Oxygen microenvironment and respiratory oscillations in cultured mammalian cells

Werrlein, Robert J.; Glinos, André D.

doi:10.1038/251317a0

Cited by 69 publications

(29 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Corkey, unpublished data). It is well known that oscillations in glycolysis exist in many cell types (25)(26)(27)(28)(29). Like oscillatory insulin secretion from ␤-cells, we suggest that oscillatory glycolysis may be the pacemaker for the intrinsic lipolytic oscillation in adipocytes.…”

Section: Discussionmentioning

confidence: 91%

Free Fatty Acid Regulation of Glucose-Dependent Intrinsic Oscillatory Lipolysis in Perifused Isolated Rat Adipocytes

2005

View full text Add to dashboard Cite

Free fatty acids (FFAs) and glycerol oscillate in plasma. This study examined intrinsic lipolytic oscillations within adipocytes. Rat adipocytes were perifused with Krebs-Ringer bicarbonate buffer: 1) ؎ 2 mmol/l glucose; 2) ؉1 mol/l isoproterenol ؎ 2 mmol/l glucose; 3) ؉ increasing oleate; and 4) ؉ increasing percent BSA. At 2 mmol/l glucose, there were 9 ؎ 1 glycerol, FFAs, and lactate pulses per hour with a pulse duration of 5 ؎ A bnormal fat metabolism plays an important role in the pathogenesis of obesity-related type 2 diabetes (1-4), and elevated plasma free fatty acid (FFA) concentrations are associated with peripheral and hepatic insulin resistance (5-7). Adipose tissue is a dynamic organ that is vital to the regulation of glucose homeostasis, whole-body energy fuel regulation, feeding behavior, and body composition. It has previously been shown by Getty et al. (8), in dogs, that in the basal fasted state, FFA and glycerol oscillate in plasma with an average of nine pulses per hour and an average pulse duration of 5 min. It has also been shown that there is oscillatory lipolysis from the omentum with an average of 10 pulses per hour and an average pulse length of 6 min.Because lipolysis is primarily regulated by adrenergic modulation and insulin concentration, it is possible that either could be driving the plasma FFA oscillation. With the plasma insulin oscillation removed by the insulin clamp, FFAs still showed an oscillation in plasma, suggesting that insulin does not drive the FFA oscillation (8). The study also looked at the effect of ␤-adrenergic blockade. In three of the nine dogs studied, propranolol infusion seemed to suppress the FFA oscillation. In dogs where the FFA oscillation remained, propranolol infusion significantly disrupted the regularity of the plasma FFA oscillation (9,10). Further investigation of the role of the central nervous system in the regulation of in vivo lipolytic oscillations by Hucking et al. (11) suggested that lipolysis in the fasting state consisted of an oscillatory component dependent upon sympathetic innervation and a nonoscillatory component. In both above-mentioned studies, it is possible that lipolysis was still oscillating on the level of individual fat pads or even individual adipocytes and that these oscillations became unsynchronized and thus were lost, dampened, or below detection when sympathetic input was blocked.Thus, the present study determined whether the plasma FFA oscillation originates within the adipocyte from an internal pacemaker similar to that seen in the ␤-cell of the pancreas (12)(13)(14). The basal profiles of FFA, glycerol, and lactate release from isolated perifused adipocytes were determined in the basal state (Ϯ glucose), during stimulation of lipolysis with 1 mol/l isoproterenol (Ϯ glucose), during perifusion with increasing concentrations of oleate, and during perifusion with increasing percent BSA (ϩ isoproterenol). The results demonstrated that there were intrinsic lipolytic oscillations in adipocytes that were dependent on glucos...

show abstract

Section: Discussionmentioning

confidence: 91%

Free Fatty Acid Regulation of Glucose-Dependent Intrinsic Oscillatory Lipolysis in Perifused Isolated Rat Adipocytes

2005

View full text Add to dashboard Cite

show abstract

“…Fluid depths in vitro that exceed 0.34 mm are known to markedly impede cellular oxygen access (14,15,23). We began these studies using HT29 cells, which express high levels of CFTR, form electrically resistant monolayers, and are capable of vectoral Cl -transport either submerged or with air-exposed culture (24).…”

Section: Cftr Mrna Levels Are Repressed In Submerged Cellsmentioning

confidence: 99%

“…oxygen (9)(10)(11)(12)(13)(14)(15); (2) exposure to 1% O 2 /5% CO 2 (balance consisting of N 2 ) in a tightly sealed modular incubator chamber (Billups-Rothenberg, Del Mar, CA) for 24 to 48 hours at 378C; (3) treatment with dimethyloxalylglycine (DMOG) to specifically block prolyl hydroxylation, and therefore lead to HIF-1a accumulation; (4) treatment with cobalt chloride (CoCl 2 ), a hypoxia mimetic; and (5) combinations of the above conditions as a means of testing for additive or synergistic effects. The cells were incubated in media containing 3% FBS for a minimum of 24 hours before each experiment.…”

Section: Clinical Relevancementioning

confidence: 99%

Role of Oxygen Availability in CFTR Expression and Function

Guimbellot¹,

Fortenberry²,

Siegal³

et al. 2008

Am J Respir Cell Mol Biol

View full text Add to dashboard Cite

The cystic fibrosis transmembrane conductance regulator (CFTR) serves a pivotal role in normal epithelial homeostasis; its absence leads to destruction of exocrine tissues, including those of the gastrointestinal tract and lung. Acute regulation of CFTR protein in response to environmental stimuli occurs at several levels (e.g., ion channel phosphorylation, ATP hydrolysis, apical membrane recycling). However, less information is available concerning the regulatory pathways that control levels of CFTR mRNA. In the present study, we investigated regulation of CFTR mRNA during oxygen restriction, examined effects of hypoxic signaling on chloride transport across cell monolayers, and related these findings to a possible role in the pathogenesis of chronic hypoxic lung disease. CFTR mRNA, protein, and function were robustly and reversibly altered in human cells in relation to hypoxia. In mice subjected to low oxygen in vivo, CFTR mRNA expression in airways, gastrointestinal tissues, and liver was repressed. CFTR mRNA expression was also diminished in pulmonary tissues taken from hypoxemic subjects at the time of lung transplantation. Environmental factors that induce hypoxic signaling regulate CFTR mRNA and epithelial Cl 2 transport in vitro and in vivo.

show abstract

“…Thus, the total sulfhydryl contents in the media may be lower than in the control media. For a high density culture of cells, the oxygen tension in the medium is lower than in the gas environment (17), and serum is powerful antioxidant (6,16). Therefore, no effect of sulfhydryl compounds added to a serum-containing medium has been found in mass cultures.…”

Section: Discussionmentioning

confidence: 99%

Effects of sulfhydryl groups and oxygen tension on the cell proliferating activity of bovine serum albumin in culture.

Kan¹,

Yamane²

1982

Cell Struct. Funct.

View full text Add to dashboard Cite

Oxygen microenvironment and respiratory oscillations in cultured mammalian cells

Cited by 69 publications

References 8 publications

Free Fatty Acid Regulation of Glucose-Dependent Intrinsic Oscillatory Lipolysis in Perifused Isolated Rat Adipocytes

Free Fatty Acid Regulation of Glucose-Dependent Intrinsic Oscillatory Lipolysis in Perifused Isolated Rat Adipocytes

Role of Oxygen Availability in CFTR Expression and Function

Effects of sulfhydryl groups and oxygen tension on the cell proliferating activity of bovine serum albumin in culture.

Contact Info

Product

Resources

About