IMMUNOLOGICAL STUDIES IN RELATION TO THE SUPRARENAL GLAND : I. HEMOLYSIN FORMATION IN NORMAL RATS.

Hemolysin formation was studied in normal rats. It was found that a single intraperitoneal injection of 1 cc. of a 10 per cent suspension of red blood cells results in an optimum high hemolysin titer 5 days after injection. The titer gradually falls, the hemolysin disappearing from 14 to 18 days after the injection. Larger amounts are less effective in the production of amboceptor. Much smaller amounts produce correspondingly lower hemolysin titers, although the ratio is not mathematically proportional. Repeated injections of 1 cc. of a 10 per cent suspension of red blood cells at daily intervals or at intervals of 3 or 5 days for three injections do not increase the hemolysin titer over that resulting from a single injection. Furthermore, the curve of antibody formation following a single small intraperitoneal injec tion of red blood cells is not altered by subsequent injections of similar amounts

THE USE OF HISTAMINE AS A STANDARD TEST FOR DIMINISHED RESISTANCE IN SUPRARENALECTOMIZED RATS

Of all the drugs thus far used in testing the resistance of suprarenalectomized rats, histamine has been found to be the most satisfactory. It is a readily obtainable and comparatively stable drug, producing characteristic symptoms. Its M.L.D. for a given strain of rats can be established within narrow limits, and the difference between the M.L.D. for normal and suprarenalectomized rats is comparatively great (1:20)

FURTHER STUDIES ON T. LEWISI INFECTION IN ALBINO RATS : I. THE EFFECT OF SPLENECTOMY ON T. LEWISI INFECTION IN ALBINO RATS AND THE PROTECTIVE ACTION OF SPLENIC AUTOTRANSPLANTS II. THE EFFECT OF THYMECTOMY AND BILATERAL GONADECTOMY ON T. LEWISI INFECTION IN ALBINO RATS

T. lewisi infection in normal adult 3 month old albino rats raised from a single stock and maintained under identical conditions was studied. Daily quantitative estimates of the trypanosomes in the circulating blood were made and the course of the infection was studied. Bilateral suprarenalectomy in rats lowers the resistance to a subsequent infection with T. lewisi. About 70 per cent of these rats die in an average period of 5.8 days after injection. The multiplication of the parasites, in the circulating stream, however, is not more considerable in the suprarenalectomized than in the previously normal rats, nor is the duration of the disease in the surviving rats any longer than in the normal group. The removal of the suprarenal glands does not alter the immune reaction to the parasite, but lowers the natural resistance of the animal to the toxic effects of the protozoan infection. Bilateral suprarenalectomy does not lessen the immunity of rats recovered from T. lewisi infection to subsequent infection. Unilateral nephrectomy does not influence the course of a subsequent infection with T. lewisi infection. The mortality of splenectomized rats from Bartonella muris anemia increases from 30 to 100 per cent following the injection of T. lewisi at the height of the anemia 7 days after splenectomy. T. lewisi infection 48 days after splenectomy that is to say at a time when the Bartonella anemia is no longer present produces a more severe infection than in normal rats. The number of trypanosomes at the height of infection averages 3 times the ordinary and the infection endures twice as long. Both the immune substance that inhibits the reproduction of the parasite and the lytic factor are markedly depressed. Splenic autotransplantation performed 4 weeks prior to splenectomy raises the resistance of rats to a subsequent T. lewisi infection. Thymectomy in 6 week old rats diminishes the severity of a subsequent trypanosome infection and shortens its course. Both the formation of the immune substance which inhibits reproduction of the trypanosomes and formation of trypanolytic antibodies are stimulated by this procedure. In the adult rat thymectomy shortens the course of the infection but the severity is only slightly diminished. Bilateral gonadectomy in the adult increases the severity of the infection. The number of trypanosomes at the height of the infection is almost three times the normal. However, the duration of the infection is the same as in the normal rats. The reproduction-inhibiting factor is depressed by bilateral gonadectomy but not the trypanocidal factor. Unilateral gonadectomy does not influence the infection

STUDIES ON BARTONELLA MURIS ANEMIA : VI. A LIPOID EXTRACT OF THE SPLEEN THAT PREVENTS BARTONELLA MURIS ANEMIA IN SPLENECTOMIZED ALBINO RATS

An aqueous lipoid extract of ox spleen was prepared which protects adult male albino rats of carrier stock in a large percentage of instances against Bartonella muris anemia following splenectomy. It is suggested that the extract contains a specific hormonal substance

STUDIES ON BARTONELLA MURIS ANEMIA : VII. THE PROTECTIVE ACTION OF COPPER AND IRON AGAINST BARTONELLA MURIS ANEMIA

The effect on Bartonella muris anemia of adding copper or iron or both to an adequate diet was studied. The addition to the diet of copper (0.1 mg. per rat per day), or iron (1 mg. per day), or both during a period of 2 days prior to splenectomy and 1 month subsequent thereto failed to protect adult albino rats against Bartonella muris anemia. The addition of copper to an adequate diet for a period of 10 days prior to splenectomy and 1 month subsequent thereto protected 75 per cent of the rats against the anemia. The addition of iron (1 mg. per rat per day) for a period of 10 days prior to and 1 month subsequent to splenectomy protected 50 per cent of the rats against this anemia. The addition of both copper and iron for a period of 10 days prior to and 1 month subsequent to splenectomy protected 75 per cent of these rats against Bartonella muris anemia. The addition of copper alone for a period of 2 months prior to and 1 month subsequent to splenectomy protected 63 per cent of the rats against Bartonella muris anemia. The addition of iron, or of both copper and iron during a period of 2 months prior to splenectomy and 1 month subsequent thereto protected about one-third of the rats against Bartonella murisanemia

STUDIES ON BARTONELLA MURIS ANEMIA : IV. PATHOLOGICAL CHANGES DURING THE ACUTE ANEMIA

The pathological changes that follow a severe infection with Bartonella muris in the adult or young albino rat are: First, those that result from the release of large quantities of cellular debris in the circulating blood. There is phagocytic activity and hyperplasia of the endothelial elements of the liver, thymus, lymph nodes and, in the young rat, of these elements in the spleen, with resultant capillary thromboses and focal necroses. Second, changes result from the anemia as such—fatty metamorphosis of heart, liver and kidneys. Third, there is a severe nephrosis and in some instances a degenerative process in the glomeruli. In the bone marrow hyperplasia of erythropoietic elements occurs

STUDIES ON BARTONELLA MURIS ANEMIA OF ALBINO RATS : III. THE PROTECTIVE EFFECT OF AUTOPLASTIC SPLENIC TRANSPLANTS ON THE BARTONELLA MURIS ANEMIA OF SPLENECTOMIZED RATS

Autoplastic splenic transplants were made in adult albino rats 4 weeks and 7 weeks prior to splenectomy and the protective effects against infection with the Bartonella muris anemia observed. 1. One-fourth of the spleen left in situ will protect adult albino rats against the Bartonella muris anemia. 2. Autotransplantation of splenic tissue in adult rats is successful in over 90 per cent of instances. 3. Autoplastic splenic transplants performed 7 weeks prior to splenectomy afford protection against Bartonella muris anemia in more than 50 per cent of instances, whereas 4 week old transplants do not protect. 4. A comparative histological study of the transplants of protected and unprotected rats reveals a regeneration of the pulp cells in the protected rats and an exhaustion destruction of the pulp in the unprotected rats. 5. The reticular cells play a specific rôle in protecting the adult albino rat against Bartonella muris anemia

THE EFFECT OF BILATERAL SUPRARENALECTOMY IN ADULT ALBINO RATS ON THE NATURAL AND ACQUIRED RESISTANCE TO BARTONELLA MURIS ANEMIA

Normal adult Wistar rats (non-carrier stock) are readily infected with Bartonella muris and develop a severe anemia if large amounts of infecting material are used. The normal adult rat of Wistar stock possesses a relatively high natural resistance to spontaneous infection with this organism. Bilateral suprarenalectomy in Wistar rats lowers the natural resistance to a subsequent infection with Bartonella muris. This procedure does not alter the type of tissue response to the virus but lowers the natural resistance of the rat to toxic effects of the infection. The acquired immunity to Bartonella muris conferred by a first infection is not broken down by subsequent suprarenalectomy. The mechanisms of acquired and natural resistance are dependent on different physiological processes in the organism and are not merely quantitative variations of the same process as is generally assumed

IMMUNOLOGICAL STUDIES IN RELATION TO THE SUPRARENAL GLAND : II. HEMOLYSIN FORMATION IN SUPRARENALECTOMIZED RATS.

In a large series of suprarenalectomized rats, hemolysin formation, to a fixed amount of sheep cells injected intraperitoneally (1 cc. of a 10 per cent suspension), was studied 48 hours, 7, 14 and 28 days after operation. The hemolysin formation was studied in suprarenalectomized rats injected 2 weeks following the operation, with one-twentieth and ten times this amount. Hemolysin formation in rats traumatized by tearing the perisuprarenal tissue and injected 2 weeks after the operation with 1 cc. of a 10 per cent suspension of sheep cells was studied and the results compared with those in the normal control rats. The effect of the operative procedure was controlled by removing one kidney in a series of rats and determining the antibody response to sheep cells. 1. Bilateral suprarenalectomy in rats subsequently injected intraperitoneally with 1 cc. of a 10 per cent suspension of sheep cells resulted in a depression of hemolysin titer during 5 weeks following the operation, the depression being most marked during the 1st week. 2. Bilaterally suprarenalectomized rats injected intraperitoneally 2 weeks after operation with 1 cc. of undiluted sheep cells gave hemolysin titers higher than did normal rats. 3. The quantity of antigen necessary to yield the maximum titer in suprarenalectomized rats 2 weeks after operation is ten times the quantity necessary to yield the same titer in normal rats. 4. Traumatization of the perisuprarenal tissue in rats produced the same effect on the antibody-forming capacity as suprarenalectomy

IMMUNOLOGICAL STUDIES IN RELATION TO THE SUPRARENAL GLAND : III. THE EFFECT OF INJECTIONS OF EPINEPHRINE ON THE HEMOLYSIN FORMATION IN NORMAL RATS.

The effect of subcutaneous injections of varying amounts of epinephrine on the hemolysin formation of normal adult albino rats was studied. In one group of experiments the rats received 0.4 mg. per kilo per day in two injections during 3 days prior and 4 days subsequent to the injection of sheep cells. Another series received the same daily amounts but only during 4 days subsequent to the injection of antigen. A third series received the same daily amounts only during 1 day prior and 2 days subsequent to the injection of sheep cells. In a second group of experiments smaller amounts of epinephrine were given during 3 days prior and 4 days subsequent to the injection of antigen. The amounts used were 1/5th, 1/20th, 1/40th, and 1/60th the daily quantity of epinephrine injected in the first group of experiments