Acute effect of phosphorus ingestion on postprandial protein synthesis in rats.

Abstract

Phosphorus is vital to energy production as it provides the phosphate in adenosine triphosphate (ATP). Protein synthesis is a high energy demanding process. Therefore, phosphorus is important for protein synthesis required for the growth, maintenance, and repair of all tissues and cells. The objective of this study was to investigate the acute effect of phosphorus in meal on in vivo postprandial protein synthesis in rats. Forty male Sprague-Dawley rats weighing around 230-270 grams each were randomly divided into five groups as follows: a control group (fasting), two phosphorus-free groups (one with rats sacrificed 2 hours after food ingestion and the other 4 hours after) and two phosphorus adequate groups (one with rats sacrificed 2 hours after food ingestion and the other 4 hours after). In vivo fractional protein synthesis in plasma and liver was measured by an intraperitoneal injection of a flooding dose of L-phenylalanine containing L-[ring-2H5] Phenylalanine as a stable isotope tracer (1.5 mmol-kg body weight). The protein synthesis rates in the different groups did not differ significantly at p-value 0.05, although the rats, fed a phosphorus containing diet 2 hours before their sacrifice, had an overall higher mean protein synthesis rates as compared to rats fed a phosphorus free diet, but the latter failed to reach statistical significance.