TY - JOUR
T1 - Effects of ageing on morphology, amylase release, cytosolic Ca2+ signals and acyl lipids in isolated rat parotid gland tissue
AU - Mahay, Sukhbinder
AU - Pariente, Jose A.
AU - Lajas, Ana I.
AU - Adeghate, Ernest
AU - Rolph, Carole E.
AU - Singh, Jaipaul
N1 - Funding Information:
The authors would like to thank Lisa Whittaker for typing the manuscript and the Physiological Society for financial support.
PY - 2004/11
Y1 - 2004/11
N2 - Xerostomia (oral dryness sensation) is due to dryness of the oral cavity and it is more prevalent in the elderly. This study investigated the effect of ageing on parotid gland structure and function of control (2-6 months) and aged (12, 16-18 and 22-24 months) rats employing light microscopic, colorimetric, gas chromatographic and microspectrofluorimetric methods to investigate the morphological changes of the parotid glands, amylase release, endogenous lipid distribution and cytosolic free calcium levels, respectively. When compared to controls, age-related changes were apparent in glands obtained from rats aged 16-18 and 22-24 months, which included reduced acinar cell distribution, enlarged parotid ducts with fatty and connective tissue and mast cell infiltrations. Parotid acini from 12, 16-18 and 22-24-month-old glands showed significant (p < 0.05) age-related decreases in amylase release, compared to controls when challenged with acetylcholine (ACh). No change in basal calcium signals was observed in parotid acini from 2-6 to 16-18-month-old-animals. However, stimulation of 16-18-month-old parotid acini with 10-5M ACh resulted in a significant (p < 0.001) decrease in both peak and plateau phases of the cytosolic Ca2+ signal when compared to control. Gas chromatography of de novo and essential acyl lipids revealed no changes in the amount of either acyl lipid group in glands obtained from 2-6 to 22-24-month-old animals. Lipid analysis of phospholipid associated acyl chains showed a higher relative proportion of linoleic acid in older glands. The results reveal that ageing is associated with marked and distinct morphological changes including infiltrations of lipids and mast cells of the parotid gland and decreases in amylase release and cytosolic Ca2+ signals.
AB - Xerostomia (oral dryness sensation) is due to dryness of the oral cavity and it is more prevalent in the elderly. This study investigated the effect of ageing on parotid gland structure and function of control (2-6 months) and aged (12, 16-18 and 22-24 months) rats employing light microscopic, colorimetric, gas chromatographic and microspectrofluorimetric methods to investigate the morphological changes of the parotid glands, amylase release, endogenous lipid distribution and cytosolic free calcium levels, respectively. When compared to controls, age-related changes were apparent in glands obtained from rats aged 16-18 and 22-24 months, which included reduced acinar cell distribution, enlarged parotid ducts with fatty and connective tissue and mast cell infiltrations. Parotid acini from 12, 16-18 and 22-24-month-old glands showed significant (p < 0.05) age-related decreases in amylase release, compared to controls when challenged with acetylcholine (ACh). No change in basal calcium signals was observed in parotid acini from 2-6 to 16-18-month-old-animals. However, stimulation of 16-18-month-old parotid acini with 10-5M ACh resulted in a significant (p < 0.001) decrease in both peak and plateau phases of the cytosolic Ca2+ signal when compared to control. Gas chromatography of de novo and essential acyl lipids revealed no changes in the amount of either acyl lipid group in glands obtained from 2-6 to 22-24-month-old animals. Lipid analysis of phospholipid associated acyl chains showed a higher relative proportion of linoleic acid in older glands. The results reveal that ageing is associated with marked and distinct morphological changes including infiltrations of lipids and mast cells of the parotid gland and decreases in amylase release and cytosolic Ca2+ signals.
KW - Ageing
KW - Amylase secretion
KW - Calcium
KW - Lipids
KW - Morphology
KW - Parotid gland
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U2 - 10.1023/B:MCBI.0000049158.85447.4f
DO - 10.1023/B:MCBI.0000049158.85447.4f
M3 - Article
C2 - 15646043
AN - SCOPUS:9444228866
SN - 0300-8177
VL - 266
SP - 199
EP - 208
JO - Molecular and cellular biochemistry
JF - Molecular and cellular biochemistry
IS - 1-2
ER -