ACUTE EFFECTS OF GONADOTROPHINS AND PROSTAGLANDINS ON THE METABOLISM OF ISOLATED OVARIAN FOLLICLES FROM PMSG-TREATED IMMATURE RATS

1974 ◽  
Vol 77 (3) ◽  
pp. 540-558 ◽  
Author(s):  
Lars Nilsson
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Production ◽  
Isobutyric Acid ◽  
Bicarbonate Buffer ◽  
Immature Rats ◽  
Prostaglandin F ◽  
Protein Incorporation ◽  
Ovulatory Follicles

ABSTRACT Pre-ovulatory follicles from immature rats injected with a low dose of PMSG have been used for studies of carbohydrate and protein metabolism in vitro. The follicles were isolated by free-hand dissection and incubated in modified Krebs bicarbonate buffer for periods up to 4 h. The lactic acid content of the medium was analyzed after various incubation periods. In most experiments the tissue uptake of [14C]α-amino-isobutyric acid and [3H] leucine as well as the incorporation of [3H] leucine into follicular protein were determined. Addition of LH or FSH to the incubation medium markedly stimulated the production of lactic acid, whereas prostaglandins of the E-type were less effective. Prostaglandin F2α and dibutyryl cyclic 3′, 5′-AMP had no effect at all. No in vitro effects were seen on the uptake and incorporation af labelled amino acids. When LH or FSH was injected to the animals in vivo 1 or 2 h before incubation of the follicles, the lactic acid production was also stimulated, but only the injection of LH stimulated the protein incorporation of [3H] leucine.

Oestradiol synthesis by granulosa cells from immature rats treated with pregnant mare's serum gonadotrophin

1983 ◽  
Vol 104 (3) ◽  
pp. 372-380 ◽  
Author(s):  
Donald C. Johnson ◽  
Roger C. Hoversland
Keyword(s):  
Granulosa Cells ◽  
Steroid Synthesis ◽  
Bicarbonate Buffer ◽  
Immature Rats ◽  
Hypophysectomized Rats ◽  
System Inclusion ◽  
Ovulatory Follicles ◽  
Generating System

Abstract. Granulosa cells harvested from follicles in hypophysectomized or intact immature rats treated with 20 IU of pregnant mare's serum gonadotrophin (PMS) produced immunoreactive oestradiol (E2) when incubated in Krebs Ringer bicarbonate buffer containing an NADPH generating system; inclusion of steroid substrates in the medium increased the rate of synthesis. Further, tritiated E2 was synthesized when labelled progesterone was used as substrate. Granulosa cells removed from pre-ovulatory follicles on the morning of prooestrus in adult females also produced E2 in vitro. Although E2 synthesis was apparent by cells from immature hypophysectomized rats within 12 h of PMS treatment, it inceased greatly with longer in vivo exposure to the gonadotrophin. Production was linear with the number of cells incubated and with time, at least through the first 30 min; the production rate decreased slightly with longer incubations. Exposure of the cells in vivo to hCG or ovine LH, before incubation, destroyed most of their ability to synthesize E2 even if progesterone or pregnenolone was added to the medium, but conversion of testosterone to E2 was reduced by only about 50%. Inhibitors of steroid synthesis, i.e. 4-OH-androstenedione, SU-10603, cyanoketone, or aminoglutethimide, greatly reduced the amount of E2 synthesized by the cells. The results indicate that granulosa cells exposed in vivo to gonadotrophins can synthesize E2 without the addition of androgenic substrate provided that cofactors are supplied. This finding has important implications for the current 'two cell' theory for oestrogen production by the ovary. A deficiency in steroidogenic enzymes within the granulosa cell appears to be an inadequate basis for the theory. However, the total synthesis of E2 in vivo by granulosa cells has not been shown.

Inhibition of LH-stimulated cyclic AMP formation in pre-ovulatory rat granulosa cells by follicular fluid

1980 ◽  
Vol 95 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Knut Nordenström ◽  
Anita Sjögren ◽  
Lars Hamberger
Keyword(s):  
Granulosa Cells ◽  
Follicular Fluid ◽  
Phosphodiesterase Inhibitor ◽  
Inhibitory Effect ◽  
Female Rats ◽  
Bicarbonate Buffer ◽  
Ovulatory Follicles

Abstract. Immature female rats were injected sc with a single dose of PMSG to induce growth and maturation of ovarian follicles. In the morning of prooestrus the rats were given a single ip injection of LH (10 μg/rat) or 0.154 m NaCl, 2 h prior to sacrifice. Granulosa cells were isolated from the pre-ovulatory follicles and incubated in Krebs bicarbonate buffer, for 1 h with or without in vitro addition of various test substances. Following incubation the amounts of cAMP in tissue plus medium were determined. It was found that the isolated granulosa cells exposed to LH in vivo responded to the addition of LH in vitro with a production of high amounts of cAMP, i.e. these cells were not refractory to LH stimulation and in fact responded better than granulosa cells isolated from ovaries not exposed to LH in vivo. The addition to the incubation medium of follicular fluid (FFl) obtained from pre-ovulatory follicles decreased the effect of LH in vitro when added at a final concentration of 1% and completely abolished it at a concentration of 3%. Removal of steroids from the FFl did not influence the inhibitory effect and the addition of a phosphodiesterase inhibitor (IBMX) in vitro did not alter the results in principle. These results point to the existence of a factor in the FF1 which interacts with the sensitivity of the isolated preovulatory granulosa cells to repeated exposures to LH. Characterization of this factor is subject to further investigations.

Effects of in vivo and in vitro production of lactic acid on ionized, protein-bound, and complex-bound calcium in blood.

1989 ◽  
Vol 35 (6) ◽  
pp. 935-938 ◽  
Author(s):  
J Toffaletti ◽  
B Abrams
Keyword(s):  
Lactic Acid ◽  
Calcium Ions ◽  
Lactic Acid Production ◽  
Respiratory Alkalosis ◽  
Ionized Calcium ◽  
In Vitro Production ◽  
Vitro Production ◽  
Lithium Lactate

Abstract We have studied, both in vitro and in vivo, the quantitative effects of lactic acid production on concentrations of ionized calcium, bound calcium, pH, bicarbonate, and albumin. To do so, we examined the effects of addition of aqueous solutions of either hydrochloric acid, lactic acid, or lithium lactate to blood; we studied in vitro accumulation by storing blood sealed in tubes at room temperature for 5 h, then exposing the blood to air; and we induced in vivo production of lactic acid in healthy individuals who climbed stairs for 10 min. Lactic acid evidently affects the ionized, protein-bound, and complex-bound calcium concentrations in the following ways: (a) hydrogen ions from lactic acid bind to protein, which decreases protein-bound calcium; (b) lactate chelates calcium ions from free ionized calcium and protein-bound calcium about equally; and (c) the loss of a millimole of bicarbonate, either by exposure of blood to air or by respiratory alkalosis, results in the release of about 7 mumol of calcium ions, which re-equilibrate with both the protein-bound and ionized calcium. Because lactate apparently removes calcium ions directly from albumin, our study indicates that protein-bound calcium readily provides calcium ions that buffer changes in the concentration of ionized calcium.

THE EFFECT OF INSULIN ON THE UPTAKE OF MONOSACCHARIDES BY THE RAT LENS

1961 ◽  
Vol 22 (4) ◽  
pp. 361-369 ◽  
Author(s):  
RUTH LEVARI ◽  
W. KORNBLUETH ◽  
E. WERTHEIMER
Keyword(s):  
Lactic Acid ◽  
Glucose Uptake ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Bicarbonate Buffer ◽  
Total Uptake ◽  
Order Of Magnitude ◽  
Normal Rat ◽  
Stimulation Of

SUMMARY 1. A direct stimulatory effect of insulin, in vitro, on the uptake of galactose, glucosamine and some pentoses by the intact lens, has been established. Stimulation of glucose uptake is perceptible only under certain conditions, and was more pronounced in a medium of bicarbonate buffer than in phosphate. 2. Insulin increased lactic acid production from glucose and from galactose. 3. Chronic diabetes decreased galactose uptake. Insulin, in vitro, restored the uptake to the level of that of normal rat lenses. 4. Phloridzin was found to cancel the effect of insulin. 5. The increase in uptake by insulin was of the same order of magnitude for glucose and galactose, irrespective of the total uptake. The decrease in uptake due to diabetes was quantitatively the same as the increase by insulin in normal rat lenses. The effect of insulin on lactic acid production was identical for both hexoses. 6. The possible existence of two pathways of glucose uptake in the rat lens is discussed.

scholarly journals Protective Effects of Novel Lactobacillaceae Strains Isolated from Chicken Caeca against Necrotic Enteritis Infection: In Vitro and In Vivo Evidences

2022 ◽  
Vol 10 (1) ◽  
pp. 152
Author(s):  
Nuria Vieco-Saiz ◽  
Yanath Belguesmia ◽  
Ruth Raspoet ◽  
Eric Auclair ◽  
Connor Padgett ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Production ◽  
Survival Rates ◽  
Control Group ◽  
Necrotic Enteritis ◽  
Protective Effects ◽  
Infected Chicken ◽  
Significant Survival

The present study aimed to show the benefits of novel lactic acid bacteria (LAB) strains isolated from the caeca of healthy chickens. These novel strains, identified as Limosilactobacillus reuteri and Ligilactobacillus salivarius, displayed high levels of lactic acid production, capability of biofilm formation, high aggregation and adhesion scores, and significant survival rates under conditions mimicking the chicken gastrointestinal tract (GIT). In addition, these novel Lactobacillaceae isolates were neither hemolytic nor cytotoxic. In vivo trials were able to establish their ability to reduce necrotic enteritis. Notably, a significant weight gain was registered, on day 10 of treatment, in the group of chickens fed with a mixture of L. reuteri ICVB416 and L. salivarius ICVB430 strains, as compared with the control group. This group has also shown a reduced number of lesions in the gut compared with other infected chicken groups. This study provides in vitro and in vivo evidence supporting the benefits of these novel Lactobacillaceae isolates for their use in poultry livestock as protective cultures to control the bacterial necrotic enteritis (NE) Clostridium perfringens.

CHARACTERISTICS OF THE CYCLIC 3′, 5′-AMP FORMATION IN ISOLATED OVARIAN FOLLICLES FROM PMSG-TREATED IMMATURE RATS AFTER STIMULATION IN VITRO WITH GONADOTROPHINS AND PROSTAGLANDINS

1974 ◽  
Vol 77 (3) ◽  
pp. 559-574 ◽  
Author(s):  
Lars Nilsson ◽  
Sten Rosberg ◽  
Kurt Ahrén
Keyword(s):  
Binding Assay ◽  
Prostaglandin E ◽  
Maximal Effect ◽  
Bicarbonate Buffer ◽  
Protein Binding Assay ◽  
Immature Rats ◽  
Significant Release ◽  
Time Courses ◽  
Ovulatory Follicles

ABSTRACT Isolated pre-ovulatory follicles from PMSG-injected immature rats, described in a previous publication, have been used for the investigation of the pattern of cyclic 3′,5′-AMP synthesis after in vitro addition of gonadotrophins and prostaglandins. The follicles were incubated in a modified Krebs bicarbonate buffer for periods up to 4 h and the cyclic 3′,5′-AMP content in tissue and medium was analyzed with the protein binding assay of Gilman (1970). Addition of LH, FSH or prostaglandin E2 (PGE2) increased the cyclic 3′,5′-AMP level in follicular tissue dramatically. HCG and TSH, but not STH or prolactin, also induced a similar increase. The effect of FSH was blocked by a highly specific antiserum to LH. The effect of LH had a maximum after approximately 1 h of incubation, whereas the maximal effect of PGE2 was seen between 5 and 15 min of incubation. When LH was present in the incubation medium a significant release of cyclic 3′,5′-AMP into the medium occurred. Theophylline potentiated the effects of LH and PGE2. The different time-courses of the effects of LH and PGE2 on the cyclic 3′,5′-AMP production by follicular tissue are discussed in relation to the hypothesis of prostaglandins as obligatory mediators of all LH effects on the ovary (Kuehl et al. 1970).

scholarly journals Protective effect of titanium tetrafluoride and silver diamine fluoride on radiation-induced dentin caries in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Beatriz Martines de Souza ◽  
Mayara Souza Silva ◽  
Aline Silva Braga ◽  
Patrícia Sanches Kerges Bueno ◽  
Paulo Sergio da Silva Santos ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Protective Effect ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Negative Control ◽  
Titanium Tetrafluoride ◽  
Silver Diamine Fluoride ◽  
Dentin Caries ◽  
Radiation Induced

AbstractThis in vitro study evaluated the protective effect of titanium tetrafluoride (TiF4) varnish and silver diamine fluoride (SDF) solution on the radiation-induced dentin caries. Bovine root dentin samples were irradiated (70 Gy) and treated as follows: (6 h): 4% TiF4 varnish; 5.42% NaF varnish; 30% SDF solution; placebo varnish; or untreated (negative control). Microcosm biofilm was produced from human dental biofilm (from patients with head-neck cancer) mixed with McBain saliva for the first 8 h. After 16 h and from day 2 to day 5, McBain saliva (0.2% sucrose) was replaced daily (37 °C, 5% CO2) (biological triplicate). Demineralization was quantified by transverse microradiography (TMR), while biofilm was analyzed by using viability, colony-forming units (CFU) counting and lactic acid production assays. The data were statistically analyzed by ANOVA (p < 0.05). TiF4 and SDF were able to reduce mineral loss compared to placebo and the negative control. TiF4 and SDF significantly reduced the biofilm viability compared to negative control. TiF4 significantly reduced the CFU count of total microorganism, while only SDF affected total streptococci and mutans streptococci counts. The varnishes induced a reduction in lactic acid production compared to the negative control. TiF4 and SDF may be good alternatives to control the development of radiation-induced dentin caries.

scholarly journals In Vitro and In Vivo Biosafety Analysis of Resorbable Polyglycolic Acid-Polylactic Acid Block Copolymer Composites for Spinal Fixation

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 29
Author(s):  
Seung Kyun Yoon ◽  
Jin Ho Yang ◽  
Hyun Tae Lim ◽  
Young-Wook Chang ◽  
Muhammad Ayyoob ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Animal Experiments ◽  
Polymeric Materials ◽  
Polyglycolic Acid ◽  
Poly Lactic Acid ◽  
Skin Sensitization ◽  
Spinal Fixation ◽  
In Vivo Degradation

Herein, spinal fixation implants were constructed using degradable polymeric materials such as PGA–PLA block copolymers (poly(glycolic acid-b-lactic acid)). These materials were reinforced by blending with HA-g-PLA (hydroxyapatite-graft-poly lactic acid) and PGA fiber before being tested to confirm its biocompatibility via in vitro (MTT assay) and in vivo animal experiments (i.e., skin sensitization, intradermal intracutaneous reaction, and in vivo degradation tests). Every specimen exhibited suitable biocompatibility and biodegradability for use as resorbable spinal fixation materials.

scholarly journals The impact of indole-3-lactic acid on immature intestinal innate immunity and development: a transcriptomic analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wuyang Huang ◽  
Ky Young Cho ◽  
Di Meng ◽  
W. Allan Walker
Keyword(s):  
Lactic Acid ◽  
Mechanistic Model ◽  
Transcriptomic Analysis ◽  
Dependent Manner ◽  
Protective Effects ◽  
Very Preterm Infants ◽  
Anti Inflammatory ◽  
The Impact

AbstractAn excessive intestinal inflammatory response may have a role in the pathogenesis of necrotizing enterocolitis (NEC) in very preterm infants. Indole-3-lactic acid (ILA) of breastmilk tryptophan was identified as the anti-inflammatory metabolite involved in probiotic conditioned media from Bifidobacteria longum subsp infantis. This study aimed to explore the molecular endocytic pathways involved in the protective ILA effect against inflammation. H4 cells, Caco-2 cells, C57BL/6 pup and adult mice were used to compare the anti-inflammatory mechanisms between immature and mature enterocytes in vitro and in vivo. The results show that ILA has pleiotropic protective effects on immature enterocytes including anti-inflammatory, anti-viral, and developmental regulatory potentials in a region-dependent and an age-dependent manner. Quantitative transcriptomic analysis revealed a new mechanistic model in which STAT1 pathways play an important role in IL-1β-induced inflammation and ILA has a regulatory effect on STAT1 pathways. These studies were validated by real-time RT-qPCR and STAT1 inhibitor experiments. Different protective reactions of ILA between immature and mature enterocytes indicated that ILA’s effects are developmentally regulated. These findings may be helpful in preventing NEC for premature infants.

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