LUTEINISATION INDUCED IN »CONSTANT OESTRUS RATS« BY LOWERING OESTROGEN PRODUCTION

1961 ◽  
Vol 37 (3) ◽  
pp. 418-422 ◽  
Author(s):  
Béla Flerkó ◽  
Vera Bárdos
Keyword(s):  
Ovarian Tissue ◽  
Albino Rats ◽  
Reciprocal Relation ◽  
Corpora Lutea ◽  
Renal Capsule ◽  
Experimental Conditions ◽  
Optic Chiasma ◽  
Paraventricular Nuclei ◽  
Oestrogen Level ◽  
Electrolytic Lesions

ABSTRACT In albino rats with bilaterally placed electrolytic lesions between the optic chiasma and paraventricular nuclei and in constant vaginal oestrus with no corpora lutea in the ovaries, luteinisation could be induced (1) by unilateral ovariectomy and hemiresection of the other; (2) by grafting half of one ovary after bilateral ovariectomy into the renal capsule or (3) into the spleen. While under the experimental conditions (1) and (2) the degree of luteinisation was found to be in a reciprocal relation to the amount of the remaining or grafted ovarian tissue, intrasplenic ovarian grafts (3) always contained a large number of corpora lutea. Formation of corpora lutea could accordingly be induced in rats with constant vaginal oestrus due to hypothalamic lesions by decreasing the oestrogen level in the blood. Luteinisation was most pronounced in the intrasplenic grafted animals in which a reduction of the oestrogen producing tissue had been combined with a practically quantitative oestrogen inactivation by the liver.

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.

HYPOTHALAMIC SEXUAL PRECOCITY IN FEMALE RATS OPERATED SHORTLY AFTER BIRTH

1962 ◽  
Vol 41 (2) ◽  
pp. 301-313 ◽  
Author(s):  
S. Horowitz ◽  
J. J. Van der Werff ten Bosch
Keyword(s):  
Anterior Commissure ◽  
Anterior Hypothalamus ◽  
Female Rats ◽  
Vaginal Opening ◽  
Sexual Precocity ◽  
Paraventricular Nuclei ◽  
Gonadotrophin Secretion ◽  
Electrolytic Lesions

ABSTRACT Electrolytic lesions were placed in the anterior hypothalamus of 3–4 day-old female rats; vaginal opening was hastened in comparison with blank-operated littermates in 12 of 17 rats bearing a lesion in the basal supra-and post-chiasmatic area. In the animals with the earliest vaginal opening, lesions reached upward towards the region of the anterior commissure and the paraventricular nuclei. The degree of advancement of puberty in rats operated at the age of 3 or 4 days was similar to that caused by lesions made at 10, 14 or 15 days. This finding suggests that the effect of a lesion upon gonadotrophin secretion does not begin to take place until after the age of at least two weeks.

THE EFFECT OF HYPOTHALAMIC LESIONS ON REPRODUCTIVE ACTIVITY IN SHEEP

1967 ◽  
Vol 39 (3) ◽  
pp. 415-NP ◽  
Author(s):  
H. M. RADFORD
Keyword(s):  
Median Eminence ◽  
Reproductive Activity ◽  
Mammillary Body ◽  
Optic Chiasma ◽  
Hypothalamic Lesions ◽  
Apparent Change ◽  
Electrolytic Lesions ◽  
Releasing Factors ◽  
Bilateral Lesions ◽  
Made In

SUMMARY Electrolytic lesions were made in the hypothalamus of 41 Merino ewes which were subsequently observed for 2–16 months. Ovarian inactivity resulted from bilateral medial and ventral lesions placed immediately posterior to the optic chiasma (four ewes) or immediately anterior to the mammillary body (five ewes). Failure to show oestrus while apparently still ovulating regularly was a feature in another four ewes in which bilateral medial and ventral lesions were placed between the sites already described. Small bilateral lesions in these ventral regions led initially to ovarian inactivity, but final re-establishment of apparently normal reproductive activity in three ewes. Bilateral lesions in regions other than those described above resulted in no apparent change in reproductive activity (eight ewes). Similarly, unilateral or asymmetrical lesions in the remaining 17 ewes failed to affect their reproductive activity. The results are consistent with the hypothesis that in sheep a region of the median eminence responsible for the production of gonadotrophin-releasing factors requires neural inputs traversing both anterior and posterior hypothalamic areas.

PVN lesions prevent the endothelin 1-induced increase in arterial pressure and vasopressin

2001 ◽  
Vol 280 (2) ◽  
pp. E349-E356 ◽  
Author(s):  
Noreen F. Rossi ◽  
Haiping Chen
Keyword(s):  
Central Nervous System ◽  
Cerebrospinal Fluid ◽  
Arterial Pressure ◽  
Paraventricular Nuclei ◽  
Artificial Cerebrospinal Fluid ◽  
Electrolytic Lesions ◽  
The Central Nervous System ◽  
Baseline Values ◽  
Long Evans

Endothelin (ET) acts within the central nervous system to increase arterial pressure and arginine vasopressin (AVP) secretion. This study assessed the role of the paraventricular nuclei (PVN) in these actions. Intracerebroventricular ET-1 (10 pmol) or the ETA antagonist BQ-123 (40 nmol) was administered in conscious intact or sinoaortic-denervated (SAD) Long-Evans rats with sham or bilateral electrolytic lesions of the magnocellular region of the PVN. Baseline values did not differ among groups, and artificial cerebrospinal fluid (CSF) induced no significant changes. In sham-lesioned rats, ET-1 increased mean arterial pressure (MAP) 15.9 ± 1.3 mmHg in intact and 22.3 ± 2.7 mmHg in SAD ( P < 0.001 ET-1 vs. CSF) rats. PVN lesions abolished the rise in MAP: −0.1 ± 2.8 mmHg in intact and 0.0 ± 2.9 mmHg in SAD. AVP increased in only in the sham-lesioned SAD group 8.6 ± 3.5 pg/ml ( P < 0.001 ET-1 vs. CSF). BQ-123 blocked the responses. Thus the integrity of the PVN is required for intracerebroventricularly administered ET-1 to exert pressor and AVP secretory effects.

Specific alterations in sodium chloride intake after hypothalamic lesions in the rat

1963 ◽  
Vol 205 (5) ◽  
pp. 922-926 ◽  
Author(s):  
Miguel R. Covian ◽  
José Antunes-Rodrigues
Keyword(s):  
Sodium Chloride ◽  
Urinary Excretion ◽  
The Other ◽  
Urinary Output ◽  
Water Ingestion ◽  
Hypothalamic Lesions ◽  
Paraventricular Nuclei ◽  
Electrolytic Lesions ◽  
Specific Increase ◽  
Sodium Chloride Intake

Bilateral electrolytic lesions in the hypothalamus of the rat elicited either a decrease or increase in 2% NaCl intake, without a significant change in water ingestion. Lesions placed in the anterior hypothalamus involving supraoptic or paraventricular nuclei, or both, resulted in a conspicuous fall (as much as 93%) of NaCl intake. The decreased consumption remained to the end of the experiments which in some rats lasted 105 days and was accompanied by a decrease in NaCl urinary output. On the contrary, lesions placed in the central hypothalamus determined a specific increase of NaCl intake together with an augmented urinary excretion. The increased ingestion was permanent and lasted to the end of the experiment, attaining in one rat the value of 290%. To account for these results two provisional explanations are advanced, one of them considering the possibility of the existence of two areas of opposite effects regarding NaCl ingestion and the other claiming a neurohumoral mechanism in which oxytocin and aldosterone could be the two responsible hormones.

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 &lt; 0.01) but unaffected by ALT supplementation. Feed intake (FI) was reduced (P &lt; 0.01) by HS but unaltered by ALT treatment. Corpora lutea (CL) weight was reduced (P &lt; 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 &gt; 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 &lt; 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.

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.

Generation of Fractionated Goal Response by Differential Activity at the Goal-Box

1968 ◽  
Vol 23 (1) ◽  
pp. 251-262
Author(s):  
Marvin J. Herbert ◽  
Norman Greenfeld
Keyword(s):  
Correct Response ◽  
Choice Point ◽  
Albino Rats ◽  
Experimental Conditions ◽  
Differential Learning ◽  
Goal Response ◽  
Effector Activity

It was hypothesized that the probability of making a correct response at the choice point of a simple T-maze is increased when goal-box conditions serve to heighten the kind and degree of effector activity demanded in making that response. 60 albino rats were divided equally among each of 5 experimental conditions reflecting differences in effector activity at the goal-box. Predictions suggested that occurrence of the correct response at the choice-point decreases with decreasing amounts of kinesthetic activity generated at the goal-box. The results generally support the contention that varied kinesthetic-interoceptive stimulation from S's own body produces differential learning.

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.

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