Walter Marx

Specificity of the Epiphyseal Cartilage Test for the Pituitary Growth Hormone.

Summary 1. Purified anterior hypophyseal hormones other than the growth hormone were administered to hypophysectomized rats for a period of 4 days and measurements made of the width of the uncalcified portion of the proximal epiphyseal cartilage of the tibia. 2. While adrenotropic hormone slightly decreased the cartilage width, thyroxin and the thyrotropic as well as the mammotropic hormones caused slight enlargement of the epiphyseal cartilage. The effect was smaller, however, than the response caused by a single growth hormone unit, at all dose levels tested, and the effect did not show gradation with dosage which is a characteristic of the growth substance.

Synergism between thyrotropic and growth hormones of pituitary. Body weight increase in hypophysectomized rat.

Summary Purified pituitary growth hormone, when given in combination with purified pituitary thyrotropic hormone, is markedly increased in its capacity to stimulate body weight gain in the hypophysectomized rat. Since the thyrotropic preparation, given alone at the same dose level, is almost free of intrinsic growth-promoting potency, this action must be considered more than additive, and would appear to constitute a true synergistic effect.

Effect of Growth Hormone on Glycosuria of Fed Partially Depancreatized Rats.

Conclusions It has been shown that a purified growth hormone preparation of the anterior pituitary which is practically free of lactogenic, adrenocorticotropic, thyrotropic, and gonadotropic hormones, produces a marked increase in glucose excretion in the sucrose-fed partially depancreatized rat.

Effect of Pituitary Growth Hormone on the Thymectomized Rat

Summary 1. The growth in body weight of female rats thymectomized at the age of 8 days and followed to the age of 6 months is the same as that of sham operated littermate controls. 2. The response of hypophysectomized-thymectomized female rats to a preparation of the pituitary growth hormone is the same as that of similarly treated hypophysectomized littermate controls which had been subjected to a sham thymectomy. 3. The response of plateaued thymectomized female rats with intact pituitaries to a potent growth hormone preparation of the anterior pituitary is the same as that of sham operated littermate controls. 4. Under the conditions of this experiment, therefore, the thymus gland was not necessary either for the growth in weight of otherwise normal animals or for the marked increase in body weight produced by the administration of anterior pituitary growth hormone.

Rate of Inactivation of Equine Encephalomyelitis Virus (Eastern Strain) Relative to H ion Concentration.

Detailed studies of the pH stability range of infectivity of plant viruses, summarized recently by Stanley, 1 show that for each virus studied there is a well defined region where infectivity is relatively stable. On both sides of this region infectivity is lost in a regular way so that the curve plotted to relate infectivity with pH of the medium is smooth and trapezoidal. Certain of the animal viruses 2 , 3 appear to behave in a like manner. It was entirely unexpected, then, when conditions were encountered under which the virus of equine encephalomyelitis (Eastern Strain) seemed to behave in a different way. The experiments were made on virus propagated in chick embryos. 4 Virus-infected embryos were “harvested” when moribund and ground with sand in hormone broth to a 10% suspension. Centrifuged free of sand and gross tissue particles, the whole extract was mixed with composite buffer solution (0.05M) of various pHs. 2 , 3 Mixtures were maintained between 0°C and 5°C, and after various intervals, usually 1 hour, 1 day, and 1 week, portions were removed for test. The pH of each was readjusted approximately to neutrality and virus infectivity determined by titrations in decimal dilutions in mice. 5 pH was determined and frequently checked with the glass electrode. Four such experiments covering the range from pH 1.0 to pH 12.0 have shown essentially uniform results, and one is summarized in Fig. 1. The curve after 1 hour is similar in contour to those of other viruses, the region of greatest stability lying between pH 3.5 and pH 11.5. After 1 week, maximum stability is at pH 7.5 to pH 8.5, while a second region of relative stability is apparent between pH 3.5 to pH 5.0.

Renin Substrate and Angiotonase in Dogs' Lymph and Plasma.

Summary Cervical lymph and plasma from normal dogs were compared as to their contents of renin substrate and angiotonase. It was observed that renin substrate occurs in similar concentrations in both lymph and plasma, but that the quantity of angiotonase present in lymph is considerably less than that in plasma.

Lack of Effect of Growth Hormone on Deposition of Radiostrontium in Bone.

Summary Hypophysectomized rats treated with growth hormone and consequently in a state of rapid growth, deposited in femur and mandible, when injected with radioactive strontium, essentially the same amounts of strontium, as did untreated hypophysectomized control rats injected simultaneously with the same amount of radioactive strontium.

Cataphoretic Separation of Toxic Components of Moccasin Venom.

Attempts at separation of the various active components of snake venoms have not been very successful. These principles are probably proteins or substances closely related to proteins. 1 They are quite unstable. 1 , 2 For this reason, chemical procedures used in their separation, such as precipitation, extraction or absorption often resulted in the destruction of the less stable elements. Separation of the hemorrhagic and hemolytic components of moccasin venom by cataphoresis was attempted because it was thought that this procedure might be less destructive. This method had been tried by others without success in an attempt to separate the neurotoxic and coagulant principles of Bothrops venom 3 and the neurotoxin and hemolysin of cobra venom. 4 In the present studies, a cataphoresis chamber was used as described by Todd. 5 An electrical potential of 120 volts D.C. was applied to solutions of moccasin venom for 3 to 5 hours at different hydrogen ion concentrations. The liquids in the anode and cathode chambers were then tested for hemorrhagin and hemolysin. The hemorrhagin was assayed by using the intradermal venom test in rabbits. 2 It was found that at pH values of 6 and above, the hemorrhagin migrated only to the anode, below pH 4 only to the cathode. Very little migration occurred in the neighborhood of pH 4-5. This indicated that the isoelectric point of the hemorrhagic component of moccasin venom was between pH 4 and 5.

Absence in Lymph of Capillary Permeability Factors in Traumatic Shock.

It has been postulated by various investigators 1 that in traumatic shock, substances increasing capillary permeability are liberated in the injured tissues. It might be expected that such substances appear in the lymph draining the traumatized region in higher concentration than in blood, In an attempt to demonstrate such factors, canine lymph was collected during shock and tested in rabbits for its effects on capillary permeability. Shock was produced by vigorous intestinal massage, peripheral circulatory collapse being verified by blood pressure, hematrocrit and autopsy observations. Lymph was obtained from a duct lying between the first and second intestinal nodes, prior to massage, and shortly before death during the period of permanently depressed blood pressure (below 70 mm Hg.). simultaneously femoral vein blood was drawn for plasma and serum samples. Permeability effects were determined in rabbits according to Menkins method 2 (intradermal injection of 0.1 cc samples of test fluids, followed by intravenous injection of 2.0 cc per kg of a 1% saline solution of Trypan Blue). In an initial series of 12 dogs and 15 rabbits, in which heparin was used as anticoagulant, the skin reactions did not show any significant difference between the responses to control and to “shock” fluids: a slight to a marked increase in permeability occurred with each type of fluid. Heparin controls were negative. In a second series of 12 dogs and 6 rabbits, in which defibrinated fluids were tested without heparin, again no differences were observed between reactions to control and to shock samples; in these instances the responses were only slight or negative. Similarly, both control and shock fluids caused practically the same degree of extravasation of dye in a third series of experiments using 8 dogs and 8 rabbits, in which the non-protein fractions of lymph and of plasma were compared after the proteins had been removed by acetone precipitation.