Sq. Alam et Yy. Shi, THE EFFECT OF ESSENTIAL FATTY-ACID DEFICIENCY ON THE FATTY-ACID COMPOSITION OF DIFFERENT SALIVARY-GLANDS AND SALIVA IN RATS, Archives of oral biology, 42(10-11), 1997, pp. 727-734
The main purpose was to compare the changes in fatty acid composition
of lipids induced by essential fatty acid (EFA) deficiency in the rat
submandibular, parotid and sublingual glands. Three groups of rats wer
e fed for 28 weeks (1 week gestation, 3 weeks lactation and 24 weeks t
hereafter) diets containing 7% hydrogenated coconut oil (HCO) (EFA-def
icient in both n-6 and n-3), 7% soybean oil (SBO) (control) and 7% saf
flower oil (SFO) (deficient in n-3). Rats were killed and salivary gla
nds were dissected out. Lipids were extracted and the fatty acid compo
sition of total lipids and phospholipids was determined by gas chromat
ography-mass spectrometry. The fatty-acid compositional changes indica
tive of an EFA deficiency; such as decreases in the levels of 18:2 dag
ger n-6, along with an accumulation of 20:3 n-9, were generally observ
ed in all the salivary glands of rats fed 7% HCO diet. In the submandi
bular glands, the proportions of 16:1, 18:1 n-9 and 18:1 n-7 were also
higher in the HCO-fed group than in the other two groups. There were
some differences in the fatty acid composition of the three glands. To
tal lipids of parotid gland had higher levels of 12:0 and 18:1 n-9 as
compared to the other two glands. The levels of 18:0, 20:3 n-9, 20:3 n
-6 and 20:4 n-6 were, however, lower in the parotid Bland as compared
with the other glands. In total phospholipids of rats fed SBO- and SFO
-containing diets, the sublingual gland had lower levels of 18:2 n-6 a
nd higher levels of 20:4 n-6 than the parotid or the submandibular. Th
ese differences in fatty acid composition may be related to possible d
ifferences in chain elongation/desaturation. The changes in fatty acid
composition were also reflected in total lipids of plasma, liver and
whole saliva of rats fed the various diets. A number of fatty acids we
re identified in saliva by gas chromatography-mass spectrometry. (C) 1
997 Elsevier Science Ltd.