EFFECTS OF PITUITARY HORMONES ON PROGESTATIONAL HORMONE PRODUCTION BY THE RABBIT OVARY IN VIVO AND IN VITRO

1966 ◽  
Vol 35 (1) ◽  
pp. 53-63 ◽  
Author(s):  
J. H. DORRINGTON ◽  
R. KILPATRICK
Keyword(s):  
Ovarian Tissue ◽  
Venous Blood ◽  
Interstitial Tissue ◽  
Corpora Lutea ◽  
Hormone Production ◽  
Stimulatory Action ◽  
Steroid Synthesis ◽  
Ovine Prolactin

SUMMARY Ovine luteinizing hormone (LH) increased the output of progestational steroids (20α-hydroxypregn-4-en-3-one and progesterone) in rabbit ovarian venous blood. Similar increases were found with ovine follicle-stimulating hormone (FSH) and growth hormone, but much larger amounts were necessary. Ovine prolactin was without effect. The increased output was due to increased synthesis and not only to release of stored steroids. Synthesis of these progestational steroids was stimulated by LH incubated with rabbit ovarian tissue. The stimulation produced by FSH was probably due to contamination by LH since the log dose-response lines for LH and FSH were parallel, and FSH was approximately 100 times less active than LH. Ovine prolactin had no stimulatory activity in concentrations up to 20 μg./ml. The stimulatory action of LH was unrelated to the presence of corpora lutea. Separated corpora lutea showed only a slight response to LH, whereas the response of interstitial tissue was similar to that found with undissected ovaries. Hence LH caused progestational steroid synthesis by stimulating the ovarian interstitial tissue.

scholarly journals Activities of enzymes responsible for steroid biosynthesis and cholesterol ester metabolism in rabbit ovarian interstitial tissue and corpora lutea. A comparison of enzyme activities with flow rates

1973 ◽  
Vol 132 (2) ◽  
pp. 301-311 ◽  
Author(s):  
A. P. F. Flint ◽  
D. T. Armstrong
Keyword(s):  
Cholesterol Ester ◽  
Cholesterol Esterase ◽  
Interstitial Tissue ◽  
Corpora Lutea ◽  
Chain Cleavage ◽  
Cleavage Enzyme ◽  
Storage Granules ◽  
Ester Synthetase

A method involving the use of isolated cholesterol ester-storage granules as substrate is described for the assay of cholesterol esterase in rabbit ovarian tissues. Activities of cholesterol esterase 100–200-fold higher than those previously reported in ovarian tissues were measured by using this method. In addition to that of cholesterol esterase, activities of cholesterol ester synthetase, cholesterol side-chain cleavage enzyme and 3β-hydroxy steroid dehydrogenase were determined in rabbit ovarian interstitial tissue and corpora lutea. Activities of these enzymes are in general compatible with the flows through them measured under a variety of conditions both in vivo and in vitro. It is concluded that, in the rabbit ovarian tissues investigated, these enzymes are capable of catalysing the conversions usually attributed to them.

REPTILIAN OVARIAN STEROIDOGENESIS AND THE INFLUENCE OF MAMMALIAN GONADOTROPHINS (FOLLICLE-STIMULATING HORMONE AND LUTEINIZING HORMONE) IN VITRO

1974 ◽  
Vol 62 (2) ◽  
pp. 267-275 ◽  
Author(s):  
S. W. C. CHAN ◽  
I. P. CALLARD
Keyword(s):  
Luteinizing Hormone ◽  
Ovarian Function ◽  
Cholesterol Metabolism ◽  
Ovarian Tissue ◽  
Follicle Stimulating Hormone ◽  
Sampling Period ◽  
Steroid Synthesis ◽  
Stimulating Hormone

SUMMARY The synthesis of steroids from [7α-3H]cholesterol, [7α-3H]pregnenolone and [7α-3H]progesterone by lizard and turtle ovarian tissues in vitro was studied. Progesterone, 17α-hydroxyprogesterone, dehydroepiandrosterone, androstenedione, testosterone, oestrone and oestradiol were identified as products. In the turtle (Pseudemys), conversion of pregnenolone to progesterone was efficient, but transformation of progesterone to other steroids was relatively slow as indicated by the accumulation of progesterone over the incubation period. In Dipsosaurus, accumulation of radioactivity was greatest in testosterone, the quantities of which continued to increase at each sampling period. The rate of utilization of pregnenolone as a substrate was similar for the two species studied and the quantities of oestrone and oestradiol formed were lower in Pseudemys. The use of progesterone as precursor by Dipsosaurus ovarian tissue revealed a similar pattern of Δ4-steroid metabolism to that obtained with pregnenolone as precursor. The effects of addition of purified follicle-stimulating hormone (FSH) and luteinizing hormone (LH) on the metabolism of [14C]cholesterol in vitro was studied using Pseudemys follicular tissue. The pattern of cholesterol metabolism was similar to that for pregnenolone in this species. The synthesis of pregnenolone, progesterone, dehydroepiandrosterone and androstenedione in vitro was significantly enhanced in the presence of LH. Follicle-stimulating hormone had no effect on steroid synthesis except for a decrease of androstenedione formation. The stimulatory effect of LH on steroidogenesis in vitro is discussed in relation to the literature suggesting that mammalian FSH, but not LH, stimulates all phases of reptilian ovarian function when injected in vivo.

AN ASSESSMENT OF THE POSSIBLE ROLE OF 17α,20α-DIHYDROXY-4-PREGNEN-3-ONE IN THE REGULATION OF TESTOSTERONE SYNTHESIS BY RAT AND RABBIT TESTIS

1974 ◽  
Vol 61 (3) ◽  
pp. 401-410 ◽  
Author(s):  
H. W. A. de BRUIJN ◽  
H. J. van der MOLEN
Keyword(s):  
Venous Blood ◽  
Competitive Inhibitor ◽  
Testicular Tissue ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Lyase Activity ◽  
Testosterone Biosynthesis

SUMMARY 17α,20α-Dihydroxy-4-pregnen-3-one is a competitive inhibitor of C17,20-lyase activity in rat testicular tissue in vitro and the significance of this inhibition in vitro was evaluated for testosterone biosynthesis in rat and rabbit testis in vivo. It is concluded that 17α,20α-dihydroxy-4-pregnen-3-one is not involved in the regulation of C17,20-activity in vivo, because it was not possible to detect any 17α,20α-dihydroxy-4-pregnen-3-one in rat and rabbit testicular tissue or in testicular venous blood. If present, the levels are lower than 10 pmol/g testis. Levels of 17α-hydroxyprogester-one are in the order of 50 pmol/g testis. The C17,20-lyase has a higher affinity for 17α-hydroxyprogesterone than for 17α,20α-dihydroxy-4-pregnen-3-one and hence inhibition under in-vivo conditions is not favoured. In rat testes the 20α-hydroxysteroid dehydrogenase activity, which can convert 17α-hydroxyprogesterone to 17α,20α-dihydroxy-4-pregnen-3-one, was found to be mainly (97%) localized in the seminiferous tubules and not at the site of testosterone formation in the interstitial tissue.

In vivo and in vitro strategies to support caprine preantral follicle development after ovarian tissue vitrification

2018 ◽  
Vol 30 (8) ◽  
pp. 1055 ◽  
Author(s):  
N. J. Donfack ◽  
K. A. Alves ◽  
B. G. Alves ◽  
R. M. P. Rocha ◽  
J. B. Bruno ◽  
...  
Keyword(s):  
In Vitro Culture ◽  
Ovarian Function ◽  
Ovarian Tissue ◽  
Preantral Follicle ◽  
Hormone Production ◽  
Treatment Groups ◽  
Morphology Development ◽  
Fresh Culture

The aim of the present study was to compare fresh and vitrified goat ovarian tissue after autotransplantation and in vitro culture. Adult goats were completely ovariectomised and each ovarian pair was sliced and distributed among six different treatment groups: fresh control, fresh transplant, fresh culture, vitrified control, vitrified transplant and vitrified culture. Follicular morphology, development, growth, density, revascularisation and hormone production were evaluated in all groups. Three antral follicles (two in the fresh transplant and one in the vitrified transplant groups) were observed on the surface of the graft 90 days after transplantation. The percentage of morphologically normal follicles was similar in the fresh control, fresh transplant and vitrified transplant groups. The percentage of developing (transition, primary and secondary) follicles was higher after in vitro culture of fresh or vitrified tissue. Transplantation resulted in a lower follicle density. Serum oestradiol concentrations remained constant during the entire transplantation period. In contrast, progesterone production decreased significantly. Expression of CD31 mRNA was lower in fresh culture. In conclusion, restoration of goat ovarian function can be successfully achieved following transplantation of both fresh and vitrified goat ovarian tissue. However, transplantation induced higher follicle loss than in vitro culture.

scholarly journals Control of ovarian cholesterol ester biosynthesis

1973 ◽  
Vol 132 (2) ◽  
pp. 313-321 ◽  
Author(s):  
A. P. F. Flint ◽  
D. L. Grinwich ◽  
D. T. Armstrong
Keyword(s):  
Luteinizing Hormone ◽  
Cyclic Amp ◽  
Cholesterol Ester ◽  
Cholesterol Esterase ◽  
Interstitial Tissue ◽  
Steroid Synthesis ◽  
Precursor Pool ◽  
Ester Synthetase

1. Experimental evidence is presented for a role of progesterone and 20α-hydroxypregn-4-en-3-one as inhibitors of cholesterol ester synthetase in the acute depletion of ovarian cholesterol ester after trophic stimulation. 2. Luteinizing hormone in vitro decreased by 84% the rate of esterification of cholesterol with added [14C]oleate by slices of rabbit ovarian interstitial tissue; this effect was mimicked by cyclic AMP (adenosine 3′:5′-cyclic monophosphate) in vitro, and occurred without large changes in precursor pool sizes or membrane permeability. 3. Cyclic AMP was shown to have no direct effect on cholesterol ester synthetase or cholesterol esterase in cell-free extracts of rabbit ovarian interstitial tissue, but decreased the activity of cholesterol ester synthetase (not that of cholesterol esterase) in extracts prepared from slices previously incubated with it. 4. The inhibitory effect of cyclic AMP on esterification of cholesterol with added [14C]-oleate was prevented by both cycloheximide and aminoglutethimide phosphate (which also inhibited steroid synthesis in response to cyclic AMP). 5. Cyclic AMP raised the intracellular concentrations of progesterone and 20α-hydroxypregn-4-en-3-one in incubated slices by factors of 2.8 and 3.9 respectively. 6. Cycloheximide and aminoglutethimide phosphate administered in vivo blocked cholesterol ester depletion in response to luteinizing hormone in rats; in these ovaries cycloheximide and aminoglutethimide phosphate decreased the concentrations of progesterone and 20α-hydroxypregn-4-en-3-one and luteinizing hormone raised them. 7. Progesterone and 20α-hydroxypregn-4-en-3-one added to cell-free extracts of rabbit ovarian interstitial tissue in vitro (at concentrations comparable with those found in incubated slices) inhibited cholesterol ester synthetase by up to 85%. 8. The results are discussed with reference to the acute control of cholesterol ester concentrations in the ovary and adrenal cortex.

The procoagulant effects of factor V Leiden may be balanced against decreased levels of factor V and do not reflect in vivo thrombin formation in newborns

2006 ◽  
Vol 95 (03) ◽  
pp. 434-440 ◽  
Author(s):  
Satu Hyytiäinen ◽  
Ulla Wartiovaara-Kautto ◽  
Veli-Matti Ulander ◽  
Risto Kaaja ◽  
Markku Heikinheimo ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Platelet Rich Plasma ◽  
Venous Blood ◽  
Factor V Leiden ◽  
Factor V ◽  
Cord Plasma ◽  
Adult Plasma ◽  
Thrombin Formation

SummaryThrombin regulation in newborns remains incompletely understood.We studied tissue factor-initiated thrombin formation in cord plasma in vitro, and the effects of Factor VLeiden (FVL) heterozygosity on thrombin regulation both in vitro and in vivo in newborns. Pregnant women with known thrombophilia (n=27) were enrolled in the study. Cord blood and venous blood at the age of 14 days were collected from 11 FVL heterozygous newborns (FVL-positive) and from 16 FVL-negative newborns. Prothrombin fragment F1+2 and coagulation factors were measured. Tissue factor-initiated thrombin formation was studied in cord platelet-poor plasma (PPP) of FVL-negative and -positive newborns, and in both PPP and platelet-rich plasma (PRP) of healthy controls. The endogenous thrombin potential (ETP) in cord PPP or PRP was ∼60% of that in adult plasma, while thrombin formation started ∼55% and ∼40% earlier in cord PPP and PRP, respectively. Further, in FVL-positive newborns thrombin formation started significantly earlier than in FVL-negative newborns. Exogenous activated protein C (APC) decreased ETP significantly more in cord than in adult PRP. In FVL-negative cord plasma 5nM APC decreased ETP by 17.4±3.5% (mean±SEM) compared with only 3.5±3.8% in FVL-positive cord plasma (p=0.01). FVL-positive newborns showed similar levels of F1+2 but significantly decreased levels of factor V compared with FVL negative newborns both in cord plasma (FV 0.82±0.07 U/ml vs. 0.98±0.05 U/ml, p=0.03) and at the age of two weeks (FV 1.15±0.04 U/ml vs. 1.32±0.05 U/ml, p=0.03). In conclusion, newborn plasma showed more rapid thrombin formation and enhanced sensitivity to APC compared with adult plasma. FVL conveyed APC resistance and a procoagulant effect in newborn plasma. Lack of elevated F1+2 levels in FVL-positive infants, however, suggested the existence of balancing mechanisms; one could be the observed lower level of factor V in FVL heterozygous newborns.

scholarly journals Suppression of parathyroid hormone production in vitro and in vivo by RNA interference

2009 ◽  
Vol 75 (5) ◽  
pp. 490-498 ◽  
Author(s):  
Genta Kanai ◽  
Takatoshi Kakuta ◽  
Kaichiro Sawada ◽  
Tun A. Yokoyama ◽  
Reika Tanaka ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Rna Interference ◽  
Hormone Production

scholarly journals Overexpression of the Matrix Metalloproteinase Matrilysin Results in Premature Mammary Gland Differentiation and Male Infertility

1998 ◽  
Vol 9 (2) ◽  
pp. 421-435 ◽  
Author(s):  
Laura A. Rudolph-Owen ◽  
Paul Cannon ◽  
Lynn M. Matrisian
Keyword(s):  
Matrix Metalloproteinase ◽  
Transgenic Animals ◽  
Reproductive Organs ◽  
Mammary Development ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Wild Type ◽  
The Matrix

To examine the role of matrilysin (MAT), an epithelial cell-specific matrix metalloproteinase, in the normal development and function of reproductive tissues, we generated transgenic animals that overexpress MAT in several reproductive organs. Three distinct forms of human MAT (wild-type, active, and inactive) were placed under the control of the murine mammary tumor virus promoter/enhancer. Although wild-type, active, and inactive forms of the human MAT protein could be produced in an in vitro culture system, mutations of the MAT cDNA significantly decreased the efficiency with which the MAT protein was produced in vivo. Therefore, animals carrying the wild-type MAT transgene that expressed high levels of human MAT in vivo were further examined. Mammary glands from female transgenic animals were morphologically normal throughout mammary development, but displayed an increased ability to produce β-casein protein in virgin animals. In addition, beginning at approximately 8 mo of age, the testes of male transgenic animals became disorganized with apparent disintegration of interstitial tissue that normally surrounds the seminiferous tubules. The disruption of testis morphology was concurrent with the onset of infertility. These results suggest that overexpression of the matrix-degrading enzyme MAT alters the integrity of the extracellular matrix and thereby induces cellular differentiation and cellular destruction in a tissue-specific manner.

scholarly journals Active immunization against the proregions of GDF9 or BMP15 alters ovulation rate and litter size in mice

Reproduction ◽  
2012 ◽  
Vol 143 (2) ◽  
pp. 195-201 ◽  
Author(s):  
C Joy McIntosh ◽  
Steve Lawrence ◽  
Peter Smith ◽  
Jennifer L Juengel ◽  
Kenneth P McNatty
Keyword(s):  
Litter Size ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Cross Reactivity ◽  
Full Length ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Immunization Group

The transforming growth factor β (TGFB) superfamily proteins bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9), are essential for mammalian fertility. Recent in vitro evidence suggests that the proregions of mouse BMP15 and GDF9 interact with their mature proteins after secretion. In this study, we have actively immunized mice against these proregions to test the potential in vivo roles on fertility. Mice were immunized with either N- or C-terminus proregion peptides of BMP15 or GDF9, or a full-length GDF9 proregion protein, each conjugated to keyhole limpet hemocyanin (KLH). For each immunization group, ovaries were collected from ten mice for histology after immunization, while a further 20 mice were allowed to breed and litter sizes were counted. To link the ovulation and fertility data of these two experimental end points, mice were joined during the time period identified by histology as being the ovulatory period resulting in to the corpora lutea (CL) counted. Antibody titers in sera increased throughout the study period, with no cross-reactivity observed between BMP15 and GDF9 sera and antigens. Compared with KLH controls, mice immunized with the N-terminus BMP15 proregion peptide had ovaries with fewer CL (P<0.05) and produced smaller litters (P<0.05). In contrast, mice immunized with the full-length GDF9 proregion not only had more CL (P<0.01) but also had significantly smaller litter sizes (P<0.01). None of the treatments affected the number of antral follicles per ovary. These findings are consistent with the hypothesis that the proregions of BMP15 and GDF9, after secretion by the oocyte, have physiologically important roles in regulating ovulation rate and litter size in mice.

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.

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