title: Effects of protein deficiency and diet consistency on the parotid gland and parotid saliva of rats.
abstract: Protein deficiency results in an increased susceptibility to dental caries, suggesting that oral host-defense properties are compromised. An important component of oral host defense is salivary gland function, which is affected by both protein deficiency and diet consistency. This study describes the effects on rat parotid gland growth and secretory function induced by feeding rats diets of normal (20%) or moderately low (7%) protein content, provided in either a powdered or solid form. In addition, since protein deficiency may result in a secondary zinc deficiency which, in turn, may affect salivary gland function, the effects of these diets on liver zinc concentration were also measured. From 22 to 47 days of age, rats (18/group) were fed the following diets: normal protein, powdered; normal protein, solid; low protein, powdered; and low protein, solid. With each diet consistency, liver zinc was higher for the normal protein group. Within each protein level, liver zinc was higher for the solid diet. This latter observation suggests that food mastication and the resultant stimulation of salivary gland function may also play a role in zinc metabolism. With the normal-protein diet, parotid gland weight was higher for the solid diet; with the low-protein diet, parotid gland weight was similar for both consistencies and did not differ from that of the group fed the "normal protein, powdered" diet. For both consistencies, parotid saliva protein concentration was greater for malnourished rats.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Community Dentistry, University of Texas Health Science Center at San Antonio 78284-7917, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Johnson
authors.forename: H
authors.initials: H
authors.lastname: Lopez
authors.forename: J M
authors.initials: JM
authors.lastname: Navia
mesh_terms: D000818:Animals; D003851:Deoxyribonucleases / Q000032:analysis; D004032:Diet; D004044:Dietary Proteins / Q000008:administration & dosage; D005260:Female; D006023:Glycoproteins / Q000032:analysis; D008099:Liver / Q000737:chemistry; D008297:Male; D008409:Mastication; D009748:Nutrition Disorders / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D009929:Organ Size; D010306:Parotid Gland / Q000254:growth & development* / Q000378:metabolism / Q000473:pathology; D010455:Peptides / Q000032:analysis; D011392:Proline / Q000032:analysis; D055232:Proline-Rich Protein Domains; D011488:Protein Deficiency / Q000473:pathology / Q000503:physiopathology*; D051381:Rats; D012463:Saliva / Q000737:chemistry / Q000378:metabolism*; D012471:Salivary Proteins and Peptides / Q000032:analysis; D012472:Salivation; D012636:Secretory Rate; D015032:Zinc / Q000032:analysis / Q000172:deficiency / Q000378:metabolism
chemical_list: D004044:Dietary Proteins; D006023:Glycoproteins; D010455:Peptides; D012471:Salivary Proteins and Peptides; D011392:Proline; D003851:Deoxyribonucleases; D015032:Zinc