Concentrations Of Procaine Research Articles

Kinetics of procaine-acetyl-choline antagonism.

The depression in action potential induced by procaine can be arrested or even reversed by acetylcholine in the previously eserinized frog sciatic single fiber preparation. The extent and time course of the reversal are related to the relative concentrations of both procaine and acetylcholine and to the duration of the previous procaine exposure. Resting membrane potential is not affected. Repeated exposures to procaine are characterized by increasingly rapid onset of block, reduced susceptibility to actylcholine competition, and failure of complete recovery after removal of procaine. The time parameters of recovery from procaine depression are independent of the previously applied concentrations of either acetylcholine or procaine. Since acetylcholine has been shown not to cross the nerve membrane, the results are interpreted as indicating that the receptor involved in the competition exists on the external surface of the membrane.

Effects of Procaine Concentration and Duration of Contact on Oxygen Consumption in Bovine Dental Pulp

Effects of Procaine Concentration and Duration of Contact on Oxygen Consumption in Bovine Dental Pulp

A reliable colorimetric method for the quantitative determination of procaine in human whole blood.

A method which has been developed for the satisfactory estimation of procaine in whole blood avoids the loss of procaine which was apparent in methods where blood proteins were precipitated by use of trichloroacetic acid. Approximately 85 per cent of the added procaine was constantly recovered by this method from test samples of blood and the procedure was considered to be satisfactory for determining concentrations of procaine m patients’ blood The peak concentration of procaine m blood twenty minutes after the infiltration of procaine (2.06-3.7 gm) varied from 0 7 ¼g to 50 ¼g. per gram of blood m the patients studied

Principles in the Spectrophotometric Determination of Propoxycaine in the Presence of Procaine

A Spectrophotometric method for the determination of propoxycaine in the presence of procaine has been developed. Aqueous mixtures of these two local anesthetics in the form of their hydrochloride salts, which are commercially marketed, may be assayed for propoxycaine by an extension of principles developed in a study of a series of simple model compounds. The use of 2 N hydrochloric acid as a solvent permits the direct determination of propoxycaine with only a minimum of interference from comparable concentrations of procaine which may be present.

Actions of Procaine on the Central Nervous System of Rabbits

Earlier concepts on the central action of procaine appear to have been limited to such untoward effects as restlessness, tremor and convulsion. Clinical experiences during the past decade, however, have revealed the usefulness of procaine as an analgesic when administered intravenously in a nontoxic dose. Bigelow and Harrison (1) evidenced this effect experimentally by the measurement of cutaneous pain threshold in human subjects. As Goodman (8) and Keats et al. (15) pointed out, such an action cannot be attributed, to the local action on sensory nerves, since the concentration of procaine in the peripheral tissue should be far below the minimal concentration necessary for nerve block. This naturally leads to the concept that the central nervous system should be responsible for the procaine analgesia.

Actions of procaine on the central nervous system of rabbits.

Earlier concepts on the central action of procaine appear to have been limited to such untoward effects as restlessness, tremor and convulsion. Clinical experiences during the past decade, however, have revealed the usefulness of procaine as an analgesic when administered intravenously in a nontoxic dose. Bigelow and Harrison (1) evidenced this effect experimentally by the measurement of cutaneous pain threshold in human subjects. As Goodman (8) and Keats et al. (15) pointed out, such an action cannot be attributed, to the local action on sensory nerves, since the concentration of procaine in the peripheral tissue should be far below the minimal concentration necessary for nerve block. This naturally leads to the concept that the central nervous system should be responsible for the procaine analgesia.Despite the wide clinical uses of intravenous procaine (9), there has been no investigator who found pharmacologically any distinct action of procaine on the central nervous system, except excitatory effects, in experimental animals. The present investigation is an attempt to discover depressant effects of procaine on the central nervous system in a nontoxic dose. The yielded results seem to be sufficient to convince us of the variegated central actions of this drug.

プロカインの家兎體内代謝の研究

Procaine was injected intravenously to the normal and the eviscerated rabbits and the concentration of procaine and PABA in the blood was measured. Moreover, the decomposition of procaine in plasma and homogenated liver cells was investigated. The experimental data led us to the following conclusions. Procaine in the blood will be liberated from its ester conjugation at the rate in proportion to about 2 powers of concentration. In the blood most of procaine conjugate rapidly with, perhaps, plasma proteins, but its decomposition product, p-aminobenzoic acid, does not so. The liver is comparatively poor in activity to decompose procaine, but rich in that to conjugate. In the eviscerated rabbits PABA accumulates in the body. Procaine is destroyed chiefly by the blood, though. the disposition of its decomposition products depends greatly upon the liver. Very little of procaine is excreted by the kidney, and most of PABA and its conjugation substances are excreted by it.

The Fate of Intrathecal Procaine and the Spinal Fluid Level Required for Surgical Anesthesia

1. The decline of procaine concentration which limits the duration of spinal anesthesia is not due to chemical breakdown of the drug in the spinal fluid, but to absorption into the systemic circulation where it is metabolized to p-aminobenzoic acid and diethylaminoethanol. 2. The concentrations of procaine at various levels of the subarachnoid space decline at the same rate. 3. There is a critical concentration of procaine, about 0.2 mgm. per ml., which is necessary for sensory anesthesia.

The Fate of Intrathecal Procaine and the Spinal Fluid Level Required for Surgical Anesthesia

1. The decline of procaine concentration which limits the duration of spinal anesthesia is not due to chemical breakdown of the drug in the spinal fluid, but to absorption into the systemic circulation where it is metabolized to p-aminobenzoic acid and diethylaminoethanol. 2. The concentrations of procaine at various levels of the subarachnoid space decline at the same rate. 3. There is a critical concentration of procaine, about 0.2 mgm. per ml., which is necessary for sensory anesthesia.

The clinical effectiveness of different concentrations of procaine for mandibular extractions

1. 1. The results of 865 inferior alveolar nerve injections with different concentrations of procaine (using epinephrine, 1:50,000, or Neosynephrine, 1:2,500, as vasoconstrictor) for mandibular extractions, were analyzed. 2. 2. Using epinephrine, 1:50,000, as vasoconstrictor, it was found that 1.5 per cent procaine was as effective as 2 per cent or 4 per cent for mandibular extractions. One per cent procaine was less effective than the higher concentrations. 3. 3. Using Neosynephrine, 1:2,500, as vasoconstrictor, it was found that 2 per cent procaine was as effective as 4 per cent procaine for mandibular extractions. One per cent and 1.5 per cent procaine were less effective than 2 per cent or 4 per cent procaine. 4. 4. One and one-half per cent procaine with epinephrine, 1:50,000, may be more effective for mandibular extractions than 1.5 per cent procaine with Neosynephrine, 1:2,500. 5. 5. The theoretical possibility of poorer technique on the part of students compared with that of instructors could not have influenced the results obtained in this study.

On the Procaine Concentration in the Blood after Injection of Procaine Hydrochloride

On the Procaine Concentration in the Blood after Injection of Procaine Hydrochloride

Concentration of Procaine in the Cerebrospinal Fluid of the Human Being after Subarachnoid Injection

Concentration of Procaine in the Cerebrospinal Fluid of the Human Being after Subarachnoid Injection

Inhibition of Sulfapyridine by the Procaine in Chest Fluids after Procaine Anesthesia.

Summary1. The average concentration of procaine in pleural fluids removed with this anesthetic was 0.0002%. 2. Sulfapyridine in concentrations as high as 0.005% was inhibited by procaine in vitro. 3. Concentrations of urethane as high as 0.05% do not inhibit the action of sulfapyridine in vitro.

REMOVAL OF PROCAINE FROM THE CEREBROSPINAL FLUID DURING ANESTHESIA

The duration of spinal anesthesia as ordinarily managed is not affected by any measures undertaken after the anesthetic has once been placed in the subarachnoid space. Studies on the concentration of procaine in the cerebrospinal fluid of patients under spinal anesthesia 1 have shown that after an initial period during which mechanical distribution away from the site of injection takes place there is a gradual disappearance of the procaine from the cerebrospinal fluid. These findings suggested that it might be possible to terminate anesthesia more quickly by removing the procaine from the subarachnoid space. Adult patients were anesthetized by the subarachnoid injection of 150 mg. of procaine hydrochloride between the second and the third lumbar vertebra, 3.5 cc. of cerebrospinal fluid being used as the solvent. 2 In different patients at various intervals after the initial injection a needle was reinserted at the site of injection and another was inserted

CONCENTRATION OF PROCAINE IN THE CEREBROSPINAL FLUID OF THE HUMAN BEING AFTER SUBARACHNOID INJECTION

In previous communications1we presented data on the concentration of procaine at three levels in the cerebrospinal fluid of 122 adult patients at various times after the subarachnoid injection of 150 mg. of procaine hydrochloride in 3.5 cc. of cerebrospinal fluid. To obtain more information regarding the factors which influence the distribution of the anesthetic in the subarachnoid space we investigated the effect of varying (1) the dose, (2) the volume and (3) the dose and the volume in the same proportion. METHOD Adult patients each received an injection of procaine hydrochloride, dissolved in cerebrospinal fluid, into the subarachnoid space at the interspace between the second and the third lumbar vertebra and were immediately placed in the Trendelenburg position (5 to 8 degrees). The patients in group B received 300 mg. of procaine hydrochloride dissolved in 3.5 cc. of cerebrospinal fluid, and those in group C received 300 mg.