Immunohistochemical evidence of nNOS and changes after intraglandular application of botulinum toxin A in cephalic salivary glands of adult rats

Hydrogen sulfide: a novel gaseous signaling molecule and intracellular Ca2+ regulator in rat parotid acinar cells

In addition to nitric oxide (NO), hydrogen sulfide (H2S) is recognized as a crucial gaseous messenger that exerts many biological actions in various tissues. An attempt was made to assess the roles and underlying mechanisms of both gases in isolated rat parotid acinar cells. Ductal cells and some acinar cells were found to express NO and H2S synthases. Cevimeline, a muscarinic receptor agonist upregulated endothelial NO synthase in parotid tissue. NO and H2S donors increased the intracellular Ca2+ concentration ([Ca2+]i). This was not affected by inhibitors of phospholipase C and inositol 1,4,5-trisphosphate receptors, but was decreased by blockers of ryanodine receptors (RyRs), soluble guanylyl cyclase, and protein kinase G. The H2S donor evoked NO production, which was decreased by blockade of NO synthases or phosphoinositide 3-kinase or by hypotaurine, an H2S scavenger. The H2S donor-induced [Ca2+]i increase was diminished by a NO scavenger or the NO synthases blocker. These results suggest that NO and H2S play important roles in regulating [Ca2+]i via soluble guanylyl cyclase-cGMP-protein kinase G-RyRs, but not via inositol 1,4,5-trisphosphate receptors. The effect of H2S may be partially through NO produced via phosphoinositide 3-kinase-Akt-endothelial NO synthase. It was concluded that both gases regulate [Ca2+]i in a synergistic way, mainly via RyRs in rat parotid acinar cells.

Reduction of Salivary Flow With Botulinum Toxin: Extended Report on 33 Patients with Drooling, Salivary Fistulas, and Sialadenitis

OBJECTIVES/HYPOTHESIS

The aim of the study was the evaluation of the clinical data of 33 patients who had had drooling attributable to various diseases, salivary fistulas, and sialadenitis and had been treated with injection of botulinum toxin type A (Botox). A controlled follow-up study documenting efficiency, possible side effects, and duration of the effect of treatment was also performed.

STUDY DESIGN

Retrospective clinical evaluation.

METHODS

Thirty-three patients with drooling attributable to head and neck carcinoma, neurodegenerative diseases, stroke, or idiopathic hypersalivation or with salivary fistula or chronic sialadenitis received injections of 20 to 65 U botulinum toxin type A into salivary glands under sonographic control. The entire salivary flow rate and the output per minute of the salivary analytes thiocyanate, total protein, alpha-amylase, acid phosphatase, kallikrein, and immunoglobulin A were measured at various times before and after injection. The patients were examined with regard to severity of their symptoms, including sonographic control investigation of their cephalic salivary glands.

RESULTS

Twenty-six patients (79% of all patients) reported a distinct improvement of their symptoms after toxin injection. Seven patients noted a return of high salivation rates and requested a second injection after 4 to 7 months. Duration of toxin effect varied widely among individuals. In general, salivary flow rates and thiocyanate output dropped sharply within 1 week after injection and had increased again after a period of 12 to 16 weeks. Conversely, amylase outputs increased during this period, whereas the outputs of the other analytes remained roughly constant. Sonography did not reveal any major changes in salivary gland parenchyma, and side effects were not noted.

CONCLUSION

Reduction of salivary flow in patients with drooling, salivary fistulas, or chronic sialadenitis by local injection of botulinum toxin type A into the salivary glands proved to be a dependable therapy for these disorders, as shown in the present extended report on 33 patients. Side effects were not observed. The effect of toxin application lasted for approximately 3 months. Based on their results, the authors recommend botulinum toxin injection as the therapy of choice in patients with the problem of drooling.

Treatment of iatrogenic submandibular sialocele with botulinum toxin. Case report

We report the case of a 40-year-old woman with a submandibular sialocele (diagnosed by ultrasonography and magnetic resonance sialography) after sialoadenectomy for sialolithiasis. Type A botulinum toxin was injected percutaneously under colour Doppler ultrasonographic guidance into the sialocele and the residual salivary gland. Five months later the submandibular swelling had gone, and we gave a second injection of botulinum toxin to block any residual secretory activity. There were no side effects. This is, as far as we know, the first published report of the use of botulinum toxin to treat an iatrogenic submandibular sialocele.

Immunohistochemical investigations of the influence of botulinum toxin A on the immunoreactivity of nNOS in the parotid gland of the rat

PURPOSE

We wanted to prove the hypothesis that local injections of botulinum toxin A have an influence on the immunoreactivity of neuronal nitric oxide synthase (nNOS) in parotid glands of adult rats.

MATERIALS AND METHODS

Our group carried out immunohistochemical reaction of neuronal nitric oxide synthase (nNOS) in the parotid gland of female adult Wistar rats, in native (untreated) glands and after intraglandular injection of botulinum toxin A under general anesthesia. The immunoreactivity of nNOS was investigated on different times after injection.

RESULTS

Compared with the untreated glands, there was a significant decrease of nNOS in the treated organs that became stronger with extended toxin exposure time. After our laboratory in a pilot study had already shown in general a decrease of nNOS immunoreactivity after injection of botulinum toxin A into the cephalic salivary glands of the rat, the present study shows more explicit data on the effect of botulinum toxin A injection on a higher number of examined parotid glands and analyzes a time course of the effect duration.

CONCLUSIONS

In our study, it was shown that botulinum toxin A had an influence on the immunoreactivity of neuronal nitric oxide synthase (nNOS) in parotid glands. Participation of nitric oxide (NO) in the regulation of secretion from the parotid gland of the rat seems to be likely. It might be assumed that the influence of botulinum toxin A on nNOS in the parotid gland of the rat is able to explain the sometimes longer duration of toxin effect at the neuroglandular junction than at the motor endplate.

Botulinum toxin in dermatology - beyond wrinkles and sweat

Botulinum toxin (BTX) types A and B have been used with success in cosmetic dermatology and hyperhidrosis treatment. The present review focuses on other uses of BTX in dermatology. Discussed in particular are the available data on BTX in inflammatory diseases, proctology, and some other indications. From studies in various types of eczema, it seems that BTX-A not only acts as a potent inhibitor of acetylcholine but also as an inhibitor of substance P and of glutamate as well. By those mechanisms, BTX-A may be antipruritic, which may help explain the benefits of BTX-A in lichen simplex and dyshidrotic hand eczema. In Hailey-Hailey disease, facial eccrine hidrocystomas, salivary fistulas, and intrinsic rhinitis, BTX-A blocks the secretion of sweat/saliva/mucus. BTX-A has important applications in proctology where it has become the most powerful nonsurgical therapy for anal fissures. In proctalgia fugax and after hemorrhoidectomy, BTX-A is analgesic. Current treatment applications of BTX-A and its limitations are reviewed in this paper.