secretion of 20α-dihydroprogesterone only on days 7 and 9. The development of the corpus luteum and interstitial tissue and their content of progestational steroids were also examined during this period. The progesterone content of corpus luteum tissue fell towards the end of pseudopregnancy, while the corpora lutea remained large. Levels of 20α-dihydroprogesterone were generally higher in the interstitial tissue after the first few days. A significant alteration in the pattern of steroid synthesis and secretion occurred at a time corresponding to the period of implantation in the pregnant rabbit.

Oestrogen metabolism in the endometrium, corpus luteum and ovarian residual tissue of the rabbit

1983 ◽  
Vol 96 (2) ◽  
pp. 201-213 ◽  
Author(s):  
T. Wise ◽  
N. Ackland ◽  
I. R. Fleet ◽  
R. B. Heap ◽  
D. E. Walters
Keyword(s):  
Corpus Luteum ◽  
Ovarian Tissue ◽  
Major Metabolite ◽  
Maternal Factors ◽  
Uterine Endometrium ◽  
Tissue Weight ◽  
Reproductive Tissues ◽  
Oestrone Sulphate ◽  
Luteal Tissue ◽  
Residual Tissue

Reproductive tissues (uterine endometrium, corpus luteum and ovarian residual tissues) from pregnant and pseudopregnant rabbits were incubated with equimolar concentrations of [3H]oestrone and [3H]oestrone sulphate (0·375 pmol) to monitor the changes in oestrogen metabolism during the early stages of pregnancy (days 0, and 3–8 post coitum) and to investigate the embyonic effect upon maternal oestrogen metabolism. Oestradiol-17β was the major metabolite formed from oestrone and sulphoconjugation occurred in all tissues studied. Oestrone sulphate was converted primarily to oestradiol-17β-3-monosulphate. Endometrial 17β-oxidoreductase significantly decreased and sulpho-transferase increased in activity during the preimplantation period, but no differences were noted between gravid and non-gravid horns in unilaterally pregnant animals, nor between pregnant or pseudopregnant animals. Significant decreases occurred in 17β-oxidoreductase and sulphotransferase activity in luteal tissue, but these were more than offset by increases in tissue weight. No differences in the activities in luteal tissues were detected between pregnant or pseudopregnant animals, nor between ovarian tissue adjacent to gravid or non-gravid uterine horns. The results show that significant changes occur in oestrogen metabolism in the rabbit endometrium and corpus luteum within 8 days after ovulation, and that these changes result from maternal factors expressed systemically rather than by the effects of the developing conceptus expressed locally.

The hormone control of ovulation in the calf

1953 ◽  
Vol 43 (4) ◽  
pp. 381-406 ◽  
Author(s):  
William G. R. Marden
Keyword(s):  
Corpus Luteum ◽  
Fallopian Tube ◽  
Individual Variation ◽  
Inhibitory Effect ◽  
Corpora Lutea ◽  
Treated Animal ◽  
Intravenous Injections ◽  
Luteal Tissue ◽  
Hormone Control ◽  
Follicular Response

1. Unlike many other mammals, the calf is capable of responding to pituitary injections almost from birth. Age has little effect on the ability of the follicles to develop during a series of a.p.h. injections, the follicular response generally being as good 3 weeks after birth as in calves 6–8 months old.2. Ovulation can occur spontaneously in the a.p.h. treated calf before the end of the first month of post-natal life.3. Ova obtained from such ovulations are capable of fertilization, although the percentage becoming fertilized is very low. This is thought to be due to the infantile state of the Fallopian tube and the difficulty in inseminating into the uterus, rather than faulty maturation of ova.4. Although many follicles (10–60) can develop during a series of a.p.h. injections, superovulation was not consistently obtained either by intravenous injections of a.p.h., l.h. or p.u., or combinations of any of these three.5. Superovulation can generally be obtained, with the formation of many corpora lutea, if the a.p.h. treatment is repeated a second time after a period of luteal activity.6. The inhibitory effect of a corpus luteum on ovulation in cattle can be overridden in tho a.p.h. treated animal if suitable quantities of a.p.h., l.h. or p.u. are intravenously injected when the newly formed follicles are approaching maturity.7. Ovulation in the calf at all ages up to 8 or 9 months of age, either in the presence or absence of luteal tissue, is unaccompanied by oestrus. Oestrus, when occurring during a series of a.p.h. injections, commenced after 90–100 hr. of treatment. In such cases slaughter has always revealed the presence of luteal tissue, indicating that ovulation during a ‘silent heat’ had occurred before the commencement of pituitary treatment.8. Great individual variation exists in the ability of the ovary to respond to pituitary injections. This insensitivity to gonadotropins is not confined to young calves and has been observed in calves 4–6 months of age.

The reproduction of the African elephant, Loxodonta Africana

1953 ◽  
Vol 237 (643) ◽  
pp. 93-149 ◽  
Keyword(s):  
Corpus Luteum ◽  
Reproductive Organs ◽  
Gestation Period ◽  
Striking Similarity ◽  
Phylogenetic Position ◽  
Interstitial Tissue ◽  
Corpora Lutea ◽  
Linear Measurements ◽  
Hormonal Stimulus ◽  
Control Work

Between December 1946 and December 1948, and January to March 1950, 150 elephants made available in the course of control work carried out by the Uganda Game Department were examined in greater or less detail according to circumstances. Eighty-one were females, of which sixty-seven were adult and thirty-one had an embryo in the uterus. All the dissections were carried out in the field, and the present account includes observations on the terrain, the food of the elephant, and other aspects of its ecology. Linear measurements of the carcasses and photographs of the molar teeth provide a guide to the age of specimens. Tusk growth is nearly similar in males and females until puberty, after which those of females generally cease to grow. The reproductive organs of the male are briefly described; those of the female are described in more detail, and discrepancies between existing accounts are considered in the light of this relatively extensive series of specimens. The mode of formation of the ovarial sac is unusual and is described from foetal, neonatal and adult specimens. There is marked hypertrophy of the interstitial tissue of the foetal gonads during the later stages of gestation. Breeding occurs at all times of year, but mating is possibly more frequent in the period December to March than at other times. Both sexes reach maturity at 8 to 12 years, and the female continues to breed until old age. Parturition is followed by a lactation anoestrus, after which the female undergoes a number of brief oestrous cycles until pregnancy ensues, lactation being continued throughout the subsequent gestation period. The interval between parturition and subsequent conception is normally of the same order of duration as the gestation period, and the normal calving interval appears to be rather less than four years. The ovarian cycle of the adult is characterized by the occurrence of multiple ovulation and the presence of many apparently active and histologically indistinguishable corpora lutea in both ovaries at all the stages of pregnancy which were encountered. It is probable that the corpus luteum of pregnancy develops from one of a number of follicles which ovulate under the same hormonal stimulus, and that it persists together with the accessory corpora lutea, some of which arise from follicles which ovulate and some from follicles which luteinize without ovulating. The corpora lutea are replaced about mid-pregnancy by a second set, which are formed by the luteinization of all the follicles with antra in both ovaries; some at least of the larger ones ovulate while many smaller ones do not. Follicular growth is suppressed in the later stages of pregnancy. The cycle of events bears some resemblance to that which occurs in the mare, and the comparison is discussed in detail. The ovarian periphery is characterized by numerous subsurface crypts and papillose projections which increase the area of the germinal epithelium. A description of the placenta and foetal membranes is in preparation, and preliminary study reveals a striking similarity to Hyrax , particularly in the quadri-lobulate allantois. The findings are discussed with reference to the phylogenetic position of the genus, the probable role of the corpus luteum in pregnancy, and the significance of the results in relation to the conservation of existing wild elephant populations.

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