HISTOCHEMICAL CHANGES IN THE OVARIES OF NORMAL AND EXPERIMENTALLY TREATED RATS

1961 ◽  
Vol 36 (3) ◽  
pp. 361-374 ◽  
Author(s):  
Fletcher B. Taylor
Keyword(s):  
Ovarian Tissue ◽  
Blood Stream ◽  
Histochemical Staining ◽  
Interstitial Tissue ◽  
List Type ◽  
Histochemical Reaction ◽  
Adult Rat ◽  
Immature Rats ◽  
Luteal Tissue ◽  
Histochemical Changes

ABSTRACT Results from histochemical staining of ovaries of normal and experimentally treated rats using a method allegedly specific for 3β-ol steroids, together with blood progestin, progesterone (pregn-4-ene-3,20-dione) and urine pregnanediol (5β-pregnane-3α-20α-diol) determinations suggested that: 1. Thecal and interstitial tissue as well as luteal tissue of adult rat ovaries all produced progesterone and consequently the production of progesterone was not limited to a specific anatomic unit (e. g. corpus luteum). 2. The progesterone thus produced was secreted in part into the blood stream, for with each significant increase in the intensity of the histochemical reaction there was an associated rise in blood progestin, progesterone and urine pregnanediol. This did not quantitate the amount of progesterone involved in intermediary metabolism (e. g. of allopregnane3β-ol-20-one, pregn-4-ene-3β-ol-20-one). 3. The ovarian tissue of immature rats also produced progesterone.

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.

STIMULATION BY β2-ADRENERGIC RECEPTORS OF THE PRODUCTION OF CYCLIC AMP AND PROGESTERONE IN RAT OVARIAN TISSUE

1980 ◽  
Vol 87 (1) ◽  
pp. 123-129 ◽  
Author(s):  
ALBERT RATNER ◽  
G. K. WEISS ◽  
CAROLYN R. SANBORN
Keyword(s):  
Cyclic Amp ◽  
Adrenergic Receptors ◽  
Ovarian Tissue ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Adrenergic Stimulation ◽  
Immature Rats ◽  
Luteal Tissue ◽  
Pregnant Mare Serum Gonadotrophin ◽  
Stimulation Of

Ovarian tissue from immature rats treated with pregnant mare serum gonadotrophin (PMSG) or PMSG and human chorionic gonadotrophin was incubated in Medium 199. Stimulation of the formation of cyclic AMP in follicular and luteal tissue by terbutaline (10−5 mol/l), a selective β2-agonist, was blocked by butoxamine (10−5 mol/l), a selective β2-antagonist, whereas practolol (10−5 mol/l), a selective β1-antagonist, was ineffective. Propranolol (10−5 mol/l), a non-selective β-antagonist, butoxamine nor practolol affected the increase in cyclic AMP promoted by the addition of 1 μg LH. Stimulation of the production of progesterone in both follicular and luteal tissue by terbutaline was blocked by butoxamine, but not by practolol. These findings indicated that β-adrenergic stimulation of ovarian cyclic AMP and progesterone is mediated by β2-adrenergic receptors.

EFFECT OF HYPOPHYSECTOMY ON BINDING OF HUMAN CHORIONIC GONADOTROPHIN TO IMMATURE AND ADULT RAT OVARIES

1977 ◽  
Vol 75 (2) ◽  
pp. 271-276 ◽  
Author(s):  
J. W. SIEBERS ◽  
W. ENGEL
Keyword(s):  
Binding Capacity ◽  
Ovarian Tissue ◽  
Binding Activity ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Scatchard Analysis ◽  
Adult Rats ◽  
Adult Rat ◽  
Immature Rats ◽  
Pituitary Ablation

The binding of 125I-labelled human chorionic gonadotrophin (HCG) to ovarian tissue was studied in hypophysectomized immature and adult rats. The ability of the ovaries of adult rats to bind HCG was markedly reduced within 3 days of hypophysectomy and remained low for at least 20 days. The extent of the reduction depended on the stage of the oestrous cycle at which hypophysectomy was performed. The highest loss of HCG binding capacity was seen in rats hypophysectomized at dioestrus II, while rats hypophysectomized at the oestrous stage exhibited similar HCG binding to control rats at the same stage of the cycle. Scatchard analysis indicated that the reduction in the capacity of the ovary to bind HCG after hypophysectomy was caused by the loss of specific receptors and not by a decrease in binding affinity. In contrast to adult rats, in immature rats the HCG binding capacity of the ovaries did not change during the 3 days after hypophysectomy, but after this a slow decline took place. Twenty days after pituitary ablation, almost identical values for binding of HCG were found in immature and adult rats. Since hypophysectomy in adult rats causes a rapid regression of large follicles, our results indicate that the remaining HCG binding activity arises largely from small follicles which are known to be unaltered by the deprivation of hypophysial hormones. This assumption is supported by our observation that in the ovaries of 25-day-old immature rats, which lack large follicles, only a slow decrease in the ability of the ovaries to bind HCG occurs in the 20 days after the operation.

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.

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.

P10 Evaluation of existing line-locking practice in central venous catheters of paediatric patients on home parenteral nutrition

2018 ◽  
Vol 103 (2) ◽  
pp. e1.14-e1
Author(s):  
Tustin Amy ◽  
Hartley Karen ◽  
Derry David ◽  
Thomas Julian
Keyword(s):  
Parenteral Nutrition ◽  
Meta Analysis ◽  
Bloodstream Infections ◽  
Venous Catheter ◽  
Blood Stream ◽  
Central Venous Catheters ◽  
Home Parenteral Nutrition ◽  
List Type ◽  
Central Venous ◽  
Paediatric Patients

AimTo review current line-locking practice of central venous catheters (CVCs) to reduce catheter related blood stream infections (CRBSIs) and preserve line integrity in paediatric patients on home parenteral nutrition (HPN), with the secondary aim of producing a concise, evidence-based guideline for use in this cohort and inpatient PN patients as well.MethodAll 19 paediatric HPN patients were reviewed retrospectively over 6 months (January–June 2017). Data was collected from clinic letters, HPN prescriptions and blood cultures. Information gathered per patient:Line lock(s)Infective episode(s)CVC replacement(s)Establishment of current practice: All patients use TaurolockTM first-line. If CVC is stiff or stops bleeding back switch to TauroLockTM-Hep100. Should problems persist introduce alcohol 70% on alternate days or alone if recurrent infections occur on TaurolockTM. Blocked CVCs are instilled with urokinase or alteplase and CVC replaced if unsuccessful.Results18/19 patients were prescribed line locks as per above practice. One patient is prescribed heparin 10units/ml – due to a documented TauroLockTM allergy – and remained infection- free throughout. 7 infections occurred overall in 6 patients with 13 patients infection-free. 2.2 infections/1000 catheter days occurred in patients on TauroLockTM with 2 patients requiring CVC changes due to infection and broken CVC respectively.1 infection/1000 catheter days occurred on TauroLockTM- Hep100 with 2 CVC changes required due to occlusion. 11 infections/1000 catheter days occurred in 1 patient on daily alcohol 70%, although result validity is uncertain due to potential contamination of blood culture specimen from skin organisms during sampling. No infections occurred in 248 catheter days in patients alternating TauroLockTM-Hep100 and alcohol 70% with one line change required as CVC moved position.ConclusionCRBSIs pose a serious problem in paediatric HPN patients.1,2 Taurolidine has proven efficacy at preventing CRBSIs and proven superiority to heparin.3 The effectiveness of alcohol at reducing CRBSI rates and preventing CVC replacement has been proven when compared to heparin4 however, due to adverse effects (thrombosis and CVC degradation)4 use is limited to ensure benefits outweigh risks. These studies, although limited, and results in our patient cohort support the continued use of these line locks as per existing practice. Future work includes need to formalise written guideline and discuss clear pathway if patients have multiple CRBSIs on their existing line lock as presently information is unclear.ReferencesKoletzko B, Agostoni C, Ball P, et al. ESPEN/ESPGHAN guidelines on paediatric parenteral nutrition. Journal of Paediatric Gastroenterology and Nutrition2005;41:S76–S84.Candusso M, Faraguna D, Sperli D, et al. Outcome and quality of life in paediatric home parenteral nutrition. Current Opinion in Clinical Nutrition and Metabolic Care2005;5:309–14.Chu HP, Brind J, Tomar R, et al. Significant reduction in central venous catheter-related bloodstream infections in children on HPN after starting treatment with taurolidine line lock. J Pediatr Gastroenterol Nutr2012;55:403–7.Oliveira C, Nasr A, Brindle M, et al. Ethanol locks to prevent catheter-related bloodstream infections in parenteral nutrition: A meta-analysis. Paediatrics2012;129:318–329.

3β-HYDROXYSTEROID DEHYDROGENASE ACTIVITY IN THE HUMAN FOETAL ADRENAL CORTEX

1965 ◽  
Vol 48 (3) ◽  
pp. 423-428 ◽  
Author(s):  
M. Niemi ◽  
A. H. Baillie
Keyword(s):  
Dehydrogenase Activity ◽  
Adrenal Cortex ◽  
Substrate Binding ◽  
Hydroxysteroid Dehydrogenase ◽  
List Type ◽  
Histochemical Reaction ◽  
Enzyme Substrate ◽  
Human Male ◽  
Foetal Life ◽  
Free Steroid

ABSTRACT 3β-Hydroxysteroid dehydrogenase activity was studied histochemically in the adrenal cortex of ten human male foetuses, ranging in crownrump length from 3.0 cm to 18.3 cm, with the following steroids: 3β-hydroxy-pregn-5-en-20-one (pregnenolone). 3β,17α-dihydroxy-pregn-5-en-20-one (17α-hydroxypregnenolone). 3β-hydroxy-androst-5-en-17-one (DHA). 3β,17β-dihydroxy-androst-5-ene (androstenediol). 3β-sulphoxy-pregn-5-en-20-one (pregnenolone sulphate). 3β-sulphoxy-17α-hydroxy-pregn-5-en-20-one (17α-hydroxy-pregnenolone sulphate) 3β-sulphoxy-androst-5-en-17-one (DHAsulphate). 3β-hydroxy-5α-androstan-17-one (epiandrosterone). After incubation with pregnenolone, 17α-hydroxypregnenolone, DHA and androstenediol a positive histochemical reaction was obtained in the inner part of the »definitive« cortex and throughout the foetal cortex of all adrenals studied. Initially very weak, the reaction became strongly positive about the twelfth week of foetal life. Pregnenolone sulphate and 17α-hydroxypregnenolong sulphate also gave a histochemical reaction in all the adrenals investigated, but DHA sulphate differed significantly from the free steroid by giving a very poor reaction. Formazan deposition followed incubation with epiandrosterone in all adrenals used and this may imply that a δ5 configuration is not necessary for enzyme-substrate binding.

Intragonadal regulation of immune system functions

1990 ◽  
Vol 2 (3) ◽  
pp. 263 ◽  
Author(s):  
MP Hedger ◽  
JX Qin ◽  
DM Robertson ◽  
Kretser DM de
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Germ Cell ◽  
Conditioned Medium ◽  
Leydig Cells ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Short Term ◽  
Adult Rat

Immune responses within the mammalian gonads, and in particular the testis, are deficient in spite of adequate lymphatic drainage and the presence of lymphocytes and MHC II+ macrophages. There is considerable evidence from in vivo and in vitro studies that this 'suppression' of the immune system may be due, at least in part, to localized inhibition or regulation of normal lymphocyte and/or macrophage functions within the gonads. In the testis, both steroidal and non-steroidal products of the Leydig cells, including androgens, endorphins, and inhibin-related proteins, have been implicated in mediating this activity. In turn, a number of immune cell cytokines affect steroidogenic cell function in vitro. The studies described in this paper indicated that [3H]-thymidine incorporation by adult rat thymocytes in vitro was inhibited by conditioned medium collected from short-term incubations of Percoll-purified adult rat Leydig cells, but stimulated by testicular interstitial fluid and by conditioned medium collected from short-term incubations of adult rat seminiferous tubules. The factors responsible for these effects on thymocyte function appeared to be of large molecular weight, as they were retained by ultrafiltration membranes with exclusion limits of 10,000 or 30,000 daltons. It is hypothesized that an 'immunosuppressive' mechanism, principally mediated by non-steroidal factors secreted by the steroidogenic cells of the gonadal interstitial tissue, exists within the gonads in order to prevent activation of the immune system by germ cell antigens and growth factors associated with germ cell proliferation and differentiation. This mechanism probably acts in parallel with normal antigen-specific tolerance mechanisms operating at the gonadal level. As immune responses to germ cells are believed to be a significant causative factor in infertility, particularly in men, this represents an important area for further study.

scholarly journals ACETYL DISULFIDE, (CH3COS)2, AND BIS-(THIOACETOXY) AURATE (I) COMPLEX, Au(CH3COS)2–, HISTOCHEMICAL SUBSTRATES OF UNUSUAL PROPERTIES WITH ACETYLCHOLINESTERASE

1968 ◽  
Vol 16 (12) ◽  
pp. 754-764 ◽  
Author(s):  
GEORGE B. KOELLE ◽  
RICHARD DAVIS ◽  
MARTINA DEVLIN
Keyword(s):  
Metal Ion ◽  
Histochemical Staining ◽  
Histochemical Reaction ◽  
Black Precipitate ◽  
Spontaneous Hydrolysis ◽  
Sigmoid Curve ◽  
Fine Localization ◽  
Thiolacetic Acid ◽  
Bell Shaped Curve ◽  
Supernatant Solution

The histochemical reaction for acetylcholinesterase (AChE) employing acetyl disulfide ([CH3COS]2, or AcDiS) as substrate and 0.006 M Pb(NO3)2 as capturing agent was characterized by (1) a sigmoid curve for velocity of hydrolysis versus substrate concentration and (2) a red precipitate (presumably [CH3COSS]2Pb) at sites of AChE at the motor endplates (MEP's) and (from spontaneous hydrolysis) in the supernatant solution. With the addition of 0.03 M thiolacetic acid (TA) to the incubation medium, which by itself produced little or no histochemical staining, the foregoing characteristics were changed to (1) a bell-shaped curve, with the peak at 0.003 M AcDiS, and (2) a black precipitate (presumably PbS) at the MEP's and in the supernatant solution; in addition, the velocity of hydrolysis was increased approximately 100-fold. Comparable differences were obtained with AcDiS as substrate when using ionic Au+ or Au(S2O3)2–3 as the capturing agent. Results are explained on the basis that in the absence of free heavy metal ion ( i.e., with the Pb[TA]2 or Au[S2O3]2–3 complex), AcDiS combines with AChE at both the anionic and esteratic sites, whereas, in the presence of Pb2+ or Au+, attachment of the substrate occurs only at the esteratic site of the enzyme. Results similar to the former type were obtained when the bis-(thioacetoxy) aurate (I) complex (Au[CH3COS]2– or Au[TA]2– served as both substrate and capturing agent. With both the AcDiS-Au(S2O3)2–3 and Au (TA)2– methods, extremely fine localization of AChE was obtained at the MEP's by electron microscopy.

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