The relation between the effect of a subhypnotic dose of thiopental on claw pain threshold in rats and adrenalin, noradrenalin and dopamine levels

Abstract

Thiopental sodium (TPS) needs to be applied together with adrenalin in order to establish its analgesic effect in general anesthesia. We aimed to investigate the effect of TPS on the claw pain threshold in rats and evaluated its relationship with endogenous adrenalin (ADR), noradrenalin (NDR), and dopamine (DOP) levels. Intact and adrenalectomized rats were used in the experiment. Intact animals were divided into the following groups: 15 mg/kg TPS (TS), 0.3 mg/kg ADR+15 mg/kg TPS (ATS) and 0.3 mg/kg ADR alone (ADR). Adrenalectomized animals were divided into the following groups: 15 mg/kg TPS (A-TS), 0.3 mg/kg ADR+15 mg/kg TPS (A-ATS) and 0.3 mg/kg ADR alone (A-ADR). Claw pain threshold and blood ADR, NDR, and DOP levels were measured. The TS group’s claw pain threshold was found low. However, the claw pain thresholds of the ATS and ADR groups increased significantly. In the A-TS group, the pain threshold decreased compared with normal, and in the A-ATS and A-ADR groups, the pain threshold increased. TPS reduced the blood ADR levels in intact rats; however, no significant changes were observed in the NDR and DOP levels. #TPS provides hyperalgesia by reducing the production of ADR in rats. The present study shows that to achieve analgesic activity, TPS needs to be applied together with ADR.

The effect of thiamine and its metabolites on peripheral neuropathic pain induced by cisplatin in rats

“…For this reason, chemotherapy-induced PNP models have gained importance when they are directed toward the prevention of the side effects of cancer drugs. In recent years, the paw withdrawal test has been widely used as a method of pain evaluation [ 2 , 20 ]. In particular, the reason for choosing the paw withdrawal test to assess chemotherapy-induced PNP is that neuropathic pain first appears in this region [ 28 ].…”

“…Increases in MDA were reported in the cisplatin-induced peripheral neurotoxicity model, whereas tGSH levels were decreased [ 33 ]. Recent studies have also suggested a significant link between pain/analgesia and oxidant/antioxidant parameters [ 2 , 9 ]. In the present study, increased amounts of IL-1 β and MDA and a decreased amount of tGSH were observed in the blood serum of the rats given cisplatin.…”

The effects of ketamine and thiopental used alone or in combination on the brain, heart, and bronchial tissues of rats

“…Thiopental administered at subanesthetic and anesthetic doses leads to oxidative stress in the brain striatum, likely because of the suppressed production of adrenaline, which causes systemic hypotension and associated high-risk complications [ 18 ]. Published studies have shown that, unlike ketamine, thiopental suppresses release of catecholamines [ 36 ] and decreases the amount of adrenaline in rats even at subanesthetic doses [ 16 ]. Furthermore, it was reported that hyperalgesia occurred in the animals receiving thiopental alone, while analgesia was observed in the animals receiving thiopental combined with adrenaline.…”

“…However, no studies were found in the literature demonstrating that thiopental induces oxidative stress in heart tissue. Unlike ketamine, thiopental decreases the release of adrenaline, blood pressure, and cardiac pulse power [ 16 , 17 ]. These negative effects (hypotension) increase the risk for myocardial infarction [ 18 ].…”

“…The second compound for which we investigated effects on the tissues of the heart and brain as well as on bronchial tissues is thiopental [ 15 ]. Unlike ketamine, thiopental reduces the amount of endogenous adrenaline, noradrenaline, and dopamine in animals [ 16 ]. Thiopental use decreases systemic blood pressure [ 17 ], potentially leading to high-risk complications such as hypotension and cerebral vascular events [ 18 ].…”