Biological Parameters of the Blood in the Genetically Obese Zucker Rat

Schirardin, H; Bach, André; A, Schaeffer; Bauer, Marthe; Weryha, A

doi:10.3109/13813457909070500

Cited by 25 publications

(14 citation statements)

References 29 publications

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“…This genetically obese diabetic rat is characterized by elevated plasma Ca levels [36][37][38]. At slaughtering, in our animals, the difference between obese and lean animals was about 9 mg/l (data not shown).…”

Section: Discussionmentioning

confidence: 92%

Isoflavone Consumption Does Not Increase the Bone Mass in Osteopenic Obese Female Zucker Rats

Picherit¹,

Horcajada²,

Mathey³

et al. 2003

Ann Nutr Metab

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Some controversy exists in the literature concerning the effects of leptin on bone metabolism. Thus we have compared femoral bone density and biochemical markers of bone metabolism in male and female fatty (leptin-resistant) Zucker rats and their lean homozygous controls at 3 and 6 months of age. At 3 months, no differences concerning total, diaphyseal (cortical bone), and distal metaphyseal (trabecular bone) femoral bone densities, plasma osteocalcin concentrations, and urinary deoxypyridinoline excretion were observed between fatty and lean rats. On the opposite, at 6 months of age, in both males and females, total, diaphyseal, and distal metaphyseal femoral bone densities and plasma osteocalcin concentrations were lower in Zucker than in lean rats. Soybean isoflavone consumption (40 µg/g body weight/day for 90 days, a dose which prevents osteopenia following ovariectomy both in lean Zucker homozygous controls and in Wistar rats) by obese female Zucker rats had no significant effect upon their bone mass.

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Section: Discussionmentioning

confidence: 92%

Isoflavone Consumption Does Not Increase the Bone Mass in Osteopenic Obese Female Zucker Rats

Picherit¹,

Horcajada²,

Mathey³

et al. 2003

Ann Nutr Metab

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“…Blood glucose [36] and insulin [20] were measured in the basal state samples with standard methods. Oxygen concentration in blood samples was derived from the blood haemoglobin content in the samples -a mean of 159 g/l for lean and 153 g/l for obese rats [30] -corrected by the packed cell value, the pH and the pO 2 values using nomograms [11] and standard equations [8, 10] applicable to rat blood, taking into account the blood temperature.…”

Section: Blood Gases and Lactate Interchangesmentioning

confidence: 99%

Hind leg heat balance in obese Zucker rats during exercise

Ardévol

Adán

Remesar

et al. 1998

Pfl�gers Archiv European Journal of Physiology

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To analyse the effect of obesity on exercise-derived heat dissipation, lean and obese Zucker rats were exercised on an inclined treadmill until they would no longer run with gentle prodding. We measured their oxygen consumption, water vapour loss, the concentrations of adenosine tri- and diphosphate, creatine phosphate, and lactate in quick-frozen leg muscles, and the temperature of muscle, skin and blood in the aorta. We determined blood flow to leg muscle, fat and skin by measuring the entrapment of fluorescent microspheres. From the measurements we calculated heat flow rates between hind leg muscle, blood, fat and skin and the environment. The obese rats weighed twice as much as the lean (340-400 g and 175-200 g respectively) and ran half as fast (113 +/- 7 m versus 257 +/- 17 m). The differences between the two groups for basal oxygen consumption (lean: 6.7 +/- 0.9 micromol/min, obese: 5.0 +/- 1.9 micromol/min) and exercising oxygen consumption (lean: 37.8 +/- 5.6 micromol/min, obese: 22.2 +/- 3.8 micromol/min) were not significant. Both groups stopped running after the same time at their maximal speed (lean: 4.5 +/- 0.3 min, obese: 4.2 +/- 0.2 min). During exercise, lean rats had higher increases in core temperature (lean: 0.7 degrees C, obese: 0.4 degrees C) and muscle temperatures (lean: 1.3 degrees C, obese: 0.7 degrees C) than the obese rats. The calculated heat flows indicated a predominant conductive transfer of heat from muscle through the skin in lean rats but a higher proportion of heat transfer to the blood in obese rats. It is concluded that muscle heat accumulation did not cause fatigue in either case.

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“…Furthermore, in vivo studies of adrenergic pressor reactivity in OZR have constructed reactivity curves with the autonomic nervous system intact (1) or from doses based on body weight with the assumption that plasma volume can be comparably estimated from body weight in OZR vs. LZR (19,29). Given reports of reduced blood mass (21) and impaired baroreflex control in OZR (2,4,19), these variables must be considered to determine the true adrenergic pressor reactivity in the setting of obesity.…”

mentioning

confidence: 99%

Reduced plasma volume and mesenteric vascular reactivity in obese Zucker rats

Schreihofer

Hair

Stepp

2005

American Journal of Physiology-Regulatory, Integrative and Comp

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Zucker rats (OZR) are mildly hypertensive with an apparently elevated sympathetic vasomotor tone compared with lean Zucker rats (LZR). Studies have also suggested enhanced adrenergic pressor reactivity in OZR but assumed comparable baroreflexes, or blood volume-to-body weight ratio, to LZR. In 15-wk-old OZR and LZR, we measured plasma volume and vascular reactivity to norepinephrine (NE) and phenylephrine (PE) with doses evaluated by body weight and plasma volume. Plasma volume measured by dye dilution (Evans blue; 200 l of 0.5%) showed that OZR had comparable blood volumes to LZR but lower blood volume-to-body weight ratio (3.4 Ϯ 0.2 ml/100 g) than LZR (5.7 Ϯ 0.2 ml/100 g, P Ͻ 0.05). Ganglionic blockade (mecamylamine, 4 mg/kg) in isoflurane-anesthetized rats produced larger decreases in arterial pressure in OZR compared with LZR (52 Ϯ 2 vs. 46 Ϯ 2 mmHg). Pressor responses to NE (0.01-10 g/kg) were exaggerated with doses analyzed by body weight but not analyzed by drug quantity. Pressor responses to PE (1-24 g/kg) showed no difference with doses analyzed by body weight, but, analyzed by drug quantity, OZR showed a slight decrease in pressor reactivity. PE-induced increases in vascular resistance were exaggerated in the hindlimb circulation of OZR, normal in the renal circulation, and attenuated in the mesenteric circulation. The timing of the peak pressor response to PE corresponded with the increase in mesenteric vascular resistance, followed by rises in hindlimb and renal resistance. These data suggest that systemic adrenergic pressor reactivity is not enhanced in OZR, despite exaggerated vascular reactivity in the hindlimb of the OZR.

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Biological Parameters of the Blood in the Genetically Obese Zucker Rat

Cited by 25 publications

References 29 publications

Isoflavone Consumption Does Not Increase the Bone Mass in Osteopenic Obese Female Zucker Rats

Isoflavone Consumption Does Not Increase the Bone Mass in Osteopenic Obese Female Zucker Rats

Hind leg heat balance in obese Zucker rats during exercise

Reduced plasma volume and mesenteric vascular reactivity in obese Zucker rats

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