Nature of Exchange in Parabiotic Rats

Huff, Rex L.; Trautman, Richard; Dyke, Donald C. Van

doi:10.1152/ajplegacy.1950.161.1.56

Cited by 42 publications

(14 citation statements)

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“…Parabiotic rats such as those used in the present experiments have a common circulation and an exchange of blood between rats with a half-time of about 1 hour (17).…”

Section: Discussionmentioning

confidence: 99%

Cholesterol Concentration and Cholesterol Synthesis in Aortas of Rats With Renal Hypertension*

Daly¹,

Deming²,

Raeff³

et al. 1963

J. Clin. Invest.

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Hypertension has been shown to increase the severity of atherosclerosis in both man and experimental animals (1). Most observers attribute this effect of hypertension to local damage to the vessels produced by the augmented pressure or turbulence of the blood. This concept is supported by the more frequent occurrence and greater severity of atherosclerotic lesions at locations of high pressure or turbulence. It has also been suggested that high blood pressure increases the filtration of blood across arterial walls and, presumably, affords an opportunity for retention of lipid in the walls (2).The present report is concerned with two other factors that may affect the concentration of lipid in the aortas of hypertensive rats: the concentration of lipid in the blood, and lipid synthesis in the aorta itself. Cholesterol concentrations were found to be significantly higher in aortas of hypertensive rats than in those of normotensive controls. This difference was observed when hypertensive animals had higher serum cholesterol levels than their controls, but the difference persisted when experimental conditions were adjusted so that the serum cholesterol levels were comparable in the two groups of animals. It was found that the rate of cholesterol synthesis in vitro is increased in the aortas of hypertensive rats. A Gaertner cuff 22 mm long 'and an "Infraton" 4 pickup were used.Parabiotic pairs. Wistar rats were inbred in this laboratory by mating siblings for at least ten generations; CFN rats were inbred in the same way for three generations. Parabiotic pairs were prepared by suturing the previously divided lateral abdominal musculature of the two rats while maintaining separation of the peritoneal cavities and joining the scapulae.Cholesterol concentration in serum. To obtain blood for the measurement of serum cholesterol levels at intervals, rats under light ether anesthesia were bled by

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“…Parabiotic rats such as those used in the present experiments have a common circulation and an exchange of blood between rats with a half-time of about 1 hour (17).…”

Section: Discussionmentioning

confidence: 99%

Cholesterol Concentration and Cholesterol Synthesis in Aortas of Rats With Renal Hypertension*

Daly¹,

Deming²,

Raeff³

et al. 1963

J. Clin. Invest.

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“…Therefore, with each parabiosis procedure it is essential that blood exchange be established and that the rate of blood exchange between partners is measured. In the early 1900’s there was some disagreement as to whether whole blood could exchange between parabiosed animals, or whether there was a “parabiotic barrier” (see review by Huff et al [38]). Starting with the initial studies by Bert [1] a number of investigators identified common blood vessels in parabiosed pairs of rats and Suaerbruch and Heyde [20] recorded the exchange of many different substances including bacteria and concluded that there was anastomosis of capillaries that allowed large cells to exchange between animals.…”

Section: 1 Parabiosis Techniques and Limitationsmentioning

confidence: 99%

“…Starting with the initial studies by Bert [1] a number of investigators identified common blood vessels in parabiosed pairs of rats and Suaerbruch and Heyde [20] recorded the exchange of many different substances including bacteria and concluded that there was anastomosis of capillaries that allowed large cells to exchange between animals. Other investigators, however, failed to see equilibrium in the concentration of specific factors in the two members of a pair, or observed a limited physiologic response to administration of a toxin or a hormone in the partner of a treated animal [see [38]]. This led to the conclusion that there was a “parabiotic barrier” which limited transport of certain substances and it was suggested that the exchange of factors between parabiotic partners was dependent on the lymphatic system and exchange of body fluids in the common peritoneal cavity (see [2]).…”

Section: 1 Parabiosis Techniques and Limitationsmentioning

confidence: 99%

Contribution made by parabiosis to the understanding of energy balance regulation

Harris

2013

Biochimica et Biophysica Acta (BBA) - Molecular Basis of Diseas

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Parabiosis is a chronic preparation that allows exchange of whole blood between two animals. It has been used extensively to test for involvement of circulating factors in feedback regulation of physiological systems. The total blood volume of each animal exchanges approximately ten times each day, therefore, factors that are rapidly cleared from the circulation do not reach equilibrium across the parabiotic union whereas those with a long half-life achieve a uniform concentration and bioactivity in both members of a pair. Involvement of a circulating factor in the regulation of energy balance was first demonstrated when one member of a pair of parabiosed rats became hyperphagic and obese following bilateral lesioning of the ventromedial hypothalamus. The non-lesioned partner stopped eating, lost a large amount of weight and appeared to be responding to a circulating “satiety” factor released by the obese rat. These results were confirmed using different techniques to induce obesity in one member of a pair. Studies with phenotypically similar ob/ob obese and db/db diabetic mice indicated that the obese mouse lacked a circulating signal that regulated energy balance, whereas the diabetic mouse appeared insensitive to such a signal. Positional cloning studies identified leptin as the circulating factor and subsequent parabiosis studies confirmed leptin’s ability to exchange effectively between parabionts. These studies also suggest the presence of additional unidentified factors that influence body composition.

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“…It is important to note that the nature of exchange between parabiotic rats is relatively slow, with total blood volume exchanging approximately ten times per day (Huff, Trautman, & Van Dyke, 1950). For a factor to reach equilibrium across the parabiotic union it has to have a half life that is longer than the rate of removal from the circulation by two animals.…”

Section: The Parabiotic Modelmentioning

confidence: 99%

“…For a factor to reach equilibrium across the parabiotic union it has to have a half life that is longer than the rate of removal from the circulation by two animals. The size of the factor is not an issue because Huff et al (Huff, Trautman, & Van Dyke, 1950) demonstrated that radiolabeled red blood cells exchanged between parabiosed rats and this has recently been confirmed using mice expressing green fluorescent protein (Gibney, et al, 2012). In 1950 Van Dyke et al (Van Dyke, Simpson, Li, & Evans, 1950) showed that growth hormone, which was estimated to have a half life of 9 hours in the circulation, reached approximately half the concentration in a hypophysectomized partner as that of the intact parabiont.…”

Section: The Parabiotic Modelmentioning

confidence: 99%

Is leptin the parabiotic “satiety” factor? Past and present interpretations

Harris

2013

Appetite

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In 1959 Hervey hypothesized that a circulating feedback signal informed the hypothalamus of the size of fat stores and initiated appropriate corrections to energy balance. The hypothesis resulted from a parabiosis study in which one animal became obese following lesioning of the ventromedial hypothalamus. The partner of the lesioned rat was hypophagic and lost a large amount of body fat. Similar results came from parabiosis studies with obese Zucker rats and rats that overate due to stimulation of the lateral hypothalamus. In studies in which one parabiont was made obese by overfeeding the non-overfed partners lost substantial amounts of fat with a minimal reduction in food intake and no loss of lean tissue. The loss of fat was due to inhibition of adipose lipogenesis and other metabolic adjustments typical of food restriction. Parabiosis with genetically obese mice implied that ob/ob mice did not produce the feedback signal and subsequently the mutant ob protein, leptin, was identified. This paper provides a review and interpretation of parabiosis work that preceded the discovery of leptin, an evaluation of leptin in relation to its function as the circulating feedback signal and evidence for additional circulating factors involved in the control of adipose tissue mass.

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Nature of Exchange in Parabiotic Rats

Cited by 42 publications

References 0 publications

Cholesterol Concentration and Cholesterol Synthesis in Aortas of Rats With Renal Hypertension*

Cholesterol Concentration and Cholesterol Synthesis in Aortas of Rats With Renal Hypertension*

Contribution made by parabiosis to the understanding of energy balance regulation

Is leptin the parabiotic “satiety” factor? Past and present interpretations

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