Effect of low-power radiation (helium/neon) upon submandibulary glands.
OBJECTIVE
The aim of this work was to study the effect of low-power laser radiation on guinea pig salivary glands.


BACKGROUND
Low-power laser radiation changes some cellular functions. The effect on salivary glands has not been sufficiently studied.


METHODS
One hundred and forty-four male guinea pigs (150 +/- 30 g body weight) were used. The animals were divided into two groups: control group (fed animals and those undergoing 2, 4, 8, 10, and 12 h of fasting) and experimental group (irradiated). Both the right and left submandibular glands were later irradiated with helium-neon laser at 7-mW power, with a 0.75-mm spot, under continuous pulse for 2 min in a one-session exposure; a 11.2 J/cm(2) energy density was applied. Then, the irradiated animals were fed, or underwent 2, 4, 8, 10 and 12 h of fasting. Samples of submandibular glands were taken with a punch (5 mm diameter) and were used for optic and transmission electron microscopy studies.


RESULTS
The structural observations showed that the irradiation effect was progressive; and showed a trophic stimulant effect at 2 h following irradiation, with vasodilatation, vascular congestion, perivascular infiltrate, and a necrotic picture of glandular parenchyma at longer times. The ultrastructural observations showed alterations of rough endoplasmic reticulum.


CONCLUSIONS
We propose that low-power laser radiation with the doses applied in this study disturbs protein synthesis and secretion of guinea pig submandibulary glands.
D000818:Animals; D004721:Endoplasmic Reticulum / Q000528:radiation effects / Q000648:ultrastructure; D006168:Guinea Pigs; D006371:Helium; D007249:Inflammation; D007834:Lasers; D008297:Male; D009336:Necrosis; D009356:Neon; D013363:Submandibular Gland / Q000473:pathology / Q000528:radiation effects* / Q000648:ultrastructure
D006371:Helium; D009356:Neon