The cause of venous ulceration.

Glycolytic control mechanisms. i. inhibition of glycolysis by acetate and pyruvate in the isolated, perfused rat heart.

It has been reported from this laboratory that under the proper experimental conditions corticotropin is capable of modifying metabolic processes in the mouse and rat through mechanisms other than by stimulating the secretion of steroid hormones by the adrenal cortex (1-5). Similar observations have been made by Astwood (6). The metabolic responses to adrenocorticotropic hormone (ACTH) in both intact and adrenalectomized animals bear a striking similarity to those induced by growth hormone (Table I) and some have also been elicited with the thyroid stimulating hormone (2, 3). Available data so far do not support the notion that these common metabolic actions are due to impurity of the hormone preparations used, with either growth hormone or some as yet unidentified \"metabolic\" hormone being the common contaminant. Elsewhere the hypothesis has been proposed that the sharing of a variety of metabolic activities by pituitary hormones may simply reflect the fact that the tropic hormones serve as growth and metabolic hormones for their target glands in addition to being specific stimulators of hormone synthesis and release (3). Since the pathways for growth and general metabolism presumably are largely the same in almost all tissues it should not be surprising to find that the tropic hormones might be capable of influencing metabolism in tissues other than their target glands. The specificity of the tropic hormones might then relate either to a greater affinity of the hormone to the target gland or, alternatively, to a greater sensi-

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Lipolytic Action of Corticotropin on Rat Adipose Tissue In Vitro

Publisher Summary This chapter analyzes the physiological mechanisms involved in the migration of marine and amphihaline fish. It reveals that the combination of external and internal factors is particularly evident in downstream migration, in the regions of young Atlantic salmon. In a given sector of a Pyrenean stream, young salmon acquire the characteristics of the smolt—either at the end of the first, the second, or the third year—which clearly demonstrates the essential intervention of a physiological preparation; the speed at which it occurs depends on genetic traits inherited from the parents, because they are apparently all submitted to the same environmental conditions. However, in the spring, if the level of the stream remains the same when smoltification has been accomplished, migration only occurs sporadically, individually, or in small groups; but as soon as the water level rises—however, slightly as a result of a spring flood— then an absolute rush takes place, carrying down thousands of individuals. Fishes respond to a temperature gradient by choosing a given temperature (thermopreferendum)—which appears to be the optimal one for a given physiological state—and there exists—at least in the sockeye salmon ( Oncorhynchus nerka )—a behavioral thermoregulation, the consequence of which is to ensure a maximal bio-energetic yield.

Physiological Mechanisms in the Migration of Marine and Amphihaline Fish

Some Hormonal Influences on Fat Mobilization from Adipose Tissue

Based on the observation that only insulin will increase the concentration of glycogen in rat adipose tissue both in the presence and the absence of the pancreas, evidence for insulin secretion in response to growth hormone treat-ment was sought by measuring adipose tissue glycogen levels in fed intact and eviscerated rats. It had previously been shown that growth hormone had no influence on adipose tissue glycogen in 48-hour fasted rats, but the pancreas of these animals may be presumed to have been depleted of insulin. In fed rats given 2 ml. of 50 per cent glucose by stomach tube both insulin and growth hormone brought about significant increases in the glycogen content of the dorsal interscapular brown fat pad. Acutely eviscerated rats, which lack the pancreas, showed no accumulation of adipose tissue glycogen in response to a subcutaneous glucose load compared to intact controls unless given insulin.

Evidence for stimulation of insulin secretion by growth hormone in the rat1

Some extra-adrenal actions of corticotropin on carbohydrate metabolism in the rat.

Corticotropin has been found to share with growth hormone the capacity to diminish the accumulation of blood urea nitrogen consequent to the intravenous infusion of an amino acid solution (protein hydrolysate) into acutely adrenalectomized nephrectomized rats maintained with hjdrocortisone. Milligram for milligram ACTH is as active as growth hormone. The nitrogen retaining action of ACTH is abolished by boiling in 0.1N NaOH but not by more gentle treatment with NaOH. ACTHactivity is destroyed by oxidation with hydrogen peroxide but can be restored by incubation with cysteine, in keeping with other adrenal and extra-adrenal activities of ACTH.Growth hormone activity is not definitely destroyed by H2O2 treatment. It is concluded that the above action of ACTH on nitrogen metabolism is another extra-adrenal action of ACTH which is sharedwith growth hormone but cannot be accounted for by contamination of the ACTH with growth hormone, or vice versa.

An effect of corticotropin on urea formation in adrenalectomized-nephrectomized rats.

IN A previous report (Engel, Hewson and Cole, 1954) it was shown that the administration of sodium fluoroacetate (SFA) to the fasted rat resulted in the development of a striking hyperglycemia and ketonemia beginning in a few hours and most apparent in 24 hours. However, no observations were made beyond the latter time. The ketonemia and hyperglycemia were explained in terms of primary and secondary responses to the block in the tricarboxylic acid cycle caused by the SFA. Ketonemia, thus, was considered a consequence of failure of oxidation of acetate as well as of acetoacetate itself with resultant accumulation of the latter compound. The hyperglycemia was interpreted as secondary to a decrease in hexokinase activity resulting from a declining supply of high energy phosphate from the impaired Krebs cycle. In addition the possibility was considered that Krebs cycle blockade might interfere specifically with insulin synthesis by the beta cells of the islets of Langerhans and hence insulin deficiency might ...

Sodium fluoroacetate diabetes: correlations between glycemia, ketonemia and tissue citrate levels.

THE occurrence of large amounts of androgen in the urine of humans with adrenogenitalism resulting from adrenal cortical neoplasia is well known (1). Little is known concerning the hormone content of the tumors themselves. Except for the report of Slot (2), who found in the tumor of a patient with adrenogenitalism a “ quantity of male and female hormone not more than in organs (for instance liver) of normal people,” the authors are not aware of any attempts to correlate the hormone content of the tumor with that of the urine. The present study consisted of hormonal analyses of urine before and after operation and of the tumor removed at operation from a 7-year-old female with adrenogenitalism. METHODS Urinary and tumor extract measurements were made by the following methods, appropriately modified wherever necessary in the case of the tumor extracts: 17-ketosteroids by the method of Drekter, Pearson, Bartczak and McGavack (3); corticosteroid by the method of Lloyd and Lobotsky (4); pregnanediol by the met...

Joan Fredericks

Papers

Evidence for stimulation of insulin secretion by growth hormone in the rat1

Some extra-adrenal actions of corticotropin on carbohydrate metabolism in the rat.

An effect of corticotropin on urea formation in adrenalectomized-nephrectomized rats.

Sodium fluoroacetate diabetes: correlations between glycemia, ketonemia and tissue citrate levels.

Hormone studies in a case of adrenogenitalism due to neoplasm of the adrenal cortex.