Effects of Manganese Porphyrins on Cellular Sulfur Metabolism

Manganese porphyrins (MnPs), MnTE-2-PyP5+, MnTnHex-2-PyP5+ and MnTnBuOE-2-PyP5+, are superoxide dismutase (SOD) mimetics and form a redox cycle between O2 and reductants, including ascorbic acid, ultimately producing hydrogen peroxide (H2O2). We previously found that MnPs oxidize hydrogen sulfide (H2S) to polysulfides (PS; H2Sn, n = 2–6) in buffer. Here, we examine the effects of MnPs for 24 h on H2S metabolism and PS production in HEK293, A549, HT29 and bone marrow derived stem cells (BMDSC) using H2S (AzMC, MeRho-AZ) and PS (SSP4) fluorophores. All MnPs decreased intracellular H2S production and increased intracellular PS. H2S metabolism and PS production were unaffected by cellular O2 (5% versus 21% O2), H2O2 or ascorbic acid. We observed with confocal microscopy that mitochondria are a major site of H2S production in HEK293 cells and that MnPs decrease mitochondrial H2S production and increase PS in what appeared to be nucleoli and cytosolic fibrillary elements. This supports a role for MnPs in the metabolism of H2S to PS, the latter serving as both short- and long-term antioxidants, and suggests that some of the biological effects of MnPs may be attributable to sulfur metabolism.

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Flavored e-liquids increase cytoplasmic Ca2+ levels in airway epithelia

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00123.2019 ◽

2020 ◽

Vol 318 (2) ◽

pp. L226-L241 ◽

Cited By ~ 6

Author(s):

Temperance R. Rowell ◽

James E. Keating ◽

Bryan T. Zorn ◽

Gary L. Glish ◽

Stephen B. Shears ◽

...

Keyword(s):

Cell Growth ◽

Biological Effects ◽

Potential Toxicity ◽

Airway Epithelia ◽

Unknown Mechanism ◽

Kinase C ◽

Short And Long Term ◽

Cellular Ca ◽

Affect Cell Growth

E-cigarettes are noncombustible, electronic nicotine-delivery devices that aerosolize an e-liquid, i.e., nicotine, in a propylene glycol-vegetable glycerin vehicle that also contains flavors. While the effects of nicotine are relatively well understood, more information regarding the potential biological effects of the other e-liquid constituents is needed. This is a serious concern, because e-liquids are available in >7,000 distinct flavors. We previously demonstrated that many e-liquids affect cell growth/viability through an unknown mechanism. Since Ca2+ is a ubiquitous second messenger that regulates cell growth, we characterized the effects of e-liquids on cellular Ca2+ homeostasis. To better understand the extent of this effect, we screened e-liquids for their ability to alter cytosolic Ca2+ levels and found that 42 of 100 flavored e-liquids elicited a cellular Ca2+ response. Banana Pudding (BP) e-liquid, a representative e-liquid from this group, caused phospholipase C activation, endoplasmic reticulum (ER) Ca2+ release, store-operated Ca2+ entry (SOCE), and protein kinase C (PKCα) phosphorylation. However, longer exposures to BP e-liquid depleted ER Ca2+ stores and inhibited SOCE, suggesting that this e-liquid may alter Ca2+ homeostasis by short- and long-term mechanisms. Since dysregulation of Ca2+ signaling can cause chronic inflammation, ER stress, and abnormal cell growth, flavored e-cigarette products that can elicit cell Ca2+ responses should be further screened for potential toxicity.

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Short- and Long-Term Variability of Selected Indices Related to Nutritional Status. II. Vitamins, Lipids, and Protein Indices

Clinical Chemistry ◽

10.1093/clinchem/38.8.1449 ◽

1992 ◽

Vol 38 (8) ◽

pp. 1449-1453 ◽

Cited By ~ 7

Author(s):

S K Gallagher ◽

L K Johnson ◽

D B Milne

Keyword(s):

General Chemistry ◽

Ascorbic Acid ◽

Biological Variability ◽

Free Living ◽

Dietary Practices ◽

Analytical Variability ◽

Short And Long Term ◽

Metabolic Unit ◽

Control Samples

Abstract Five free-living women (ages 23-38 years) who consumed a self-selected diet and five women (ages 23-44 years) residing in a metabolic unit who were fed constant diet were assessed for variation in vitamin and general chemistry indices. Blood was drawn from these women once a month for five months, once a week for five weeks, and once a day for five days to assess analytical and biological variability of the indices. Analytical variability was determined by concurrently analyzing control samples prepared from plasma and serum pools. All samples were analyzed in duplicate. Of the measured indices, vitamins and lipids seemed to be the most variable. Diet had a significant effect only on ascorbic acid. We were unable to show any seasonal change for these analytes. Estimations of analytical variability, along with estimates of biological variability, and knowledge of dietary practices are essential when interpreting differences in analytes.

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Stressor Effect of Hypothermia in the Rat

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1957.188.3.470 ◽

1957 ◽

Vol 188 (3) ◽

pp. 470-472 ◽

Cited By ~ 2

Author(s):

Edwin R. Fisher ◽

E. J. Fedor ◽

B. Fisher

Keyword(s):

Ascorbic Acid ◽

Initial Stress ◽

Adrenal Cortex ◽

Acid Content ◽

Ascorbic Acid Content ◽

Adrenal Weight ◽

Ether Anesthesia ◽

Short And Long Term ◽

Nembutal Anesthesia

The effect of hypothermia upon the adrenal cortex of the rat was evaluated by comparing the weights, histochemical and morphological appearance and ascorbic acid content of adrenals from cooled animals under ether and Nembutal anesthesia with normothermic controls. Hypothermia with ether narcosis for 2 hours resulted in a statistically significant decrease in adrenal weight related to loss of water and solids. Histologically, a decrease of adrenal cortical sudanophilia and cholesterol and/or esters was noted in approximately one-half of these animals and the ascorbic acid content of these glands was significantly decreased. The adrenals of rats subjected to hypothermia with ether for 6 hours however, were similar to those of normothermic controls. Similarly, short and long term hypothermia with Nembutal anesthesia failed to reveal any alteration in the adrenal cortex. These findings have been interpreted as indicating that in the rat an initial stress is attendant with hypothermia when ether anesthesia is employed.

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Effect of ascorbic acid on food preference and consumption in captive capybaras (Hydrochoerus hydrochaeris)

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132009000300011 ◽

2009 ◽

Vol 52 (3) ◽

pp. 593-600 ◽

Cited By ~ 2

Author(s):

Martín Roberto Alvarez ◽

Fernando Osvaldo Kravetz

Keyword(s):

Ascorbic Acid ◽

Vitamin C ◽

Food Preference ◽

Daily Basis ◽

Adaptive Value ◽

Hydrochoerus Hydrochaeris ◽

Short And Long Term ◽

Free Ranging

The aim of this work was to study the short and long term influences of ascorbic acid on Hydrochoerus hydrochaeris, if supplemented in their food. No differences regarding food intake were observed in the absence of vitamin C. On a daily basis, animals accustomed to food containing ascorbic acid prefered to continue eating the same food. Food preference in capybaras did not seem to depend on ascorbic acid availability; however, when accustomed to vitamin C, capybaras might recognize and select ascorbic acid in subsequent food. Mechanisms allowing capybaras to "evaluate" the nutritional quality of their food are discussed, as well as the adaptive value of this behavior in free ranging populations.

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Experience with Short and Long Term Courses of Local Adrenal Steroid Therapy For Ulcerative Colitis

Gastroenterology ◽

10.1016/s0016-5085(62)80117-6 ◽

1962 ◽

Vol 42 (6) ◽

pp. 669-677 ◽

Cited By ~ 18

Author(s):

Jean A. Spencer ◽

Joseph B. Kirsner

Keyword(s):

Ulcerative Colitis ◽

Steroid Therapy ◽

Adrenal Steroid ◽

Short And Long Term

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Short- and Long-Term Results of Total vs Subtotal Thyroid- ectomies in the Surgical Treatment of Graves' Disease

Swiss Surgery ◽

10.1024/1023-9332.7.1.20 ◽

2001 ◽

Vol 7 (1) ◽

pp. 20-24 ◽

Cited By ~ 14

Author(s):

Robert ◽

Mariéthoz ◽

Pache ◽

Bertin ◽

Caulfield ◽

...

Keyword(s):

Recurrent Laryngeal Nerve ◽

Nerve Palsy ◽

Recurrent Laryngeal Nerve Palsy ◽

Laryngeal Nerve ◽

Long Term Results ◽

Graves Disease ◽

Laryngeal Nerve Palsy ◽

Short And Long Term

Objective: Approximately one out of five patients with Graves' disease (GD) undergoes a thyroidectomy after a mean period of 18 months of medical treatment. This retrospective and non-randomized study from a teaching hospital compares short- and long-term results of total (TT) and subtotal thyroidectomies (ST) for this disease. Methods: From 1987 to 1997, 94 patients were operated for GD. Thirty-three patients underwent a TT (mostly since 1993) and 61 a ST (keeping 4 to 8 grams of thyroid tissue - mean 6 g). All patients had received propylthiouracil and/or neo-mercazole and were in a euthyroid state at the time of surgery; they also took potassium iodide (lugol) for ten days before surgery. Results: There were no deaths. Transient hypocalcemia (< 3 months) occurred in 32 patients (15 TT and 17 ST) and persistent hypocalcemia in 8 having had TT. Two patients developed transient recurrent laryngeal nerve palsy after ST (< 3 months). After a median follow-up period of seven years (1-15) with five patients lost to follow-up, 41 patients having had a ST are in a hypothyroid state (73%), thirteen are euthyroid (23%), and two suffered recurrent hyperthyroidism, requiring completion of thyroidectomy. All 33 patients having had TT - with follow-ups averaging two years (0.5-8) - are receiving thyroxin substitution. Conclusions: There were no instances of persistent recurrent laryngeal nerve palsy in either group, but persistent hypoparathyroidism occurred more frequently after TT. Long after ST, hypothyroidism developed in nearly three of four cases, whereas euthyroidy was maintained in only one-fourth; recurrent hyperthyroidy was rare.

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