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American Journal of Veterinary Research May 2007To determine the durations of the local anesthetic effect and plasma procaine concentrations associated with 5- and 10-mg doses of procaine hydrochloride (with or... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
To determine the durations of the local anesthetic effect and plasma procaine concentrations associated with 5- and 10-mg doses of procaine hydrochloride (with or without 100 microg of epinephrine) administered SC over the lateral palmar digital nerves of horses.
ANIMALS
6 healthy adult horses.
PROCEDURES
The hoof withdrawal reflex latency (HWRL) period was determined by use of a focused heat lamp before and after administration of procaine with and without epinephrine. Blood samples were collected immediately before determination of each HWRL period to assess plasma concentrations of procaine via liquid chromatography-mass spectrometry-mass spectrometry (LC-MS-MS).
RESULTS
10 but not 5 mg of procaine alone and 5 and 10 mg of procaine administered with epinephrine significantly prolonged the HWRL period (mean durations of effect, 5, 120 and 180 minutes, respectively), compared with baseline values. Plasma procaine concentrations did not correlate well with local anesthetic activity; for example, although the HWRL was prolonged to the maximum permitted duration of 20 seconds at 60 to 180 minutes following administration of the 5-mg dose of procaine with epinephrine in certain horses, plasma procaine concentrations were less than the limit of quantitation of the LC-MS-MS assay.
CONCLUSIONS AND CLINICAL RELEVANCE
Small doses of procaine coadministered with epinephrine provided long-lasting local analgesia and resulted in plasma procaine concentrations that were not always detectable via LC-MS-MS. On the basis of these results, the use of regulatory limits or thresholds for procaine concentration in equine plasma samples obtained after racing should be seriously reconsidered.
Topics: Anesthesia, Local; Anesthetics, Local; Animals; Cross-Over Studies; Dose-Response Relationship, Drug; Female; Horses; Injections, Subcutaneous; Male; Procaine; Time Factors
PubMed: 17472448
DOI: 10.2460/ajvr.68.5.495 -
Journal of Anatomy Mar 1985The effects of procaine and pentobarbital on lens placodes, otic placodes and non-placodal head ectoderm of the chick embryo in vitro have been examined by scanning and... (Comparative Study)
Comparative Study
The effects of procaine and pentobarbital on lens placodes, otic placodes and non-placodal head ectoderm of the chick embryo in vitro have been examined by scanning and transmission electron microscopy. Both types of placode cells were less sensitive to both drugs than non-placodal cells. Cellular responses to pentobarbital were microvilli formation, reduction in cetylpyridinium chloride-stainable surface coat and epithelial dissociation with thinning of the basement membrane. Procaine treatment induced the formation of large cytoplasmic blebs and cytoskeletal condensations but did not affect the surface coat. Examination of head ectoderm appears to be of value in the evaluation and comparison of drug effects on differentiating tissues. Anaesthetics also form useful probes for structural and functional changes in the cells of such developing systems.
Topics: Animals; Cell Differentiation; Chick Embryo; Ectoderm; In Vitro Techniques; Microscopy, Electron; Pentobarbital; Procaine
PubMed: 4077684
DOI: No ID Found -
Anesthesiology Aug 1994There are significant physiologic differences between spinal and epidural anesthesia. Consequently, these two types of regional anesthesia may influence thermoregulatory... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
BACKGROUND
There are significant physiologic differences between spinal and epidural anesthesia. Consequently, these two types of regional anesthesia may influence thermoregulatory processing differently. Accordingly, in volunteers and in patients, we tested the null hypothesis that the core-temperature thresholds triggering thermoregulatory sweating, vasoconstriction, and shivering are similar during epidural and spinal anesthesia.
METHODS
Six male volunteers participated on three consecutive study days: epidural or spinal anesthesia were randomly assigned on the 1st and 3rd days (approximately T10 level); no anesthesia was given on the 2nd day. On each day, the volunteers were initially warmed until they started to sweat, and subsequently cooled by central venous infusion of cold fluid until they shivered. Mean skin temperature was kept constant near 36 degrees C throughout each study. The tympanic membrane temperatures triggering a sweating rate of 40 g.m-2.h-1, a finger flow less than 0.1 ml/min, and a marked and sustained increase in oxygen consumption (approximately 30%) were considered the thermoregulatory thresholds for sweating, vasoconstriction, and shivering, respectively. Twenty-one patients were randomly assigned to receive epidural (n = 10) or spinal (n = 11) anesthesia for knee and calf surgery (approximately T10 level). As in the volunteers, the shivering threshold was defined as the tympanic membrane temperature triggering a sustained increase in oxygen consumption.
RESULTS
The thresholds and ranges were similar during epidural and spinal anesthesia in the volunteers. However, the sweating-to-vasoconstriction (inter-threshold) range, the vasoconstriction-to-shivering range, and the sweating-to-shivering range all were significantly increased by regional anesthesia. The shivering thresholds in patients assigned to epidural and spinal anesthesia were virtually identical.
CONCLUSIONS
Comparable sweating, vasoconstriction, and shivering thresholds during epidural and spinal anesthesia suggest that thermoregulatory processing is similar during each type of regional anesthesia. However, thermoregulatory control was impaired during regional anesthesia, as indicated by the significantly enlarged inter-threshold and sweating-to-shivering ranges.
Topics: Adult; Anesthesia, Epidural; Anesthesia, Spinal; Anesthetics, Local; Body Temperature Regulation; Humans; Male; Monitoring, Physiologic; Procaine; Reference Values; Shivering; Sweating; Vasoconstriction
PubMed: 8053576
DOI: 10.1097/00000542-199408000-00004 -
Postgraduate Medical Journal Apr 1987
Clinical Trial Review
Topics: Central Nervous System Stimulants; Clinical Trials as Topic; Dementia; Humans; Meclofenoxate; Piracetam; Procaine; Pyrithioxin; Vasodilator Agents
PubMed: 2891126
DOI: 10.1136/pgmj.63.738.237 -
The Journal of Neuroscience : the... Jul 1991The nature of the control of hippocampal formation field activity [theta (theta) and large-amplitude irregular activity (LIA)] and theta-on/theta-off cell discharges by...
The nature of the control of hippocampal formation field activity [theta (theta) and large-amplitude irregular activity (LIA)] and theta-on/theta-off cell discharges by an ascending hypothalamo-septal pathway was investigated in urethane-anesthetized rats. Electrical stimulation of the dorsomedial-posterior hypothalamus in the range of 0.1-1.0 mA in 0.1-mA steps produced theta in the hippocampal formation, with a linear positive relation between stimulus intensity, theta frequency, and theta amplitude. Reversible blockade of the medial septal (MS)/vertical limb of the diagonal band of Broca (vDBB) region by microinjection of procaine hydrochloride abolished spontaneous and hypothalamically elicited theta, resulting in a field activity at 1-min post-procaine that had a lower power than pre-procaine LIA levels. The efficacy and recovery of the MS/vDBB suppression was tested at 1, 10, 20, 30, 40, 50, and 60 min post-procaine using 0.5, 0.8, and 1.0 mA of hypothalamic stimulation. All three of the dependent measures of hippocampal field activity (frequency, amplitude, and power) showed a progressive recovery during the 60-min post-procaine period. Frequency exhibited a rapid recovery with a shallow slope between 20 and 60 min post-procaine. In contrast, the amplitude and power of theta exhibited a gradual recovery with a steeper slope between 20 and 60 min post-procaine. During the time of maximal MS/vDBB suppression, theta-on cell discharges were reduced to 0 in most cases. The initial recovery of theta-on cells in the post-procaine condition was correlated with the first appearance of theta and was characterized by low discharge rates.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Animals; Electric Stimulation; Electrophysiology; Frontal Lobe; Hippocampus; Hypothalamus; Male; Procaine; Rats; Septum Pellucidum; Theta Rhythm
PubMed: 2066781
DOI: 10.1523/JNEUROSCI.11-07-02241.1991 -
The Journal of General Physiology May 1967Squid giant axons were internally perfused with tetrodotoxin and procaine, and excitability and electrical properties were studied by means of current-clamp and... (Comparative Study)
Comparative Study
Squid giant axons were internally perfused with tetrodotoxin and procaine, and excitability and electrical properties were studied by means of current-clamp and sucrose-gap voltage-clamp methods. Internally perfused tetrodotoxin was virtually without effect on the resting potential, the action potential, the early transient membrane ionic current, and the late steady-state membrane ionic current even at very high concentrations (1,000-10,000 nM) for a long period of time (up to 36 min). Externally applied tetrodotoxin at a concentration of 100 nM blocked the action potential and the early transient current in 2-3 min. Internally perfused procaine at concentrations of 1-10 mM reversibly depressed or blocked the action potential with an accompanying hyperpolarization of 2-4 mv, and inhibited both the early transient and late steady-state currents to the same extent. The time to peak early transient current was increased. The present results and the insolubility of tetrodotoxin in lipids have led to the conclusion that the gate controlling the flow of sodium ions through channels is located on the outer surface of the nerve membrane.
Topics: Action Potentials; Animals; Axons; Cell Membrane Permeability; Electrophysiology; Membrane Potentials; Mollusca; Neural Conduction; Potassium; Procaine; Sodium; Tetrodotoxin; Toxins, Biological
PubMed: 6033593
DOI: 10.1085/jgp.50.5.1413 -
British Journal of Pharmacology Jan 19801 Effects of 4-aminopyridine (4-AP) and procaine on the membrane and contractile properties of smooth muscle cells of the guinea-pig pulmonary artery and portal vein...
1 Effects of 4-aminopyridine (4-AP) and procaine on the membrane and contractile properties of smooth muscle cells of the guinea-pig pulmonary artery and portal vein were observed.2 The membrane potential and length constant of smooth muscle cells of the guinea-pig pulmonary artery were -53.2 mV and 1.2 mm, respectively, and those of the portal vein were -52.6 mV and 0.71 mm, respectively. The membrane was electrically quiescent in the pulmonary artery and it was electrically active in the portal vein.3 Both 4-AP and procaine depolarized the membrane, increased the membrane resistance and suppressed the rectifying properties in both tissues. Both agents evoked a graded response from the muscle membranes of the pulmonary artery by outward current pulse. Procaine had a greater effect than 4-AP on the above membrane properties.4 4-AP (10(-5) M) produced contraction without depolarization of the membrane. The contraction evoked by 10(-5) M 4-AP was completely suppressed but that evoked by 5 x 10(-4) M 4-AP was only partly suppressed by phentolamine (10(-7) M). However, the contraction evoked by procaine was not suppressed by phentolamine.5 4-AP enhanced but procaine suppressed the amplitude of 118 mM [K](0)-induced contraction.6 The results suggest that 4-AP and procaine suppress K-conductance of the muscle membrane, and 4-AP but not procaine increases noradrenaline release from the nerve terminal. Presumably intracellular free Ca concentrations are also modified by these agents. The effects of 4-AP and procaine on the vascular muscle were compared with those on other excitable tissues.
Topics: 4-Aminopyridine; Aminopyridines; Animals; Electric Stimulation; Female; Guinea Pigs; In Vitro Techniques; Male; Membrane Potentials; Muscle Contraction; Muscle, Smooth, Vascular; Phentolamine; Portal Vein; Procaine; Pulmonary Artery
PubMed: 7357204
DOI: 10.1111/j.1476-5381.1980.tb10704.x -
The Journal of General Physiology Mar 1966The effects of tetrodotoxin, procaine, and manganese ions were examined on the Ca spike of the barnacle muscle fiber injected with Ca-binding agent as well as on the...
The effects of tetrodotoxin, procaine, and manganese ions were examined on the Ca spike of the barnacle muscle fiber injected with Ca-binding agent as well as on the action potential of the ventricular muscle fiber of the frog heart. Although tetrodotoxin and procaine very effectively suppress the "Na spike" of other tissues, no suppressing effects are found on "Ca spike" of the barnacle fiber, while the initiation of the Ca spike is competitively inhibited by manganese ions. The initial rate of rise of the ventricular action potential is suppressed by tetrodotoxin and procaine but the plateau phase of the action potential is little affected. In contrast the suppressing effect of manganese ions is mainly on the plateau phase. The results suggest that the plateau phase of the ventricular action potential is related to the conductance increase in the membrane to Ca ions even though Na conductance change may also contribute to the plateau.
Topics: Animals; Anura; Calcium; Crustacea; Electrophysiology; Heart; In Vitro Techniques; Manganese; Muscles; Procaine; Sodium; Tetrodotoxin; Toxins, Biological
PubMed: 5943615
DOI: 10.1085/jgp.49.4.793 -
British Medical Journal Mar 1947
Topics: Administration, Intravenous; Humans; Procaine
PubMed: 20343481
DOI: 10.1136/bmj.1.4497.354-b -
British Journal of Anaesthesia Dec 1978
Topics: Anesthesia, Local; Bupivacaine; Drug Interactions; Humans; Hydrogen-Ion Concentration; Lidocaine; Procaine
PubMed: 34414
DOI: 10.1093/bja/50.12.1269