Observations have been made following the administration of KClO4, MMI TU and MTU for 2 or 7 weeks and KI for 3 weeks in drinking water to adult male rats and relation between the change in the weight of the salivary glands and the iodine metabolism has been examined using radio-iodine. The results are as follows:
1) The inhibition of iodine metabolism by the thyroid gland did not always result in the decrease in the weight of the salivary glands. There seems to be little evidence of the direct relationship between the function of the thyroid gland and the salivary glands from this experiment.
2) The significant iodide concentration by the salivary glands was not observed in the normal animals, and also the antithyroid drugs employed had no influence upon the concentration.

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The ultraviolet absorption of the perchloric acid-soluble fraction in digested parotin by trypsin and chymotrypsin rapidly increased within 1hr. and showed the maximum rate of digestion after 3hrs. of incubation. At the ultraviolet estimation, the use of perchloric acid as protein-precipitating reagent was proved more preferable than trichloroacetic acid.

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The hydrolyzates in the digested parotin by trypsin were separated into the 3 fractions by the isoelectric precipitation and acetone fractionation: the pH 4.5-precipitate, the insoluble fraction in the acetone of 80% concentration, and the soluble fraction in the same solvent. The first pH 4.5-precipitate was relatively pure in view of the paper electrophoresis and the paper partition chromatography, and showed the same biological activities as the parotin before digestion. The 80% acetone-insoluble fraction was the mixture of some hydrolyzates and showed only the leukocyte increasing activity. The 80% acetone-soluble fraction contained many hydrolyzates and was negative in the biological activities.

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Both the calcium activity and the leukocyte activity of parotin were relatively resistant to the action of chymotrypsin, and remained even after 7hrs. of digestion. The ultraviolet absorption of the perchloric acid-soluble fraction in digested parotin by chymotrypsin rapidly increased within 1hr. owever the shift of the isoelectric point of parotin as seen in the tryptic digestion was not seen by the chymotryptic digestion.
The following 3 fractions were separated from the parotin digested for 3 hrs.; the precipitate yielded at its isoelectric point, pH 5.4, an insoluble fraction in 80% concentration of acetone, and a soluble fraction in this acetone solution.Among these 3 fractions only the first, pH 5.4-precipitate, showed all biological activities.

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The nucleic acids contents in the mammary glands were measured in an attempt to estimate the extent of involution during normal lactation, the effect of nonremoval of milk and further the effects of administration of progesterone, prolactin or simultaneous pregnancy on the mammary glands in mice undergoing the unilateral ligation of nipples. The results obtained were as follows.(1) The decline of mammary function began to occur from day 14 of lactation towards day 26 because of not only the quantitative decrease of total amount of mammary parenchymal tissues but also the qualitative decrease of mammary synthetic activity.(2) Mammary gland proliferation might be actively stimulated by concurrent pregnancy.(3) Mammary function might be more susceptible to such inhibitory factor as accumulation of milk in the declining stage than in the peak stage of secretory activity.(4) Six or 12 days after unilateral ligation of nipples on day 14, involution due to cellular atrophy occurred in the ligated side whereas hyperplasia and hypersecretory function might be evoked in the unligated side, supposedly by frequent removal of milk.(5) Although atrophic figure otherwise occurring in the ligated side 6 days after unilateral ligation could be recovered by the administration of progesterone and prolactin or the concurrent pregnancy, the latter most effectively, the removal of secretion might be necessary to maintain the mammary gland in a full functional state. These findings were in quite agreement with the author's previous results.

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The effects of purified saliva-patorin-A on the development of 9-day chick embryo femora growing in vitro were studied. Pair-mate bones were cultivated for 6 days by the roller-tube culture method without plasma. One of each pair was grown in the medium consisting of 1 part of chick embryo extract, 2 parts of horse serum and 7 parts of saline solution, and another in the plus-purified salivaparotin-A medium.
The longitudinal growth of the bones was determined from measurement of the over-all length recorded every day throughout the cultivation period. The dry weight of the bones was also obtained. The degree of calcification of the bones was estimated from determination of the phosphorus deposited as bone salt. Finally the formation of cartilage matrix was evaluated from estimation of the amount of hydroxyproline in the acid hydrolysate of the bones.
These experiments resulted in the following;(a) on the longitudinal growth of the bones, purified saliva-parotin-A exhibited a slightly stimulative tendency at concentrations of 0.05 and 0.1μg/ml, (b) on the dry weight and the amount of hydroxyproline, no clear directed change was found within the concentrations ranging from 0.01 to 10μg/ml and a marked decrease was observed at concentration of 50μg/ml, (c) on the amount of phosphorus, however, evident increase was found over a wide range of concentration from 0.01 to 1.0μg/ml, while at concentration of 50μg/ml a marked decrease was seen.
From these findings it was suggested that purified saliva-parotin-A has a direct stimulative effect selectively upon calcification of the bone under certain optimal condition, though the overdoses of it retard the over-all growth of the bone.

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1. Glucocorticoids, cortisol and prednisolone, inhibited the ACTH effect in vitro. At the concentration of about 10^-5M of glucocorticoid, the ACTH effect was almost completely inhibited, but this inhibitory action was not observed below the concentration of 10^-6M. The inhibitory action on the ACTH effect of glucocorticoid could be removed by a previous addition of ACTH.
2. Tetrahydrocortisol, methyltestosterone and estradiol-17β did not inhibit the ACTH effect. Estradiol-17β increased the production of corticosterone in an ACTH-free medium.
3. It was suggested that the inhibitory action of glucocorticoid might be based on the result of inhibited metabolism of phosphorous in the adrenal cortex.
4. The data obtained indicate a possibility that the inhibition of the pituitary adrenal system following the administration of corticoids occurs not only at the level of the pituitary but also at the level of the adrenal cortex.

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Mature mice, acclimatized in a low ambient temperature at -5±1°C, were exposed to the extreme cold at -30--35°C and the survival time was determined. The mice were treated with various preparations during acclimatization or immediately before the exposure.
The results obtained are as follows: 1) The time required for acquisition and disappearance of acclimatization to cold was less than 1 week. 2) Prednisolone increased the survival time of mice when treated before exposure, while it decreased the cold tolerance probably due to adrenal suppression when treated during acclimatization. 3) DOCA was without effect. 4) Thyroxine increased the survival time regardless of the time of medication, whereas methylmercaptoimidazole decreased it when treated during acclimatization. 5) Chloropromazine increased the cold tolerance directly, while reserpin was without effect. 6) Castration appeared to increase the cold tolerance. 7) The survival time of the male mice was longer than the female. 8) Androgen was without effect, while estrogen increased the cold tolerance when treated during acclimatization of the castrated mice of both sexes.

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(I) Determination of insulin was examined by the rat-diaphragm method, and the following results were obtained: A linear regression was observed between extraglucose uptake and log-concentration of insulin in the range of 10 to 0.01mU/kg. The minimum detectable concentration was 0.003mU/ml, slope of regression line (regression coefficient) b=0.6610, standard deviation of regression line S=0.1674, index of precision λ=0.253 (intervals between consecutive doses, 10-fold).
(II) Plasma insulin activity in 14 normal fasting dogs, estimated by this method was 0.347±0.184mU/ml. Change in plasma insulin activity was observed after administration of insulin, glucose and BZ 55 (N-sulfanylyl-N'-n-butyl-carbamide) with the following results:
1. After intravenous administration of 1U/kg of insulin, plasma insulin activity increased from 0.229mU/ml before to 4.655m, U/ml at 10mins. became 0.645mU/ml at 30 mins. after.
2. After subcutaneous administration of 0.2-0.8U/kg of insulin the results were as follows: In case of 0.2U/kg, plasma insulin activity always remained in the normal range; but in the case of 0.6U/kg, it increased significantly after the injection. The minimum dose of insulin in subcutaneous injection which produced increase in plasma insulin activity was 0.4U/kg.
3. After the intravenous injection of 1g/kg of glucose, 0.347mU/ml before the injection became 0.933mU/ml at 30mins., indicating increase.
4. After intraperitoneal administration of 50mg/kg of BZ 55, 0.287-0.382mU/ml before the injection became 0.180mU/ml at 1hr. and 2hrs. After the intravenous administration of 100mg/kg, 0.471mU/ml before the injection became 0.336mU/ml at 1hr., 0.283mU/ml at 2hrs. and 0.301mU/ml at 4 hrs. In all the cases, there was no significant difference in plasma insulin activity between before and after the administration.
(III) No significant effect of BZ 55 was observed in vitro experiments on the basal uptake and insulin effect by the isolated rats diaphragm.

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