Shingo Nagasawa

Effect of snack eating on sensitive salivary stress markers cortisol and chromogranin A.

ObjectivesTo investigate the effect of snack eating on salivary cortisol and chromogranin A (CgA).MethodsFrom 14∶00 to 18∶00, starting two hours after consumption of a midday meal, saliva samples were collected every 30 minutes from 15 healthy males, 7 of whom (snack group) ate a snack immediately after the sampling at 15∶00. Salivary cortisol and CgA levels were determined by ELISA. Samples were controlled according to salivary flow rates.ResultsFor the snack group, after snack consumption, salivary cortisol increased to exceed significance (p<0.05) at 15∶30 and rose even higher at 16∶00. In the control group, there was no such change. There was no significant change in salivary CgA in either the snack group or the control groups during the sampling period.ConclusionsThese findings suggest that no food should be consumed for at least 90 mins before saliva sampling for cortisol determination and that salivary CgA is probably not affected by snack eating.

Immunohistochemical Localization of Chromogranin A in the Acinar Cells of Equine Salivary Glands Contrasts with Rodent Glands

We investigated the existence of chromogranin A (CgA) in salivary glands of the horse by Western blotting and enzyme immunoassay (EIA) using an antiserum against a peptide sequence of equine CgA. We also compared its cellular distribution between the horse and rat salivary glands with a tyramide signal amplification immunofluorescence technique. Western blotting gave three significant immunoreactive bands (74, 56 and 48 kDa) in adrenal medulla and three major salivary glands of horses. Immunoreactivities for CgA measured by EIA in horses were 154.05 ± 41.46, 20.32 ± 5.59 and 4.43 ± 2.23 pmol/g wet weight in the parotid gland, submandibular gland and sublingual gland, respectively, and 1.03 ± 0.407 pmol/mg protein in the saliva. Immunohistochemically, the positive reactivity was mainly recognized at acinar cells in equine salivary glands. This exhibits a contrast to the finding in the rat salivary glands that the CgA immunoreactivity is localized at the duct cells of the submandibular gland. These results provide novel evidence that in the horse, CgA is stored in the acinar cells of salivary glands, and secreted into saliva.

VIP‐ and PACAP‐Induced Salivary Chromogranin A Secretion in the Isolated Perfused Submandibular Gland of Rats

Abstract: In the study reported in this paper, sensitive ELISA for rat CgA was developed using synthetic rat CgA(359–389) as antigen, Nα‐biotinylated glycylglycyl rat CgA(359–389), and antirat CgA(359–389) serum for the measurement of CgA‐LI in rat saliva. CgA‐LI in rat submandibular tissues and saliva was characterized by both immunohistochemical and immunochemical methods. Using isolated perfused rat submandibular gland. VIP at 0.1–1.0 nM in the presence of 0.1 μM ACh was found to cause CgA‐LI secretion, whereas neither PACAP‐27 nor PACAP‐38 showed any effect on CgA secretion.