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PubMed1976

Hemopoietic recovery in bone marrow of lethally irradiated rats following parabiosis. I. Granulopoiesis.

Aplasia was induced in rats by total body irradiation. Three days later, the animal was conjugated by aortic anastomoses with a healthy untreated litter-mate. 6 h after parabiosis, the bone marrow of irradiated animals contained some granulocytes showing RNA synthesis. At 18 h, many myelocytes and promyelocytes were present but no myeloblast was encountered. These myeloid precursor cells showed active DNA synthesis but no mitoses, and no erythroblasts were observed at this time period. At 24 h, mitoses of myeloblasts were found. At 42--60 h, erythropoiesis was evident. Chromosome analysis and investigations of cells of irradiated parabionts conjugated with partners having labeled cells, revealed that these newly formed myeloid and erythroid cells originated from the untreated parabiont. The mechanism of triggering myelopoiesis in the aplastic bone marrow by parabiosis is discussed.

Animals↗

PubMed1981

Relationship of age at parabiosis and time of embryonic death on extent of mixing of embryonic blood.

Two studies were conducted to determine the extent of blood chimerism from parabionts joined at different ages and the mortality pattern after joining. Complete mixing of blood was found in 100% of the pairs joined at 13 days, 80% at 15 days, and 25% at 17 days of incubation. Therefore, interfusing of blood components could only be assured when the embryos were joined no later than 13 days of incubation. Mortality after parabiosis occurred in three peaks. The first and largest peak (16.4% mortality) occurred at 12 hr after parabiosis with substantial mortality through 36 hr. The second peak (4.6% mortality) occurred between 108 and 120 hr after joining of the eggs. The third and final peak (5.6% mortality) occurred between 192 hr and hatch. Surgical trauma, bacterial contamination, and the inability of the embryo to escape the shell once pipped are possible explanations since these events were associated with clusters of embryo deaths. The use of single surviving parabiont as a means of increasing the efficiency of the parabiotic technique is discussed.

Age Factors↗

PubMed1987

Parabiosis between avian embryos selected for high and low competences of the graft-versus-host reaction.

Parabiosis of chicken embryos was conducted to determine if changes in immunological competences could occur by parabiosis between lines of chickens selected for high (H) and low (L) graft-versus-host reaction (GVHR). Eggs of the B9B9 genotype from the H line (H-B9B9) were parabiosed to eggs of the B11B11 from the L line (L-B11B11) and also the H-B11B11 were parabiosed to the L-B9B9. There were significant differences in hatchability between the line-genotype groups. The percentage of blood chimerism of parabionts showed also significant genetic differences. Chimerism was the highest in the H-B11B11 birds and the lowest in the L-B11B11. All chimeric parabionts showed immunological tolerance and almost all nonchimeric parabionts did not. Immunological competence was measured by splenomegaly index (SI) based on GVHR. The SI value of parabionts changed in the direction of the SI value of the partner. The SI value of chimeric parabionts differed significantly from those of nonchimeric parabionts and controls. Antibody response to bovine serum albumin was tested only for the H-B11B11. Antibody titers of parabionts were significantly lower than those of controls.

Animals↗

PubMed1990

Curtailment of autoimmunity following parabiosis with a normal partner.

The development of thyroiditis in DA rats that had been exposed to 131I in utero was prevented by parabiosis to normal, syngeneic partners. However, if the normal partner had received sublethal irradiation before parabiosis, thyroid implants placed in either partner were likely to manifest spontaneous thyroiditis.

Animals↗

PubMed1987

Body composition of lean and obese Zucker rats in parabiosis.

Parabiosis is the surgical union of two animals to produce a chronic blood exchange. This model has previously been used to demonstrate the involvement of a blood-borne factor in the feedback control of food intake and regulation of energy balance. It has been hypothesized that obese rats produce a humoral agent that acts centrally to inhibit food intake and accumulation of fat. In this study 50-day-old male or female Zucker rats were joined in either lean-lean pairs or lean-obese pairs. They ate ad libitum until 152 days of age when body composition was determined. Parabiosis inhibited growth in all rats compared with single controls. Lean partners of obese rats had reduced carcass weights, the same percent body protein but less fat than members of lean-lean pairs. Female rats showed larger changes in body composition than did males. These results suggest that obese Zucker rats produce the hypothesized regulatory signal but do not respond to it.

Animals↗

PubMed1981

Effects of cryptorchidy, parabiosis, and estrogen administration upon Leydig cell tumorigenesis in Fischer rats.

The effects on Leydig cell tumorigenesis of surgical cryptorchidy, parabiotic union with a castrate male partner, and a combination on the two procedures as well as of the continuous exposure to a high level of diethylstilbestrol stimulation were studied in the high-tumor Fischer rat. Localized foci of adenomatous hyperplasia were found to have developed in the scrotal testes of most animals by 13.5 months of age. Parabiosis with a castrate male partner did not appear to alter the process significantly, but surgical cryptorchidy, even when combined with parabiosis, completely prevented the development of this pretumorous lesion as did the chronic administration of diethylstilbestrol. Furthermore, intraabdominal residency throughout the life span of animals was found to inhibit Leydig cell tumor formation almost completely. Comparative end organ weights as well as plasma testosterone determinations reported earlier indicated that, with continued intraabdominal residency 3 months and longer, the Leydig cells in this strain of rat became significantly less responsive to stimulation by pituitary gonadotropic hormones. The data are interpreted as indicating that the endocrine stimuli most centrally involved in the genesis of this tumor type are quite different in the mouse and the rat, an abnormal response to gonadotropic stimulation being pivotal in the rat while reaction to estrogens is the most significant factor in the mouse.

Animals↗

PubMedDate not supplied

The influence of UV on the rhythmic activity of some lysosomal hydrolases in supernatant from mice in parabiosis.

The influence of UV radiation on the rhythmic activity of lysosomal hydrolases in parabiotic mouse liver was tested when one partner in parabiosis was irradiated. The enzymatic activity was determined by biochemical methods. Significant differences in the rhythmic activities of the enzymes from both partners in parabiosis were found. It was suggested that the blood might be a mediator which transfers the information of radiation action.

Animals↗

PubMed1977

[Hypophysian and ovarian function following a single postnatal estradiol injection. II. Studies on rats in parabiosis (author's transl)].

We have studied the functioning of the axis hypophysis-ovary in rats which had received an injection of 100 microgram estradiol benzoate, in the first days of life. The experimental method was the parabiosis of two animals (male or female, normal or estrogenized, intact or spayed) in different combinations. We established that estrogenization damages the hypopysis as well as the ovary to such a degree that both glands cease to function normally. --Injected gonadotrophins can procude luteinization of estrogenized ovaries. This effect, however, appears only as a direct consequence of hormone administration. Exogenous gonadotrophins can never trigger cyclical function of estrogenized ovaries.

Animals↗

PubMed1980

Changes in hepatic cell mitochondria during parabiosis between old and young rats.

Electron-micrographic measurement studies have been made on the hepatic cell mitochondria of the long-lived parabiotic unions between old and young rats. The mitochondria of the younger partners were significantly larger in size and those of the older partners were significantly larger in number and smaller in size compared with those of young and old control rats, respectively. The mitochondrial cristae seemed to become more compactly arranged in the younger partners and more sparsely in the older ones. The influence of parabiosis between different aged rats upon age changes in mitochondria and their function is discussed.

Aging↗

PubMed1974

Restoration of immune competence in tolerant mice by parabiosis to normal mice.

These studies demonstrate that mice tolerant to human gamma globulin (HGG) regain their ability to make antibody to HGG after parabiosis to normal mice. This can be demonstrated by enumeration of PFC in the spleens of both the normal and tolerant partners. Hemagglutinin titers of normal-tolerant parabionts, however, are exceptionally low; serum antibody appears to be neutralized by circulating HGG present originally in the serum of the tolerant partner. These data support the hypothesis that tolerance to HGG in mice is a "defective" state due to the absence of cells capable of responding to this antigen.

Animals↗

PubMed1999

Parabiosis between db/db and ob/ob or db/+ mice.

Genetically obese C57B1/6J-m db/db mice were parabiosed with either lean male db/+ or obese female ob/ob mice. Male db/db mice had lower serum leptin than females, and this was reflected in the amount of protein that crossed the parabiotic union into their partners. Eighteen days post operation, ob/ob partners of db/db mice had increased body temperature, lost 50% body weight and 60% body fat, but maintained carcass protein. The db/+ partners of db/db mice had a normal gut content and (by implication) food intake, did not raise their body temperature, but lost significant amounts of both lean and fat tissue during 25 days of parabiosis. The differences between the db/+ and ob/ob partners of db/db mice may be caused by leptin inhibiting growth of male mice, but not of female mice that are on a slower growth curve, or by the excess lipid in ob/ob mice sparing body protein. The db/db partners of ob/ob mice lost a small amount of body fat, but carcass protein was increased by 30%, compared with their controls. These results imply that leptin stimulated release of a circulating growth factor, possibly through activation of the long-form leptin receptor, in ob/ob partners of db/db mice.

Animals↗

PubMed1985

Parabiosis between avian embryos resistant and susceptible to Rous sarcoma virus.

Parabiosis of chicken embryos was used to determine if resistance or susceptibility to Rous sarcoma virus (RSV) tumors could be transferred between RSV-resistant (R) and RSV-susceptible (S) embryos. Eggs from RSV-R and RSV-S lines were parabiosed at 12 days of incubation. One week after hatching the chicks were inoculated in the wing web with RSV. Birds were examined for tumor lesions through 9 weeks of age. Lesion scores of the nonparabiosed RSV-S line were significantly higher than nonparabiosed RSV-R lines. Lesion scores of RSV-R chicks that had been parabiosed to RSV-S chicks were higher than nonparabiosed RSV-R chicks. Lesion scores of RSV-S chicks parabiosed to RSV-R chicks were not different from nonparabiosed RSV-S chicks. These results suggest that the resistance to RSV was not transferred between parabionts but that there was significant transfer of susceptibility from the RSV-S embryos to the RSV-R embryos.

Animals↗

PubMed1981

Attempts to transfer the resistance of Schistosoma mansoni-infected and irradiated cercaria-immunized mice by means of parabiosis.

Acquired resistance to Schistosoma mansoni infection was measured in S. mansoni-infected or irradiated cercaria-immunized mice, and in normal mice to which the former had been surgically joined. Such parabiotic partners were shown to freely exchange humoral and cellular blood constituents. There was no detectable transfer of resistance from mice infected for 8, 12, or 28 weeks to their uninfected partners, even if parabiosis was established before the initial infection and maintained to autopsy. In comparison with parabiosed controls, the number of adult worms surviving from a challenge infection was reduced by 51-96% in the previously infected mice but was not significantly reduced in their uninfected partners. In contrast, mice immunized with irradiated cercariae and their nonimmunized parabiotic partners showed similar levels of resistance. These data indicate that the resistance induced in mice by irradiated cercariae can be transferred, confirm that at least under some experimental conditions the resistance induced in mice by a previous S. mansoni infection is not readily transferred, and provide additional evidence that the resistance induced by normal infection and irradiated cercarial immunization differ in some fundamental way.

Animals↗

PubMed1975

Parabiosis in Nya:NYLAR mice.

Mice from our Nya:NYLAR colony were parabiosed using the skin-to-skin or coelomic method, and more than 150 such pairs survived for periods greater than 1 mo. The oldest pair at this writing survived for 27 mo after parabiosis, which is equivalent to the normal life span of the Nya:NYLAR mouse. No evidence of parabiotic intoxication in any pair, even those kept for several mo, was noted.

Anesthesia, General↗

PubMed1975

Chimeric analysis of hemopoietic cells after cross-sex parabiosis.

Anemia or polycythemia was induced in male rats. These males were conjugated with healthy, untreated female litter mates by FANG'S method of aortic parabiosis that resulted in complete cross circulation of blood between the two animals. The sex chromosomes of cells in erythropoiesis in various hemopoietic organs were examined in the treated male animals. The anemic parabionts indicated sharp increases in chimerical rates with erythroid marrows being evident. Polycythemic parabionts indicated marked decreases in chimerical rates with evidence of myeloid marrows. These findings suggested that the so-called stem cells in peripheral blood of the female parabiont migrated to the bone marrow of the male partner and that these migrating cells differentiated to erythroblast. The possible relationships between erythropoiesis and other cell proliferations in the hemopoietic organs are discussed.

Anemia↗

PubMed2005

[Parabiosis theory and effective stimulating amount, reinforcing-reducing, therapeutic time and course of acupuncture].

Parabiosis theory clearly expounds the change course of stimulatiom, namely, parabiotic equalization phase, parabiotic deregulation phase and parabiotic inhibition phase, and it can clearly explain that the effective stimulating amount is directly related to the reinforcing or reducing, and establishment of the therapeutic course. That is, the large effective stimulating amount is reducing method and the small effective stimulating amount is reinforcing method. In clinical application, for deficiency syndrome and chronic diseases, the effective intensity of acuti puncture should be smaller and the needle should be retained for 20-30 min, and for excess syndrome and acute disd eases, the effective stimulating intensity of acupuncture should be larger and the needle should be retained for longer time. In acupuncture treatment, acupoints should be grouped and used alternately, and the interval between therapeutic courses should be established.

Acupuncture↗

PubMedDate not supplied

[Radiation-induced changes in critical organs in rats irradiated in the state of parabiosis].

A study was made of the influence of parabiosis on the critical organ status in rats exposed to supralethal doses. The presence of a nonirradiated partner was shown to accelerate the recovery processes both in the intestine and the haemopoietic organs. The X-ray dose leading to a 50% decrease in the number of crypts was 11.9 Gy for parabionts, and 6.6 Gy for single animals.

Animals↗

PubMed1981

[Mechanism of immune response inhibition during parabiosis of animals of different ages].

Experiments were made of CBA mice aged 4-5 and 24-27 months under 2-months heterochronic parabiosis to determine the primary immune response to administration of sheep red blood cells. One and three months after parabionts separation the magnitude of the immune response did not significantly differ from that of non-separated parabionts and approximated the immune response in old mice. Splenectomy in old partners did not remove the inhibitory effect on young parabionts. X-Ray irradiation of old parabionts 3-5 days after coupling with young ones caused an appreciable recovery of immune function both in old and young partners.

Age Factors↗