Effects of vasopressin administration in the oral cavity on cardiac function and hemodynamics in rats

Abstract

Background: The vasoconstrictive effect of epinephrine in local anesthetics affects the heart, which leads to hesitation among dentists in injecting local anesthetics into patients with cardiovascular disease. Due to its vasoconstrictive effects, the present study investigated the effects of vasopressin administration on cardiac function in rats.

Methods: Experiment 1 aimed to determine the vasopressin concentration that could affect cardiac function. An arterial catheter was inserted into the male Wistar rats. Next, 0.03, 0.3, and 3.0 U/mL arginine vasopressin (AVP) (0.03V, 0.3V, and 3.0V) was injected into the tongue, and the blood pressure was measured. The control group received normal saline only. In Experiment 2, following anesthesia infiltration, a pressure-volume catheter was placed in the left ventricle. Baseline values of end-systolic elastance, end-diastolic volume, end-systolic pressure, stroke work, stroke volume, and end-systolic elastance were recorded. Next, normal saline and 3.0V AVP were injected into the tongue to measure their effect on hemodynamic and cardiac function.

Results: After 3.0V administration, systolic blood pressures at 10 and 15 min were higher than those of the control group; they increased at 10 min compared with those at baseline. The diastolic blood pressures at 5-15 min were higher than those of the control group; they increased at 5 and 10 min compared with those at baseline. The preload decreased at 5 and 10 min compared to that at baseline. However, the afterload increased from 5 to 15 min compared with that of the control group; it increased at 10 min compared with that at baseline. Stroke volume decreased at 10 and 15 min compared with that of the control group; it decreased from 5 to 15 min compared with that at baseline. Stroke work decreased from 5 to 15 min compared with that of the control group; it decreased from 5 to 15 min compared with that at baseline.

Conclusion: Our results showed that 3.0 U/mL concentration of vasopressin resulted in increased blood pressure, decreased stroke volume and stoke work, decreased preload and increased afterload, without any effect on myocardial contractility.

Keywords: Cardiac Catheters; Cardiac Volume; Cardiovascular System; Hemodynamics; Vasopressins; Ventricular Pressure.

Fig. 1. Under sedation, NS or 3.0V is injected into the tongue of the rats to measure the blood pressure and cardiac function. NS, normal saline; 3.0V, 900 µL of arginine vasopressin + 5100 µL NS.

Fig. 2. Changes in SBP until 20 min after injection (n = 6) show significantly increased values in the 3.0V group compared to that of NS and that at B (Left). Changes in DBP until 20 min after injection (n = 6) show significantly increased values in the 3.0V group compared to that of NS and that at B (Right). *: significant difference from B. #: significant difference between the two groups. AVP, arginine vasopressin; B, baseline; DBP, diastolic blood pressure; SBP, systolic blood pressure,NS, normal saline; 3.0V, 900 µL of AVP + 5100 µL NS.

Fig. 3. Changes in Ved until 20 min after injection (n = 6) show significantly decreased values in the 3.0V group compared to that at B. *: significant difference from B. AVP, arginine vasopressin; B, baseline; NS, normal saline; Ved, left ventricular end-diastolic volume; 3.0V, 900 µL of AVP + 5100 µL NS.

Fig. 4. Changes in the Pes until 20 min after injection (n = 6) show significant increase in the value of the 3.0V group compared to that after administering NS and that at B. *: significant difference from B. #: significant difference between two groups. AVP, arginine vasopressin; B, baseline; NS, normal saline; Pes, left ventricular end-diastolic pressure; 3.0V, 900 µL of AVP + 5100 µL NS.

Fig. 5. Changes in the SV until 20 min after injection (n = 6) demonstrate significantly decreased SV in the 3.0V group compared to that after administering NS and that at B. *: significant difference from B. #: significant difference between two groups. AVP, arginine vasopressin; B, baseline; NS, normal saline; SV, stroke volume; 3.0V, 900 µL of AVP + 5100 µL NS.

Fig. 6. Changes in the SW until 20 min of injection (n = 6) demonstrate significantly decreased SW in the 3.0V group compared to that after administering NS and that at B. *: significant difference from B. #: significant difference between two groups. AVP, arginine vasopressin; B, baseline; NS, normal saline; SW, stroke work; 3.0V, 900 µL of AVP + 5100 µL NS.