scholarly journals Activity of Enzymes of Glycogen Metabolism in the Reproductive Tract of the Ewe at Mating and during Early Pregnancy

1978 ◽  
Vol 31 (4) ◽  
pp. 355 ◽  
Author(s):  
T O'Shea ◽  
BE Murdoch
Keyword(s):  
Early Pregnancy ◽  
Enzyme Activities ◽  
Reproductive Tract ◽  
Glycogen Metabolism ◽  
Glycogen Concentration ◽  
Mucosal Tissues ◽  
Activity Of Enzymes

The glycogen concentration and the activity of several enzymes of glycogen metabolism have been measured in the mucosal tissues of the oviduct, cervix and vagina, as well as in the endometrium and caruncIes of ewes at days 0, 8, 15, 22, 30 and 44 of pregnancy. Enzyme activities were also determined in uterine and cervical rinsings.

scholarly journals Activity of Enzymes in the Mucosal Tissues and Rinsings of the Reproductive Tract of the Naturally Cyclic Ewe

1978 ◽  
Vol 31 (4) ◽  
pp. 345 ◽  
Author(s):  
BE Murdoch ◽  
T O'Shea
Keyword(s):  
Reproductive Tract ◽  
Oestrous Cycle ◽  
Vaginal Mucosa ◽  
Mucosal Tissues ◽  
Activity Of Enzymes ◽  
Cervical Mucosa

The activity of several enzymes has been measured in the oviducal mucosa, endometrium, caruncles, cervical mucosa and vaginal mucosa as well as in uterine, cervical and oviducal rinsings of ewes at days 0 (oestrus), 1, 8 and 15 of the oestrous cycle.

Glycogen in the uterus and fallopian tubes is an important source of glucose during early pregnancy†

2019 ◽  
Vol 101 (2) ◽  
pp. 297-305 ◽  
Author(s):  
Matthew Dean
Keyword(s):  
Early Pregnancy ◽  
Pregnancy Loss ◽  
Glycogen Content ◽  
Glycogen Metabolism ◽  
Current Evidence ◽  
Growth Factor Signaling ◽  
Fallopian Tubes ◽  
Maternal Circulation ◽  
Ovarian Steroids ◽  
Implantation Period

Abstract Pregnancy loss is common during the peri-implantation period in mammals when glucose is required for both embryonic development and decidualization of the endometrium. As the uterus cannot synthesize glucose, all glucose must come directly from maternal circulation as needed or transiently stored as the macromolecule glycogen. Glycogen acts as a glucose reservoir, storing up to 55 000 glucose moieties per molecule. Endometrial glycogen concentrations are correlated with fertility in humans, indicating that glycogen is an essential source of glucose during early pregnancy. In humans and primates, endometrial glycogen concentrations peak during the luteal phase due to progesterone. In contrast, in rats and mink, estradiol triggers an accumulation of uterine glycogen during proestrus and estrus. In mated rats, the glycogen content of the endometrium increases again after implantation due to high levels of glycogen stored in the decidua. In mink, endometrial glycogen reserves are localized in the uterine epithelia at estrus. These reserves are mobilized before implantation, suggesting they are used to support embryonic growth. Uterine glycogen concentrations continue to decrease after implantation in mink, probably due to a lack of decidualization. How ovarian steroids stimulate glycogenesis in the endometrium is unclear, but current evidence suggests that estradiol/progesterone interacts with insulin or insulin-like growth factor signaling. In summary, endometrial glycogen is an essential source of glucose during the peri-implantation period. More work is needed to characterize differences among species, elucidate the fate of the glucose liberated from glycogen, and understand how ovarian steroids regulate glycogen metabolism in the uterus.

308. FOLLISTATIN SPLICE VARIANTS FST288 AND FST315 INCREASE DURING EARLY MOUSE PREGNANCY: REGULATION BY PROGESTERONE?

2010 ◽  
Vol 22 (9) ◽  
pp. 108
Author(s):  
R. G. Craythorn ◽  
W. R. Winnall ◽  
M. P. Hedger ◽  
P. A. W. Rogers ◽  
D. M. De Kretser ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Early Pregnancy ◽  
Reproductive Tract ◽  
Splice Variants ◽  
Heparan Sulphate ◽  
Activin A ◽  
Female Reproductive Tract ◽  
Mouse Uterus ◽  
Rate Of Increase ◽  
Exogenous Progesterone

Follistatin acts by binding and neutralising the activity of activin-A, which has important regulatory roles in development, reproduction and inflammation. There are two isoforms of follistatin comprising 288 and 315 amino acids (FST288 and FST315), resulting from alternative gene splicing. FST288 binds spontaneously to heparan sulphate and is largely bound to cell surface proteoglycans. FST315 is the predominant circulating form and can only bind to heparan sulphate after binding activin-A. The regulation of these splice variants in the female reproductive tract have not been investigated in detail. In this study, our aim was to quantify the expression of FST288 and FST315 mRNA in the mouse uterus during early pregnancy (days 1–4, pre-implantation), and in response to exogenous oestradiol-17b (100 ng × single s.c. injection, dissection after 24 h) and progesterone (1 mg × three daily s.c. injections, dissection 24 h after last injection) in ovariectomised mice. Gene expression was analysed using quantitative RT-PCR. Primers amplifying a product from exon 5 to 6a (unique to FST288) or from exon 5 to 6b (unique to FST315) were used to discriminate the isoforms. In early pregnancy, expression of both FST288 and FST315 increased significantly (approximately 35-fold and 100-fold, respectively) on days 3–5, relative to days 1–2, corresponding with the increase in circulating progesterone levels that occurs at day 3. A significant increase in FST288 and FST315 mRNA expression (both approximately 35-fold) was also observed in ovariectomised mice in response to exogenous progesterone, but there was no increase in response to oestradiol-17β. In contrast to the similar rate of increase in response to exogenous progesterone, FST315 mRNA expression increased more rapidly than FS288 in early pregnancy, indicating that differential regulation of the two isoforms also occurs. We conclude that progesterone regulates both FST288 and FST315 mRNA expression during early pregnancy in the mouse uterus.

Effect of nonworking heterotopic transplantation on rat heart glycogen metabolism

1995 ◽  
Vol 268 (1) ◽  
pp. E48-E54 ◽  
Author(s):  
P. H. McNulty ◽  
W. X. Liu ◽  
M. C. Luba ◽  
J. A. Valenti ◽  
G. V. Letsou ◽  
...  
Keyword(s):  
Rat Heart ◽  
Insulin Infusion ◽  
Glycogen Synthase ◽  
Glycogen Metabolism ◽  
Work History ◽  
Glycogen Concentration ◽  
Mechanical Unloading ◽  
History Of ◽  
Stimulation Of

To determine whether the contractile work history of cardiac muscle influences its responsiveness to insulin, we examined the effect of insulin infusion on glycogen metabolism in the rat heart 1 wk after transplantation into a nonworking heterotopic infrarenal position. Nonworking heterografts had higher basal glycogen concentrations than did in situ working hearts of the same animals (29.9 +/- 2.7 vs. 23.3 +/- 0.8 mumol/g; P < 0.05), and a smaller fraction of their glycogen synthase enzyme activity was in the physiologically active glycogen synthase I form (8 +/- 2 vs. 22 +/- 3%; P < 0.02). During a 25-min infusion of insulin (1 U/min) and glucose (30 mg.kg-1.min-1), the fractional glycogen synthase I activity of heterografts remained lower than that of in situ hearts (29 +/- 5 vs. 56 +/- 7%; P < 0.02) and heterografts synthesized glycogen more slowly (0.126 +/- 0.07 vs. 0.352 +/- 0.06 mumol.g-1.min-1; P < 0.02). These effects could be duplicated by a 24-h fast, which similarly increased myocardial glycogen concentration (to 32.9 +/- 5.6 mumol/g). These observations suggest that the performance of repetitive contractile work is necessary to maintain the myocardium maximally responsive to insulin. Mechanical unloading increases myocardial glycogen concentration, thereby reducing the magnitude of insulin's stimulation of glycogen synthase and consequently the rate of incorporation of circulating glucose into glycogen.

Comparison of enzyme activities on glycogen metabolism in rabbit slow and fast muscles

1985 ◽  
Vol 81 (3) ◽  
pp. 641-645 ◽  
Author(s):  
Akimitsu Tsutou ◽  
Shun-ichi Nakamura ◽  
Akira Negami ◽  
Toshiko Nakaza ◽  
Tomoko Kobayashi ◽  
...  
Keyword(s):  
Enzyme Activities ◽  
Glycogen Metabolism ◽  
Fast Muscles ◽  
Slow And Fast Muscles

scholarly journals Mucosal Immunity in HIV/SIV Infection: T Cells, B Cells and Beyond

2019 ◽  
Vol 15 (1) ◽  
pp. 63-75 ◽  
Author(s):  
Barbara L. Shacklett
Keyword(s):  
T Cells ◽  
Mucosal Immunity ◽  
Reproductive Tract ◽  
Cell Types ◽  
Female Reproductive Tract ◽  
Multiparameter Flow Cytometry ◽  
Mucosal Tissues ◽  
New Information ◽  
Innate Lymphocytes ◽  
Hiv 1

As our understanding of mucosal immunity increases, it is becoming clear that the host response to HIV-1 is more complex and nuanced than originally believed. The mucosal landscape is populated with a variety of specialized cell types whose functions include combating infectious agents while preserving commensal microbiota, maintaining barrier integrity, and ensuring immune homeostasis. Advances in multiparameter flow cytometry, gene expression analysis and bioinformatics have allowed more detailed characterization of these cell types and their roles in host defense than was previously possible. This review provides an overview of existing literature on immunity to HIV-1 and SIVmac in mucosal tissues of the female reproductive tract and the gastrointestinal tract, focusing on major effector cell populations and briefly summarizing new information on tissue-resident memory T cells, Treg, Th17, Th22 and innate lymphocytes (ILC), subsets that have been studied primarily in the gastrointestinal mucosa.

Effects of glucagon with or without insulin administration on liver glycogen metabolism

1995 ◽  
Vol 269 (2) ◽  
pp. E231-E238 ◽  
Author(s):  
N. Ercan ◽  
M. C. Gannon ◽  
F. Q. Nuttall
Keyword(s):  
Plasma Glucose ◽  
Glycogen Phosphorylase ◽  
Glycogen Metabolism ◽  
Liver Glycogen ◽  
Hepatic Glycogen ◽  
Insulin Administration ◽  
Similar Increase ◽  
Glycogen Concentration ◽  
Ad Libitum ◽  
Glucagon And Insulin

Rats fed ad libitum were given insulin alone (4 U/kg), glucagon alone (25 micrograms/kg), or insulin and glucagon sequentially. Phosphorylase a and synthase R activities, hepatic glycogen, uridine diphosphoglucose, inorganic phosphate (Pi), and plasma glucose, lactate, glucagon, and insulin concentrations were determined over the subsequent 40 min. In separate animals, muscle extraction of 2-deoxy-D-[3H]glucose also was determined. After glucagon administration, glycogen phosphorylase a and plasma glucose were increased within 5 min. However, the glycogen concentration did not decrease for 20 min. Glucagon administration to rats pretreated with insulin stimulated a similar increase in phosphorylase a activity. Again, glycogen was not degraded for 20 min. After insulin only, glycogen concentration remained unchanged. Plasma glucose decreased as expected. In each group, muscle extraction of 2-deoxy-D-[3H]glucose increased compared with the controls (P < 0.05). In summary, glucagon and/or insulin administration did not stimulate significant glycogen degradation for 20 min, even though phosphorylase was activated. The mechanism remains to be determined.

Glycogen metabolism and ultimate pH of muscle in Merino, first-cross, and second-cross wether lambs as affected by stress before slaughter

1999 ◽  
Vol 50 (2) ◽  
pp. 175 ◽  
Author(s):  
G. E. Gardner ◽  
L. Kennedy ◽  
J. T. B. Milton ◽  
D. W. Pethick
Keyword(s):  
Dry Matter ◽  
Citrate Synthase ◽  
Lactate Concentration ◽  
Glycogen Metabolism ◽  
Barley Grain ◽  
Significant Loss ◽  
Glycogen Concentration ◽  
Muscle Tissues ◽  
Pelleted Diet ◽  
Muscle Biopsies

This experiment compared the metabolism of muscle glycogen and the ultimate pH (pHu) of muscle in Merino and crossbred lambs fed the same diet but subjected to different levels of stress pre-slaughter. Twenty- five Merino, 24 first-cross (Merino dam × Poll Dorset sire), and 23 second-cross (Border Leicester × Merino dam and Poll Dorset sire) wether lambs (6 months old, 30 kg liveweight) were maintained for 8 weeks on a complete pelleted diet based on lupin seed, straw, and barley grain (metabolisable energy, 10.8 MJ/kg; protein, 17.4% in dry matter), with a feed intake of 1.3 kg dry matter /day for each breed. At Week 6, muscle biopsies were taken from 15 lambs of each breed, and at Week 8, 5 animals from each breed were slaughtered at an experimental abattoir 10 min after removal from their pens (low pre-slaughter stress). The remaining lambs, separated into breeds, were transported for 2 h and slaughtered after 24 h lairage at a commercial abattoir. Muscle samples were taken at slaughter, and assayed with the biopsy samples for glycogen concentration (corrected for lactate concentration), myoglobin concentration, and citrate synthase activity. The pHu of muscle was measured 48 h post slaughter. Compared with commercially slaughtered lambs, the muscle tissues of lambs subjected to low pre-slaughter stress had higher glycogen concentrations post mortem, lower pHu, and no significant loss of glycogen between pen and slaughter. Breed had no effect on glycogen, pH, or the colour of muscle under low-stress slaughter conditions or when the muscle biopsy was taken. In contrast, breed had a significant influence under commercial slaughter conditions, the muscle of Merino lambs having the lowest glycogen concentration post portem, and the highest pHu and loss of glycogen between pen and slaughter. Irrespective of stress, second-cross lambs had higher myoglobin concentrations and citrate synthase activities than the Merino lambs, indicating greater pigmentation of muscle in the second-cross animals. We conclude that higher proportions of Merino genes are associated with a greater sensitivity to stress in lambs destined for slaughter.

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