E. M. K. Geiling

Placental transfer of radioactive digitoxin in rats and guinea pigs.

Summary 1. Digitoxin, and possibly its metabolic products, crosses the placenta of rats and guinea pigs. 2. Larger amounts of both unchanged digitoxin and its metabolites were found in the fetuses of guinea pigs than in the fetuses of rats. 3. Embryonic tissue may have a marked ability to catabolize the drug, or there may be a selective penetration of the metabolites across the placenta, as noted by its high metabolite-digitoxin ratio. 4. On a tissue weight basis, digitoxin and its metabolites were found in higher concentrations in the embryonic heart than in the maternal heart.

Glycolysis in Trypanosoma equiperdum.

Conclusions Our experiments indicate that glucose is degraded into pyruvic acid through phosphorylative processes in a blood-free preparation of lysed Trypanosoma equiperdum.

Distribution of Melanophore-Dispersing Hormone in Anterior Lobe of Cetaceans and Armadillo.

Summary In the cetacean and armadillo hypophysis, the melanophore-dispersing hormone is found in greatest concentration in the antero-ventral region. The postero-dorsal (juxta-neural) region contains the lowest concentration. These findings accord well with those of DeLawder, Tarr and Ceiling and of Kleinholz and Rahn in the chicken hypophysis, in which the highest concentration of melanophore-dispersing activity was found in the anterior region of the gland.

Antidiuretic Effect of Posterior-Pituitary Extract in Completely and Partially Hypophysectomized Rats.

Summary Water diuresis in rats is greatly decreased both in rate and in quantity by complete hypophysectomy or by removal of the anterior hypophysis. Completely hypophysectomized rats are not suitable for the estimation of the antidiuretic principle of the posterior hypophysis. Rats after removal of the posterior hypophysis respond to the antidiuretic principle of the posterior-pituitary extract similarly as the normal animals.

Effect of Posterior Pituitary Extract on Water Up-Take in Frogs After Hypophysectomy and Infundibular Lesions.∗†

Summary The effect of posterior pituitary principles on the water up-take in hypophysec-tomized frogs is lower than in the normal. This applies not only to totally hypophysec-tomized frogs but also to those in which only the anterior or the posterior lobe is removed. After a wide lesion at the base of the third ventricle, the response to posterior pituitary principles falls off very sharply. When the third ventricle is merely punctured in the midline, the response decreases somewhat but not to the same extent as in the case of a wide lesion. A wide lesion at the base of the third ventricle results in a reduction of the same magnitude in response to posterior pituitary principles as does hypophysectomy.

Water and Electrolyte Content of Dolphin Kidney and Extraction of Pressor Substance (Renin)

Conclusions 1. The values for the water content and electrolyte concentrations of a normal dolphin kidney were as follows: Total water, 821.0 g; chloride, 65.3 mM; sodium, 84.2 mM; potassium, 56.8 mM; calcium, 1.53 mM; and magnesium, 6.3 mM per kg of fat-free tissue. 2. A pressor substance was isolated from the kidney of the dolphin which behaved chemically and physiologically like the renin prepared from the kidney of the dog or pig.

Effect of N-Allyl Normorphine on Excretion of G-14-Labeled Morphine in Mice

The use of X-allyl normorphine in the treatment of respiratory depression resulting from overdosage of morphine or one of its synthetic substitutes (1,2) has been indicated by the many favorable responses which have been obtained both experimentally and clinically. The practical application of this antagonism, however, precedes any reasonable explanation of the mechanism involved in the spectacular recoveries reported in the literature. The experiments reported here indicate that N-Allyl normorphine is capable of producing at least two secondary effects in intact, morphinized animals, in addition to central stimulation. These results were obtained in the course of studies on the excretion of C-14-labeled, biosynthesized (3) morphine, utilizing small amounts of the drug; the quantity of alkaloid was not sufficient to cause central depression of remarkable degree. Morphine has been shown to produce an antidiuretic response in experimental animals (4); the mouse shares this property of the alkaloid. This finding and other data suggested that a partial explanation of N-Allyl normorphines action might rest in an increased ability to excrete morphine, free or conjugated, by activation of renal or other mechanisms, thereby decreasing the time that the drug could exert its effects. Methods. Eight mice weighing 20 g each were injected intraperitoneally with 0.070 mg of C-14-labeled morphine base, each dose equivalent to 2100 counts (the specific activity of the compound isolated from Papaver somniferum was 30000 counts per mg per minute). Four of the animals were then injected intraperitoneally with 500 y of N-allyl normorphine (“Nalline”, Merck). The Straub reaction appeared in each animal approximately 2 minutes after injection of the C-14 morphine. The urine was collected hourly in glass metabolism cages and suitable aliquots of each sample were plated on copper discs and counted in open window, gas-flow counters; results are expressed as counts recovered per hour.

Effect of SKF Compound 525A on Excretion of Pentothal-S35 in Mice.

Summary Administration of SKF Compound 525A to mice (50 mg/kg, 75 mg/kg) prolongs significantly Pentothal-induced sleeping time, the duration of which is dependent on the dose of SKF-525A. The excretion of tracer amounts of Pentothal-S35 has been shown to be delayed by pretreatment with SKF-525A. Over a 7 hour period control animals excreted the maximum percentage of the injected dose (13.455%) within one hour, while treated animals retained S35 until the fourth hour after injection (11.228%). At the end of the 7 hour observation period, 31.1 and 30.08% of the injected doses were recovered from treated and control series, respectively. These observations are being extended to other barbiturates and the possible mechanism of action of SKF-525A.