ALPHA-ADRENERGIC RECEPTOR ACTIVITY, CYCLIC AMP AND LIPOLYSIS IN ADIPOSE TISSUE OF HYPOTHYROID MAN AND RAT

SUMMARY Lipolysis and intracellular levels of cyclic AMP of adipose tissue from man and rat in both hypothyroid and euthyroid states were studied in response to stimulation by catecholamines in vitro. Hypothyroid patients were studied before and after treatment, and were also compared with euthyroid obese controls. The experimental group of rats was rendered hypothyroid by the addition of 2·9 mm-propylthiouracil to their drinking water, and their status confirmed by plasma thyroid function tests. Evidence for α-adrenergic receptor activity was found in rat adipose tissue, but was less marked than the pronounced α-adrenergic activity in human adipose tissue. Glycerol release from adipose tissue in response to noradrenaline stimulation was less marked in hypothyroidism in both species, and was related to an increased α-adrenergic activity. No evidence was found for increased α-adrenergic effects on cyclic AMP level in hypothyroid subjects, and little evidence was found in adipose tissue from hypothyroid rats. This discrepancy may be due to the presence of the phosphodiesterase inhibitor, theophylline, in the incubation system. The possible modulatory role of thyroid hormones on receptor and phosphodiesterase activity, and on lipolysis, is discussed.

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Effects of hormones on cyclic AMP release from rat adipose tissue in vitro

FEBS Letters ◽

10.1016/0014-5793(74)80633-2 ◽

1974 ◽

Vol 49 (1) ◽

pp. 65-69 ◽

Cited By ~ 26

Author(s):

P. Zumstein ◽

J. Zapf ◽

E.R. Froesch

Keyword(s):

Adipose Tissue ◽

Cyclic Amp ◽

Adipose Tissue In Vitro ◽

Rat Adipose Tissue

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In Vitro and In Vivo Impairment of α2-Adrenergic Receptor-Dependent Antilipolysis by Fatty Acids in Human Adipose Tissue

Hormone and Metabolic Research ◽

10.1055/s-2001-19140 ◽

2001 ◽

Vol 33 (12) ◽

pp. 701-707 ◽

Cited By ~ 5

Author(s):

S. Gesta ◽

J. Hejnova ◽

M. Berlan ◽

D. Daviaud ◽

F. Crampes ◽

...

Keyword(s):

Fatty Acids ◽

Adipose Tissue ◽

Adrenergic Receptor ◽

Human Adipose Tissue

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Lipoprotein Lipase in Human Adipose Tissue

Clinical Science ◽

10.1042/cs0460753 ◽

1974 ◽

Vol 46 (6) ◽

pp. 753-762

Author(s):

R. S. Elkeles

Keyword(s):

Adipose Tissue ◽

Lipoprotein Lipase ◽

Human Adipose Tissue ◽

Weight Basis ◽

Consistent Effect ◽

Monoglyceride Lipase ◽

Rat Adipose Tissue

1. The presence of lipoprotein lipase has been confirmed in acetone-ether extracts of human adipose tissue. 2. The properties of the enzyme appear to be similar to that in rat adipose tissue though it is less active on a weight basis. 3. The presence of a separate monoglyceride lipase has been demonstrated in human adipose tissue. 4. In eluates of human adipose tissue the activity of lipoprotein lipase is dependent on heparin, whereas that of the monoglyceride lipase does not require heparin. 5. No consistent effect of insulin in vitro on the enzyme in human adipose tissue has been demonstrated. Possible reasons for this are discussed.

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Isoproterenol decreases leptin release from rat and human adipose tissue through posttranscriptional mechanisms

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00446.2004 ◽

2005 ◽

Vol 288 (4) ◽

pp. E798-E804 ◽

Cited By ~ 22

Author(s):

Matthew R. Ricci ◽

Mi-Jeong Lee ◽

Colleen D. Russell ◽

Yanxin Wang ◽

Sean Sullivan ◽

...

Keyword(s):

Adipose Tissue ◽

Relative Rate ◽

Human Adipose Tissue ◽

Rapid Decline ◽

Mrna Levels ◽

Adrenergic Regulation ◽

Obese Subjects ◽

Rat Adipose Tissue

In vivo and in vitro studies indicate that β-adrenergic receptor agonists decrease leptin release from fat cells in as little as 30 min. Our objective was to determine whether alterations in leptin biosynthesis or secretion were involved in the short-term adrenergic regulation of leptin in human and rat adipose tissue. Isoproterenol (Iso) decreased leptin release from incubated adipose tissue of both nonobese and obese subjects to similar extent (−28 vs. −21% after 3 h). Inhibition of protein synthesis with cycloheximide did not block the effect of Iso on leptin release from human adipose tissue, suggesting that the Iso effect is independent of leptin synthesis. Iso also tended to increase tissue leptin content at the end of the 3-h incubation, as expected from the observed inhibition of release. Consistent with a posttranslational mechanism, Iso treatment did not affect leptin mRNA levels or relative rate of leptin biosynthesis as directly assessed by [35S]methionine incorporation into immunoprecipitable leptin. In contrast to these results in human adipose tissues, Iso did not decrease basal leptin release from rat adipose tissue. However, Iso did decrease insulin-stimulated leptin release by inhibiting the ability of insulin to increase leptin biosynthesis without detectably affecting leptin mRNA levels. Thus, in both human and rat, adrenergic regulation of posttranscriptional events (secretion in humans, translation in rats) may contribute to the rapid decline in circulating leptin that occurs when the sympathetic nervous system is activated, such as during fasting and cold exposure. Furthermore, the rat does not provide an ideal model to study mechanisms of cellular leptin regulation in humans.

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EFFECT OF BICARBONATE AND PHOSPHATE ON THE ADRENERGIC RECEPTOR RESPONSE IN HUMAN ADIPOSE TISSUE IN VITRO

Acta Medica Scandinavica ◽

10.1111/j.0954-6820.1974.tb08151.x ◽

2009 ◽

Vol 195 (1-6) ◽

pp. 345-350 ◽

Cited By ~ 4

Author(s):

Urban Rosenqvist

Keyword(s):

Adipose Tissue ◽

Adrenergic Receptor ◽

Human Adipose Tissue ◽

Receptor Response ◽

Adipose Tissue In Vitro

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IN VITRO STUDIES ON LIPOLYSIS IN HUMAN ADIPOSE TISSUE

Acta Endocrinologica ◽

10.1530/acta.0.061s156 ◽

1969 ◽

Vol 61 (1_Suppl) ◽

pp. S156

Author(s):

Suad Efendić ◽

Peter Amer ◽

Jan Östman

Keyword(s):

Adipose Tissue ◽

Human Adipose Tissue ◽

In Vitro Studies

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Long-Term Severe In Vitro Hypoxia Exposure Enhances the Vascularization Potential of Human Adipose Tissue-Derived Stromal Vascular Fraction Cell Engineered Tissues

International Journal of Molecular Sciences ◽

10.3390/ijms22157920 ◽

2021 ◽

Vol 22 (15) ◽

pp. 7920

Author(s):

Myroslava Mytsyk ◽

Giulia Cerino ◽

Gregory Reid ◽

Laia Gili Sole ◽

Friedrich S. Eckstein ◽

...

Keyword(s):

Adipose Tissue ◽

Therapeutic Potential ◽

Stromal Vascular Fraction ◽

Human Adipose Tissue ◽

Bioreactor Culture ◽

Proliferating Cells ◽

Angiogenic Potential ◽

Engineered Tissues

The therapeutic potential of mesenchymal stromal/stem cells (MSC) for treating cardiac ischemia strongly depends on their paracrine-mediated effects and their engraftment capacity in a hostile environment such as the infarcted myocardium. Adipose tissue-derived stromal vascular fraction (SVF) cells are a mixed population composed mainly of MSC and vascular cells, well known for their high angiogenic potential. A previous study showed that the angiogenic potential of SVF cells was further increased following their in vitro organization in an engineered tissue (patch) after perfusion-based bioreactor culture. This study aimed to investigate the possible changes in the cellular SVF composition, in vivo angiogenic potential, as well as engraftment capability upon in vitro culture in harsh hypoxia conditions. This mimics the possible delayed vascularization of the patch upon implantation in a low perfused myocardium. To this purpose, human SVF cells were seeded on a collagen sponge, cultured for 5 days in a perfusion-based bioreactor under normoxia or hypoxia (21% and <1% of oxygen tension, respectively) and subcutaneously implanted in nude rats for 3 and 28 days. Compared to ambient condition culture, hypoxic tension did not alter the SVF composition in vitro, showing similar numbers of MSC as well as endothelial and mural cells. Nevertheless, in vitro hypoxic culture significantly increased the release of vascular endothelial growth factor (p < 0.001) and the number of proliferating cells (p < 0.00001). Moreover, compared to ambient oxygen culture, exposure to hypoxia significantly enhanced the vessel length density in the engineered tissues following 28 days of implantation. The number of human cells and human proliferating cells in hypoxia-cultured constructs was also significantly increased after 3 and 28 days in vivo, compared to normoxia. These findings show that a possible in vivo delay in oxygen supply might not impair the vascularization potential of SVF- patches, which qualifies them for evaluation in a myocardial ischemia model.

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