Interaction of dietary fat and protein in spontaneous diseases of Syrian golden hamsters
Birt, D.F.; Pour, P.M.
Journal of the National Cancer Institute 75(1): 127-133
1985
ISSN/ISBN: 0027-8874 PMID: 3859685 Document Number: 248516
The influence of interactions between dietary fat and protein on spontaneous diseases was investigated in Syrian golden hamsters fed 2 levels of corn oil [4.5 or 18 g/385 kilocalories (kcal)] with each of 2 levels of casein (9 or 36 g/385 kcal). The 4 diets were fed to separate groups in 2 different sequences. Diets were given during wk 3-7 and followed by control diet (9 g corn oil and 18 g casein/385 kcal), or control diet was fed during wk 3-7 and the 4 diets were fed from wk 8 until death. Dietary interactions of fat and protein modified spontaneous degenerative, inflammatory and proliferative diseases in hamsters. For example, amyloidosis in the liver, kidneys, spleen and adrenal glands was reduced in females by feeding high-fat-high-protein (HF-HP) diet in comparison with low-fat-high-protein (LF-HP) diet during wk 3-7 or by feeding LP diets at either fat level after 8 wk. The incidence of hepatic abscess was highest in males consuming HP diet at either fat level after 8 wk and hepatic necrosis was observed most often in hamsters fed HF-HP diet after 8 wk. Gastric and renal vascular calcification and nephrocalcinosis incidences were reduced by 50-100% in hamsters fed HF-HP diet after 8 wk and HF diet fed at this time reduced vascular calcification in the heart in both sexes and in the lungs in males. Inflammation was generally influenced similarly by diets had either during wk 3-7 or after 8 wk. In the prostate gland, inflammation was observed most frequently in males fed HF-LP diet; however, in the vagina inflammation was elevated in females fed HF-HP diet and found in the gallbladder more commonly in hamsters fed HF-HP than in those given LF-HP. The incidence of colitis was decreased by giving HF-LP diet during wk 3-7 or LF-LP diets after wk 8. The incidence of gaastric ulcer was high in males fed HF diets during wk 3-7 and intestinal ulcers were high in those fed LF-LP at this time. The adrenal hyperplasia incidence was highest in males given HF-HP diet before or after 8 wk and in females given this diet after 8 wk. Similarly, ovarian and hepatic ductal hyperplasia was highest in females fed HF-HP diet after 8 wk and gastric and intestinal hyperplasia increased with the rise in fat at both protein levels in both sexes. In contrast, parathyroid hyperplasia was reduced in hamsters fed higher levels of fat, but parathyroid adenomas increased in these groups. Biliary cystic carcinomas (cholanglocarcinomas) were observed only in hamsters given HF diet either before or after 8 wk. The incidences of Cowper's gland adenomas was reduced in males fed this diet after 8 wk.