Radioactive 86rubidium influx into red blood cells in essential hypertension in relation to the plasma renin activity.

Changes in several mechanisms of sodium transport across the cell membranes are described in essential hypertension. We studied ouabain-sensitive and insensitive 86Rb+ influx into the red blood cells (RBC) of 16 healthy controls and 51 patients with essential hypertension (EH) divided according to their plasma renin activity (PRA) in 3 groups: 11 patients with high PRA (HREH), 18 patients with normal PRA (NREH) and 22 patients with low PRA (LREH). In addition to studying 86RB+ uptake by patients RBC, we tested also the effect of the patients' sera on 86Rb+ influx into the RBC of healthy subjects.

Biochemical regulators in cardiac hypertrophy.

In recent years research has shown that muscle is capable of reacting to mechanical stimuli by altering biochemical processes. Myocardium is probably the source of a biochemical factor, or factors which activate myocardial protein synthesis. In experimentally induced cardiac hypertrophy adaptive alterations have been shown to occur not only in the adrenal medulla but also in the adrenal cortex.

[Blockade of estradiol benzoate hyperplasia of the adenohypophysis with Deprenon and lisuride - histological findings].

Three-week administering of Estradiolbenzoate to male rats results in hyperplasia of adenohypophysis with increase of Orange G slightly positive cells and chromophobe cells, loosening of structure giving a trabecular picture, and stressed vascularization. Simultaneous administering of Ergoline compounds (Deprenon, Lisuride) rather limited the transformation. However, the differentiation of single pituitary cells due to Estradiolbenzoate remained substantially uninfluenced.

Inhibition of the oestradiol-induced increase in adenohypophyseal weight and in hypothalamic and serum polyphenol oxidase activity by dopaminergic agonists.

The administration of oestradiol (oestradiol benzoate as an aqueous microcrystal suspension, Agofolin depot SPOFA, 1 mg i.m. twice a week) leads in rats to an increase in adenohypophyseal weight and in polyphenol oxidase activity in the serum (ceruloplasmin) and in the base of the brain (the floor of the third ventricle).

Reflections on what makes the heart grow.

Under conditions of experimental cardiac overload and hypertrophy in rats, a digoxinlike immunoreactivity appears in their serum which is correlated with cardiac growth. It is hypothesized that this is caused by the presence of an endogenous cardiotropic factor displaying cross immunoreactivity with digoxin. Additional evidence of the existence of the putative cardiotropic factor is provided by the finding that the sera of rats with cardiac overload displaying digoxinlike immunoreactivity stimulate the multiplication of rat cardiac myocytes in the tissue culture.

Aminoglutethimide, an inhibitor of adrenal steroidogenesis, blocks heart growth after ligation of the abdominal aorta and in hyperthyroidism in rats.

With reference to the indirect evidence showing that heart growth in the presence of a cardiac overload is modulated by the adrenal cortex, we studied heart reactions to overloading (ligation of the abdominal aorta or hyperthyroidism) with simultaneous administration of aminoglutethimide, an inhibitor of steroidogenesis. Aminoglutethimide (Elipten CIBA, 0.5% in the diet) markedly inhibited the growth reaction of the heart 14 days after ligation of the abdominal aorta (reducing the aortal blood flow to about 40%) or after the administration of dried thyroid (Thyreoidin SPOFA, 0.

Inhibition by an ergoline derivative (dopaminergic agonist) of oestradiol-induced adenohypophyseal growth and of the decrease in the hypothalamic ascorbic acid (HAA) concentration in rats.

The increase in adenohypophyseal weight and the decrease in the ascorbic acid concentration in the hypothalamus of rats injected i.m. twice a week with oestradiol benzoate as an aqueous microcrystal suspension in doses of 2.

Effect of alloxan diabetes on kidney growth in intact and castrated mice.

The mouse kidney is particularly responsive to the withdrawal or administration of androgens. The absence of endogenous androgens after castration led to decreased RNA synthesis and subsequent decrease in weight of the kidney. The induction of diabetes in 21 days castrated mice restored kidney weight.

Digitalis-like biological activity and immunoreactivity in chromatographic fractions of rabbit adrenal extract.

Dichloromethane extract of rabbit adrenals was subjected to thin-layer chromatography (Kieselgel 60F-254, MERCK) and digoxin immunoreactivity and digitalis glycoside-like biological activity were determined in the fractions by homogeneous enzymoimmunoassay and by inhibition of 86Rb uptake by red blood cells in vitro, respectively. Both the immunoreactivity and the biological activity maximum were present in two fractions which moved (in chromatography) between the corticosterone and deoxycorticosterone and showed a different RF from the deoxycorticosterone and aldosterone. In association with previous findings on digoxin-like immunoreactivity in the serum of animals with a cardiac overload, the possible existence of a cardiotropic steroid of adrenocortical origin is suggested.

Correlations between adrenal weight and heart weight in rats with a cardiac overload.

A significant positive correlation between heart weight and adrenal weight was found in rats with myocardial hypertrophy induced by experimental hyperthyroidism or ligation of the abdominal aorta. The simultaneous administration of digitoxin partly inhibited myocardial hypertrophy after ligation of the abdominal aorta, but not after experimental hyperthyroidism. Digitoxin also inhibited adrenal hypertrophy after ligature of the abdominal aorta but, again, not after experimental hyperthyroidism.

Modulation oestradiol effects by silver nitrate: inhibition of the adenohypophyseal reaction, block of the ceruloplasmin increase and block of hypothalamic ascorbic acid depletion.

Chronic oestradiol treatment (1 mg oestradiol benzoate, as an aqueous microcrystal suspension, i.m. twice a week for 6 weeks) produces in rats increased thyroxine-binding capacity of the adenohypophyseal proteins in vitro, an increase in the ceruloplasmin (polyphenol oxidase) level in blood and a decrease in the hypothalamic ascorbic acid concentration.