Involvement of glucocorticoid and mineralocorticoid receptors in lipid accumulation and depressed G6PD activity in the livers of rats treated with postpartum oral estrogen-progestin

Suppression of Adenosine Deaminase and Xanthine Oxidase Activities by Mineralocorticoid and Glucocorticoid Receptor Blockades Restores Renal Antioxidative Barrier in Oral Contraceptive-Treated Dam

OBJECTIVE

We tested the hypothesis that postpartum combined oral contraceptive (COC) treatment would induce oxidative stress via the adenosine deaminase-xanthine oxidase pathway in the kidney. We also sought to determine whether mineralocorticoid receptor (MR) or glucocorticoid receptor (GR ) blockade would suppress the activities of ADA and xanthine oxidase caused by postpartum COC treatment in the kidney.

METHODS

Twenty-four Wistar dams were randomly assigned to 4 groups (n = 6/group). Dams received vehicle (po), COC (1.0 μg ethinylestradiol and 5.0 μg levonorgestrel; po), COC with GR blockade (mifepristone; 80.0 mg/kg; po), and COC with MR blockade (spironolactone; 0.25 mg/kg; po) daily between 3rd and 11th week postpartum.

RESULTS

Data showed that postpartum COC caused increased plasma creatinine and urea, increased renal triglyceride/high-density lipoprotein ratio, free fatty acid accumulation, alanine aminotransferase, gamma-glutamyltransferase, uric acid, and activities of renal XO and ADA. On the other hand, postpartum COC resulted in decreased plasma albumin, renal glutathione, and Na+-K+-ATPase activity with no effect on lactate production. However, MR or GR blockade ameliorated the alterations induced by postpartum COC treatment. The present results demonstrate that MR or GR blockade ameliorates postpartum COC-induced increased activities of ADA and xanthine oxidase and restores glutathione-dependent antioxidative defense.

CONCLUSION

These findings implicate the involvements of GR and MR in renal dysfunctions caused by COC in dams via disrupted glutathione antioxidative barrier.

Insulin resistance and depressed cardiac G6PD activity induced by glucocorticoid exposure during pregnancy are attenuated by maternal estrogen-progestin therapy

This study aimed to investigate the effects of maternal combined oral contraceptive (COC) on dams that were exposed to late gestational glucocorticoids (GC). Twenty-four pregnant female rats were randomly allotted into 4 groups of 6 dams each. Dams received COC (combination of 1.0 μg ethinylestradiol and 5.0 μg levonorgestrel p.o.) between 3rd and 11^th week after delivery with or without prior exposure to GC (dexamethasone; 0.2 mg/kg p.o.) that was administered between gestational days 14-19. Data showed that late-gestational GC exposure led to insulin resistance (IR), increased cardiac adenosine deaminase (ADA), xanthine oxidase (XO), lactate, lactate dehydrogenase (LDH), and disrupted cardiac glucose-6-phosphate dehydrogenase (G6PD)-dependent antioxidant defenses. On the other hand, maternal COC treatment in dams not exposed to gestational GC led to IR, increased cardiac XO, LDH and defective cardiac G6PD-dependent antioxidant defenses. However, maternal COC with prior gestational GC exposure led to attenuated IR, cardiac ADA, UA, LDH, and improved cardiac G6PD-dependent antioxidant defenses but worsened cardiac triglyceride (TG) accumulation when compared with dam with gestational GC exposure without maternal COC. Taken together, the findings of this study provide evidence that maternal COC treatment improves late gestational GC-programmed effects. This is however accompanied with enhanced cardiac TG accumulation.