The effect of starvation on the diurnal variation of amylase secretion from rat parotid glands.
The purpose of this study was to investigate the effect of starvation on the cellular function of rat parotid glands in relation to the diurnal variation of amylase secretion from the tissue. Salivary amylase secreted from the glands of rats starved for 24 h showed diurnal variation, with two peaks at 13 and 21 h. The peak at 21 h was more notable than that in fed rats, because of the accumulation of a large amount of amylase in the tissue due to starvation. Maximal binding (Bmax) values of [3H]dihydroalprenolol in the parotid membrane of starved rats also showed diurnal variation, with marked peak at 13 and 21 h. However, phosphorylation of nuclear non-histone proteins in starved rat parotid glands showed diurnal variation, with peaks at 17 and 1 h. This phasing was delayed by 4 h in comparison to that of fed rats, suggesting that the delay of diurnal variation of amylase secretion commences at least a few days after the beginning of starvation. These results indicate that changes in salivary amylase secreted from parotid glands of rats starved for 24 h coupled with those in the number of beta-adrenoceptors in the tissue show the same diurnal variation as observed in fed rats. Starvation of rats for 24 h does not appear to influence the response of parotid gland cells to stimuli.
Ishikawa
Y
Y
Department of Pharmacology, Tokushima University School of Dentistry, Japan.
Chen
C
C
Ishida
H
H
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D002940:Circadian Rhythm / Q000502:physiology*; D008297:Male; D010306:Parotid Gland / Q000201:enzymology* / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000378:metabolism; D012463:Saliva / Q000201:enzymology; D013217:Starvation / Q000503:physiopathology*
D002868:Chromosomal Proteins, Non-Histone; D011943:Receptors, Adrenergic, beta; D000681:Amylases