Current determination of lithium-induced minimum sodium requirement in rats

Lithium administration raises the minimum sodium requirement of the organism. Lithium treated-rats drink spontaneously a hypertonic sodium chloride solution and thereby protect themselves against the toxic effects of lithium. In the present paper it was studied whether the consumption of sodium chloride can be used as a quantitative measure of the sodium requirement. Rats given different amounts of lithium with food for about 2 months were given free access to water and a 0.46 M NaCl solution, and the 24-h intake of the latter was followed. It was found that the consumption of hypertonic sodium chloride increased with the lithium dosage and the serum lithium level. The consumption showed the following characteristics: (a) It was sufficient to prevent death from lithium poisoning. (b) When access to hypertonic chloride was discontinued for 48 h, the rats lost body weight; the body weight was reestablished within 1 h when the rats again had access to sodium chloride solution. (c) When sufficient amounts of sodium were given with the food, the lithium-treated rats drank no more sodium chloride solution than did the control rats. (d) When lithium administration was discontinued, the consumption of sodium chloride solution fell within 10 days to the control level. (e) The lithium-treated rats developed polyuria, but this was not the cause of the extra intake of sodium chloride. (f) The lithium-treated rats did not drink more of the hypertonic sodium chloride solution than was necessary to cover the minimum sodium requirement. The results indicate that the intake of hypertonic sodium chloride solution can, in fact, be used as a measure of the minimum sodium requirement in lithium-treated rats.

Effect of prolonged lithium ingestion on the response to mineralocorticoids in rats

The effect of long-term lithium administration on the response to mineralocorticoids was studied in rats which were adrenalectomized in order to avoid the effects of endogenous hormone. The hormone response was estimated from the changes in urinary excretion of sodium and potassium in rats on low and high sodium intake and from the consumption of a hypertonic NaCl solution by rats given a free choice between this and demineralized water. Lithium was found to lower the response to aldosterone and deoxycorticosterone acetate both in acute and chronic experiments. It was further found that in adrenalectomized rats given no hormone, those given lithium consumed significantly more NaCl solution than those given no lithium. The experiments therefore provide evidence that lithium induces a sodium requirement beyond that induced by the inhibition of the response to mineralocorticoids.

The narrow vestibular aquaeduct. An unspecific radiological sign?

Tomography of the vestibular aquaeduct was carried out in patients with Ménière's disease, patients with chronic otitis and in patients without ear disorders. Visualization of the vestibular aquaeduct was evaluated blindly. The descending part of the aquaeduct was clearly visible in 95% of patients without ear disease. In the other groups, including contralateral non-affected ears in Ménière patients, the aquaeduct was clearly visible in only about 50%. The incidence of narrow or invisible aquaeducts in ducts in Ménière patients and in patients with chronic otitis was essentially the same. This radiologic finding seems to be an unspecific sign, present possibly in a variety of ear disorders.

Two complex translocations in chronic granulocytic leukemia involving chromosomes 22, 9, and a third chromosome

Among 13 Ph-positive cases of chronic granulocytic leukemia (CGL), banding studies revealed two with complex rearrangements involving translocation of the long arm of number 22 to another autosome and a segment of that chromosome translocated to the long arm of number 9. In a patient with both CGL and sickle cell anemia, the 3-way rearrangement involved chromosomes 5, 9, and 22; and he also had a second Philadelphia chromosome and two constitutional variants: pericentric inversion of the other number 9 chromosome and satellite polymorphism in the G group. The karyotype of the leukemic cells was interpreted as: 47,XY,inv(9) (p11q13),t(5;9;22)(q13;q34;q11)+del(22)(q11). In the second patient, the complex translocation in the Ph-positive cells involved chromosomes 3, 9, and 22, resulting in a karyotype interpreted as: 46,XX,t(3;9;22)(p21;q34;q11). Several reports indicate that an abnormality of chromosome 9 is not essential for the development of Ph-positive CGL, but the very high frequency of its involvement (including these unusual translocations) suggests that some type of non-random somatic association may exist between 9q and 22q which makes simultaneous breakage likely. Attempts to correlate specific types of pH chromosome rearrangements with the clinical course of CGL must await the identification of more cases and longer follow-up.

Coronary disease in familial hypercholesterolemia

A report of 20 years' experience with coronary disease in 11 Danish families with hypercholesterolemia and normal serum triglycerides is given. A significantly higher death rate was found in family members who inherited the trait of hypercholesterolemia than in those who did not. The death rate of hypercholesterolemic family members was significantly higher than that found in all other persons of their age and sex living from 1943 to 1964 in Denmark; the death rate for the normocholesterolemic families was not. Most hypercholesterolemic family members died from coronary disease and at an earlier age than is usual for persons with coronary disease in Denmark. There was nothing to indicate that increase in triglycerides rather than increase in cholesterol is related to coronary disease in these families. No environmental factor was found to account for the higher death rate among the members with hypercholesterolemia.

Anaphylatoxin in its relation to the complement system

The fifth component of complement that reacts hemolytically in the guinea pig or rat complement system, C'3b, is intimately associated with the generation of anaphylatoxin. Anaphylatoxin was formed (i) if this purified component reacted with a washed, intermediate complex consisting of antigen, antibody, and the first four components of complement; (ii) if the component was treated with trypsin; or (iii) if the component was incubated with a material isolated from cobra venom together with a fraction from serum other than complement. The significance of this fifth component as anaphylatoxinogen is discussed, and a common mechanism is proposed for the generation of anaphylatoxin in whole serum.