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The blood serum of the pregnant mare has been found to contain large amounts of an ovary-stimulating substance (Cole and Hart, 1). We have some evidence that the urine of pregnant mares is relatively free of this factor.* It has been demonstrated that in the human the ovary-stimulating substance is more concentrated in the urine than in the blood serum. These facts suggested the possibility that the substances from the two sources, producing an apparently similar biological reaction in the rat, might be different in chemical or physical composition. Evidence has been obtained by Collip (2) which indicates that the ovary-stimulating material prepared from placenta may not be identical with the hormone in the urine of pregnant women. In the present investigation, an attempt has been made to determine some of the chemical properties of the ovary-stimulating factor present in mare serum during pregnancy. In this paper we have designated as the ovary-stimulating principle, from whatever its source, that factor...

ALTHOUGH EVANS ET AL. (i) and Hellbaum (2) reported the separation of mare serum into follicle stimulating (FSH) and luteiriiziing (LH) fractions, critical confirmatory studies are still lacking. Our inability to confirm these findings (3) led us to adopt a new approach to the problem; that is, instead of attempting to fractionate two types of gonadotropic hormones we endeavored to fractionate gonadotropic hormone from the inert material in mare serum. Using the method of purification proposed by Cartland and Nelson (4) together with an isoelectric precipitation procedure of our own, we succeeded in preparing extracts testing 4000 to 7000 R.U. per mg. total solids (5). In the original serum there were approxi′mately 2 to 4 R.U. per mg. total solids (the serum assayed 200 to 400 R.U. per cc.) as compared to 7000 R.U. per mg. in the best purified material.

From a quantitative standpoint calcium and phosphorus occupy a foremost place in the list of mineral elements needed by the vertebrate animal organism. The necessity for an adequate supply of these elements is particularly striking during the period of growth and during the lactation period. In pregnancy, the normal adult female, which, prior to the onset of this condition, may be in calcium and phosphorus equilibrium, is required to build new tissue for the fetus and at parturition must secrete milk for the nourishment of the young. Up to the age of weaning, all the food elements obtained by the offspring are derived from the mother’s milk. Experimental work dealing with calcium and phosphorus metabolism during pregnancy and lactation has been carried out chiefly on cows. A few experiments on humans have also been reported. It is well known that heavy producing cows are generally in negative calcium and phosphorus balance. Thus Forbes and his coworkers (1) found that in forty-nine balance trials during liberal milk production without exception all of his animals were in negative calcium balance. Supplementing the diet with additional calcium did not alter the negative balances, indicating that the ability of the animal to absorb calcium is limited. The calcium balances changed from negative to positive during the period of pregnancy when the cows were dry. The phosphorus balances were in most cases negative but not invariably so, indicating that the conditions for the assimilation of this

AMONG THE METHODS used for separating the gonadotropic hormone from pregnant mare serum, the fractional precipitation method of Cartland and Nelson (1) has proved most suitable, in our hands, for consistently yielding fractions of high potency with low nitrogen and solids content. We are now reporting some experiments upon the purification of the hormone obtained from very potent sera from pregnant ponies, testing 100 to 400 rat units1 per cc, together with some studies in which the starting material was obtained from less potent mare sera. The blood was collected from mares pregnant 65 to 75 days. The freshly drawn blood was defibrinated by whipping, and the serum obtained by centrifuging out the cellular constituents. Each batch of serum was worked up immediately; that is, treated according to the Cartland-Nelson process through the first precipitation of hormone by 70% acetone with the exception of two modifications.

In the course of an experiment in which sheep and cow rumen contents were being assayed for vitamin B6 by a modification of the method of Dimick and Schreffler1 we observed, in addition to the usual dermatitis of the face, ears and paws, ring-like (see plate I) lesions on the tail. This condition was first noted after the rats had been on the depletion diet for a period of 5 to 6 weeks and it developed in about 10 out of 100 animals used during the depletion period of approximately 7 weeks.The basal diets used had the following composition:In the first assay, using diet A. factor II was supplied by feeding 0.5 cc daily of a liver filtrate concentrate prepared from Lilly Liver Extract Powder 343∗ by 5 treatments with fuller's earth after the method of Lepkovsky, Jukes and Krause.3 The filtrate secured by this procedure was further treated with 8 volumes of 95% ethanol and the resulting precipitate was discarded. The final filtrate was concentrated under reduced pressure to the point where 1 cc represented ...

We have previously reported1 that there is an increase in concentration of glutathione in muscles of mature rats after 15 daily injections of a potent growth hormone obtained by alkaline extraction of beef pituitary. In control animals similarly treated with a heat inactivated solution of the hormone we found no such change. Analyses of the livers showed no significant change. However, if animals were sacrificed a few hours after a single injection of the potent hormone we found a decided fall in the glutathione concentration of the liver with only a slight change, if any, in the muscle glutathione. We have no explanation to offer for this sudden change in the liver but believe that it may furnish a method for estimation of the potency of the growth hormone that is more rapid than the usual method by measuring growth after 20 days of injection. It may prove to have a more important significance since by its use the fundamental biochemical reactions induced by the growth hormone may be studied quantitative...

Rhode Island Red embryos, destined to develop into adults of comparatively large size, proliferate cells at a faster rate than White Leghorn embryos, destined to develop into adults of comparatively small size.1 It is known that glutathione (sulphydryl) stimulates cell proliferation, and that rapidly growing rats and rabbits have a greater concentration of glutathione in their body tissues than less rapidly growing controls.2-3 Furthermore, fasted new-born rabbits which are destined to develop into large adults have a greater concentration of glutathione than those destined to develop into small adults.4The following experiment was performed in order to determine the glutathione concentration of White Leghorn and Barred Plymouth Rock embryos, and to ascertain whether or not a difference in concentration exists between the two breeds. Most of the Leghorns, and all of the Barred Plymouth Rocks used in the experiment were descendants of the stocks used by Asmundson and Lerner in studies on the inheritance of...

Rats were placed on a constant diet and periodic collections of excreta were analyzed in order to follow the calcium and phosphorus balances during the period of pregnancy and lactation. The diet was made alkaline by the addition of calcium carbonate. All of the necessary factors were included in the diet.After the onset of pregnancy and prior to parturition, the animals stored calcium and phosphorus in excess over that estimated to be contained in the litter at birth. During the period of lactation, the input of both calcium and phosphorus increased markedly, but this increase was not sufficient in most cases to account for the storage of these elements by the young. The animals were consequently in negative balance. Balances were carried out during 2 successive periods of pregnancy and lactation.Other experiments to determine the effects of variations in the reaction of the diet are in progress.