Biomedical subjects

D Sanchis

Publications and source records attributed to D Sanchis.

23 records · Page 2Linked to original sources

PubMed1997

Effect of the slimming agent oleoyl-estrone in liposomes on the body weight of Zucker obese rats.

OBJECTIVE: To determine whether the mechanisms by which estrone acyl-esters carried by lipoproteins induce the loss of body fat can affect Zucker fa/fa rats, since they are hyperphagic and could not eliminate excess energy through thermogenesis, two aspects essential for the slimming effect of oleoyl-estrone in normal rats. DESIGN: The rats were infused for 28 d (osmotic minipumps) with oleoyl-estrone in liposomes (Merlin-2) at a dose of 3.5 mmol/day.kg. SUBJECTS: Lean (L) and obese (O) Zucker rats. MEASUREMENTS: Body weight changes. Oxygen consumption, body composition (water, lipid, protein), nitrogen balance, plasma chemistry. RESULTS: Treatment resulted in loss of body weight: 12.0% (28 g) L, 9.4% (34 g) O, mainly due to fat: 37.5% (10.8 g) L, 11.7% (15.5 g) O and water, preventing further increases in body weight and fat storage. Untreated rats increased their body weight: 10.5% (24 g) L, 32.2% (101 g) O and lipid stores: 20.3% (5.9 g) L, 39.8% (49.0 g) O, making the differences more marked. On day 28, glucose levels were maintained in all groups; in L, triacylglycerols increased and total cholesterol decreased; O showed no changes in plasma composition. In all rats, food intake decreased with treatment, and heat production (oxygen consumption) was unchanged (L) or slightly decreased (O). Energy expenditure per unit of fat-free mass remained unchanged. Protein balance was maintained in all groups; slimming was achieved without loss of body protein. CONCLUSION: Treatment of genetically obese rats with oleoyl-estrone in liposomes (Merlin-2) results in sustained loss of body weight-mainly lipid, sparing protein-for up to 28 d, essentially preventing further increase in body weight and accumulation of lipid and protein. This is achieved through lower food intake and relatively small changes (if any) in energy expenditure.

Animals↗

PubMed1997

Effect of the slimming agent oleoyl-estrone in liposomes on the body weight of rats fed a cafeteria diet.

Weaned lean Zucker rats, 21-days old, were fed a cafeteria diet for 70 days. The cafeteria diet-obese rats were infused for 28 days (using miniosmotic pumps) with oleoyl-estrone in liposomes (Merlin-2) at a dose of 3.5 mmol/day.kg. Treatment resulted in loss of body weight: 11.6% (32 g), mainly due to fat: 20.0% (8.8 g), protein 5.2% (2.0 g) and water, preventing further increases in body weight and fat storage. Untreated rats increased their body weight: 7.6% (20 g), lipid: 10.5% (4.2 g) and protein: 13.2% (4.8 g). Plasma glucose, urea, triacylglycerols and cholesterol practically did not change with treatment. Merlin-2 decreased energy intake (to 83.7%) and energy output (to 87.7%, oxygen consumption). Decreases in nitrogen intake were partly compensated by higher digestive efficiency in treated rats. The size of the nitrogen gap was higher in treated rats than in controls. Essentially, protein balance was maintained and slimming was achieved with a minimal loss of body protein. Treated rats selected less carbohydrate, in particular sugars, in their diet than controls, but consumed practically the same protein and lipid. Treatment of cafeteria diet-fed rats with oleoylestrone in liposomes results in sustained loss of body weight--mainly lipid--for up to 28 days. Nitrogen balance is maintained overall. This is achieved through lower food intake--mainly of sugars--and less marked changes in energy output.

Animals↗

PubMed1997

Rats receiving the slimming agent oleoyl-estrone in liposomes (Merlin-2) decrease food intake but maintain thermogenesis.

Oleoyl-estrone given i.v.--incorporated in liposomes to mimic lipoprotein delivery--(Merlin-2) to normal weight rats, induces a dose-dependent weight loss. Analysis of body composition showed that body protein concentration was preserved and fat stores wasted. The respiratory quotient was consistent with the massive oxidation of body fat, since the diet contained practically no lipid. Appetite was affected by Merlin-2, and thus food intake showed a transient decrease. But oxygen consumption (and basal metabolic rates) was kept practically unchanged at the levels of the controls, i.e. higher than needed to oxidize the food ingested during the weight loss period. Brown adipose tissue uncoupling protein levels were proportionally preserved with a 2-week treatment, but it lost a substantial amount of lipid. In conclusion, Merlin-2 is a slimming agent with considerable potential given its powerful fat-wasting action, since it maintains thermogenesis despite lowered energy intake.

Adipose Tissue↗

PubMed1997

3-Hydroxybutyrate co-infused with noradrenaline decreases resulting plasma levels of noradrenaline in Wistar rats.

Pentobarbital-anaesthetized male Wistar rats were infused with 6microgkg-1min-1 of noradrenaline. The infusion was supplemented with 8.5 mgkg-1min-1 of D-3-hydroxybutyrate (3-OHB) for 15 min in order to determine its effect on the adrenergic response of the rat. Plasma levels of noradrenaline rose to a plateau of approximately 50 nmoll-1 with infusion. In the group infused with noradrenaline alone, noradrenaline levels were maintained for 1h. Supplementation with 3-OHB induced a decrease in plasma noradrenaline level that was inversely correlated with 3-OHB level. Aortic and interscapular brown adipose tissue temperatures increased with noradrenaline infusion, but the rise was arrested by 3-OHB; replacing 3-OHB with glucose had no effect. Infusion of saline, glucose or 3-OHB in the absence of noradrenaline did not induce a rise in temperature in either tissue. Blood 3-OHB concentration increased to 1.2 mmoll-1 during 3-OHB infusion, decreasing rapidly at the end of infusion. Blood glucose levels increased with noradrenaline infusion; the presence of high 3-OHB levels decreased glucose concentration. The effects observed were transient and dependent on 3-OHB concentration; these effects may help explain most of the other effects of noradrenaline described here. The role of 3-OHB as a regulator of adrenergic responses seems to be part of a complex fail-safe mechanism which prevents wasting.

3-Hydroxybutyric Acid↗

PubMed1996

Oleoyl-estrone induces the loss of body fat in rats.

OBJECTIVE: Four experiments were devised to test the possible role of estrone fatty esters as adipose tissue signals carried by the blood within lipoproteins. DESIGN: Oleoyl-estrone was synthesized and incorporated in liposomes; it was administered i.v. (to mimic lipoprotein delivery) for 14-day periods using implantable osmotic minipumps. The study included the finding of oleoyl-estrone in blood lipoproteins, the correlations of the effects of body weight to the dose and the uptake of labelled oleoyl-estrone by tissues, its internalization and disposal. SUBJECTS: Normal-weight Wistar female rates were used. Pooled human blood was used as source of HDL3. MEASUREMENTS: Oleoyl-estrone was identified in rat white adipose tissue and in human blood HDL3 lipoprotein fraction. Changes in body weight, food intake, oxygen consumption, respiratory quotient and nitrogen balance were measured in chronically injected rats. The uptake and hydrolysis of oleoyl-estrone by tissues was also determined following its acute administration. RESULTS: Oleoyl-estrone induced a dose-dependent loss of weight, with decreased food intake. In 14 days, and compared with controls at the end of this period, a dose of 0.78 mumol/day induced the loss of 16.4 +/- 5.5% of body weight; the difference was maximal for doses of 15 mumol/day or higher: 24.7 +/- 3.1%. Under oleoyl-estrone treatment, body protein was preserved (positive nitrogen balances) and fat stores were wasted: lowered respiratory quotient, and deficit in energy balance; a dose of 0.78 mumol/day induced the loss of 9.6 +/- 2.2 g of total body lipids in 14 days. Most of oleoyl-estrone taken up by tissues was hydrolysed; however, in part it reached intact the cell nucleus of incubated adipocytes. Oleoyl-estrone effects were different from those of free estrone. CONCLUSION: A lipophilic pathway for oleoyl-estrone transport by lipoproteins is postulated, allowing chemical communication between tissues. Oleoyl-estrone may be directly involved in the control of body weight.

Adipocytes↗