The effects of glutamate on the noradrenergic innervation of the rat vas deferens have been investigated. Administration of a single dose of kainate (50 micrograms) to the peripheral noradrenergic ganglia innervating the vas deferens induced a time-dependent decrease of norepinephrine in the organ; after 10 days the norepinephrine concentration had fallen to 35% of control values. This effect was accompanied by a 70% decrease in the potassium-induced release of recently incorporated 3H-norepinephrine. Concomitantly, postsynaptic hypersensitivity to both norepinephrine and dopamine appeared. The finding that adrenergic ganglia possess high-affinity glutamate binding sites suggests that the effect of kainate may be ascribed to glutamate receptors present on the perikarya of the noradrenergic neurons. It is concluded that noradrenergic neurons of the vas deferens are under glutamatergic control and that this might be important in the motor control of the organ.
-It was studied in Antarctic fishes the anesthetic and/or analgesic actions of central depressors ketamine, fentanyl and thiopental as well as the local anesthetic benzocaine. The drugs were added to aerated marine water at temperatures of 1-1.5 C. Ketamine (15 mg/L) and fentanyl (50 g/L) failed in inducing anesthesia but caused a long lasting analgesia and sedation. Thiopental was required in doses of 100 mg/L to anesthetize the fishes, that is, about 30 times higher than the usual anesthetic dose for mammals. The anesthesia was long lasting, that is, 3-4 h, and difficult to control. One fish remained in a comatose state for four days with survival. Benzocaine in doses of 100 mg/L was successful in anesthetizing the fishes within 6-8 min, anesthesia lasting for 15-20 min, with a minor respiratory depression.Key Words: Antarctic fish; Nototheniidae; benzocaine; fentanyl; ketamine; thiopental; analgesia; anesthesia.RESUMO -Foi levado a efeito em peixes antárticos um estudo sobre as ações anestésicas e/ou analgésicas de depressores centrais ketamine, fentanyl e thiopental bem como do anestésico local benzocaina. As drogas foram adicionadas à água marinha aerada nas temperaturas de 1 a 1,5 o C. Ketamine (15 mg/L) e fentanyl (50 g/L) não induziram anestesia mas causaram demorada analgesia e sedação. Doses de 100 mg/L de Thiopental foram necessárias para anestesiar peixes, ou seja, em concentração 30 vezes maior do que a dose anestésica usual utilizada para mamíferos. A anestesia ocasionada nos peixes foi longa -de 3 a 4 horas -e difícil de ser controlada. Um dos peixes utilizados na experimentação permaneceu em estado de comatose por quatro dias com sobrevida. Benzocaina em doses de 100 mg/L foi eficiente para anestesiar peixes dentro de 6 a 8 minutos após a sua administração. A anestesia, neste caso, teve duração de 15 a 20 minutos acompanhada de pequena depressão respiratória.
O verapamil e outros bloqueadores dos canais de cálcio são usados como antihipertensivos e antiarrítmicos tratamentos prolongados ou por toda a vida, podendo ser indicados em gestantes. Foi estudado o efeito do bloqueador dos canais de cálcio sobre o germe dental, tempo de erupção dentária de filhotes nascidos de mães tratadas e mineralização óssea nas mães. As fêmeas tratadas foram divididas em dois grupos: o primeiro recebeu verapamil na dose de 2,4 mg/rato/dia e o segundo, 24 mg/rato/dia. Os animais foram divididas em dois subgrupos: o primeiro recebeu a droga durante 10 semanas: 7 semanas antes do acasalamento e 3 semanas durante a gestação realizando-se a operação cesariana ao 21o dia; o outro foi tratado como o primeiro, porem os filhotes nasceram de parto natural e o tratamento das mães foi continuado por 15 dias. Foram determinados os níveis plasmáticos de cálcio e fosfato de mães e filhotes. As cabeças dos filhotes foram seccionadas para histologia dos germes dentários e determinados os pesos úmido e seco do osso femoral das mães. Os resultados mostraram que a droga, na dose mais elevada, diminuiu os níveis séricos de cálcio e fosfato nas mães, enquanto que nos filhotes, os valores foram significativamente mais baixos em comparação com as mães. O verapamil causou aumento da mineralização óssea nas mães durante a gestação, mas não após o parto. Um aumento da calcificação dos germes dentários dos filhotes não pôde ser demonstrada, porem na dose mais elevada, o verapamil causou retardo significativo na erupção dentária. Abstract Verapamil and other calcium blocker drugs are used as antihypertensive and antiarrhythmic in long term treatments and appropriate to be prescribed for pregnant women. It was studied in rats the effects of verapamil on dental germ calcification, the time of dental eruption in offspring born from treated mothers and on mothers bone mineralization. The rats were divided in two groups: one received verapamil in doses of 2.4 mg/rat/day and the other, 24 mg/rat/day. The animals were divided in two subgroups: one was treated during 10 weeks: 7 before mating and 3 during pregnancy, cesarean surgery performed on the 21st day; the other was treated in the same way but the offspring were born by natural delivery and the mothers treatment continued for 15 days. Plasma calcium and phosphate were assayed in mothers and offspring. The offsprings heads were isolated to histology of dental germs and determined mothers femoral bone fresh and dry weights. Results show that the higher dose verapamil lowered mothers plasmatic calcium and phosphate while a significant lower values were observed in offspring as compared to their mothers. Verapamil increased mothers femoral bone mineralization during mineralization but not after delivery. An increased calcium deposition of dental germ could not be demonstrated but verapamil significantly delayed newborns dental eruption.
A study was carried out on the effects of the human amniotic membrane (HAM) during wound healing fresh extraction dental sockets on rat maxillary incisors after HAM implantation. Material and Methods. A new method of HAM storage was developed and was denominated as Modified Criovac Technique, which can be divided into 3 phases: cell disintegration, dehydration, and sterilization by gamma irradiation. This method increased the membrane life time, is safe and its sterilization was effective, facilitating the future use of the material. Experiments were performed in 30 male rats, with an average weight of 320 grams each. The animals were divided into 2 groups: experimental and control. The observation times were 2, 7, 14, and 30 days. Three animals of each group were sacrificed, and the specimens were processed for histological routine. Results. Studies under light microscopy revealed that HAM was biologically compatible with bone tissue, did not show signs of rejection. In addition, we observed resorption of HAM during healing time that has been increased at the dental socket because of HAM presence.
Calcium blockers are important therapeutic agents used in cardiovascular diseases. Their effects on osseous tissue are about unknown and an action on dental tissues was not previously studied. It was intended in the preent study to analyze the action of calcium blocker verapamil on dental caries induced by cariogenic diet and to correlate the results with alkaline phosphatase inhibition. Material and Methods. Thirty four Wistar male rats were divided in four groups as follows: a)-animals treated with normal diet and no drug (control 1); b)-animals treated with cariogenic diet and no drug (control 2); c)-animals treated with normal diet and verapamil (24 mg/rat/day); c) animals treated with normal diet and verapamil. Salivary alkaline phosphatase was assayed in all the rats. A total of 160 teeth were examined under light stereoscopic microscope regarding to the presence of dental caries in enamel, dentine and pulp. Results. Results are presented as percentage of caries in each group. a)-Control 1-normal diet: no caries; b)-Control 2-cariogenic diet: 48 % of caries; c)-cariogenic diet and verapamil: 75% of caries; d)-normal diet and verapamil: 71% of caries. In the verapamil treated rats, a significant increase of dentine caries was observed. The drug increased salivar phosphatase alkaline activity. Conclusion. Verapamil significantly stimulated dental caries by itself, a result not dependent of the diet and the increasethe in salivary alkaline phosphatase activity; these two phenomena are possibly related between them.
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