• Alexander Rouch, Ph.D. Oklahoma State University Center for Health Sciences College of Osteopathic Medicine (OSU-COM)
  • Joseph Meter, B.S. Oklahoma State University Center for Health Sciences College of Osteopathic Medicine (OSU-COM)
  • Liming Fan, M.S. Oklahoma State University Center for Health Sciences College of Osteopathic Medicine (OSU-COM)
Keywords: Estrogen, Blood Pressure, Kidney, Sodium, Fructose


Consuming high levels of salt and fructose leads to hypertension and obesity in both males and females, but comparatively, the latter appear to be protected against dietary-induced pathologies. The purpose of this study was to determine the effects of 17β-estradiol (E2) on blood pressure and renal sodium excretion in mice consuming a diet of high salt and high fructose. Previous studies suggest that E2 administration via a 1.5mg E2 pellet and a 0.05mg E2 pellet in mice provide either too much or too little E2, respectively. This pilot study was designed to analyze the effects induced by a 0.7mg E2 pellet. Ovariectomized CD-1 mice were placed in metabolic cages for 17 days while consuming 4% salt chow with a fluid containing 1% NaCl and 20% fructose. Daily measurements included body weight, food and fluid intake, urine volume, and renal sodium excretion (Nae). Sodium intake (Nai) was determined from food and fluid intake and Nae was calculated by multiplying urine flow rate by urine [Na+]. Molecular expression of renal markers for sodium transport was measured via real-time PCR. Blood pressure was measured via the tail-cuff technique. Mice were divided into two groups: placebo (P) and E2 (n=5/group). No treatment was performed for the first four days of the study, i.e., control period. On the fifth day, pellets (placebo or 0.7mg E2) were implanted subcutaneously for the remainder of the study (i.e., E2 period). Blood pressure was not different between P and E2 mice. Significant results included: 1) body weight was not different at the beginning but decreased in both groups with the P group having higher body weight at the end of the study (p<0.01); 2) the P group consumed more fluid (p<0.0005) and excreted more urine (p<0.01) than the E2 group in the E2 period; 3) average Nae/Nai ratio during the E2 period was lower in the E2 group (p<0.03); and 4) the E2 group had higher mRNA expression of renal cortical NKCC2 (p<0.01) and ENaCβ (p<0.005) sodium-transport markers. Results clearly indicate that the 0.7mg E2 pellet induced significant effects on fluid intake, urine output, and renal sodium handling, with no observed pathologies. The 0.7mg pellet appears to provide an effective method of administering E2 in mice for future longer-term studies investigating the many yet-to-be discovered effects of E2 on physiological function.

Author Biography

Joseph Meter, B.S., Oklahoma State University Center for Health Sciences College of Osteopathic Medicine (OSU-COM)
Medical Student OSU-CHS


Gordish KL, Kassem KM, Ortiz PA, Beierwaltes WH. Moderate (20%) fructose-enriched

diet stimulates salt-sensitive hypertension with increased salt retention and decreased

renal nitric oxide. Physiological Reports. 2017; 5(7): e13162.

Marriott BP, Cole N, Lee E. National estimates of dietary fructose intake increased from

to 2004 in the United States. J Nutr. 2009; 139(6): 1228S-1235S.

Hayes JE, Sullivan BS, Duffy VB. Explaining variability in sodium intake through oral

sensory phenotype, salt sensation and liking. Physiology Behavior. 2010; 100(4): 369-

Soleimani M, Alborzi P. The role of salt in the pathogenesis of fructose induced

hypertension. Int J Nephrol. 2011; Epub: doi: 104061/2011/392708.

Fu Y, Vallon V. Mineralocorticoid-induced sodium appetite and renal salt retention:

evidence for common signaling and effector mechanisms. Nephron Physiol. 2014; 128:


Morris RC, Schmidlin O, Sebastian A, Tanaka M, Kurtz TW. Vasodysfunction that

involves renal vasodysfunction, not abnormally increased renal retention of sodium,

accounts for the initiation of salt induced hypertension. Circulation. 2017; 133(9): 881-

Carlström M, Wilcox CS, Arendshort WJ. Renal autoregulation in health and disease.

Physiology Review. 2015; 95(2): 405-511.

Klein VA, Kiat H. The mechanisms underlying fructose induced hypertension: a review.

J Hypertens. 2015; 33(5): 912-930.

Sandberg K, Ji H. Sex differences in primary hypertension. Biology of sex differences.

; 3(7): doi: 10.1186/2042-6410-3-7.

Reckelhoff JF. Gender differences in the regulation of blood pressure. Hypertension.

; 37(5): 1199-1208.

Reckelhoff JF, Zhang H, Srivastava K, Granger JP. Gender differences in hypertension in

spontaneously hypertensive rats. Hypertension. 1999; 34(2): 920-923.

Ojeda NP, Intapad S, Alexander BT. Sex differences in the developmental programming

of hypertension. Acta Physiol. 2015; 210(2): 307-316.

Sabolić I, Asif AR, Budach WE, Wanke C, Bahn A, Burckhardt G. Gender differences in

kidney funtion. Pflugers Arch. 2007; 455: 397-429.

Sharma N, Li L, Ecelbarger CM. Sex differences in renal and metabolic responses to a

high-fructose diet in mice. Am J Physiol Renal Physio. 2015; 308: F400-F410.

Livak KJ, Schmittgen TD. Analysis of relative gene expression data using real-time

quantitative PCR and the 2-DDCT method. Methods 2001; 25: 402-408.

Feng M, Whitesall S, Zhang Y, Beibel M, D'Alecy L, Dipetrillo K. Validation of volumepressure

recording tail-duff blood pressure measurements. Am J Hyper. 2008; doi


Couchepin C, Le KA, Bartolotti M, Encarnacao JA, Oboni JB, Tran C, Schneiter P,

Tappy L. Markedly blunted metabolic effects of fructose in healthy young female

subjects compared to male subjects. Diabetic Care. 2008; 31(6): 1254-1256.

Kim SY, Joo SJ, Shin MS, Kim C, Cho EJ, Sung KC, Kang SM, Kim DS, Lee SH,

Hwang KK, Park JB. Clinic and home blood pressure lowering effect of an angiotensin

receptor blocker, Fimasartan, in postmenopausal women with hypertension. Medicine.

; 95(22): e3764.

Rouch AJ, Curtis KS, Fan L, Kudo L, Toal S, Naukam R. Estrogen supplementation in

female mice yields higher sodium retention than that of testosterone in male mice.

FASEB J. 2012; 26: 1096-1098A.

Reckelhoff JF, Yanes LL, Iliescu R, Fortepiani LA, Granger JP. Testosterone

supplementation in aging men and women: possible impact on cardiovascular-renal

disease. Am J Physiol Renal Physiol. 2005; 289: F941-F948.

Khalil R. Estrogen, vascular estrogen receptor and hormone therapy in postmenopausal

vascular disease. Biochem Pharmacol. 2013; 82(12): 1627-1642.

Fan L, Saberi A, Dehghani A, Watauruocha C, Kudo L, Rouch AJ. Estrogen does not

protect ovariectomized mice from increased blood pressure and sodium retention induced

by high fructose and high salt diet. FASEB J. 2016; 30(1): 731.6.

Santollo J, Daniels D. Control of fluid intake by estrogens in the femal rat: rote of the

hypothalamus. Front Syst Neurosci. 2015; 9:25, doi: 10.3389/fnsys.2015.00025.

Chappell MC, Westwood BM, Yamaleyeva LM. Differential effects of sex steroids in

young and aged female mRen2.Lewis rats: a model of estrogen and salt-sensitive

hypertension. Gend Med. 2008; 5(Suppl A): S65-S75.

Cohen JA, Lindsey SH, Pirro NT, Brosnihan KB, Gallagher PE, Chappell MC. Influence

of estrogen depletion and salt loading on renal angiotensinogen expression in the

mRen(2).Lewis strain. Am J Physiol Renal Physiol. 2010; 299: F35-F42.

Xue B, Pamidimukkala J, Hay M. Sex differences in the development of angiotensin IIinduced

hypertension in conscious mice. Am J Physiol Heart Circ Physiol. 2005; 288:


Hutchens MP, Nakano T, Kosaka Y, Dunlap J, Zhang W, Herson PS, Murphy SJ,

Anderson S, Hurn PD. Estrogen is renoprotective via a nonreceptor-dependent

mechanism after cardiac arrest in vivo. Anesthesiology. 2010; 112(2): doi:


Yamaleyeva LM, Pendergrass KD, Pirro L, Gallagher PE, Groban L, Chappell MC.

Ovariectomy is protective against renal injury in the high-salt-fed older mRen2.Lewis rat.

Am J Physiol Heart Circ Physiol. 2007; 293: H2064-H2071

Biomedical Sciences