Is Hypercalcemic Diet A Possible Antidote To Oral Contraceptive-Induced Hypertension?

  • JI Okwusidi
  • KI Alabi
  • LA Olatunji
  • TO Oyesola

Abstract

Administration of oral contraceptive (OC) has been associated with body fluid retention and in high doses over a long period, promotes hypertension (Oelkers 1996). This present investigation tests the hypothesis that the dietary calcium supplementation increases salt and water excretion in OC (norgestre/ethinylestradiol) treated 32 female albino rats randomly distributed into four (1-4) groups of 8 rats each: Control, OC-treated, OC-treated+ Calcium diet fed and Calcium diet fed only respectively. OC was administered to the appropriate groups by gavage. Experimental diet contained 2.5% calcium supplement. Plasma and urinary [Na+] [K+] were evaluated after 8 weeks of experimentation by flame photometry and plasma [Ca2+] by colorimetric method. OC-treatment induced a significant fall in urinary [Na+]. Water excretion was significantly reduced in these animals (control, 3.1±0.56 Vs OC-treated rats, 1.47±0.16; p< 0.05). OC-treated rats had significantly higher (p<0.05) plasma [K+] compared to control rats. Calcium supplementation induced increases in plasma [Na+], [K+] and augmented urinary Na+ excretion (OC-treated + Ca2+ diet Vs OC-treated only, p<0.05). Compared with the control rats, high Ca2+ diet fed rats exhibited significant increases in plasma [Nasup>+] and [K+] accompanied by significant decreases in urinary H20 excretion (p<0.05). These results strongly suggest that high dietary Ca2+ supplementation increases salt and water excretion in OC-treated rats and potentially moderates fluid retention and blood pressure in these animals, and may be of clinical significance in OC-induced abnormal fluid retention and perhaps OC-induced hypertension.

Keywords: Hypercalcemic-diet, Oral contraceptive, Plasma electrolytes, Hypertension, Female-albino-rats

Nig. J. Physiol. Sci. 25(December 2010) 115 – 119

Author Biographies

JI Okwusidi
Department of Physiology, College of Medicine, University of Ilorin, Ilorin, Nigeria
KI Alabi
Department of Physiology, College of Medicine, University of Ilorin, Ilorin, Nigeria
LA Olatunji
Department of Physiology, College of Medicine, University of Ilorin, Ilorin, Nigeria
TO Oyesola
Department of Physiology, School of Basic Medical Sciences, Igbinedion University, Okada, Nigeria
Published
2013-01-18
Section
Articles

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eISSN: 0794-859X