Anabolic Action Of Bovine Parathyroid Hormone In Male Rats

Abstract

This study aimed to evaluate the anabolic actions of bovine parathyroid hormone (bPTH) and to throw more lights on the mechanisms of these anabolic effects through studying the effect of this hormone on some biochemical parameters in male albino rats. Animals were divided into three major groups each one equally subdivided into two subgroups of twelve rats each. Subgroup Ia and subgroup Ib (control groups), rats were subcutaneous (sc) injected with 0.5 ml phosphate buffer (pH 7.0)/Kg B.W/day for three and six weeks respectively. Subgroup IIa and subgroup IIb, rats were sc injected with 5 μg bPTH /Kg B.W/day for three and six weeks respectively. Subgroup IIIa and subgroup IIIb, rats were sc injected with 25 μg bPTH /Kg B.W/day for three and six weeks respectively. The parameters used to monitor the anabolic actions of bPTH have been included: determination of hepatic total proteins, total lipids, DNA, RNA and activities of some lipogenic enzymes such as ATP-citrate lyase, malic enzyme and Glucose-6-phosphate dehydrogenase (G6PDH). Whereas, total proteins, albumin, globulin, transaminases (ALT and AST) and some markers of bone formation (alkaline phosphatase; ALP and osteocalcin) were determined in serum of all studied groups. The main biochemical findings in this study demonstrated that, bovine parathyroid hormone stimulate total proteins, total lipids and nucleic acids syntheses and has a direct stimulatory effect on the investigated lipogenic enzyme activities; thus favoring lipogenesis. Moreover, bPTH has stimulatory effects on the activities of both transaminases (thus favoring gluconeogenesis) and serum markers of bone formation in male albino rats. The changes described above in response to bPTH are dose and time dependant. These findings give insight into possible mechanisms of anabolic actions of bPTH in normal male albino rats.

Keywords: bovine parathyroid hormone, nucleic acids, lipogenic enzymes, alkaline phosphatase, osteocalcin.

Egyptian Journal of Biochemistry and Molecular Biology Vol. 26 (1) 2008 pp. 101-116