Normal Dog Plasma Research Articles

Antirabbit platelet and red-cell factors in normal blood.

Abstract Normal human, dog, and sheep plasma or serum contains antirabbit platelet and erythrocyte factors which produce thrombocytopenia and anemia in rabbits following intravenous injection. These factors are relatively stable to heat, but labile on aging. Their effect is not opposed by ACTH, cortisone, antihistaminics, or splenectomy. The antiplatelet factor can be separated from the plasma by chemical means that also remove prothrombin.

The Quantitative Estimation of the Removal of Bacteria from the Blood by the Various Organs of the Immunized Animal

Summary By a method of constant intravenous infusion of bacteria combined with the determination of the numbers of bacteria in the circulation at various sites by venous catheterization, further quantitative data have been obtained concerning factors influencing the removal of bacteria from the blood stream. Total canine splanchnic removal of Klebsiella pneumoniae type B averaged 42 ± 15% (S.D.). There was no significant removal of organisms in the pulmonary circulation. During a second infusion of K. pneumoniae type B given after a two to four week interval, the average splanchnic removal rose to 77 ± 11% (S.D.). The degree of removal in the pulmonary area may have been significant. The splanchnic removal of K. pneumoniae type B rose abruptly to 83 ± 16% (S.D.) following intravenous administration of homologous plasma obtained from immunized dogs. Normal dog plasma (given 1.5–3 hours prior to the immune plasma) failed to affect significantly the splanchnic removal during this period. In dogs given a K. pneumoniae type B infusion two weeks after having received plasma obtained from an immunized dog, splanchnic removal averaged 70 ± 10% (S.D.) and was not altered by administration of additional immune dog plasma.

PLASMA PROTEIN METABOLISM—ELECTROPHORETIC STUDIES

Electrophoretic patterns of normal dog plasma in veronal buffer at pH 8.5 are shown to be essentially similar to patterns of human plasma. Dog albumin has a higher mobility than human albumin and in a mixture of dog and human plasmas migrates as a partially separated peak. Normal dog plasma frequently shows four alpha globulin peaks. Rates of restoration of plasma protein components in dogs subjected to acute plasmapheresis have been studied by electrophoresis. During the first 24 hours following such acute depletion, appreciable quantities of all electrophoretic components of the plasma proteins enter the circulating blood stream even when food is not given and has not been given for 12 hours before plasmapheresis. In such fasting periods albumin and total globulin appear in approximately the proportions present in normal plasma. Alpha and beta globulins continue relatively elevated during subsequent days in which caloric and protein intakes are adequate for weight and nitrogen gains. Initial albumin levels, however, are regained more slowly than those of total globulin. The relative proportions of the electrophoretic components of plasma proteins may be disturbed from normal following a single acute depletion for as long as 2 to 3 weeks after the total protein level has returned to normal. Abnormally high beta globulin and fibrinogen, but a low albumin, were found in a dog with an acute and chronic cholangitis and hepatitis. Similar elevation of gamma globulin was noted in a dog in which a hemolytic reaction occurred.

Assay of Tryptases by Lysis of Fibrinogen

A recent method, for assay of tryptases by lysis of fibrin clot is sufficiently sensitive to give excellent results with normal dog, cat and human plasma tryptases, which, in a limited series of observations to date, fall within the range of 20-200 “units” (v. infra), in which the test is accurate to within 5-10%. The principle of the method is the comparison of the “lytic times” of activated tryptase ounknown” with a standard reference series of known trypsin concentrations. A convenient practical standard of 100 “units” is defined as the lytic activity of 1 mg per cc of a reliable commercial trypsin (prepared by dilution of a “stock” 2% solution preserved in glycerol-borate buffer, according to Burdon). Since some species (e.g. rabbit) and certain human bloods yield plasma tryptase values under 5 “units” by the above test, a new method has been devised to operate with a sensitivity of ten times that of the original test. It has the same (5-10%) experimental error in the new range of 10-1 “units.” Like a number of older attempts (e.g.), the new method involves lysis of fibrinogen. This is timed by testing the residual clotting activity with a potent thrombin. As in the fibrinolytic method, the assay depends upon comparison of the “unknown” with a series of standard enzyme dilutions. Reagents. 1. Simplified borate bufler solution. 2.5% H3BO3 (45 parts), 0.5% NaCl (45 parts), 4% Na3B4O7,10H2O (10 parts): pH = 7.7 ± 0.1 (glass electrode). This solution is used as solvent and diluent for fibrinogen and thrombin. 2. Fibrinogen. A lyophilized preparationa is convenient and an especially pure preparation (about 50% coagulable protein) of human fibrinogen, prepared by Dr. R. M. Ferry and the staff of the Harvard Plasma Fractionation Laboratory and kindly supplied by Dr. E. J. Cohn for this work, is excellent.

Vaso-Pressor Action of Extracts of Plasma of Normal Dogs and Dogs with Experimentally Produced Hypertension

ConclusionHypertension produced in dogs by means of compression of the renal artery has not been shown by the method employed to be caused by liberation of pressor substances into the blood stream which act directly on the peripheral blood vessels to cause vaso-constriction. Nor is the known pressor secretion of the pituitary gland present in amounts large enough to be detected by the method employed, in the blood of animals with hypertension. These conclusions are based on the following evidence: 1. Alcoholic extracts of plasma of dogs with hypertension when injected into anesthetized cats raises the cat's arterial pressure no more effectively than extracts from plasma of normal animals. 2. Removal of the hypophysis in animals with experimental hypertension does not alter the character of the pressor response to extracts of plasma.

NUTRITIONAL EDEMA IN THE DOG

1. The concentration of protein in the serum and plasma of normal dogs is given. Analyses of serum from 38 animals yielded the following averages and standard deviations, (a) for albumin: 3.26 +/- 0.48 gm. per cent, (b) for globulin: 2.72 +/- 0.76 gm. per cent, and (c) for total protein: 5.98 +/- 0.67 gm. per cent. Analyses of plasma from 19 animals showed, (a) for albumin: 3.38 +/- 0.38 gm. per cent, (b) for globulin: 2.98 +/- 0.55 gm. per cent, and (c) for total protein: 6.36 +/- 0.71 gm. per cent. 2. A diet for dogs is described, the feeding of which results in a progressive decline in the concentration of protein in the serum. A composite curve constructed from the findings with 21 animals discloses a rapid initial fall and a slower subsequent decrease in albumin and total protein and an approximately constant level for globulin. The course of the globulin curve was subject to wide variation in separate experiments, both increases and decreases being recorded. 3. With five dogs the nitrogen balance was followed through a total of 42 metabolism periods of approximately 7 days each. The average daily loss of nitrogen was 1.15 gm. Approximate calculations disclose that only 3 or 4 per cent of the nitrogen eliminated is accounted for by the decline in circulating protein, the remainder being represented by loss from the tissues. 4. An episode is described with one dog when, during a period of self-imposed fasting, the serum albumin regenerated to a normal level, apparently at the expense of catabolized tissue protein. 5. The course of serum proteins is described during the recovery which follows interruption of the low protein diet and return to a regime of adequate feeding. 6. A discussion is given of the relationship between tissue proteins and plasma proteins. The data permit one to entertain the hope that a way will be found for stimulating an internal readjustment to provide temporary relief from hypoproteinemia, a way which will depend upon the potential ability of the tissues to provide sufficient protein for the needs of the plasma.