Otto Rosenthal

PHOTOCHEMICAL ACTION SPECTRUM OF THE TERMINAL OXIDASE OF MIXED FUNCTION OXIDASE SYSTEMS.

The reversal of the carbon monoxide inhibition by bands of monochromatic light was determined for the oxidative demethylation of codeine and monomethyl-4-aminopyrine and the hydroxylation of acetanilide by rat liver microsomes and for the hydroxylation of 17-hydroxyprogesterone at carbon-21 by bovine adrenocortical microsomes. Maximum reversal occurred at 450 millimicrons, the light absorption maximum of the CO compound of the CO-binding pigment of microsomes. The agreement between photochemical action spectrum and spectrophotometric difference spectrum supports the conclusion that the CO-binding pigment is the terminal oxidase of mixed function oxidase systems of mammals.

Adrenal cortical regulation of the distribution of water and electrolytes in the human body.

Marked disturbances of fluid and electrolyte distribution have been reported to accompany experimental adrenal insufficiency. Swingle and his associates (1-4), studying the development of acute adrenal insufficiency in dogs, noted that the external loss of sodium and water appeared to be quantitatively inadequate to account for the observed dehydration and hemoconcentration. They concluded that adrenal cortical hormone renders intracellular water and electrolytes available for replenishment of the depleted extracellular fluid in adrenal insufficiency (3, 4). More recently, other studies in dogs have shown that a large decrease of the inulin space follows adrenalectomy (5), and that the calculated loss of sodium and chloride from the mannitol and thiocyanate spaces during acute adrenal insufficiency consistently exceeds net external loss (6). Internal transfers of water and electrolytes are therefore indicated. Analyses of the soft tissues of animals of various species dying in acute adrenal insufficiency have, however, been consistently reported to indicate either no change or an actual decrease of cellular sodium in all soft tissues studied, although cell water and potassium are said to be increased (7-11). The intracellular migration of water has generally been assumed to be a passive osmotic process resulting from extracellular hyponatremia (8, 9, 10). Bone has been suggested as a possible site for the sodium transferred from the mannitol space, but

Steroid Formation by Adrenal Tissue from Hypertensives

The adrenal cortical hormones have been thought to play a role in the pathogenesis of hypertension for the following reasons: 1) Hypertension is a characteristic finding in Cushings disease; 2) large doses of desoxycorticosterone (DCA) and salt administered to Addisonian patients produce hypertension (1); 3) hypertensive patients who developed Addisons disease had blood pressure falls to normal limits which were restored to previous levels with DCA(2) ; and 4) 80 per cent of the patients with severe hypertension have had significant improvement for three to seven years following 90 to 100 per cent adrenalectomy and limited sympathectomy (3). Moreover, animal experiments (4, 5) have shown that hypertension following renal artery occlusion cannot be produced in the absence of adrenal cortical steroids. Despite these observations, altered adrenal function in hypertension has not been clearly demonstrated. While mean levels of cortical steroids in blood and urine (6-9) are not elevated in hypertensive patients, disturbances in salt and water metabolism observed in early hypertension prior to the development of renal damage by Green, Johnson, Bridges and Lehmann (10) and BraunMenendez (11) indirectly support the idea that the pattern of adrenal corticoids is altered. Brady (12) found that slices of canine adrenal tissue produce large quantities of steroids when incubated in vitro in autologous plasma and proposed the measurement of steroid formation in vitro as a direct assessment of the functional ca-

[29] Adrenal steroid hydroxylases

Publisher Summary This chapter discusses the general procedures used in the laboratories for separating mitochondria and microsomes from the adrenal cortex of steers and for preparing a reaction medium for the hydroxylase assays. The chapter summarizes the most common steroid assays. Modifications of these procedures are pointed out on the individual hydroxylase preparations. The chapter discusses miscellaneous enzyme activities of microsomal preparations. The chapter concludes with a discussion on the species distribution of steroid 21-hydroxylase. Although the steroid 21-hydroxylase is presumably present in the adrenocortical endoplasmic reticulum of all vertebrates that produce 21-hydroxylated corticoids, there are few data available on the specific activity of the microsomal fraction.

[96] Methods of determining the photochemical action spectrum

Publisher Summary If the degree of promotion or inhibition of a biological reaction by bands of monochromatic light of equal quantum intensity is plotted as a function of wavelength of irradiating light, a photochemical action spectrum results, which depicts the light absorption spectrum of the biocatalyst responsible for the light sensitivity of the reaction. The essential technical requirements for this method are a light source from which, monochromatic bands of sufficient intensity can be isolated, and a radiometer for the accurate measurement of the quantum energy of the bands. Carbon arcs, high pressure xenon lamps, and projector type metal filament lamps furnishes continuous spectra convenient for scanning a broad spectral range with the same light source and for resolving details of the action spectrum. Xenon lamps and tungsten filament lamps are presently the preferred sources of continuous spectra. The metal vapor lamps are mainly used to provide reliable reference points for the photochemical action spectrum, and they do not permit the resolution of every detail of the spectrum. The energy of the irradiating light is usually measured with thermopiles or bolometers. The photochemical action spectrum is usually determined at infinitely small light absorption of the reaction system in order to ensure that every enzyme molecule along the light path is exposed to the same intensity of radiation. The determination of the photochemical action spectrum of CO derivatives of the respiration enzyme is based on the assumption that the distribution of the enzyme between O 2 and CO. The chapter also discusses the determination of photochemical activation and inactivation spectra of various biocatalysts.

Quantitative evaluation of primary adrenal cortical deficiency in man

Abstract 1.1. A method designed to afford a quantitative appraisal of adrenal cortical functional capacity has been devised. It consists of a two-fold test: (1) a standard metabolic regimen capable of provoking acute adrenal insufficiency in the severely adrenal-deficient individual; and (2) powerful adrenal cortical stimulation by means of intravenous corticotrophin. 2.2. Classification of patients into one of four separate grades of adrenal cortical functional capacity is proposed on the basis of multiple criteria of response to each portion of the test. Intrinsic and extrinsic grounds for confidence in the accuracy of the method are presented.