卵巢功能丧失大鼠肾上腺皮质-髓质功能的动态变化OA

Objective To investigate the effects of ovarian function loss on adrenal cortex and medulla function in rats.Methods Thirty-six female SD rats were divided randomly into sham operation and ovariectomy groups(n=18).The rats were sacrificed in three batches at 14,28,and 42 d after surgery.The following parameters were measured:(1)Histology(hematoxylin/eosin staining)and ultrastructure(transmission electron microscopy)of adrenal cortex and medulla.(2)Serum levels of estradiol(E2),dehydroepiandrosterone sulfate(DHEAS),gonadotropin-releasing hormone(GnRH),follicle-stimulating hormone,luteinizing hormone(LH),dopamine,norepinephrine,and epinephrine(EPI)(enzyme-linked immunosorbent assay).(3)Gene expression of enzymes related to estrogen production in the adrenal cortex(Cyp17a1,Hsd3b2,Hsd17b1,Hsd17b3,Akr1c3,Cyp19a1,Por,Cyb5a)and catecholamine substance synthetases(Th,Ddc,Dbh,Pnmt)in the adrenal medulla(reverse transcription-quantitative polymerase chain reaction).Results Compared with the sham operation group,rat in the ovariectomy group:(1)Rats in the ovariectomy group showed significant body mass gain.(2)Downward trends in serum concentrations of E2,DHEAS,and GnRH,with a significant decrease in GnRH levels on days 28 and 42 after surgery(P＜0.01),significant increases in serum LH(P＜0.001)and EPI levels(P＜0.05)on day 42 after surgery.(3)Time-dependent dynamic changes in the histology and ultrastructure of the adrenal cortical zona reticularis and medulla.The zona reticularis exhibited increased cord diameter,higher cell density,and significantly enhanced cytoplasmic eosinophilia.Ultrastructurally,localized cytoplasmic dissolution and mitochondrial cristae narrowing were observed on day 14,increased lysosomes,blurred mitochondrial structures,and lipid droplet accumulation on day 28,and further mitochondrial and lipid droplet enrichment with dilated endoplasmic reticulum on day 42.In contrast,the medulla showed no significant histological changes or granular distribution,but ultrastructural alterations were time-dependent:increased norepinephrine secretory granules with mild mitochondrial swelling on day 14,persistent mitochondrial swelling on day 28,and reduced mitochondrial swelling with decreased norepinephrine granules on day 42.(4)The ovariectomy group also showed changes in gene expression of enzymes related to estrogen production in the adrenal cortex:Cyp19a1 expression was upregulated on day 14(P＜0.05)and Cyp17a1,Cyb5a,and Hsd17b1 were significantly upregulated on day 42 after surgery(P＜0.01).(5)Regarding catecholamine substance synthetases in the adrenal medulla,gene expression levels of Th(P＜0.001),Ddc(P＜0.01),Dbh(P＜0.05)and Pnmt(P＜0.001)in the adrenal gland were all significantly upregulated on day 42 after surgery in the ovariectomy group compared with the sham operation group.Conclusions Ovarian dysfunction is associated with alterations in the adrenal cortex and medulla in rats,manifested as adaptive adjustments in tissue morphology,ultrastructure and the expression of estrogen-related genes.