The treatment of most head and neck cancer patients includes ionizing radiation (IR). Salivary glands in the IR field suffer irreversible damage. Previously, we reported that adenoviral (Ad)-mediated transfer of the human aquaporin-1 (hAQP1) cDNA to rat submandibular glands following IR restored salivary flow to near normal levels. It is unclear if this strategy is useful in larger animals. Herein, we evaluated AdhAQP1-mediated gene transfer after parotid gland IR (20 Gy) in the miniature pig. Sixteen weeks following IR, salivation from the targeted gland was decreased by >80%. AdhAQP1 administration resulted in a dose-dependent increase in parotid salivary flow to approximately 80% of pre-IR levels on day 3. A control Ad vector was without significant effect. The effective AdhAQP1 dose was 2.5 x 10(5) pfu/microl infusate, a dose that leads to comparable transgene expression in murine and minipig salivary glands. Three days after Ad vector administration little change was observed in clinical chemistry and hematology values. These findings demonstrate that localized delivery of AdhAQP1 to IR-damaged salivary glands increases salivary secretion, without significant general adverse events, in a large animal model.

Therapeutic irradiation for head and neck cancer, and the autoimmune disease Sjogren's syndrome, lead to loss of salivary parenchyma. They are the two main causes of irreversible salivary gland hypofunction. Such patients cannot produce adequate levels of saliva, leading to considerable morbidity. We are working to develop an artificial salivary gland for such patients. A major problem in this endeavor has been the difficulty in obtaining a suitable autologous cellular component. This article describes a method of culturing and expanding primary salivary cells obtained from human submandibular glands (huSMGs) that is serum free and yields cells that are epithelial in nature. These include morphological (light and transmission electron microscopy [TEM]), protein expression (immunologically positive for ZO-1, claudin-1, and E-cadherin), and functional evidence. Under confocal microscopy, huSMG cells show polarization and appropriately localize tight junction proteins. TEM micrographs show an absence of dense core granules, but confirm the presence of tight and intermediate junctions and desmosomes between the cells. Functional assays showed that huSMG cells have high transepithelial electrical resistance and low rates of paracellular fluid movement. Additionally, huSMG cells show a normal karyotype without any morphological or numerical abnormalities, and most closely resemble striated and excretory duct cells in appearance. We conclude that this culture method for obtaining autologous human salivary cells should be useful in developing an artificial salivary gland.

Head and neck irradiation (IR) during cancer treatment causes by-stander effects on the salivary glands leading to irreversible loss of saliva secretion. The mechanism underlying loss of fluid secretion is not understood and no adequate therapy is currently available. Delivery of an adenoviral vector encoding human aquaporin-1 (hAQP1) into the salivary glands of human subjects and animal models with radiation-induced salivary hypofunction leads to significant recovery of saliva secretion and symptomatic relief in subjects. To elucidate the mechanism underlying loss of salivary secretion and the basis for AdhAQP1-dependent recovery of salivary gland function we assessed submandibular gland function in control mice and mice 2 and 8 months after treatment with a single 15-Gy dose of IR (delivered to the salivary gland region). Salivary secretion and neurotransmitter-stimulated changes in acinar cell volume, an in vitro read-out for fluid secretion, were monitored. Consistent with the sustained 60% loss of fluid secretion following IR, a carbachol (CCh)-induced decrease in acinar cell volume from the glands of mice post IR was transient and attenuated as compared with that in cells from non-IR age-matched mice. The hAQP1 expression in non-IR mice induced no significant effect on salivary fluid secretion or CCh-stimulated cell volume changes, except in acinar cells from 8-month group where the initial rate of cell shrinkage was increased. Importantly, the expression of hAQP1 in the glands of mice post IR induced recovery of salivary fluid secretion and a volume decrease in acinar cells to levels similar to those in cells from non-IR mice. The initial rates of CCh-stimulated cell volume reduction in acinar cells from hAQP1-expressing glands post IR were similar to those from control cells. Altogether, the data suggest that expression of hAQP1 increases the water permeability of acinar cells, which underlies the recovery of fluid secretion in the salivary glands functionally compromised post IR.

Puerarin injection has been widely used for clinic treatment of diabetes recently. To assess the relationship between the administration time of puerarin and the blood concentration of puerarin as well as its pharmacokinetic parameters, the diabetic rat model was used in current study. The rats were randomly divided into morning and evening groups according to the administration time. After the puerarin injection, blood glucose was tested in order to know whether the efficiency of puerarin was influenced by its concentration and pharmacokinetic parameters. Our results show that the average concentration of puerarin in the evening group is significantly higher than that in the morning group. The numbers of t1/2α, t1/2β, CL and AUC(0-∞) are significantly different between the morning and evening groups. The blood glucose level in the evening group was lower than that in the morning group. The speed of its onset is higher and the blood glucose level declines much more significantly in the evening group. These findings suggest that the concentration and pharmacokinetic parameters of puerarin affect its efficiency in diabetic rats. Therefore, it might be better to give puerarin in evening than in the morning for the mellitus treatment.