Study Of Acid Stimulation At Different Starting-time On Function Of Salivary Gland After Iodine-131 Therapy For Total Thyroidectomized Rat Models

Objective:Through building a rat module of ¹³¹I-therapy after total thyroidectomy to study different time to be given acid-simulation which has differential expression of Na+/I-symporter?NIS?and subcellular structures of submandibular gland in rats,and to explore the best starting time of protecting salivary gland function by acid-simulation after differentiated thyroid carcinoma with ¹³¹I treatment.Methods:Fifty male survived Wister rats after thyroidectomy were randomly divided into five groups:Group1:no ¹³¹I and no acid stimulation,control group;Group2:2 hours after ¹³¹I to acid stimulation;Group3:6 hours after ¹³¹I to acid stimulation;Group4:24hours after¹³¹I to acid stimulation;Group5:¹³¹I and no acid stimulation;10 rats in each group.Rats in G1 were given distilled water respectively,and rats in Group2,3,4 and 5 were intragastrically administered ¹³¹I?3mCi?respectively.Rats in G2,3 and 4 were given acid stimulation at 2,6 and 24 hours after¹³¹I therapy respectively and acid stimulation at 10 a.m?2p.m every day.7 days after ¹³¹I therapy,each rat was weighed,sacrificed and the submandibular gland was taken out.The content of NIS in the tissue was detected by ELISA.The expression of NIS protein in the tissue was detected by immune-histochemical method.The submandibular gland subcellular structures were observed under transmission electron microscope.observed under transmission electron microscope.Results:The NIS content and expression of submandibular glands of rats in Group2?Group3?Group4?Group5(after ¹³¹I)decreased compared with those of Group1(control group,no-¹³¹I and no-acid),the differences were statistically significant?P<0.05?.The NIS content and expression of submandibular glands of rats in Group2?Group3?Group4 after¹³¹I to acid stimulation were similar,the difference was not statistically significant?P>0.05?.The NIS content and expression of submandibular glands of rats in Group2?Group3?Group4(after¹³¹I and with acid)decreased compared with those of Group5(with¹³¹I and no acid),the differences were statistically significant?P<0.05?.Structural changes in the submandibular glands were observed by a transmission electron microscopy.Compared with the submandibular glands tissue of rats in Group2?Group3?Group4(after ¹³¹I and acid stimulation)and Group1(control group,without ¹³¹I and no acid),no obvious tissue damage was found.Endoplasmic reticulum was expanded and few heterochromatin was side setted.Compared with Group5(after ¹³¹I but no-acid)and Group1(control group,no-¹³¹I and no-acid rats),the endoplasmic reticulum disordered and dilated into tubular arrangement.Mitochondria swelled with fuzzy structure and mitochondrial crista disappeared.Nuclear malformation even rupture and heterochromatin was side setted.Apoptotic bodies may appear.Conclusion:1.The expression of NIS in the submandibular gland of the rats in the ¹³¹I and acid stimulation group was significantly different from that in the no-¹³¹I and no-acid stimulation,and there was a differences in the degree of subcellular structure damage in difference.2.There was no significant difference in the expression of NIS and subcellular structure damage of submandibular gland at different time?2 hours,6 hours and 24hours?after¹³¹I and acid stimulation?3.The expression of NIS in the submandibular gland of the rats in the ¹³¹I and acid stimulation group was significantly different from that in the ¹³¹I and no acid stimulation,and there was a differences in the degree of subcellular structure damage in difference.