Tissue-specific regulation of shell gland calbindin D28K biosynthesis by estradiol in precociously matured, vitamin D-depleted chicks
| Autor: | Curtis S. Fullmer, L P Krook, C. A. Smith, R.A. Corradino |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Vitamin
Calbindins medicine.medical_specialty animal structures Duodenum Rickets Calcium-Transporting ATPases Oviducts Biology vitamin D deficiency Intestinal absorption Egg Shell chemistry.chemical_compound Exocrine Glands S100 Calcium Binding Protein G Endocrinology Internal medicine medicine Vitamin D and neurology Animals Homeostasis Cellular localization Estradiol Vitamin D Deficiency medicine.disease Immunohistochemistry Vitamin D-dependent calcium-binding protein Diet Intestinal Absorption chemistry embryonic structures Calcium Female Chickens Calcification |
| Zdroj: | Endocrinology. 132:193-198 |
| ISSN: | 1945-7170 0013-7227 |
| DOI: | 10.1210/endo.132.1.8419123 |
| Popis: | Provision of Ca2+ for egg shell calcification in the avian uterus [egg shell gland (ESG)] derives mostly from vitamin D-dependent intestinal Ca2+ absorption from the diet. Ca2+ absorption is strongly linked to the intestinal vitamin D-dependent calbindin D28K (D28K) concentration. The laying hen ESG also contains D28K, and again, Ca2+ transport into the shell appeared to be linked to the ESG D28K concentration. However, evidence is now presented that ESG D28K synthesis may be estradiol (E2) dependent and vitamin D independent under certain conditions. One-day-old female chicks fed a vitamin D-free diet for as long as 6 weeks and then repeatedly injected im with E2 for up to 3 more weeks developed frank rickets, but possessed precociously matured reproductive tracts. While the tiny presumptive ESGs of nonestrogenized vitamin D-depleted chicks were devoid of D28K, the highly developed ESG, including the isthmus, of estrogenized chicks contained D28K. The ESGs of nonestrogenized, vitamin D-replete chicks also exhibited no development or detectable D28K. Regardless of whether vitamin D depleted or replete, estrogenized chick ESG contained similar D28K and D28K mRNA concentrations. Immunohistochemical techniques showed that the endometrial cellular localization of both D28K and Ca(2+)-ATPase (Ca2+ pump) in estrogenized chicks was similar to that in mature laying hens. There was no trace of D28K, nor was there any stimulation of Ca2+ absorption, in duodenum of vitamin D-free, immature chicks regardless of E2 treatment. As expected, both D28K and D28K mRNA were present in vitamin D-replete chick duodenum. We conclude that in E2-treated chicks, ESG D28K gene expression may be vitamin D independent and E2 dependent. This is the first clear demonstration of hormone-dependent tissue-specific D28K gene expression in the chick. |
| Databáze: | OpenAIRE |
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