Effect of chlorphentermine on hormone content and function of the adrenal cortex in rats.

Amphiphilic drugs like chlorphentermine induce a generalized lipid storage disease upon chronic application. The adrenal cortex is among the organs most heavily affected. We therefore determined the urinary corticosterone excretion during the treatment of rats with chlorphentermine and the corticosterone content of the adrenals and its blood level at the end of the treatment period. In addition, the responsiveness of adrenal cortex was tested by application of ACTH. During treatment, the corticosterone excretion declined considerably. Both the corticosterone content of the adrenals and the plasma level were found depressed at the end of a treatment period of 8 weeks. The ACTH evoked response was also diminished. The results indicate that the chlorphentermine-induced lipidosis is associated with a reduced corticosterone production of the adrenal cortex of rats. At present it cannot be decided whether the cortical insufficiency is causally related to lipidotic alterations of the cortical cells, or whether it is caused or additionally influenced by alteration at a higher level, e.g. hypothalamic centers or anterior pituitary.     

Effect of N-acylethanolamines on adrenal cortex function

The possibility of NAE to take part in the regulation of the function of adrenal glands was studied. It was shown that two times NAE (18:0) injection in a dose 5 mg/kg of weight increased the content of 11-hydroxysteroids in blood of intact male rats. NAE caused the raise of the blood hormone content by 4 times under the immobilization stress. It is apparent that augment of stress response under the influence of NAE in vivo is explained by the activation of hypophysis-adrenal cortex system. In vitro NAE lowered steroidogenesis by near 40%. One can suggest that this decrease is caused by membranotropic properties of NAE.     

Effect of the antioxidant dibunol and its combination with phenazepam on the behavior of rats in a conflict situation

The influence of dibunol, phenazepam used alone and combined on rat conflict behavior and rat blood and brain malonic dialdehyde content was studied. It was shown that dibunol exerts an unmarked anticonflict action that can be removed by bicuculline. Combined administration of dibunol and phenazepam potentiates appreciably the anticonflict effect. This permits reducing the doses of the drugs. The anxiolytic effect of dibunol alone and combined with phenazepam is attended by a decrease in the content of malonic dialdehyde in rat blood and brain, evidence of the reduction of the lipid peroxidation intensity.     

Effect of the antioxidant dibunol on the electron paramagnetic resonance signals in the tissues of rats of different ages

Changes in the intensity of EPR signals from the skeletal and heart muscles, liver, kidneys, thyroid, adrenal cortex, and blood were studied in relation to the animals age and the effect of the antioxidant dibunol. Essential changes were revealed in metabolic activity of the majority of the tissues under study as early as within the first 6 hours after antioxidant administration.     

Seasonal dynamics of cellular mitotic activity in the adenohypophysis and adrenal cortex of normal rats and under the stress reaction

The experiments have been performed in 162 white non-inbred male rats. The animals are sacrificed on the third week of every month between 11 A. M. and 13 P. M. Some essential changes in the mitotic coefficient (MC) are noted in the organs of the hypophysis-adrenal system during 1 year. In the intact rats adenohypophysis the MC reaches its maximum in March, and in September in drops to its minimal value. In the glomerular and the fascicular-retinal zones of the intact animal adrenal cortex, two periods with an elevated mitotic activity are noted during the annual cycle (in spring and in autumn). Formalin stress produces a decrease in the adenohypophysis, and in the fascicular-retinal zone of the adrenal cortex--an increase of the MC. In the fascicular-retinal zone there is not any reaction only in May and June. Perhaps, the reason is in some seasonal changes of reactivity of the zone mentioned to ACTH. The seasonal dynamics of the MC in the hypophysis-adrenal system organs is in general maintained under the stress.     

Reactions of the adrenal cortex and thyroid gland of hypophysectomized rats to hypothermia

Male Wistar rats were hypophysectomized 7 days (group 1) and 4-7 weeks (group II) before exposure to hypothermia (4 degrees C for 1 1/2 h). The hypophysectomized rats from group I were devoid of both the posterior lobe and the adenohypophysis, while the rats from group II had the posterior hypophysis but not the adenohypophysis regenerated. A decreased arginine-vasopressin (AVP) blood level in group I (32%) and a very high level of AVP in group II (311%, P less than 0.05) was determined by RIA. The exposure to hypothermia did not influence the AVP plasma level. The thyroid hypofunction was revealed morphometrically in both hypophysectomized groups. Nevertheless, cooling stimulated the thyroid glands in rats of both experimental groups, like it was in the control. Thus, there is no evidence that thyroid gland reaction to hypothermia is affected by AVP. Cooling caused an increase of corticosteroid blood and adrenal cortex content in nonoperated control rats as well as in group II, but not in group I of experimental animals. Hence, it may be assumed that when the adenohypophysis is ablated, a high AVP blood level is necessary to realize the adrenal cortex response to hypothermia.