AJP - Regulatory, Integrative and Comparative Physiology, Vol 262, Issue 5 800-R805, Copyright © 1992 by American Physiological Society
Regulation of calbindin mRNA and calbindin turnover in intestine and shell gland of the chicken
A. Bar, S. Striem, E. Vax, H. Talpaz and S. Hurwitz
Institute of Animal Science, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel.
A synthetic oligonucleotide was used as a probe for measurement of
calbindin mRNA in the shell gland and intestine of chickens. The half time
of calbindin mRNA in the duodenum and shell gland was estimated at 2 and
3.6 h and that of calbindin at 13.9 and 32.6 h, respectively. The formation
rates of calbindin mRNA were 0.37 and 0.17 pmol.h-1.g-1 and the rate of
calbindin formation was 0.099 and 0.031 microgram.pmol mRNA-1.h-1 in the
duodenum and shell gland, respectively. In the shell gland, calbindin mRNA
and calbindin appeared at the time of sexual maturation during
calcification of the first egg shell. Calbindin mRNA fluctuated markedly
during the daily egg cycle, in close temporal association with egg shell
calcification. When Ca2+ deposition was eliminated by expulsion of the
ovum, the rise in calbindin mRNA was prevented. An indirect suppression of
Ca2+ deposition by administration of the carbonic anhydrase inhibitor
acetazolamide also resulted in a decrease in calbindin mRNA. The results
are consistent with a possible role of Ca2+ flux in the regulation of
calbindin mRNA appearance in the shell gland of chickens.
