Cardiovascular effects of anatoxin-A in the conscious rat

Toxicology and Applied Pharmacology
A L Sirén, G Feuerstein

Abstract

The effects of anatoxin-A on mean arterial pressure (MAP), heart rate, cardiac index (CI), and blood flow (BF) in hindquarter (HQ), renal (R), and mesenteric (M) vascular beds were studied after intravenous (iv) and intracerebroventricular (icv) administration in the conscious rat. The pharmacological profile of anatoxin-A was further compared to nicotine administered iv and icv. MAP and heart rate were measured from femoral artery, CI by thermodilution method, and blood flow by Doppler velocimetry. Anatoxin-A and nicotine (30, 100 and 300 micrograms/kg iv) produced an increase in MAP with concomitant bradycardia. The highest doses increased CI. MBF and RBF decreased due to a vasoconstriction in M and R vasculature. These effects were attenuated by the ganglion blocker chlorisondamine (5 mg/kg, iv). Anatoxin-A (100 micrograms/kg, iv) increased plasma epinephrine levels by 2-fold with virtually no effect on norepinephrine whereas nicotine (100 micrograms/kg, iv) increased plasma epinephrine and norepinephrine by 20- to 30-fold. Central administration of anatoxin-A and nicotine (30-100 micrograms/kg icv) increased MAP with no effect on heart rate and produced M and R vasoconstriction. In summary, the present study demonstrates th...Continue Reading

References

Jan 1, 1979·Toxicon : Official Journal of the International Society on Toxinology·W W CarmichaelM A Peterson

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Citations

Aug 1, 1992·Toxicon : Official Journal of the International Society on Toxinology·O M Adeyemo, A L Sirén
Sep 1, 1992·Journal of Toxicology and Environmental Health·E BermanJ E Simmons
Apr 24, 1999·Human & Experimental Toxicology·J K FawellD J Everett

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