Prolonged steroidogenesis in luteinized ovaries of hypophysectomized rats

1981 ◽  
Vol 98 (3) ◽  
pp. 437-440 ◽  
Author(s):  
R. J. C. van Straalen ◽  
F. G. Leemborg ◽  
J. T. M. Vreeburg ◽  
G. H. Zeilmaker
Keyword(s):  
Serum Concentration ◽  
Ovarian Tissue ◽  
Blood Stream ◽  
Pituitary Hormones ◽  
Corpora Lutea ◽  
Detectable Amount ◽  
Hypophysectomized Rats

Abstract. Luteinized ovaries of rats hypophysectomized shortly after ovulation 25–80 days previously secrete considerable amounts of 20α-dihydroprogesterone (20α-hydroxy-4-pregnen-3-one, 20α-OHP) into the blood-stream. The serum concentration of 20α-OHP in these hypophysectomized animals is almost similar to that of progesterone in intact pseudopregnant rats on day 7 of pseudopregnancy, in spite of the absence of demonstrable amounts of prolactin. Isolated corpora lutea of the last generation and the remainder of the ovarian tissue both contained 20α-OHP. Six months after hypophysectomy no detectable amount of 20α-OHP was found in the serum. Androgenized rats, devoid of corpora lutea, did not produce 20α-OHP after hypophysectomy. These data show that pituitary hormones are not required for the prolonged synthesis and secretion of 20α-OHP by the luteinized ovary.

OESTRADIOL CONTENT OF OVARIAN VENOUS BLOOD AND OVARIAN TISSUE IN HYPOPHYSECTOMIZED RATS DURING LATE PREGNANCY

1972 ◽  
Vol 54 (1) ◽  
pp. 79-85 ◽  
Author(s):  
H. B. WAYNFORTH ◽  
D. M. ROBERTSON
Keyword(s):  
Corpus Luteum ◽  
Post Partum ◽  
Ovarian Tissue ◽  
Venous Blood ◽  
Late Pregnancy ◽  
Corpora Lutea ◽  
Pregnant Rats ◽  
Hypophysectomized Rats ◽  
Competitive Protein Binding ◽  
Intact Rats

SUMMARY Oestradiol-17β in ovarian venous blood and ovarian tissue was assayed by a competitive protein-binding method. Oestradiol was found in similar amounts in the ovarian vein blood of pregnant rats hypophysectomized on Day 12 and killed on Days 16 and 21 and in pregnant rats sham-hypophysectomized on Day 12 and killed on Day 16. The pituitary therefore plays no part in oestrogen production after mid-pregnancy until some time between Day 16 and Day 21, when it gives rise to an increased ovarian venous blood oestradiol content just before parturition, in intact sham-hypophysectomized rats. It is suggested that this increase is associated with the advent of the post-partum ovulation. The corpus luteum and the extraluteal component of the ovary in hypophysectomized rats autopsied on Days 16 and 21 and in sham-hypophysectomized rats autopsied on Day 16, contain similar amounts of oestradiol within each group. The extraluteal component contains about five times more oestradiol than corpora lutea in sham-hypophysectomized intact rats autopsied on Day 21. The ovaries of these animals also show an increased amount of oestradiol over that of the ovaries in the other three groups. It is suggested that secretion of oestradiol after mid-pregnancy in rats involves concurrently both the corpus luteum and the extraluteal component of the ovary.

ABSENCE OF COMPENSATORY OVARIAN HYPERTROPHY IN RATS WITH ANTERIOR HYPOTHALAMIC LESIONS

1961 ◽  
Vol 36 (2) ◽  
pp. 180-184 ◽  
Author(s):  
Béla Flerkó ◽  
Vera Bárdos
Keyword(s):  
Essential Role ◽  
Ovarian Tissue ◽  
Vaginal Smear ◽  
Corpora Lutea ◽  
Vaginal Smears ◽  
Hypothalamic Area ◽  
Unilateral Ovariectomy ◽  
Hypothalamic Lesions ◽  
Oestrogen Level ◽  
Stimulation Of

ABSTRACT Absence of compensatory ovarian hypertrophy in »constant oestrus rats« from lesions in the anterior hypothalamic area suggests that nervous elements localized in this region play an essential role in the stimulation of gonadotrophin output by diminution of the blood oestrogen level. The constant vaginal oestrus after unilateral ovariectomy in the majority of animals was, however, repeatedly interrupted by vaginal smears of a dioestrous type. The appearance of a dioestrous vaginal smear in the »hypothalamic constant oestrus rats« is often associated with some luteinisation. It is assumed that diminution of the blood oestrogen level by reduction of ovarian tissue in these animals may bring about a release of LH sufficient to cause formation of corpora lutea.

Human growth hormone treatment of hypophysectomized rats increases the proportion of type-1 fibres in skeletal muscle

1989 ◽  
Vol 123 (3) ◽  
pp. 429-NP ◽  
Author(s):  
C. M. Ayling ◽  
B. H. Moreland ◽  
J. M. Zanelli ◽  
D. Schulster
Keyword(s):  
Skeletal Muscle ◽  
Fibre Type ◽  
Extensor Digitorum Longus ◽  
Human Growth ◽  
Hormone Treatment ◽  
Pituitary Hormones ◽  
Extensor Digitorum ◽  
Replacement Treatment ◽  
Hypophysectomized Rats

ABSTRACT The studies describe alterations after hypophysectomy in the proportion of the type-1 and type-2 fibres in rat skeletal muscles, and the effects of replacement treatment with pituitary human (h) GH. Cytochemical analysis of myosin ATPase, succinate dehydrogenase and lactate dehydrogenase activities in sections of rat hind limb muscles were used as markers of fibre type and revealed that hypophysectomy reduced the proportion of type-1 fibres by 50% in soleus and in extensor digitorum longus muscles. This reduction in the proportion of type-1 fibres was accompanied by the appearance of transitional fibres (type 2C/1B). Following seven daily injections of hGH (60 mIU/day) to hypophysectomized rats, the proportion of type-1 fibres in both soleus and in extensor digitorum longus was increased with a concomitant reduction in the number of transitional fibres. After 11 days of treatment, all these transitional fibres had reverted back to type-1 fibres. Only hGH was observed to elicit this effect; injections of other pituitary hormones had no effect on the proportions of these transitional fibres. These alterations in fibre type occurred more rapidly than the changes reported after prolonged electrical stimulation of muscle or following extended exercise. These findings suggest that hypophysectomy and GH injection can result in a rapid alteration in the fibre composition of skeletal muscle, which may have important implications in terms of the resistance to fatigue and speed of contraction of the muscle. Journal of Endocrinology (1989) 123, 429–435

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.

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.

EFFECT OF α-MELANOCYTE-STIMULATING HORMONE AND OVARIAN STEROIDS ON PREPUTIAL GLAND FUNCTION IN THE FEMALE RAT

1981 ◽  
Vol 90 (1) ◽  
pp. 53-58 ◽  
Author(s):  
S. M. DONOHOE ◽  
A. J. THODY ◽  
S. SHUSTER
Keyword(s):  
Pituitary Hormones ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Preputial Gland ◽  
Melanocyte Stimulating Hormone ◽  
Experienced Male ◽  
Hypophysectomized Rats ◽  
Gland Function ◽  
Preputial Glands

Sexually experienced male rats were used to test the attractiveness of preputial gland odours of female rats. The male rats showed a clear preference for the preputial gland odours of hypophysectomized females given oestradiol benzoate (OB) for 3 or 8 days to those of control rats. Progesterone treatment had no effect on the attractiveness of the preputial gland odours of OB-treated hypophysectomized female rats. Administration of α-MSH for either 3 or 8 days, on the other hand, increased the attractiveness to male rats of preputial gland odours of OB-treated hypophysectomized females and the presence of progesterone produced no further change. When administered alone α-MSH had no effect on the attractiveness of the preputial gland odours. Other pituitary hormones, such as ACTH and prolactin, had no effect on the attractiveness of preputial gland odours of OB-treated hypophysectomized rats when administered for 3[unk]days. An increase in preputial gland size was only seen when OB, progesterone and α-MSH were administered together. It would appear that no relationship exists between the size of the preputial glands and their ability to attract male rats. It is concluded that, while α-MSH and progesterone may be important in controlling growth of the preputial glands, an interaction between α-MSH and oestrogen is more important for regulating the production of sex attractants by the preputial glands.

HORMONAL CONTROL OF AMNIOTIC AND ALLANTOIC FLUID VOLUME IN OVARIECTOMIZED SHEEP

1968 ◽  
Vol 41 (4) ◽  
pp. 477-485 ◽  
Author(s):  
G. ALEXANDER ◽  
D. WILLIAMS
Keyword(s):  
Ovarian Tissue ◽  
Allantoic Fluid ◽  
Hormonal Control ◽  
Fluid Volume ◽  
Corpora Lutea ◽  
Dose Ratio ◽  
Oestradiol Benzoate ◽  
Bovine Type ◽  
Excessive Accumulation

SUMMARY In pregnant ewes, ovariectomized 3 weeks after mating and maintained with progesterone (7 mg./day) injected intramuscularly, there was excessive accumulation of allantoic fluid after 2 months of gestation. The addition of oestradiol benzoate (5 μg./day) or an increase in the dose of progesterone reduced the allantoic fluid volume to normal; this reduction depended on the dose of oestrogen and on the dose ratio of oestrogen to progesterone. Whilst oestrogen reduced allantoic fluid volume to normal, it increased the incidence of 'bovine' type of cotyledons which are not normally seen in ewes 2 months pregnant. The large allantoic volumes were apparently due to the absence of luteal rather than other ovarian tissue, since large volumes were also present in ewes maintained on 7 mg. progesterone/day after corpora lutea had been surgically expressed from the ovaries left in situ. Embryonic survival was adversely affected when corpora lutea were removed from the ovaries, but there was no clear effect on the morphology of cotyledons.

187 OVARIAN CYCLE LIPID DYNAMICS REVEALED BY DESI-MS IMAGING AND MORPHOLOGICALLY-DRIVEN MULTIVARIATE STATISTICS

2015 ◽  
Vol 27 (1) ◽  
pp. 184
Author(s):  
A. K. Jarmusch ◽  
C. R. Ferreira ◽  
L. S. Eberlin ◽  
V. Pirro
Keyword(s):  
Multivariate Statistics ◽  
Ovarian Tissue ◽  
Univariate Analysis ◽  
Ambient Ionization ◽  
Negative Ion ◽  
Corpora Lutea ◽  
Ionization Mass ◽  
Ms Imaging ◽  
Adrenic Acid ◽  
Desi Ms

Understanding the role of lipid metabolism in ovarian physiology is crucial for the progression of reproductive biotechnology. The aim in this work was to explore the lipid composition and dynamics of ovarian tissue, specifically the stroma, follicles, and corpora lutea. Desorption electrospray ionization–mass spectrometry (DESI-MS), an ambient ionization technique, was applied in this investigation, acquiring chemical and spatial information simultaneously. A morphologically-friendly solvent, dimethylformamide-acetonitrile (1 : 1), was used for DESI-MS imaging which allowed for ovarian lipid characterisation and subsequent staining (hematoxylin and eosin) providing morphological information. By this approach, regions-of-interest (ROI) were selected from bovine (n = 8), swine (n = 3), and mice (n = 5) ovaries (including pre-pubescent and cycling adults) based on the stained morphological structures. ROI for stroma (n = 54), follicles (n = 89), and corpora lutea (n = 61) were selected and chemically profiled. Tissue sections (20 μm) were thaw mounted onto glass microscope slides and stored at –80°C until analysis. A linear ion trap mass spectrometer equipped with a custom DESI-MS imaging stage was operated in the negative ion mode (m/z 200 to 1000). A 300 × 300 µm pixel size was used in DESI-MS imaging of ovarian tissue. Hyperspectral DESI images were reconstructed and processed by principal component analysis (PCA) that allowed visualisation of relationships among spatial (i.e. morphology) and chemical features. Ions indicated by PCA were analysed using univariate analysis (ANOVA), supporting the significance of particular lipids between morphological structures, e.g. adrenic acid (P = 1.7 × 10–8) and m/z 836 (P = 8.9 × 10–9) between corpora lutea and follicles. All morphological structures could be differentiated by multivariate statistics (>90% prediction rate) independent of the species, indicating conserved lipid constitution. Smaller differences in the lipid profiles were noted between species, poly-ovulatory and mono-ovulatory species, and reproductive maturation. A large variety and abundance of lipids was observed in corpora lutea and follicles, where steroidogenesis is a prominent physiological activity. Additional insight into ovarian physiology was gained with the detection of arachidonic and adrenic acid. The spatial relationship of arachidonic and adrenic acid with the corpora lutea – the former is a known prostaglandin precursor and key signalling molecule in steroidogenesis regulation and the latter is metabolized in the prostaglandin pathway by the same enzymes – suggests the latter may also have a role in steroidogenesis regulation, previously unseen in ovarian physiology. DESI-MS imaging with morphologically-driven statistical analysis proved efficient in relating and interpreting the chemical and morphological features. This methodology can by further applied to unravel complex ovarian-related physiological mechanisms and to other physiological and physiopathological models.

271. Effect of season on sow ovarian morphology

2008 ◽  
Vol 20 (9) ◽  
pp. 71
Author(s):  
M. Bertoldo ◽  
P. K. Holyoake ◽  
G. Evans ◽  
C. G. Grupen
Keyword(s):  
Ovarian Tissue ◽  
Developmental Competence ◽  
Corpora Lutea ◽  
Ovarian Weight ◽  
Antral Follicles ◽  
Oocyte Developmental Competence ◽  
Ovarian Morphology ◽  
The Difference ◽  
Seasonal Infertility ◽  
Farrowing Rate

Reduced farrowing rate caused by embryonic mortality is a manifestation of seasonal infertility in pigs. The ability of the oocyte to mature, be fertilised and sustain embryonic development is acquired gradually by the oocyte throughout folliculogenesis. This study was undertaken to determine if seasonal differences in ovarian morphology are associated with reduced reproductive performance displayed during seasonal infertility. Sows culled after weaning were sourced from two genetically distinct herds (Farms A and B). Pairs of ovaries were collected from sows 4 days post-weaning during winter (n = 131) and summer (n = 275). Ovarian weight (Farm A only) and the numbers of small (3–4 mm) and large (5–8 mm) follicles were assessed (Farms A and B). Data did not follow normality and was analysed using the Mann–Whitney test. Mean ovarian weight per sow during winter (20.0 ± 1.3 g) was significantly heavier than that during summer (15.3 ± 0.8 g; P < 0.05). Farm A ovaries had a greater total number of antral follicles in winter compared with summer, and a greater number of antral follicles in winter compared with Farm B ovaries (P < 0.05). In Farm A ovaries, the proportion of follicles that were large was greater in summer compared with winter (78% v. 66%; P < 0.05), but the follicular distribution did not change with season in Farm B ovaries. While the findings demonstrate that ovarian weight was greater in winter compared with summer, they suggest that this difference was not the result of changes in the number or distribution of surface antral follicles. The difference in ovarian weight is possibly due to differences in ovarian tissue resulting from regressed corpora lutea. Further studies are being undertaken to assess the effect of season on oocyte developmental competence and the steroid content of follicular fluid isolated from small and large follicles.

CONCENTRATIONS OF CYCLIC AMP IN RABBIT OVARIAN TISSUE DURING THE PREOVULATORY PERIOD AND PSEUDOPREGNANCY AFTER INDUCTION OF OVULATION BY ADMINISTRATION OF HUMAN CHORIONIC GONADOTROPHIN

1975 ◽  
Vol 65 (1) ◽  
pp. 73-82 ◽  
Author(s):  
A. K. GOFF ◽  
PATRICIA W. MAJOR
Keyword(s):  
Cyclic Amp ◽  
Dose Response ◽  
Ovarian Tissue ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Corpora Lutea ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Induction Of Ovulation ◽  
Relationship Of

SUMMARY Concentrations of cyclic AMP were measured in rabbit ovaries at various times after injection of an ovulatory dose of human chorionic gonadotrophin (HCG). A biphasic increase in cyclic AMP concentration occurred during the preovulatory period, with peaks 30 min and 3–4 h after HCG injection. Concentrations of cyclic AMP had returned to those observed in ovaries of control oestrous animals before the onset of ovulation 10–12 h after administration of HCG, and remained low throughout the period of pseudopregnancy. Concentrations of cyclic AMP in the newly formed and developing corpora lutea were similar to the concentrations observed in the remainder of the tissue during this period. No significant increase in cyclic AMP concentration was observed 7–9 days after initiation of ovulation. Concentrations of ATP were also investigated during the preovulatory period. The dose– response relationship of HCG to cyclic AMP production in oestrous rabbit ovaries was investigated.

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