Details

Autor(en) / Beteiligte

• YUEN, DORIS ELIZABETH

Titel

FACTORS AFFECTING BONE MINERALIZATION OF NEONATAL PIGS NOURISHED BY TOTAL PARENTERAL NUTRITION

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

1987

Link zum Volltext

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• The present sources of Ca and P used in total parenteral nutrition (TPN) solutions, Ca gluconate or Ca chloride and potassium mono- and dibasic phosphates, form a Ca phosphate precipitate at concentrations required to meet the Ca and P requirements of low birthweight (LBW) infants. The main objective of this study was to identify an alternative source of Ca and P for use in TPN solutions. The piglet was used as an animal model for the LBW infant. The results showed that: (1) Ca glycerophosphate (CaGP) remains soluble at concentrations that meet the estimated Ca and P requirements of LBW infants; (2) Ca and P provided as CaGP are efficiently retained and utilized for bone mineralization by the piglet; (3) Ca and P do not accumulate in the plasma or soft tissue of the piglet during the infusion of CaGP; (4) CaGP increases the triglyceride content of the liver, but has no effect on the cholesterol and phospholipid content of the plasma, heart, kidney and liver. It has been demonstrated in adult humans that increased endogenous acid production and excretion is associated with decreased Ca retention. Low birthweight infants are prone to acid retention as a result of their high rate of endogenous acid production and inefficient renal acid excretion. Therefore, a study conducted to determine the effect of infusing excess amino acids on Ca and P homeostasis in neonatal pigs showed that the resultant increase in endogenous acid production caused a decrease in Ca and P retention and in bone mineralization. Bone mineralization is, theoretically, a major source of endogenous acid production in rapidly growing neonates and therefore may be another factor which influences their Ca and P requirements. The results showed that piglets receiving a liberal amount of Ca and P as CaGP excreted more acid in the urine than piglets receiving inadequate amounts of Ca and P, despite the fact that endogenous acid production from all other sources was the same. These findings indicate that bone mineralization is a major source of endogenous acid production in neonates and is a factor affecting Ca and P requirements.