Zinc metabolism in diabetes was studied in depancreatized dogs and alloxan diabetic rabbits.
Urinary zinc excretion was markedly increased 4 or 5 days after the onset of diabetes and it maintained a relatively constant value of a five-to eight-fold increase so long as the diabetic state lasted. The magnitude of an increase of urine zinc in the experimetal animals was approximately equal to that observed in severe diabetic patients. Improvement of diabetic conditions tended to regain a normal pattern of zinc excretion.
There was also obtained the finding of an early and transient increase in zinc excretion which occurred immediately after administration of alloxan. Evidence has been obtained that such early and transient increase is not related to alloxan per se but to metabolites of alloxan such as purpureate and alloxanic acids. The diabetogenic action of alloxan has been discussed in the light of the present experimental findings.

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Urinary zinc excretion was confirmed to be markedly increased in patients with diabetes mellitus. The magnitude of an increase of zinc in urine was well correlated with the severity of diabetes. Day-to-day variations of the 24 hour excretion of zinc in diabetic patients were found to be considerably slight. An effective treatment with insulin or antidiabetic sulfonylurea tended to restore a normal pattern of zinc excretion. These data could be interpreted in the light of the finding that the augmentation of chelating agents always results in an increase in urinary zinc excretion. The augmentation of endogenous chelating agents has been briefly discussed with reference to its influence upon the islets of the pancreas.

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Two types of culture method, tissue explant culture and single cell culture, were employed in cultivation of the rat anterior pituitary. In the single cell culture, cells proved to maintain the histological features similar to the pituitary cells in vivo, indicating that this technique can be used for studying the function of the pituitary cells in vitro.
The addition of the crude hypothalamic extract made from normal or castrated mature rats into the culture induced increases in gonadotropin contents of both culture fluid and cells. By the treatment of the culture cells with the extract, the cytoplasmic granules stained with Giemsa showed an increase in number and the reaction of the cells to PAS became positive. Neurohypophyseal hormones did not show the gonadotropin-increasing effect.
It is thus concluded that the hypothalamic extract contains substance which is capable of stimulating directly the anterior pituitary cells to secrete gonadotropin. The nature of this active material remains obscure.

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1) One case of primary aldosteronism was reported. Adenoma of the left adrenal was confirmed on operation.
2) In incubation experiments, overproduction of aldosterone and corticosterone was noted in the adenomatous tissue while cortisol and cortisone were produced only small amounts.
3) The non-adenomatous tissue of the removed adrenal produced aldosterone about 1/3 the adenomatous tissue, although it produced more than normal adrenal tissue. The production of corticosterone, however, was very low.
4) When corticosterone-4-C¹⁴ was added to an incubation medium with slices of adenoma, biosynthetic conversion of the radioactive steroid to aldosterone was greatly enhanced, 5 times as much as in the non-adenomatous tissue. Thus, an autonomous increase of the activity of 18-hydroxylase is reasonably considered.
5) Histologically, hyperplasia was found in zona glomerulosa of the nonadenomatous portion of the removed adrenal cortex, suggesting some stimulating factor which continuously promotes a secretion of aldosterone. The pathogenesis of primary aldosteronism was discussed from a viewpoint of a renal stimulating factor.

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A new method has been developed for measuring the adreno-cortical suppressive action of corticosteroids.This method rests on measuring in vitro steroidogenesis brought about by a standard dose of ACTH in the adrenals of rats treated with various doses of steroids. According to the obtained results, calculated as pharmacological and therapeutical equivalents, hydrocortisone and prednisolone possess similar efficiency, where, the action of dexamethasone is approximately twice higher.
Accuracy of the method has been checked by the aid of statistical evaluation.

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Sialoadenectomized 60-days-old male rats of Donryu strain were administered with the high-, middle-and low-dose of parotin, E-8, an extract of bovine parotid gland containing the alpha-parotin and saliva-parotin-A (SPA) respectively for 1 week or for 6 weeks. From sialoadenectomy no influences were imposed upon the body-weight growth, but the administrations of three compounds, if the amount used was appropriate, made a slight increase in body-weight growth both of sialoadenectmized and of sham operated control rats. The administration of an appropriate dose of parotin and E-8 for 6 weeks also stimulated slightly the body-weight growth of sialoadenectmized rats, and more profoundly than in the administration for a week; while every dose of these compounds were capable to stimulate more vigorously in the control than in the operated rats. In general, SPA was inferior in exciting ability to parotin; E-8 was superior to parotin.
Histologically, sialoadenectomy did not induce any signs of atrophy in the tibial epiphysis within a week, but resulted in the atrophic pattern within 6 weeks. In rats with or without the salivary glands, the compounds could retard the postnatal involution in tibial epiphysis, especially in the primary spongiosa. This retarding action was most prominent in E-8 and most feeble in SPA. The changes in body-weight growth tended to be in parallel to the degree of atrophy in tibial epiphysis, above all in the primary spongiosa.

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A new assay method for thyrotropic hormone (TSH) based on the in vitroiodination of thyroglobulin, is presented. After incubation of hog thyroid slices for 15mins. in a modified Krebs-Ringer phosphate buffer containing 0.05μgI/ml of iodide labeled with I¹³¹ and TSH, the radio-activity in the protein fraction of slices was measured and utilized as an index of TSH activity. The usable range of this assay was 1 I.mU./ml to 30 I.mU./ml of TSH and the index of precision varied from 0.15 to 0.30. Effects of temperature, pH and constituents of the medium upon the response were studied.

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The ultrafine structure of the contact region between the infundibulum and Pars tuberalis of the anterior pituitary was investigated in rats, and following results were obtained.
1) Pars tuberalis of the anterior pituitary consists of several layers of relatively small and variously shaped cells with large nuclei and conspicuous cell membrane. They contain neither secretory granules nor vacuoles except sparse mitochondria.
2) Around both the capillary loops and the capillaries of the primary plexus of the portal vessels, a wide pericapillary space is always present. Its maximal width measures several micra. Collagen fibrills and numerous extremely fine granules are distributed in this space, and fibroblasts as well as the endfeets of glial processes are also occasionally observed.
3) The external layer of the infundibular wall consists of numerous fibres with various calibre range. Most of these fibres are nothing but the processes of the astro lia which contain very few cytoplasmic element. The presence of nerve fibres in this layer was asccrtained. They are arranged verticaliy to the outer limiting surface of the external layer and thus parallel to each other. In addition to the sparse mitochondria, they contain a large number of small vesicles. The vesicles measure about 300-500Å in diameter and even the maximal diameter does not exceed 1000Å. They resemble “synaptic vesicles”. The fibre which contains neurosecretory granules of high electron density could not be found in the external layer.
These characteristic structures of the contact region strongly support the concept that some chemical substance (s) is released from the nerve endings in the external layer of the infundibulum into the capillaries in the median eminence. Although the small vesicles described above, which might be regarded as the morphological representation of this chemical substance, are similar in many respects to the so-called “synaptic vesicles”, the final conclusion on the nature of the small vesicles cannot be derived at present. From the present observation, however, it is very likely that, even if the small vesicles are not identical with the synaptic vesicles, but are of neurosecretory nature, they are somewhat different in character from the ordinary neurosecretory granules contained in the nerve axons of the hypochalamo-neurohypophyseal tractus.

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