The effects of various levels of dietary protein on skeletal growth and endochondral ossification in young rats

Abstract

iitc the well-known and striking efiects of protein cleprivatioii on growth, relatively few liistologic studies on skeletal growth aiicl ciiclocho~iclral ossification during protein cleficieiicy in the rat have been carried out. Lussier ('51) has i*ecently i.eportecl a stud>-011 the cffccts in adult rats of iiiaiiiteiiaiice 011 a protein-free diet for 30 days, and Chawla aiid Glickmaii ( '51) on thc effects of a 2% protein diet in \wanling rats f o r 8 weeks. The cfYccts of a diet dcficicnt in a single essciitial aniirio acid, lysinc, on skeletal growth iii young rats ( H a r r i s ct al., '43) arid in adult rats (Gillespie et al., '43) and the effects of similar diets deficient in pheiiylalaiiine, leuciiic, o r histidine (Mauii ct a]., '45a, '431, '46 ; Schwartz et al., '51) had previously been reported. The rcsults of a deficieiiey of protein or of a single essential amino acid on endochoiidral ossification of the long bones as described in the above studies inap bc summarized as follows :Aided by grants from the Smerican Foundation f o r Dental Science, the Department of Agriculture of the TJniversity of California, tlic Roclie A i m i~ crsary Foluldation, arid the Cn1ifolni:L State Dental Association. The following nlaterials IT ere generously contributed : crystalline R vitamins and ;ilplia-tocopherol from JIerck and Comp:~iiy, Iiic*., Ralrwap, X e w Jersep ; liver eluate powder (lab. no. ;-,j293) from Ledc~rlc T,abor:ttories, Tnc., Pearl River, Nrw Pork. * Mazola.

Endocrine Function in Protein‐calorie Malnutrition

“…The first clinical suspicion that growth hormone might be diminished in malnutrition resulted from reports of an abnormal histological pattern of enchondral bone formation and dimished epiphyseal plate development (Frandsen et al, 1954;Pratt & McCance, 1960); a similar picture has been shown to occur after hypophysectomy in rats and is restored by the administration of growth hormone (Ray et al, 1941 ;Ingalls & Hayes, 1941). Using the tibia1 end plate assay (Greensplan et al, 1949), reduced growth hormone, found in the pituitaries of protein deprived or starved animals, was interpreted as being due to diminished production (Srebnik & Nelson, 1962) or to increased secretion (Friedman & Reichlin, 1965).…”

Compensatory and catch-up growth in cattle

“…In relation to the effect of protein intake on the endochondral ossification process, the results observed in the present investigation are in agreement with the work reported by Frandsen et al (1954). Diets with decreasing protein content (6, 3 and 0% of casein) as well as pair-fed (24% of casein) limited to the same food intake of littermates on low protein diets were fed to rodents (Frandsen et al, 1954).…”

“…No information was provided in regards to the hormone concentrations of rodents in this experiment. However taken into consideration the previous studies discussed above (Glass et al, 124 1978;Sawaya and Lunn, 1985;Passos et al, 2001) which found increased concentration of T3 in rodents fed low protein diets during energy restriction one could argue that the results observed by Frandsen et al (1954) couldn't be justified by increases in T3 concentration. Alternately, the stimulatory effect of a higher CP diet on endochondral ossification could be mediated by autocrineparacrine action of local IGF-1 production.…”

“…Diets with decreasing protein content (6, 3 and 0% of casein) as well as pair-fed (24% of casein) limited to the same food intake of littermates on low protein diets were fed to rodents (Frandsen et al, 1954).…”

“…However it is unknown if higher CP intake will stimulate IGF-1 production during a severe ME restriction in cattle. In an early study with rodents, Frandsen et al (1954) showed that higher protein intake during severe caloric restriction (i.e. less than 50% of control intake) increased the number and size of chondrocytes at the epiphyseal growth plate and this was associated with increased length of the trunk and tail when compared to pair fed caloric restricted cohorts.…”