Morphological development of the epithelium of the embryonic chick intestine in culture: Influence of thyroxine and hydrocortisone

Abstract

A culture system with defined medium has been utilized to elucidate the role of thyroxine (T4) and hydrocortisone (HC) in growth and differentiation of the epithelium of embryonic chick duodenum during the third week of development. Duodenal explants maintained a basically normal morphology for 48 to 72 hours, but during subsequent culture, muscle and mesenchyme deteriorated, previllous ridges shrank, the epithelial surface became pitted, and the tissue lost weight. These degenerative processes were retarded by addition of HC to the culture medium. Previllous ridges of cultured duodenum failed to develop into true villi and ridge growth was subnormal. Epithelial mitotic counts were increased by T4 or HC, as compared to cultured control tissue, but dropped below values in vivo, by 72 hours in culture. Epithelial differentiation proceeded more rapidly in duodenum cultured without hormones than in vivo. Increase in cell height, flattening of the epithelial surface, attainment of uniform staining of the brush border with periodic acid-Schiff, increase in microvillar density, and formation of a terminal web were accelerated by 24 to 48 hours in culture. In the presence of T4, cell height and microvillar growth were stimulated further, reaching the state found at 19 to 21 days in vivo.

The Differentiation and Redifferentiation of the Intestinal Epithelium and its Brush Border Membrane

“…In suckling stages the intestine has so far proved refractory to culture, but the work of DeRitis et a1 (1975) illustrates the potentialities of fetal intestine, which over 72 hours continues mitotic activity, forms villi, differentiates normal columnar cells, and significantly increases the activity of several enzymes. The duodenum of the chick embryo behaves similarly, at an accelerated rate relative to development in ovo, except that villus ridges present at the onset of culture d o not develop villi (Black 1978) unless serum is present (Hayes 1965). Thyroxine enhances cell height and microvillus length and density, and sharply elevates the activity of alkaline phosphatase and maltase, which are both abundantly released into the medium in the form of microvesicles .…”

“…Thyroxine enhances cell height and microvillus length and density, and sharply elevates the activity of alkaline phosphatase and maltase, which are both abundantly released into the medium in the form of microvesicles . Although hydrocortisone also elevates the activity of the same two enzymes, as well as sucrase (Hijmans & McCarty 1969), it may be more significant that this hormone fosters the preservation of both epithelial and subepithelial structure, even permitting the persistence of peristaltic contractions for four days in culture (Black 1978).…”

“…The execution of a normal series of structural and biochemical differentiations by fetal rat intestine cultured in the absence of all hormones except gastrin is a demonstration of such an intrinsic programme (DeRitis et a1 1975), as is the similar tendency of embryonic chick duodenum to continue a normal sequence of developmental changes, even at an accelerated pace, in hormone-free medium (Black 1978;. In postnatal stages the appearance of sucrase in the jejunum of suckling rats deprived of pituitary, adrenal, or thyroid glands is a clear example of independence from hormonal stimulation (Koldovsky et a1 1975;Yeh & Moog 1975a, 1977a.…”

Hydrocortisone and 1,25(OH)2D3: Role in Proliferative Responses of the Embryonic Chick Duodenum in Organ Culture

“…L.M. Brewer and R.A. Corradino Several studies have shown that HC affects mitotic activity of the chick embryo's duodenal epithelium in vitro (Dobbins, Hijmans and McCarty 1967 ;Hijmans and McCarty 1969;Hijmans 1972;Black 1978). Vitamin D 3 has been found to stimulate proliferation in the duodenal epithelium of rachitic clucks (Spielvogel, Farley and Norman 1972) and rats (Birge and Alpers 1973), but its effect on proliferation of the embryonic chick duodenum in organ culture has not been studied in detail.…”

“…Organ culture of the embryonic chick duodenum has been used to study development and function of the vitamin Ddependent calcium absorptive mechanism (Corradino 1973a,b;1979a,b;Parkes and Reynolds 1977;Peterlik 1978) and to study control of duodenal development by glucocorticoid and thyroid hormones (Moog and Nehari 1954;Moog and Kirsch 1955;Hayes 1965a,b;Hijmans and McCarty 1966;McCarty, Hijmans and Wilhelm 1966;Dobbins, Hijmans and McCarty 1967;Hijmans 1972;Yoshizawa et al 1976;\911;Black and Moog 1977;Black 1978;Black, Yoneyama and Moog 1980). Using this system, a bioassay has been developed for glucocorticoid activity based on promotion of villus lengthening (Pedernera 1970).…”