Introduction
Bimonthly, started in 1957
Administrator
Shanxi Provincial Education Department
Sponsor
Taiyuan University of Technology
Publisher
Ed. Office of Journal of TYUT
Editor-in-Chief
SUN Hongbin
ISSN: 1007-9432
CN: 14-1220/N
Administrator
Shanxi Provincial Education Department
Sponsor
Taiyuan University of Technology
Publisher
Ed. Office of Journal of TYUT
Editor-in-Chief
SUN Hongbin
ISSN: 1007-9432
CN: 14-1220/N
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Effects of Hexavalent Chromium on Physiological Function of Heart， Skeletal Muscle and Sciatic Nerve Trunk of Bullfrog
DOI:
10.16355/j.tyut.1007-9432.20230627
Received:
Accepted:
abstract:
【Proposes】To investigate the toxicological mechanism of hexavalent chromium，the effects of hexavalent chromium on the heart，gastrocnemius muscle and action potential of sciatic nerve trunk in bullfrog were studied from the perspective of electrophysiology.【Methods】The bullfrog hearts were treated with different concentrations of potassium dichromate solution by intraperitoneal injection and isolated heart perfusion，and the effects of hexavalent chromium on heart rate and contractility in vivo and in vitro were determined. The gastrocnemius muscle was wrapped with a gauze soaked in potassium dichromate solution，and the contractility of gastrocnemius muscle was measured. The effect of hexavalent chromium on conduction velocity of sciatic nerve trunk was measured by extracellular electrode guidance.【Findings】The results show that potassium dichromate has an inhibitory effect on heart rate and contractility，and the mechanism may be related to the inhibition of T-type and L-type calcium channels activity by hexavalent chromium；However，1 mg/L chromium increases the heart rate of in vivo frog heart after 15 to 30 min，which may be due to the“hormetic effect”；0.001 to 10 mg/L hexavalent chromium has a concentration-dependent enhancement effect on gastrocnemius contractility，showing a positive inotropic effect，which may be the result of“hormetic effect”；Hexavalent chromium at 100 mg/L inhibits the gastrocnemius contractility，showing anegative inotropic effect，the mechanism is related to the inhibitory effect of hexavalent chromium on ryanodine receptor（RyR）；Hexavalent chromium reduces the conduction velocity of sciatic nerve trunk action potential in a concentration and time-dependent manner，and the mechanism was related to the inactivation of voltage-gated Na+ channels by hexavalent chromium.【Conclusions】Hexavalent chromium has toxicity on heart，skeletal muscle，and nerve，which could provide some electrophysiological experimental basis for the toxicity study of hexavalent chromium.
Keywords:
hexavalent chromium； contractility； conduction velocity of action potential； heart； skeletal muscle； sciatic nerve trunk;