Abstract
Oyster shell heated in vacuo, mainly consisting of calcium oxide (CaO), is nonirritating and highly absorbable from the intestine. The effects of oyster shell heated in vacuo on hematological and biochemical data and duration of survival of rats were compared with those of commonly used calcium carbonate (CaCO3). Ninety rats were divided into three groups and given a diet containing 1% calcium as CaCO3 from the 10th week after birth until natural death (group A), a mixture of heated oyster shell and calcium carbonate in equal amounts (group B), and heated oyster shell (group C). Hematological values and serum components such as total protein, albumin, albumin/globulin (A/G) ratio, GOT, GPT, alkaline phosphatase, total cholesterol, free cholesterol, triglycerides, urea nitrogen, creatinine, Na, K, and Ca were measured up to the 65th week. Following natural death, autopsy was performed. The results were as follows: Animals on oyster shell heated in vacuo tended to show milder anemia and leukocytosis, significantly higher serum albumin, and lower GPT, with a tendency of lower total and free cholesterol, urea nitrogen, and creatinine. The mean survival was 618 ± 22 days in group A, 665 ± 24 in group B and 685 ± 20 in group C (mean ± SEM), suggesting a longer survival on supplementation with heated oyster shell. Autopsy revealed less frequent ocurrence of tumors and nephrosclerosis in heated oyster shell-supplemented rats. These results support the hypothesis that oyster shell heated in vacuo is more beneficial for the metabolism and survival of rats than CaCO3, possibly through its high biological availability.
Similar content being viewed by others
References
Campbell AK (1983) Intracellular calcium. Its universal role as a regulator. Wiley and Sons, London
Sherman HC, Macleod FL (1925) The calcium content of the body in relation to age, growth and food. J Biol Chem 64:429–459
Schraer H, Siar WJ, Schraer R (1963) Changes in bone mass and density in living rats during manipulation of calcium intake. Arch Biochem Biophys 100:393–398
Fujita T (1986) Aging and calcium. Miner Electrolyt Metab 12:49–156
Chapuy MC, Durr F, Chapuy C (1983) Age-related changes of parathyroid hormone and 25-hydroxycholecalciferol levels. J Gerontol 38:19–22
Fujita T, Fukase M, Nakada M, Koishi M (1988) Intestinal absorption of oyster shell electrolysate. Bone Miner 4:321–327
Fujita T, Fukase M, Miyamoto H, Matsumoto T, Ohue T (1990) Increase of bone mineral density by calcium supplement with oyster shell electrolysate. Bone Miner 11:85–91
Chon SH, Teree TM, Gusmano EA (1966) Effect of varying calcium intake on the parameters of calcium metabolism in the rat. J Nutr 94:261–267
Yamori Y (1989) Experimental evidence for dietary prevention of cardiovascular diseases. Clin Exper Pharmacol Physiol 16:303–307
Peuler JD, Schelper RL (1992) Partial protection from salt-induced stroke and mortality by high oral calcium in hypertensive rats. Stroke 23:532–538
Kalu DN, Hardin RH, Cockerham R, Yu BP (1984) Aging and dietary modulation of rat skeleton and parathyroid hormone. Endocrinology 115:1239–1247
Myetes D, Bogin E, Ma A, Dukes PP, Massry SG (1984) Effect of parathyroid hormone on erythropoiesis. J Clin Invest 71:1263–1269
Rixon, RH, MacManus JP, Whitfield JF (1979) The control of liver regeneration by calcitonin, parathyroid hormone and 1, 25-dihydroxycholecalciferol. Mol Cell Endocrinol 15: 79–89
Author information
Authors and Affiliations
About this article
Cite this article
Fujita, T., Kitazawa, R., Fukase, M. et al. Effect of calcium supplementation as oyster shell heated in vacuo on metabolism and survival of rats. J Bone Miner Metab 13, 93–97 (1995). https://doi.org/10.1007/BF01771324
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01771324