Abstract
In order to evaluate the importance of a portal factor in serum calcium homeostasis, end-to-side portacaval shunts were performed in groups of adult, male Lewis rats either before or after parathyroidectomy. Subsequent changes in serum calcium values were followed. When parathyroidectomy was performed one day or 28 days after a portacaval shunt, hypocalcemic changes occurred soon after. However, in these shunted, parathyroidectomized animals which were maintained on a normal calcium diet the serum calcium concentrations soon began to rise and by three weeks after operationthe rats became normocalcemic. In animals which had a portacaval shunt performed three days after parathyroidectomy, the serum calcium levels again rose and became normal in approximately three weeks. In the shunted, parathyroidectomized animals, both the serum calcium and phosphorus concentrations remained normal as long as the rats were maintained ona normal calcium diet. When a low calcium diet was introduced, marked hypocalcemia occurred and serum parathyroid hormone values were barely detectable, both of which attest to the completeness of parathyroidectomy. These data support the hypothesis that following portacaval shunt, a calcium elevating factor, which is similar in action to parathyroid hormone but is not PTH itself, bypasses the liver and becomes effective in the systemic circulation. It acts to correct the hypocalcemia and hyperphosphatemia of parathyroidectomized rats. The possible role of various known gastrointestinal factors in this process is discussed.
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- Al-Jurf A., Ghishan F., Younoszai K. Effect of portacaval shunt on calcium homeostasis. Surg Forum. 1979;30:105–107. [PubMed] [Google Scholar]
- DeLuca H. F. Vitamin D endocrinology. Ann Intern Med. 1976 Sep;85(3):367–377. doi: 10.7326/0003-4819-85-3-367. [DOI] [PubMed] [Google Scholar]
- Fischer J. A., Oldham S. B., Sizemore G. W., Arnaud C. D. Calcium-regulated parathyroid hormone peptidase. Proc Natl Acad Sci U S A. 1972 Aug;69(8):2341–2345. doi: 10.1073/pnas.69.8.2341. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heath H., 3rd, DiBella F. P. Reduced-volume radioimmunoassays for parathyrin and calcitonin in serum, for use in pediatric and small-animal studies. Clin Chem. 1978 Oct;24(10):1833–1835. [PubMed] [Google Scholar]
- Isenberg J. I., Brickman A. S., Moore E. W. The effect of secretin on serum calcium in man. J Clin Endocrinol Metab. 1973 Jul;37(1):30–33. doi: 10.1210/jcem-37-1-30. [DOI] [PubMed] [Google Scholar]
- Kaplan E. L., Peskin G. W. Factors influencing the absorption and deposition of iron after portal systemic shunting procedures. Surg Forum. 1966;17:379–380. [PubMed] [Google Scholar]
- Martin K., Hruska K., Greenwalt A., Klahr S., Slatopolsky E. Selective uptake of intact parathyroid hormone by the liver: differences between hepatic and renal uptake. J Clin Invest. 1976 Oct;58(4):781–788. doi: 10.1172/JCI108529. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moossa A. R., Hall T. J., Hughes R. G., Wood R. A., Mackie C. R., Hall A. W. Porto-systemic gradient of immunoreactive parathyroid hormone in man. J Surg Res. 1978 Nov;25(5):445–448. doi: 10.1016/s0022-4804(78)80010-9. [DOI] [PubMed] [Google Scholar]
- Pfeffermann R., Sakai A., Kashiwabara H., Fisch H., Taha M., Goldson H., Kountz S. L. The prevention and correction of hypocalcemia in the parathyroidectomized rat by portacaval shunt. Surgery. 1977 Aug;82(2):266–270. [PubMed] [Google Scholar]
- Robin N. I., Hagen S. R., Collaço F., Refetoff S., Selenkow H. A. Serum tests for measurement of thyroid function. Hormones. 1971;2(5):266–279. doi: 10.1159/000178240. [DOI] [PubMed] [Google Scholar]
- Schedl H. P., Heath H., 3rd, Wenger J. Serum calcitonin and parathyroid hormone in experimental diabetes: effects of insulin treatment. Endocrinology. 1978 Oct;103(4):1368–1373. doi: 10.1210/endo-103-4-1368. [DOI] [PubMed] [Google Scholar]