Influence of Beta-Endorphin on Oxygen Activity of Neutrophils and Total Antioxidant Status in Rats after Chronic Administration of Methimazole

Abstract

The aim of the study was to evaluate the effect of β-endorphin on oxygen activity of polimorphonuclear neutrophils and to investigate the total antioxidant status of blood serum in rats subjected to chronic treatment with methimazole. The study was carried out on 15 male Wistar rats weighing 270-290 g, divided into two groups. The animals from experimental group were administered a 0.05% drinking water solution of methimazole. The oxygen activity of peripheral blood neutrophils was examined using a modified RBA test. The extra-receptor effect of β-endorphin on the respiratory burst of neutrophils was evaluated. The incubation of neutrophils in the presence of phorbol myristate acetate (PMA) in the control group caused a nearly threefold increase in the oxygen activity of the cells compared to the control. Slightly higher values were obtained after addition of β-endorphin at the concentration of 10 -6 . Lower concentrations of this opioid (10 -8 and 10 -10 ) also stimulated oxygen activity but at a lower level than PMA. Naloxone did not affect the oxygen activity only when using β-endorphin in the concentration of 10 -6 . Naloxone and β-endorphin in the concentrations of 10 -8 and 10 -10 evoked a linear decrease in the oxygen activity of neutrophils, below the values obtained for PMA. The obtained results suggest that methimazole significantly modulates the generation of reactive oxygen species under the influence of β-endorphin, which stimulates the respiratory burst via the receptor pathway and inhibits it via the extra-cellular pathway. Methimazole also stimulates the anti-free radical defence.

Pituitary-testicular axis dysfunction in methimazole-induced hypothyroidism in rats

“…It may attend cases of inappropriately conducted treatment of hyperthyroidism with methimazole (the treatment of choice) or with other antithyroid drugs (7, 14). This disease causes numerous multisystemic complications, not sparing the gonads; however, there are few studies that might explain its impact on testicular function, and none of them accurately defines the type of hormonal imbalance in the pituitary-testicular axis (1, 4, 6, 9-11, 20, 27). Ai et al .…”

Neuroprotective Effects of Cornus officinalis on Stress-Induced Hippocampal Deficits in Rats and H2O2-Induced Neurotoxicity in SH-SY5Y Neuroblastoma Cells

“…β-endorphin is an endogenous opioid that acts as a stress-relieving factor [41]. The opioid system plays an important role in regulating the pro-oxidative and anti-oxidative balance [42]. In this study, serum β-endorphin levels was significantly increased after immobilization stress.…”

Elastographic and morphological testicular changes in hypothyroidism – an experimental study

“…This was despite an increase in flexibility of the testes. Our earlier data suggested that methimazole significantly modulates the production of reactive oxygen species, or stimulates the mechanisms of anti-free radical defence and that this is one of the protective actions of this medicine, whereas oxidative stress is an important cause of testicular damage and infertility in males (10, 22).…”

“…In the course of many pathological metabolic conditions, these properties change and can influence the biophysical features of organs. Iatrogenic hypothyroidism, as a major clinical problem especially in people, cats, and other animal species which are treated with methimazole or other antithyroid drugs, influences numerous functions (3, 4, 10, 11, 12, 16). Naturally occurring hypothyroidism, as a systemic disease, leads to pituitary and testicular damage, especially during hypogonadotropic hypogonadism; however, other reasons for these conditions, such as testicular functional changes, have been found (7, 8, 16, 24).…”