In order to examine whether repeated sciatic nerve blocks showed tachyphylaxis and continuity of sciatic nerve with spinal cord affected development of tachyphylaxis when assayed in vivo by duration of depression compound action potentials (CAP), rats were anesthetized with halothane, ventilated, monitored and supported with stable hemodynamics and temperature. Posterior tibial nerve distally and sciatic nerve in thigh were exposed, placed on bipolar silver electrodes for stimulation and recording respectively. Three sequential sciatic nerve blocks were performed between these electrodes using 0.15 ml of 3% chloroprocaine. Nine rats were chosen to observe the effects of repeated sciatic nerve blocks on CAP. In another 18 rats, a second investigator exposed the sciatic nerve near its origin at spinal cord and randomly performed nerve cut and sham (n=9), and closed the incision blinding the electrophysiologic investigator. The results showed that electrical stimulated tibial nerve induced sciatic nerve Aalpha/beta, Adelta, C fiber mediated CAP waves. CAP amplitudes were remained stable during whole experimental procedure. CAP amplitudes were decreased completely with 3% chloroprocaine blocked sciatic nerve and recovered fully. The duration of CAP depression were reduced with repeated blocks. There were no selective blocked effects on Aalpha/beta, Adelta, C fiber mediated CAP. With sciatic nerve cut proximally, there was no statistical significant tachyphylaxis with 3% chloroprocaine repeated blocked sciatic nerve, and the duration of first and third blocked Adelta fiber mediated CAP was 108+/-20 and 92+/-14 min respectively (P>0.05). In normal rats the duration of first and third blocked Adelta fiber mediated CAP was 110+/-20 and 75+/-16 min respectively (P<0.05). It was suggested that tachyphylaxis to local anesthetics can occur in rats repeated blocked sciatic nerve when assayed in vivo by duration of depression CAP. The continuity of sciatic nerve with spinal cord is one of the important factors affecting the development of tachyphylaxis.
Anesthetics, Local/*administration & dosage ; Nerve Block ; Procaine/administration & dosage ; Procaine/analogs & derivatives ; Sciatic Nerve ; *Tachyphylaxis/physiology

AIMTo study the influence of light and heat on the stability of procaine hydrochloride injection.

METHODSAccelerated tests upon exposure to light at high temperatures were employed.

RESULTSIn experiments with either isothermal heating or exposure to light at high temperatures, the drug degradation rate obeys first-order kinetics. The total rate constant, ktotal, caused by both light and heat can be divided into two parts: ktotal = kdark + klight, where kdark and klight are the rate constants caused by heat and light, respectively. The klight can be expressed as klight = Alight x E x exp(-Ea,light/RT). Where E is the illuminance of light, Alight is an experimental constant related to light sources, and Ea,light is an experimental constant.

CONCLUSIONBecause the form of klight is similar to the Arrhenius equation, it is suggested that Ea,light might be the observed activation energy of the rate-determining step of the subsequent processes of the photochemical reaction. This viewpoint is supported by the fact that the Ea,light is independent of light sources.

Drug Stability ; Hot Temperature ; Injections ; Light ; Mathematics ; Procaine ; administration & dosage ; chemistry ; radiation effects

In order to examine whether repeated sciatic nerve blocks showed tachyphylaxis and continuity of sciatic nerve with spinal cord affected development of tachyphylaxis when assayed in vivo by duration of depression compound action potentials (CAP), rats were anesthetized with halothane, ventilated, monitored and supported with stable hemodynamics and temperature. Posterior tibial nerve distally and sciatic nerve in thigh were exposed, placed on bipolar silver electrodes for stimulation and recording respectively. Three sequential sciatic nerve blocks were performed between these electrodes using 0.15 ml of 3% chloroprocaine. Nine rats were chosen to observe the effects of repeated sciatic nerve blocks on CAP. In another 18 rats, a second investigator exposed the sciatic nerve near its origin at spinal cord and randomly performed nerve cut and sham (n=9), and closed the incision blinding the electrophysiologic investigator. The results showed that electrical stimulated tibial nerve induced sciatic nerve Aalpha/beta, Adelta, C fiber mediated CAP waves. CAP amplitudes were remained stable during whole experimental procedure. CAP amplitudes were decreased completely with 3% chloroprocaine blocked sciatic nerve and recovered fully. The duration of CAP depression were reduced with repeated blocks. There were no selective blocked effects on Aalpha/beta, Adelta, C fiber mediated CAP. With sciatic nerve cut proximally, there was no statistical significant tachyphylaxis with 3% chloroprocaine repeated blocked sciatic nerve, and the duration of first and third blocked Adelta fiber mediated CAP was 108+/-20 and 92+/-14 min respectively (P>0.05). In normal rats the duration of first and third blocked Adelta fiber mediated CAP was 110+/-20 and 75+/-16 min respectively (P<0.05). It was suggested that tachyphylaxis to local anesthetics can occur in rats repeated blocked sciatic nerve when assayed in vivo by duration of depression CAP. The continuity of sciatic nerve with spinal cord is one of the important factors affecting the development of tachyphylaxis.
Anesthetics, Local ; administration & dosage ; Animals ; Nerve Block ; Procaine ; administration & dosage ; analogs & derivatives ; Rats ; Sciatic Nerve ; Tachyphylaxis ; physiology

Postoperative muscle pain is well known to occur in man following intravenous administration of succinylcholine. The mechanism of muscle pain is yet unknown. A number of methods for preventing muscle pains or decreasing their severity have been suggested, including nondepolarizing relaxants prior to succinylcholine (Churchill-Davidson, 1954: Cullen, 1971: Wig and Bali, 1979) or lidocaine(Usubiaga et al., 1967: Haldia et al., 1973: Fry, 1975), use of vitamin C (Gupte & Savant, 1971), procaine chloride(Morris & Dunn, 1957), thiopental sodium (Craign, 1964) or diazepam (Verma et al., 1978) and the use of a "self-taming" method of succinylcholine by prior injection of a small dose(Baraka, 1977). To investigate methods of preventing muscle pains or decreasing their severity after intravenous injection of succinylcholine, we studied four groups, a control group and three experimental groups (a lidocaine group, a d- Tubocurarine group and a succinylcholine self-taming group). The following results were obtained: 1) In the lidocaine group, the incidence of muscle pain was lower than in the control group, but there was no significant difference between the two groups. However the incidence of muscle pain in the d-Tubocurarine group or the succinylcholine self-taming group were lower than in the control group and there were statistically significant differences(p<0.0005). 2) In most of the patients of each group, the degree of postoperative muscle pain was mild and a difference of degree of muscle pain was not found in each group (p>0.05).3) The muscle pain usually appeared in the first day after operation and disappeared usually within three days. 4) The degree of muscle fasciculation showed a significant decrease with lidocaine, d-Tubocurarine or the succinylcholine self-taming group over the control group(p<0.0005), but there was no significant relationship between the degree of muscle fasciculation and the incidence of postoperative muscle pain(p>0.05). 5) The degree of muscle relaxation during intubation in the d-Tubocurarine group was less complete than in the other 3 groups and it was statistically significant(Zi>1.96). It is suggested from the above results that d-Tubocurarine(0.05~0.06mg/kg) prior to succinylcholine or the method of self-taming of succinylcholine(prior use of succinylcholine 0.15mg/kg) can be used as methods to prevent muscle pain after intravenous administration of succinylcholine, but lidocaine(2mg/kg) prior to succinylcholine is not effective in preventing muscle pain following succinylcholine administration.
Administration, Intravenous ; Ascorbic Acid ; Diazepam ; Fasciculation ; Humans ; Incidence ; Injections, Intravenous ; Intubation ; Lidocaine ; Methods ; Muscle Relaxation ; Myalgia* ; Procaine ; Succinylcholine ; Thiopental ; Tubocurarine

Atropine (2.5 mg/kg), hexamethonium (1 mg/kg), Trasylol (1,000 u/kg), acetazolamide (100 mg/kg), cortisone (5 mg /kg) or procaine (5 mg/kg) were injected intraperitoneally once a day for 21 days into rats (both sexes) fed a low protein diet. The rats were fasted and sacrificed 24 hr after the last injection. Atropine and cortisone, but not the other agents, cause a significant increase in both pancreatic weight and enzymes. Serum amylase increased markedly in the cortisone group and serum GOT and GPT increased but slightly in the atropine group. Enlargement of the pancreatic acini, cellular hypertrophy and increases of zymogen granules were observed in all the groups except the procaine and normal control group. The hypertrophy of acini was more prominent in the atropine and cortisone groups. None of drugs used could induce decrease or depress the enzyme formation and weight of pancreas. This data indicates that long-term administration of these drugs, particularly atropine, cortisone or even other Ragents may induce preferential formation of pancreatic enzymes to exocrine secretions and consequently may cause enlargement of the pancreatic acini.
Acetazolamide/administration & dosage* ; Alanine Transaminase/blood ; Amylases/blood ; Animal ; Aprotinin/administration & dosage* ; Aspartate Aminotransferases/blood ; Atropine/administration & dosage* ; Cortisone/administration & dosage* ; Female ; Hexamethonium Compounds* ; Lipase/blood ; Male ; Organ Weight ; Pancreas/drug effects* ; Pancreas/enzymology ; Procaine/administration & dosage* ; Rats ; Time Factors

OBJECTIVE: To explore the effect of quadruple fluid aerosol inhalation on oral mucositis induced by radiotherapy in nasopharyngeal carcinoma (NPC) and its mechanism. METHODS: One hundred and twenty NPC patients were divided into a treatment group (n=60) and a control group (n=60). Radiation therapy was administered conventionally over 7 weeks with 2.0 Gy daily fractions for 5 days each week at the 70 Gy. Patients in the control group accepted oral care conventionally, and patients in the treatment group used quadruple fluids aerosol inhalation before the radiotherapy. The saliva volume was measured by a nurse twice a week and the concentration of epidemal growth factor (EGF) was examined by ELISA. RESULTS: The number of patients with mucositis in the treatment group was significantly fewer than that in the control group when the total doses were up to 30 Gy and 60 Gy (P<0.05). The concentration of EGF in the control group significantly decreased when total doses were up to 30 Gy and 60 Gy (P<0.01). The concentration of EGF in the treatment group was not significantly different compared with pre-radiotherapy when the total doses were up to 30 Gy, but when total doses were up to 60 Gy, the concentration of EGF in the treatment group obviously decreased compared with that of pre-radiotherapy. CONCLUSION The quadruple fluid aerosol inhalation is effective to reduce oral mucositis resulted from radiotherapy in NPC patients, which is related to the delay of the EGF decrease in the saliva.
Administration, Inhalation ; Adult ; Aerosols ; administration & dosage ; Aged ; Drug Combinations ; Enzyme-Linked Immunosorbent Assay ; Epidermal Growth Factor ; metabolism ; Female ; Gentamicins ; administration & dosage ; Humans ; Male ; Menthol ; administration & dosage ; Middle Aged ; Nasopharyngeal Neoplasms ; drug therapy ; radiotherapy ; Procaine ; administration & dosage ; Radiotherapy ; adverse effects ; methods ; Saliva ; drug effects ; metabolism ; radiation effects ; Stomatitis ; etiology ; metabolism ; prevention & control ; Treatment Outcome ; Vitamin B 12 ; administration & dosage ; Vitamins ; administration & dosage

OBJECTIVE: To study the effects of procaine on human nasopharyngeal carcinoma cell strain CNE-2Z. METHOD: CNE-2Z cells-cultured in vitro-were exposed to different concentration procaine and different time. Its growth characteristic were studied by using MTT assay and flow cytometry. The expression of p16 and RASSF1A mRNA were analyzed by RT-PCR. RESULT: Procaine could inhibit the proliferation of CNE-2Z cells and the effects were in dose- and time-dependent manners. Procaine also arrested CNE-2Z cells in G1 phase of cell cycle. The expression of RASSF1A mRNA was up-regulated in CNE-2Z cells treated with procaine, but no obvious change was found in the expression of p16 mRNA. CONCLUSION Procaine could inhibit cell growth and up-regulate the expression of RASSF1A mRNA, which may play an important role in CNE-2Z cells' proliferation inhibition induced by procaine.
Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; G1 Phase ; Gene Expression Regulation, Neoplastic ; Humans ; Nasopharyngeal Neoplasms ; metabolism ; pathology ; Procaine ; administration & dosage ; pharmacology ; Tumor Suppressor Proteins ; metabolism