Cardiovascular responses to noradrenaline in the rat before and after administration of various anaesthetics

Abstract

Summary1. Cardiovascular responses to intravenously administered noradrenaline were monitored in the rat in the conscious state and again following anaesthesia. Injections and pressure recordings were made via permanently implanted venous and arterial catheters. 2. The pressor response to noradrenaline was inhibited by diethyl ether, urethane and deep pentobarbitone anaesthesia. It was unchanged by ketamine and was potentiated by chloralose and light pentobarbitone anaesthesia. 3. Reflex bradycardia was potentiated by chloralose, blocked by ketamine and reduced by pentobarbitone. It was either reduced or unchanged by ether or urethane.

Plasma protein extravasation induced by mammalian tachykinins in rat skin: influence of anaesthetic agents and an acetylcholine antagonist

“…More recently, it has been shown that neurogenic plasma extravasation was 34% less in magnitude in animals anaesthetized with urethane than in animals anaesthetized with sodium pentobarbitone (Couture et al, 1985b). Urethane, in contrast to pentobarbitone, is known to diminish the pressor effect of noradrenaline and angiotensin (Volicer & Loew, 1971;Bunag & Mullenix, 1972;Brezenoff, 1973) as well as the sensitivity of small vessels to different vasoconstrictor agents (Miller & Wiegman, 1977;Altura & Weinberg, 1979). Furthermore, urethane has a direct depressive effect on histamine-induced contractions of guineapig tracheal smooth muscle both in vivo and in vitro (Maggi et al, 1982) and reduces cardiovascular responses that are mediated by the stimulation of M2-adrenoceptors located on the resistance blood vessels, cardiac postganglionic sympathetic nerves and in brain centres proposed to control cardiovascular functions (Armstrong et al, 1982).…”

Cardiovascular effects of 1,8-cineole, a terpenoid oxide present in many plant essential oils, in normotensive rats

“…To the best of our knowledge, this is the first time that such hypotensive effects of 1,8-cineole have been reported in rats. Different kinds of anaesthesia have been reported to alter cardiovascular responses to neurotransmitters such as norepinephrine in rats (Brezenoff 1973). It is possible that norepinephrine may interfere with the cardiovascular responses to 1,8-cineole.…”

Role of Muscarinic Cholinergic Transmission in Edinger-Westphal Nucleus-induced Choroidal Vasodilation in Pigeon

“…One important factor that can significantly modulate the cardiovascular and autonomic effects of pharmacological agents is anesthesia (Brezenoff, 1973 ;Ally et al, 1995 ;Zagvazdin et al, 1998). Studies of the modulatory effects of ketamine, which was used as anesthetic in our experiments, on cardiovascular and autonomic systems has yielded conflicting results (Yamamura, Kimura and Furukawa, 1983 ;Sasao et al, 1996).…”