Cardiovascular Effects of Felypressin

Abstract

and ‡Professor of Dentistry, School of Piracicaba-UNICAMP, Piracicaba, Brazil Cardiovascular effects of felypressin (FEL) were studied in Wistar rats. Heart rate and mean arterial pressure measurements were taken in awake rats treated with vasopressin (AVP), FEL, or epinephrine (EPI). Each group received either an intravenous (IV) or an intracerebroventricular V 1 receptor antagonist, saline, area postrema removal, or sham surgery. Analysis of variance and Student-Newman-Keuls (P Ͻ .05) were applied. Felypressin and AVP induced a pressor effect, and bradycardia was inhibited by IV V 1 antagonist. Intracerebroventricular V 1 antagonist and area postrema removal enhanced their pressor effects. Epinephrine induced a higher pressor effect and a similar bradycardia that was not affected by the treatments. It was concluded that FEL depends on V 1 receptors to induce pressor and bradycardic effects, and that it produces a high relationship between bradycardia and mean arterial pressure variation depending on area postrema and central V 1 receptors. These effects are potentially less harmful to the cardiovascular system than the effects of EPI.Key Words: Anesthesia, local; Vasoconstrictor agents; Blood pressure; Baroreflex; Vasopressin. F elypressin (FEL), a synthetic analogue of vasopressin (AVP), has been widely used as a substitute for epinephrine (EPI) in anesthetic solutions to promote local vasoconstriction during medical and dental practices.1,2 Because it has no interaction with adrenergic receptors, it is suggested that FEL has fewer side effects than EPI.3 Hence, FEL causes fewer cardiovascular 4 and metabolic 5 side effects, and it has a higher median lethal dose (LD50) 6 than EPI. However, the mechanisms and the receptors used by FEL to induce cardiovascular effects are unknown, and very few studies have been conducted on its possible systemic effects.AVP, as opposed to FEL, has been widely studied. It acts on 2 subtypes of vasopressin receptors (V 1 and V 2 receptors). In physiological conditions, the vascular V 1 receptors promote vasoconstriction when linked to AVP. It has great importance because it helps control arterial pressure by enhancing it, mainly when a reduc- tion in blood volume occurs.3 Another physiological role for AVP occurs when it is associated with central V 1 receptors, inducing an increase in baroreflex gain (BG).7,8 BG may be defined as the degree of effectiveness to which the baroreflex maintains the arterial pressure at near-normal conditions, producing reflex bradycardia and vasodilation after a rapid arterial pressure elevation or permitting tachycardia and vasoconstriction after a decrease in arterial pressure.9 Injection of the V 1 receptor antagonist in the area postrema (AP) 10 or AP lesion 11 inhibits the ability of peripheral AVP to enhance BG. The V 2 receptors are present in the kidneys, and they promote water retention when they are linked to AVP. 3Because the FEL molecule is similar to the AVP molecule, it is possible that FEL activates cardiovascular mechanisms similar ...

Felipressina aumenta pressão arterial durante procedimento odontológico em pacientes hipertensos

“…Our study is in agreement with that of Inagawa et al 17 , who found that, in male Japanese white tracheotomized rabbits, the diastolic BP increased significantly, without change in systolic BP. However, our study differs from others with human experimentation that showed that felypressin is not associated with BP increases 18 . This difference can be justified by the fact that we investigated hypertensive patients with controlled BP, and the effect of felypressin might be different in hypertensive patients with uncontrolled BP, because the presence of an already elevated BP may cover up the BP response to felypressin.…”

Evaluation of blood glucose in type II diabetic patients submitted to local anesthesia with different vasoconstrictors

“…Although minor changes in the evaluated intervals have been observed, felypressin has also proved to be a viable clinical option vasoconstrictor for type 2 diabetic patients. It is essential to observe epinephrine action on adrenergic receptors in the walls of arteries and veins causing intense vasoconstriction, while felypressin acts directly on the muscular layer of blood vessels, especially on the venous side 20 . Thus, in order to provide better hemostasis control epinephrine solutions would be recommended for major bleeding risk in surgical procedures 19 .…”

The Effect of Local Anesthesia (Lidocaine 2%) with Epinephrine (1:100,000) On Blood Pressure Level of Hypertensive Patients Reported To a Tertiary Care Hospital, Peshawar, Pakistan

“…Epinephrine acts on both α and β receptors but dominate on β. Acting on α 1 epinephrine causing vasoconstriction in the peripheral blood vessels [12] while increase in the heart rate and blood pressure is due to the effect of epinephrine on β 1 receptors [13].…”