Biomedical subjects

M Artino-Rădulescu

Publications and source records attributed to M Artino-Rădulescu.

5 recordsLinked to original sources

PubMedDate not supplied

Coagulation and fibrinolysis in rats after confinement hypokinesia.

Our previous experiments (14) (15) dealt with the dynamic of the fluid-coagulant equilibrium in rats after exposure to confinement hypokinesia (CHK) at different time intervals, 1, 3, 7, 21, 28 and 35 days. We found a decreased Quiq and Howell time (QT and HT) in some relation with the time of exposure, with a tendency to normalization after 21 days. The same evolution was shown by the number of thrombocytes and of the euglobulin lysis time (ELT). In this work we prolonged the exposure to CHK for 60 days, an interval after which a series of other functional parameters significantly approached initial control values (16). We found an important approach to normal values also with the QT, HT, Elt and with the number of thrombocytes. Concomitantly, the plasma concentration of corticosterone (the principal glucocorticoid of rats), that increased over shorter intervals, approached also control values after 60 days of exposure to CHK. Nevertheless, it can not explain the changes of coagulability, because it decreases after adrenalectomy but the QT, HT and thrombocytes are already decreased. For these and other reasons it results that the relation of adrenal hormones to coagulation needs be further clarified.

Adrenal Cortex Hormones↗

PubMedDate not supplied

Blood coagulation and fibrinolysis in hyperthermic rats.

Exposure of rats to an environment of +40 degrees C that increases central (rectal) temperature to about 40 degrees C, importantly decrease the number of thrombocytes, the blood coagulation (the Quick time and Howel time) and euglobulin lysis time (ELT). In order to search for the mechanism responsible for coagulability and fibrinolysis we studied the relations of these changes with the sympatheticoadrenergic system and with the adrenal hormonal secretion. Some parameters were thus explored after adrenalectomy and under the influence of a beta-blocking agent, Eraldin. Adrenalectomy moderately reduced these decreasing effects, excepting the ELT. Eraldin has a contrary effect. Adrenalectomy acts by suppressing the corticoid reaction and by diminishing the catecholamineones. Since Eraldin influences coagulation and fibrinolysis in an opposite sense than adrenalectomy, it may be concluded that catecholamines do moderate the effect of heating, inhibiting and not stimulating circulation, as assumed. On the contrary, corticoids (gluco- or mineralo-) contribute to the effect, influencing coagulation in hyperthermia. Both influences are slight, not determinant. Supplementary explorations revealed that repeated daily exposure for 1-2 or 3 weeks, simply in the cages in which hyperthermia was subsequently produced, decreased also the number of thrombocites, the QT and the ELT, especially the last one. The HT was less influenced. It results that these exposures, produced effects similar with hyperthermia. Heating rats after these daily repeated exposures does not influence these already changed parameters.

Adrenal Glands↗

PubMedDate not supplied

Blood coagulation and fibrinolysis in rats after hypokinesia and hyperthermia.

Coagulation and fibrinolysis were studied in rats exposed to hypokinesia (HK) obtained by including rats (for 1, 2 and 3 weeks) in small cages designed to limit their movements, permitting only spontaneous feeding (a method widely used for mimicking space flight conditions). The number of thrombocytes, the Quick time, the Howell time and the euglobulinlysis time (ELT) decreased after 1 and 2 weeks of HK; however, after 3 weeks, the parameters of coagulation approached normal control levels, while ELT was still significantly under the control values. An increased blood level of corticosterone in animals subjected to HK suggested that changes observed in the blood coagulation could be linked with it. After exposing rats to heat, similar changes were noticed, i.e. thrombocytopenia and an increase in the speed of coagulation and fibrinolysis. When hyperthermia was induced in hypokinetic animals (after 1 and 2 weeks of HK), the association of exposure to HLK and heat was not followed by a cumulative response.

Animals↗

PubMedDate not supplied

Blood coagulation and fibrinolysis after confinement hypokinesia.

Our previous studies dealt with the dynamics of the fluid-coagulant equilibrium in rats after confinement hypokinesia (CHK) for 1, 2 and 3 weeks obtained by placing them in small cages permitting only slight movements for spontaneous feeding. We found an acceleration of blood coagulation and fibrinolysis, with a maximal response after 1-2 weeks. In this work attention focussed on the initial more dynamic interval of 1, 3 and 7 days of exposure to CHK. To find certain relations between the central vegetative stimuli and the peripheral responses, experiments were done on normal and adrenalectomized rats and plasma corticosterone, the main glucocorticoid in these species, was measured. CHK accelerated the Quick and the Howell time (QT and HT) and euglobulin lysis time (ELT) progressively, beginning with the first day of exposure. Adrenalectomy as such shortened these parameters, demonstrating an inhibitory action of corticoid hormones in normal conditions. Exposure to CHK of adrenalectomised rats emphasizes these inhibitions. We did not found evident correlations between plasma corticosterone and these processes. The number of thrombocytes had a similar evolution, but in adrenalectomised and CHK rats they increase.

Adrenal Glands↗

PubMedDate not supplied

Hydroelectrolytic changes caused by prolonged clinical recumbency.

Investigations effected in 16 subjects of 20-69 years at bed rest after bone fractures demonstrated, in an interval of 10-27 days after surgery, normal plasma sodium concentration and a decreased urinary elimination, an increased plasma potassium concentration but a decreased urinary output. The osmotic changes were not significant. The plasma vasopressin activity was increased. Three urinary aldosterone determinations showed an increased output. The serum calcium level was within normal limits but its urinary output was initially slightly decreased, contrary to its augmented elimination after simple voluntary bed rest, as results from literature. The hydroxyproline elimination was increased, demonstrating an active collagen metabolism.

Adult↗