Differential effects of anesthetic agents on regional blood flow and central hemodynamic parameters in rats

Abstract

Three commonly used anesthetic agents (pentobarbital, chloralose-urethane, and inactin) were studied in a rat model. The radiolabeled microsphere technique was used to evaluate rats anesthetized (no reaction to pain stimulus) with the three drugs as compared to awake unanesthetized animals. Of the three anesthetic agents studied, pentobarbital caused the smallest alteration in central hemodynamic parameters.Chloralose-urethane significantly lowered cardiac output (56%), stroke volume (35%), and minute work (51 %). Chloralose-urethane also significantly increased total peripheral resistance (59%). lnactin at the concentration used in the present study had very little effect on cardiac index, heart rate, stroke volume, and minute work but significantly increased total peripheral resistance and mean arterial pressure. All three anesthetic agents reduced cerebral and skeletal muscle blood flows equally. While pentobarbital and chloralose-urethane significantly decreased renal blood flow (33%), inactin did not change flow to the kidney. It is concluded that anesthetic agents used in small animal experiments should be chosen carefully so that they do not influence blood flow to the organ being studied.

Fast perfusion measurements in rat skeletal muscle at rest and during exercise with single‐voxel FAIR (flow‐sensitive alternating inversion recovery)

“…Baseline measurements in all 22 animals examined in this study revealed a fairly consistent picture for the perfusion at rest, which averaged to 19.4 ± 4.8 mL/100g/min. This finding is in excellent agreement with data from previously published microsphere measurements obtained in the resting skeletal muscle (18 ± 3 mL/min/100g (2)), leg muscle (21 ± 4 mL/min/100g (27)), or in the entire hindlimb muscles (19 ± 2 mL/min/100g (28)) of rats. While these values were collected in conscious animals, ours were obtained under isoflurane anesthesia.…”

“…While these values were collected in conscious animals, ours were obtained under isoflurane anesthesia. In a study employing several anesthetics other than isoflurane, it was shown that anesthesia significantly reduced blood flow in skeletal muscle (27). On the other hand, isoflurane was reported to be vasodilatory in studies of the heart muscle (29) and the brain (30).…”

Snake constriction rapidly induces circulatory arrest in rats

“…Inactin was selected as the optimal anesthetic for our purposes because it is a long-acting (3-4 h; Vasthare et al, 1988;Phillipson et al, 2008) injectable barbiturate, with a minimal effect on the cardiovascular system (Polakowski et al, 2004). Because anesthesia inhibits voluntary skeletal muscle, we could eliminate muscular movement and struggling of the rats as a potential confounding variable on constriction behavior (Moon, 2000).…”

Robust arterial spin labeling MRI measurement of pharmacologically induced perfusion change in rat kidneys

“…Previous reports show that inactin with a lower dose of 68 mg/kg has very little effect on cardiac indices (e.g. heart rate, stroke volume), and does not change renal blood flow, 41 but has an impact on renal hemodynamics with the 100 mg/kg dose 42,43 . The 100 mg/kg dose has been used in previous functional kidney studies with MRI 9,36–39 .…”