Pigeon Plasma Research Articles

Homeostasis of the retinal micro-environment: I. Magnesium, potassium and calcium distributions in the avian eye

The concentrations of Mg 2+, K + and Ca 2+ in the intraocular fluids (IOFs) and blood plasma of chickens and pigeons were determined by atomic absorption spectrophotometry. The Mg 2+ concentration in the IOFs of both species was greatest in the liquid vitreous adjacent to the retina followed by aqueous > blood plasma > plasma dialysate. In contrast the concentration of K + in the IOFs of both chickens and pigeons was greater in the aqueous than in the liquid vitreous. The concentrations of Ca 2+ in all IOF compartments of chicken eyes were virtually identical and were lower than that of blood plasma. The concentrations of Mg 2+ in the IOFs of the chicken, especially in the liquid vitreous, was remarkably stable; experimentally lowering or raising the plasma Mg 2+ concentration over a relatively wide range had little or no effect on the Mg 2+ concentration in the IOFs of these animals. We can conclude that a high Mg 2+ and low K + concentration in the extracellular fluids of the retina is maintained in the avian eye, as in the mammalian eye, by active transport processes across the blood-retinal barrier systems. Because the avian retina is completely avascular, the site of these homeostatic transport processes must be the epithelium of the retinal choroid and/or the pecten. These findings support the concept that the contribution of the vitreous to the homeostasis of the retinal micro-environment is inversely related in vertebrates to the degree of retinal vascularization.

Mélatonine dans l'organe pinéal, la rétine et le plasma. Etude immunologique chez le Pigeon

Circadian variations in melatonin content have been studied in the pineal organ, retina and plasma of adult pigeons using radioimmunoassay. A clear-cut peak of melatonin was observed in the pineal organ at middark; this middark peak was of larger amplitude in July than in November. A nocturnal rise in melatonin concentration was also observed in the retina and plasma. We also used an immunocytochemical technique revealing the positive reactions of a melatonin-like compound in the photoreceptor cell layer (inner segments) of the pigeon's retina. Up to now, no melatonin storage has been visualized in the pineal organ of the pigeon.

Physical, chemical, and immunochemical studies of apolipoprotein A-I from pigeon plasma high density lipoproteins

Pigeon plasma high density lipoproteins (HDL) were isolated by ultracentrifugation between the densities of 1.063 and 1.21 g/ml. Gel filtration of delipidated HDL in 5 M guanidine-HCl on Sephadex G-150 yielded a major fraction which eluted at the same position as human apolipoprotein A-I isolated from HDL. In SDS-gel electrophoresis, the isolated apolipoprotein co-migrated with human apolipoprotein A-I with a molecular weight of approx. 28000. The amino acid composition was similar to the apolipoprotein A-I isolated from human and hen plasma. The isolated apolipoprotein from pigeon plasma had therefore been designated as apolipoprotein A-I. As judged by circular dichroism (CD), the apolipoprotein A-I displayed a maximum mean residue ellipticity of approx. −28 000 at 222 nm while at concentrations greater than 0.2 mg/ml. Calculations of α-helicial content gave values of 85%. Lowering the concentration of apolipoprotein A-I was found to concomitantly decrease the ellipticity (absolute value) suggesting that there was some conformational change when the apolipoprotein A-I concentration varied. The isolated pigeon apolipoprotein A-I was found bound to the phospholipid (dimyristoyl phosphatidylcholine) and there was no significant conformational change upon lipid binding as judged by CD. Under the same experimental conditions, human apolipoprotein A-I exhibited a drastic conformational change by increasing its helicity in the presence of phospholipid. The helical content of human apolipoprotein A-I was increased from 48 to 85%. This finding suggests that the apolipoprotein may not necessarily increase its helical content during lipid binding. Moreover, immunochemical studies showed that rabbit antiserum prepared against pigeon apolipoprotein A-I could partially react with human apolipoprotein A-I as determined by quantitative radioimmunoassay.

Fibrinolysis in the Pigeon (Columba livia)

The presence of plasminogen activator in the euglobulin fraction of pigeon plasma, was demonstrated by conspicuous lysis on unheated fibrin plates; human as well as bovine fibrin were susceptible to lysis. The presence of free plasmin in euglobulin fraction was indicated by lysis on heated fibrin plates.

Uptake of campesterol in pigeon intestine

Campesterol was the major plant sterol found in the gastrointestinal tract, liver, and plasma of pigeons fed diets containing large amounts of β-sitosterol and small amounts of campesterol. On feeding plant sterol mixtures, it was found that campesterol was taken up preferentially by the pigeon intestine.

Concentration of androgens in systemic plasma of rats, guinea pigs, salamanders and pigeons.

The concentrations of androstenedione, testosterone and dehydroepiandrosterone have been measured in systemic plasma of adult male specimens of domesticated rats, guinea pigs and pigeons and the salamander Necturus. Values for normal human subjects are given for comparison. Striking differences were observed in testosterone concentration among the variousspecies. Several interpretations of this finding are discussed. The androgen content of plasma of sexually mature rats was compared with that of a few pools of plasma from immature animals. The data indicate that the testosterone/androstenedione ratio increases at puberty in the rat. {Endocrinology 82: 115, 1968)

Segregation of plasma-albumin types from a species cross.

SummaryStarch gel electrophoresis of the plasma of pigeons, ring neck doves, dwarf turtle doves, and mourning doves reveals constant distinct bands in the plasma albumin different for each species. In hybrids among some of these species, the albumin shows both parental components as double bands. The hybrids from dwarf turtle doves X ring neck doves are fertile. There were 24 progeny from one family in the first backcross plus 335 offispring from 58 second and later back-crosses and matings inter se of the back-cross hybrids. The ratios conformed to expectations on the assumption of a monohy-brid, co-dominant, autosomal gene pair. No linkage of the albumin types with the other characters was noted. A blurring of the non-albumin components of the plasma was noted in certain adult females of 4 species, a probable association with egg production.

CLOTTING OF CITRATED PLASMA BY A PROTEOLYTIC ENZYME ASSOCIATED WITH AN ANTIBACTERIAL AGENT FROM SERUM.

Two to 4 mg/ml of an antibacterial agent occurring in the serum of humans and animals caused the clotting of citrated rabbit, human, calf, ox, sheep, goat, guinea pig, rat, mouse, horse, chicken, pigeon and swine plasma. Heparinized plasmas of the same species were found resistant to the clotting action of the antibacterial agent. Citrated plasma previously heated at 56 C for 30 min, treated with 640 units/ml tyrosinase for 60 min, or absorbed with 0.2M Ca3(PO4)2 and 0.2M Mg(OH)2 was also found resistant to the clotting action of the antibacterial agent. The clotting action of the antibacterial agent was not affected by heating at 66 C for 60 min, nor by multiple passage through Seitz filters. The coagulation of citrated plasma proceeded most rapidly with 0.2M Tris(hydroxymethyl)-amino-methane buffer, pH 7 to 9, or distilled water as the antibacterial agent solvent; 0.2M phosphate buffer, pH 6 to 8, reduced the clotting action of the antibacterial agent, while 0.2M citrate-phosphate buffer, pH 4.0, or 0.2M carbonate-bicarbonate buffer, pH 10.0, inhibited entirely the clotting activity of this agent.

Further studies on the cultivation of the avian malaria parasites: II. The effects of heterologous sera and added metabolites on growth and reproduction in vitro

Several series of studies have been undertaken to extend and amplify previous research on the in vitro cultivation of the avian plasmodia, using the Harvard medium, with special emphasis on Plasmodium hexamerium. Standard culture experiments with P. hexamerium yielded higher levels of growth than did earlier studies, with maximal growth and reproduction after 24 hours in vitro and a decline in parasitemia thereafter. Similar experiments with P. elongatum were not very successful, and it is concluded that survival rather than reproduction was achieved. Studies using pigeon and turkey plasma indicated that turkey plasma increased growth and reproduction of P. hexamerium in vitro, while the substitution of pigeon plasma was not beneficial to the parasite. Vitamin B 12, folic acid, and a porcine liver coenzyme concentrate were tested singly and in combination as additives to the basic Harvard medium. Growth and reproduction were enhanced in all cases, and it is suggested that these metabolites be incorporated in all future studies on the cultivation of the avian plasmodia.

ACTION OF THYROXIN ON ESTROGEN-INDUCED CHANGES IN BLOOD CHEMISTRY AND ENDOSTEAL BONE

ESTROGENS increase greatly the calcium, phosphorus and lipid content of bird plasma; they also induce growth of the oviduct and formation of endosteal bone in both birds and mammals. The literature on this subject has been reviewed by Riddle (1942) and by Gardner and Pfeiffer (1943). Riddle and Dotti (1936, 1945) noted that in pigeons thyroidectomy does not notably affect the ability of estrogens to raise the plasma calcium. Clavert (1942) reported that the hypercalcemic and osteogenic actions of estradiol dipropionate in drakes are reduced by thyroidectomy, and that these actions are restored by injections of thyroxin. Thyroidectomy has been shown to increase the cholesterol, fatty acid and phospholipid content of drake plasma (Benoit and Bogdanovitch, 1937) and the administration of thyroxin apparently decreases the fat content of pigeon plasma (Riddle, Senum and Rauch, 1945).

TECHNIQUE OF CULTIVATING HUMAN TISSUES IN VITRO

1. Unmodified human plasma is not a satisfactory culture medium for human tissues owing to the susceptibility of human fibrin to digestion by tissue ferments. The necessary framework is thus destroyed before the cells begin to migrate. The difficulty can be overcome by adding to human plasma or serum a small quantity of fowl or pigeon plasma, the fibrin of which is highly resistant to digestion. Human tissues have been propagated in this medium for several months through subcultures, and growth in vitro can probably be maintained indefinitely. 2. Human tissues show no greater sensitiveness to changes in temperature and mechanical injury associated with preparation of cultures than those of lower animals. They may be preserved in an ordinary ice box at 10-15 degrees C. as long as 6 or 8 days. Tissues obtained at operation give best results, but pieces of organs removed at autopsy 1 to 4 hours after death sometimes show active growth. 3. The presence of normally existing iso-antibodies (agglutinins and hemolysins) in human serum is without influence on the growth of human tissues in vitro. In other words, autogenous serum has no advantage in tissue cultures over homologous serum.

The fat content, morphology and length of life of cells growing in diluted blood plasma

Cells growing in unmodified blood plasma (Harrison's method) exhibit regularly an accumulation of fat droplets in their cytoplasm. In the case of the cells of the chick embryo this fat accumulation is quite marked after 24 to 48 hours, and reaches a maximum after five to seven days, at which time the cells are distended with fat droplets. The experiments herewith reported were planned to determine the effect of a reduction in the fat content of the culture medium, brought about by dilution of the plasma, on the accumulation of fat by the cells. In the course of the experiments the influence of dilution on the length of life and morphology of the cells was also observed. One part of plasma added to twenty or twenty-five parts of Ringer's solution forms a medium which coagulates satisfactorily in hanging drops. Studies were made with dilutions of 1:2, 1:5, 1:10, 1:15, and 1:20 of pigeon plasma in Ringer's solution, containing 0.9 per cent. NaCl. Pieces of chick embryo heart were used for cultivation. The tissue was finely divided into pieces of suitable size for cultures, which were washed in Ringer's solution for a half hour before using. Cultures from the various series were fixed in formalin at the end of two, three and four days and stained with hematoxylin and Sudan III. In plasma diluted 1 : 2 the cells live practically as long (5 to 10 days without transfer), as in pure plasma, and show a similar accumulation of fat. In a 1 : 5 dilution the fat content is slightly diminished; there is little or no effect on the length of life or on the morphology of the cells.

THE CULTIVATION OF TISSUE IN PLASMA FROM ALIEN SPECIES

1. Rat sarcoma may be cultivated in mouse plasma and guinea pig plasma, and the growth differs only in extent from that observed in rat plasma. The cells may show active wandering in guinea pig plasma after thirty days, if transferred at proper intervals to fresh medium. 2. Rabbit plasma is less suitable than that of guinea pigs and mice for the growth of rat sarcoma; growth is slow, but it may continue for twelve days. 3. The duration of growth of rat sarcoma in dog plasma is from two to three days. 4. The duration of the growth of rat sarcoma in pigeon plasma is four to five days. Transferring the tissue to fresh pigeon plasma does not lengthen the period of activity. 5. No growth whatever is observed of mouse and rat tissues in goat plasma. Studies of the fate of the cells indicate the presence in goat serum of a substance toxic for these tissues. 6. In preparations of rat sarcoma in human plasma, liquefaction of fibrin is regularly observed. The phenomena of growth consist in an outwandering of cells along the cover glass, and, after four to six days, the formation of giant cells. Such giant cells are produced in larger number in the cultivation of rat spleen. 7. The degree of suitability of the different kinds of alien plasma used as culture media for mouse and rat tissues does not go hand in hand with the closeness of relationship of the species. 8. Rat spleen may be cultivated as readily in foreign plasma as the virulent transplantable tumors.