[The effects of early and late weaning on the development of the small intestine in the rat: a light-microscopic morphometric study].
The small intestine of the rat shows morphologic and enzymatic changes that are associated with the weaning and may be alternated by the early weaning, however, the morphometric criteria have been disregarded.


METHODS
In this study, the effects of precocious weaning (15 days) and prolonged weaning (32 days), on the size and number of villi; and crypts of small intestine, were analyzed in rats from 16 to 70 days of age.


RESULTS
Precocious weaning increased the size of villi, depth and number of crypts in the duodenum and jejunum, while the number of villi decreased. Pups nursed up to 32 days showed no alterations in the analyzed parameters. However, the ileum showed no alterations with the precocious weaning or prolonged.


CONCLUSIONS
These data support the concept of an intrinsic biologic program as control of intestinal development while the change of diet seem to have a modifying role in duodenum and jejunum.
Rojas Castañeda
J C
JC
Laboratorio de Histomorfología, Facultad de Medicina Veterinaria y Zootecnia, UNAM, México, D.F.
Vigueras Villaseñor
R M
RM
Vences Mejía
A
A
Carmona Mancilla
A
A
D000375:Aging; D000704:Analysis of Variance; D000818:Animals; D007421:Intestine, Small / Q000033:anatomy & histology / Q000254:growth & development*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014886:Weaning
Efectos del destete precoz y tardío sobre el desarrollo del intestino delgado de la rata: un estudio morfométrico a nivel de microscopía optica.