Variations of rat skull bone robusticity evoked by malnutrition

Abstract

Weanling Holtzman rats of both sexes were fed a control (25% protein), a 10% protein, and a 2% protein semisynthetic diet. Protein deficit (PD) and protein calorie malnutrition (PCM) were estimated from comparisons between control and 10% protein, and control and 2% protein-fed animals, respectively. Animals were killed when they were 56 days old and their skulls cleaned and disarticulated. Individual bones and incisors were ovendried to constant weight. Total weight (TW), maximal projected length (MPL), and robusticity index (RI) were determined on each bone and incisor. It was found that all the bones and incisors did not behave uniformly. They followed two main patterns: (1) Proportional variation. RI values were not affected by nutritional deficiencies. All basicranial bones and 4 of 10 facial bones followed this pattern. (2) Non-proportional variation. RI values were affected by nutritional deficiencies. This pattern was subdivided into two trends: (2a) PD-diminished RI values. Both upper and lower incisors and 1 of 10 facial bones followed this trend. (2b) PCM, but not PD, decreased RI values. All vault bones and the remaining five facial bones followed this trend. It was concluded that there was a differential robusticity response among cranial base, calvaria, and incisors. This response may be connected with the differences in both histogenetic characteristics of those components and the functional roles they have to perform. The nonvault intramembranous bones showed a nonspecific behavior. This fact precluded the classification of the facial region in some of the previously defined patterns.

The experimental method in Biological Anthropology. History and current status in Argentina

“…Los primeros resultados le permitieron concluir que los factores nutricionales provocaban tanta o más variabilidad que los biológicos (Pucciarelli, 1980). Observó, además, que el efecto de la desnutrición sobre la estructura craneana no era homogéneo sino que variaba conforme el componente funcional analizado (Pucciarelli 1981;Pucciarelli y Goya, 1983;Pucciarelli et al, , 1984.…”

Influencia de la subnutrición proteico-calórica transgeneracional sobre el crecimiento de la descendencia en la rata (<i>Rattus norvegicus albinus</i> var. Wistar)

“…Ambas generaciones subnutridas, presentaron un significativo retardo de crecimiento óseo, tanto en los huesos largos (Figuras 11 y 12), como en el cráneo (Figura 13). Estos resultados coinciden con los informados previamente por Warren y Bedi (1985); Orwoll et al (1992); Boyer et al (2000) y Oyhenart et al (2002) al estudiar los efectos de la desnutrición en huesos apendiculares yPucciarelli (1980;1981); Dahinten yPucciarelli (1981;1983);Pucciarelli y Goya (1983);Pucciarelli et al (1984),Orden (1997) y Miller y German (1999) sobre el cráneo.Sin embargo, según algunos autores, no todo el tejido óseo responde de la misma manera al estrés nutricional.Al respecto, Nakamoto et al (1983) informaron que el retardo de crecimiento de huesos craneanos y apendiculares es distinto como consecuencia de tipos de osificación diferentes: intramembranosa en los primeros y endocondral en los segundos. Sin embargo, en este trabajo los huesos largos presentaron un retardo promedio de 5.1% en machos y 6.6% en hembras y el complejo craneofacial de 5.3% y 5.6% respectivamente, indicando una variación semejante en ambos tipos de huesos.…”