These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: The Bezold-Jarisch-like effect induced by veratridine and its potentiation by scropion toxin in the rat. Author: Chianca Júnior DA, Cunha-Melo JR, Freire-Maia L. Journal: Braz J Med Biol Res; 1985; 18(2):237-48. PubMed ID: 3830286. Abstract: The Bezold-Jarisch-like effect (BJE) induced by 2.5 micrograms/100 g of veratridine injected intravenously or into the left ventricle was studied in anesthetized rats. The possible potentiation of the effect by a small dose (10 micrograms/100 g) of a purified scorpion toxin (tityustoxin) was also investigated. Heart rate (HR), electrocardiogram (ECG), mean arterial pressure (MAP) and respiratory rate (RR) were recorded. Intravenous (iv) injection of veratridine induced a BJE consisting of slight bradycardia in 4 out of 8 experiments, fall of MAP (from 107 +/- 3 to 90 +/- 4 mmHg) and apnea. The control RR was 105 +/- 5 insp/min and apnea, after veratridine, lasted 8 +/- 2 s. The BJE evoked by injection of a second dose of veratridine was potentiated 20 min after an iv injection of tityustoxin. The HR decreased from 334 +/- 16 to 108 +/- 17 beats/min, the MAP fell from 110 +/- 5 to 68 +/- 4 mmHg and the control RR of 92 +/- 5 insp/min was followed by a long period of apnea (68 +/- 17 s). Injection of veratridine into the left ventricle (lv) evoked a BJE characterized by slight bradycardia in 5 out of 10 experiments, arterial hypotension (from 110 +/- 6 to 89 +/- 6 mmHg) and tachypnea (from 82 +/- 6 to 102 +/- 7 insp/min). The effects induced by a second dose of veratridine were potentiated 20 min after an lv injection of tityustoxin. The HR decreased from 377 +/- 14 to 119 +/- 18 beats/min, the MAP fell from 119 +/- 5 to 72 +/- 10 mmHg and the RR increased from 80 +/- 6 to 117 +/- 9 insp/min. This tachypnea was followed by bradypnea 20 s later (21 +/- 6 insp/min). The ECG showed that hypotension induced by iv or lv injections of veratridine coincided with a slight sinus bradycardia before tityustoxin (N = 9) and A-V block after the toxin (N = 18). Cervical bilateral vagotomy prevented the cardiac and respiratory effects induced by lv veratridine in tityustoxin-treated rats, but a slight hypotension was still recorded (from 114 +/- 10 to 94 +/- 10 mmHg, P less than 0.05). Injection of veratridine (2.5 micrograms/100 g) into the ascendent aorta evoked a slight hypotension (from 105 +/- 6 to 87 +/- 7 mmHg, P less than 0.05) and tachypnea followed by bradypnea, but bradycardia was not recorded.(ABSTRACT TRUNCATED AT 400 WORDS)[Abstract] [Full Text] [Related] [New Search]