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71.
Shortened and weakened estrous expressions could be one of the causes of poor heat detection rate. Non-specific acute stresses are assumed to depress expression of estrus by an increase of plasma progesterone which may originate from the adrenal cortex. The objective of the present study was to examine whether the adrenal cortex can secrete significant amounts of progesterone in response to exogenous adrenocorticotropic hormone (ACTH) in lactating cows. Four cows had estrus synchronized and were ovariectomized in the luteal phase. The cows were given 25 IU ACTH through an indwelling catheter 5 h after catheterization. Blood samples were collected at an interval of 30 min. In 3 of the 4 cows, plasma progesterone concentrations increased significantly 0.5-1.5 h after the first ACTH challenge with a mean peak value of 4.2 +/- 0.4 (S.D.) ng/ml. A similar response was also observed after the second ACTH challenge. Peak plasma progesterone concentrations in the 3 cows after first ACTH challenge were comparable with the progesterone values in the luteal phase of each cow. The results suggest that lactating cows have the capability to secrete a significant amount of progesterone from the adrenal cortex. 相似文献
72.
The Wx-D1 protein (granule-bound starch synthase) of Kanto 107, Tanikei A6099 (low amylose line), and Tanikei A6599-4 (waxy
line) has been analyzed by SDS-PAGE, peptide mapping and DNA sequencing. Kanto 107 and Tanikei A6099 have the same amino acid
sequences in the mature protein, but amino acid substitution (alanine to threonine) occurs at position 258 in the mature protein
in Tanikei A6599-4. A comparison of deduced amino acid sequences of the mature Wx-D1 protein in these lines indicates that
point mutation in the Wx-D1 gene of Tanikei A6599-4 is responsible for its waxy character.This mutant waxy wheat does not
show a reduction in amylose content identicalto other waxy wheats, which probably reduces activity of the GBSS I enzyme but
does not to a complete loss of activity. We discuss the function of the mutant Wx-D1 protein in starch synthesis.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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