Elva G. Shipley

Myotrophic activity of 19-nortestosterone and other steroids determined by modified levator ani muscle method.

Summary An 8-day rat levator ani muscle assay for myotrophic activity is presented. Preliminary steroid screening results indicate that 19-nortestosterone and other 19-nor analogs of androgens promise to be effective protein-anabolic, and relatively weak androgenic agents. Using the same dose levels of 19-nortestosterone and testosterone, equal myotrophic responses were produced, yet 19-nortestosterone showed only weak androgenic activity and testosterone exhibited strong androgenic activity. Androsterone possesses relatively strong androgenic and only weak myotrophic activity.

Evidence for a Sodium Retaining Factor in Toxemia of Pregnancy.

Summary A marked rise in excretion of a sodium retaining factor has been observed in toxemic pregnancies in both diabetic and non-diabetic patients. The increase has been observed in one patient before other toxemic symptoms have become evident. No parallel increases in 11-oxysteroid excretions were found in these patients.

A Biological Method for Determining Small Quantities of Sodium Retaining Substances.

Summary 1. A practical micro-bioassay technic for desoxycorticosterone acetate activity is proposed, using albino, urethra-ligated, bilaterally adrenalectomized, male rats of 150-155 g weight. 2. A calibration curve is demonstrated using desoxycorticosterone acetate as the standard hormone and the percentage sodium retained as the measure of its activity. Two μg DC A injected subcutaneously in 2 stages produce a highly significant retention of administered sodium. 3. The proposed bioassay requires 30 lapsed hours and a minimum of special technical skills and apparatus, but a high degree of sensitivity and a satisfactory degree of precision are indicated. 4. No consistent correlation was found between urine volume changes and DCA dosage levels. A significant change in urine volume was observed with 4 μg DCA relative to the control group of animals, but not with the higher or lower doses of DCA studied.

Estrogenic and gonadotrophic hormone inhibiting activity of some adrenal cortical substances.

Summary Lipo Adrenal Cortex and desoxycorticosterone acetate were found to stimulate uterine growth and to inhibit pituitary gonadotrophic hormone secretion when administered to female rats in relatively small amounts. Adrenal Cortex Extract partially inhibited gonadotrophin secretion but was less than one fourth as effective as the Lipo Adrenal Cortex. Large doses of Compound E failed to inhibit the gonadotrophin secretion. The secretion of gonadotrophic hormone is inhibited in immature rats by steroids in amounts less than those which result in uterine growth.

Enzymes in the tissues of alloxan-diabetic rats.

Abstract 1. 1. Data have been presented comparing the activities of anaerobic glycolysis, the tricarboxylic acid cycle, pyruvate oxidation, succinic dehydrogenase, glutamic dehydrogenase, and aspartic-glutamic transaminase in tissues of normal and alloxan-diabetic rats. 2. 2. Of the above enzyme systems, all except glutamic dehydrogenase were found to be increased significantly in the livers of alloxan-diabetic rats. 3. 3. The succinic dehydrogenase activities of corpora lutea of lactation, brain, and kidney of diabetic rats were normal. Likewise, the activity of aspartic-glutamic transaminase in kidney and heart was unaltered in the diabetic animal. 4. 4. The increases in activity of the various enzymes in the liver of the diabetic rat are discussed with regard to changes in metabolism occurring in diabetes.

Shock Produced by the Application of Tourniquets to the Hind Limbs of Rats.

Summary 1. A method for producing tourniquet shock in rats is described. The method yields graded and reproducible results. 2. The percentage survival of rats to tourniquet shock was progressively decreased as the time of tourniquet application was increased. Following 3% hours of tourniquets 100% of the rats survived, while after 4 hours of tourniquets only 3% survived. 3. Rats which had tourniquets applied for 4 hours with periods of release for 1 to 6 hours, followed by a second application of tourniquets, showed 100% in contrast to 3% survival for those without replacement, while 87.5% survived when the tourniquets were replaced after 7 hours. 4. The degree of hemoconcentration developing in rats in tourniquet shock was approximated by hemoglobin determinations. Increases in hemoglobin ranged between 27 and 52%.

Biological method for determination of glucocorticoid activity of crystalline compounds and urine extracts.

Summary A practical bioassay technic for glucocorticoids is proposed, using the adrenal-ectomized, 21-day-old male rat as test animal. The method offers the accuracy and precision shown by the use of the young adult rat, and the sensitivity and economy observed in methods using the laboratory mouse. Dose-response curves have been established for cortisone and for the assay of urine extracts. The regression lines for the two substances are parallel, indicating the method is valid for measurement of glucocorticoid excretion. It is suggested that this bioassay method may serve as a valuable adjunct to the chemical methods for the assay of urinary corticoids.

The Production of Shock in Rats by the Drum Method.

Summary 1. Varying degrees of shock can be produced in rats by subjecting them to various periods of trauma in Noble-Collip drums. The method appears to be suitable for use where graded and reproducible degrees of trauma are desired. 2. The percentages of survival were: for 5 minutes of tumbling, 100%; for 8 minutes, 65.6%; for 10 minutes, 71.4%; for 12 minutes, 47.2%; for 13 minutes, 9.5%; and for 15 minutes, 4.3%. 3. The Sprague-Dawley strain and a cancerresistant strain of rats were found to be less resistant to trauma of the Noble-Collip type than were rats used by other investigators. 4. Survival of previous hemorrhage did not increase resistance to Noble-Collip trauma, but appeared to decrease resistance to some extent. 5. Adrenal enucleation decreased the resistance of rats to Noble-Collip trauma although regeneration of cortical tissue had been sufficient to support normal growth and to maintain the rats in a healthy state. 6. Protection to the abdomen and taping of the paws gave only limited protection to the rats of the Sprague-Dawley strain subjected to Noble-Collip shock.