The effect of corticotrophin on liver-type lipase activity in adrenals, liver and high-density lipoprotein subfractions in the rat

Jansen, Hans; Schoonderwoerd, Kees; Baggen, M.G.A.; Greef, W. J. De

doi:10.1016/0005-2760(83)90008-5

Cited by 24 publications

(11 citation statements)

References 29 publications

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“…In the rat, -type lipase has been demonstrated in high activity in the adrenal as well as ovaries, and adrenal -type lipase activity was upregulated by treatment with ACTH analogue (Jansen & de Greef, 1981;Jansen et al 1983). Immunohistochemi¬ cal studies showed that the enzyme is present in the capillary network throughout the adrenal cortex, in a position where it can interact with plasma lipopro¬ teins and promote lipid uptake into the cells.…”

Section: Discussionmentioning

confidence: 99%

Lipoprotein lipase in guinea-pig adrenals: activity, mRNA, immunolocalization and regulation by ACTH

Gåfvels

Vilaró²,

Olivecrona³

1991

Journal of Endocrinology

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Lipase activity in homogenates of guinea-pig adrenals was studied under conditions which exclude the hormone-sensitive lipase/cholesterol ester hydrolase. Antibody inhibition and chromatography on heparin-Sepharose showed that most of the activity was due to lipoprotein lipase (LPL), and that there was only a small amount of hepatic lipase activity. Northern blot analysis of total RNA demonstrated the same three adrenal LPL mRNA species (1.8, 3.1 and 3.5 kb) as were found in adipose tissue and heart. Hence, at least part of the LPL activity in adrenals is due to enzyme synthesized within the tissue. Immunolocalization showed that LPL was associated with the endothelium of blood vessels throughout the gland. In addition, there was cytoplasmic immunoreaction, suggesting that lipase was synthesized in a subpopulation of cells in the transitional zone between the fasciculata and reticularis layer of the cortex, particularly over lipid-filled cells. There was also intense immunofluorescence over scattered cells in the adrenal medulla. Treatment with an ACTH analogue depot (20 IU, i.m.) for 11 days induced a 12-fold increase in serum cortisol and increased adrenal weight 2.2-fold. The treatment induced increases in LPL mRNA (about twofold), LPL activity and in the number of cells in the adrenal cortex which gave an immunoreaction for LPL.

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Section: Discussionmentioning

confidence: 99%

Lipoprotein lipase in guinea-pig adrenals: activity, mRNA, immunolocalization and regulation by ACTH

Gåfvels

Vilaró²,

Olivecrona³

1991

Journal of Endocrinology

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“…They were housed under controlled conditions: temperature 20-22°C, light on 07:00-19:00 h. Hypercorticism was induced by treatment with a synthetic ACTH analogue (Synacthen-depot, 2 mg/ml) [12,30]. Synacthen was administered during 3 days sub- Hepatic lipase was isolated from heparin-containing rat liver perfusates [12].…”

Section: Materials and Methods Animalsmentioning

confidence: 99%

“…Hepatic lipase binding in control and ACTH-pre-treated rats Previously we have shown that ACTH treatment leads to a diminished hepatic lipase activity in rat liver [12,30]. To study whether under these conditions binding capacity of the liver for hepatic lipase is also saturated, we performed perfusion experiments as described above with livers of ACTH-treated animals.…”

Section: Naci Perfusionmentioning

confidence: 99%

Rat liver contains a limited number of binding sites for hepatic lipase

Schoonderwoerd

Verhoeven

Jansen

1994

Biochemical Journal

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The binding of hepatic lipase to rat liver was studied in an ex vivo perfusion model. The livers were perfused with media containing partially purified rat hepatic lipase or bovine milk lipoprotein lipase. The activity of the enzymes was determined in the perfusion media before and after passage through the liver. During perfusion with a hepatic-lipase-containing medium the lipase activity in the medium did not change, indicating that there was no net binding of lipase by the liver. In contrast, more than 80% of the lipoprotein .lipase was removed from the medium. This lipoprotein lipase activity could be recovered into the perfusion medium completely by heparin perfusion of the liver. If livers, first depleted of hepatic lipase by heparin, were subsequent perfused with a hepatic-lipase-containing medium, 90 + 24 m-units of the lipase activity was bound per g of liver (up to 1000 m-units/total liver). However, heparin treatment of the liver decreases the ability of the liver to re-bind hepatic lipase by 80 %. Perfusion of rat livers with 0.3 M NaCl released 60 % of the lipase activity into the medium. Upon subsequent perfusion of these livers with hepatic-lipase-containing media, 541 + 164 munits of hepatic lipase could be bound per g of liver (up to 5000 m-units/total liver). The binding of hepatic lipase was also studied in livers of corticotropin (ACTH)-pre-treated rats. In these rats also, hepatic lipase bound only to livers which had been pre-perfused with heparin or 0.3 M NaCl. After heparin pre-perfusion, 88 + 12 m-units of hepatic lipase could be bound per g of liver, similar to that with livers of control rats not treated with ACTH. After prior salt perfusion, however, the capacity of the livers of ACTH-pre-treated rats to bind hepatic lipase was 212 + 60 m-units/g of liver. This is less than in livers of control rats (541 + 164 m-units/g of liver). These results indicate that in rat liver the binding ofhepatic lipase is heterogeneous in character and consists of heparin-resistant and heparin-sensitive components. The hepatic-lipase binding capacity of the liver is saturable and fully utilized under various conditions. The heparin-sensitive binding capacity is lowered in ACTH-treated rats, whereas the heparin-resistant binding is unaffected. We postulate that the functional hepatic lipase activity can be regulated by changes in the binding capacity of the liver.

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“…This lipase activity is thought to originate from liver and to be transported to the steroidogenic organs via the bloodstream [9] in association with HDL [10]. The activity in these organs varies in parallel with steroid hormone output [11][12][13]. At least in the rat, these organs depend largely on HDL cholesterol (HDL-C) as a source for steroid hormone production.…”

Section: Introductionmentioning

confidence: 99%

Transient induction of a variant hepatic lipase messenger RNA by corticotropic hormone in rat adrenals

et al. 2006

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The effect of corticotrophin on liver-type lipase activity in adrenals, liver and high-density lipoprotein subfractions in the rat

Cited by 24 publications

References 29 publications

Lipoprotein lipase in guinea-pig adrenals: activity, mRNA, immunolocalization and regulation by ACTH

Lipoprotein lipase in guinea-pig adrenals: activity, mRNA, immunolocalization and regulation by ACTH

Rat liver contains a limited number of binding sites for hepatic lipase

Transient induction of a variant hepatic lipase messenger RNA by corticotropic hormone in rat adrenals

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