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. 1974 Dec;243(3):619–636. doi: 10.1113/jphysiol.1974.sp010769

Factors influencing plasma renin and angiotensin II in the conscious pregnant ewe and its foetus

Fiona Broughton Pipkin, Eugenie R Lumbers, Joan C Mott
PMCID: PMC1330727  PMID: 4375185

Abstract

1. Plasma renin (measured in the presence of additional substrate) was significantly higher (10·7 ± 1·1 S.E. of mean ng/ml.hr) in foetal lambs of 111-144 days gestation age (full term 147 days) than in their mothers (1·5 ± 0·2 ng/ml.hr S.E. of mean, P < 0·001) but plasma angiotensin II concentrations were in the same range (ewe 47·3 ± 6·6 S.E. of mean, foetus 47·4 ± 14·1 S.E. of mean pg/ml.). The endogenous velocity of renin production by foetal plasma was also greater than that of maternal plasma.

2. Foetal plasma [Na+] (137 ± 0·8 S.E. of mean m-equiv/l.), was lower than that in the ewe (142 ± 1·5 m-equiv/l. S.E. of mean, P < 0·01).

3. Foetal plasma renin in lambs of less than 120 days gestation was lower (9·2 ± 2·7 S.E. of mean ng/ml.hr) than that in lambs of over 130 days gestation (12·6 ± 2·6 ng/ml.hr S.E. of mean, P < 0·01). Foetal plasma [K+] (3·8 ± 0·1 S.E. of mean m-equiv/l.) was also lower in lambs of less than 120 days gestation than in those over 130 days (4·1 ± 0·1 S.E. of mean m-equiv/l., P < 0·001).

4. When small volumes of blood (≤ 3% of blood volume) were withdrawn from foetal lambs, plasma renin increased. The% increase of plasma renin in hypoxaemic foetal lambs was significantly less (P < 0·05) than in control lambs. At the end of 60 min hypoxaemia, arterial pressure and plasma [K+] were significantly higher in hypoxaemic than in control foetal lambs.

5. During foetal hypoxaemia, plasma angiotensin II concentration increased concurrently with plasma renin.

6. Bilateral nephrectomy was performed in two foetal lambs. Plasma renin fell to very low levels and angiotensin II became undetectable.

7. Adrenaline (∼.0·42 μg/min.kg I.V.) infused into the foetus did not alter foetal plasma renin. When adrenaline was infused into the ewe (∼0·26 μg/min.kg) maternal plasma renin increased. Maternal infusion of adrenaline raised foetal plasma renin significantly more (P < 0·05) than foetal infusion.

8. It is concluded that the foetal kidney is the major source of foetal renin in the last quarter of gestation and that renin release is stimulated by very small reductions of blood volume. Hypoxaemia does not augment renin release and cannot be responsible for high levels of renin and angiotensin associated with vaginal delivery.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BROWN J. J., DAVIES D. L., LEVER A. F., ROBERTSON J. I. INFLUENCE OF SODIUM DEPRIVATION AND LOADING ON THE PLASMA-RENIN IN MAN. J Physiol. 1964 Oct;173:408–419. doi: 10.1113/jphysiol.1964.sp007464. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Boddy K., Dawes G. S., Fisher R., Pinter S., Robinson J. S. Foetal respiratory movements, electrocortical and cardiovascular responses to hypoxaemia and hypercapnia in sheep. J Physiol. 1974 Dec;243(3):599–618. doi: 10.1113/jphysiol.1974.sp010768. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Boyd G. W., Landon J., Peart W. S. Radioimmunoassay for determining plasms-levels of angiotensin II in man. Lancet. 1967 Nov 11;2(7524):1002–1005. doi: 10.1016/s0140-6736(67)90284-x. [DOI] [PubMed] [Google Scholar]
  4. Broughton Pipkin F., Kirkpatrick S. M., Lumbers E. R., Mott J. C. Renin and angiotensin-like levels in foetal, new-born and adult sheep. J Physiol. 1974 Sep;241(3):575–588. doi: 10.1113/jphysiol.1974.sp010672. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Bunag R. D., Page I. H., McCubbin J. W. Inhibition of renin release by vasopressin and angiotensin. Cardiovasc Res. 1967 Jan;1(1):67–73. doi: 10.1093/cvr/1.1.67. [DOI] [PubMed] [Google Scholar]
  6. Campbell A. G., Dawes G. S., Fishman A. P., Hyman A. I. Regional redistribution of blood flow in the mature fetal lamb. Circ Res. 1967 Aug;21(2):229–235. doi: 10.1161/01.res.21.2.229. [DOI] [PubMed] [Google Scholar]
  7. DAWES G. S., MOTT J. C., WIDDICOMBE J. G., WYATT D. G. Changes in the lungs of the new-born lamb. J Physiol. 1953 Jul;121(1):141–162. doi: 10.1113/jphysiol.1953.sp004936. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Dunne J. T., Milligan J. E., Thomas B. W. Control of renal circulation in the fetus. Am J Obstet Gynecol. 1972 Feb 1;112(3):323–329. doi: 10.1016/0002-9378(72)90471-1. [DOI] [PubMed] [Google Scholar]
  9. HUNTER W. M., GREENWOOD F. C. Preparation of iodine-131 labelled human growth hormone of high specific activity. Nature. 1962 May 5;194:495–496. doi: 10.1038/194495a0. [DOI] [PubMed] [Google Scholar]
  10. Herbert V., Lau K. S., Gottlieb C. W., Bleicher S. J. Coated charcoal immunoassay of insulin. J Clin Endocrinol Metab. 1965 Oct;25(10):1375–1384. doi: 10.1210/jcem-25-10-1375. [DOI] [PubMed] [Google Scholar]
  11. Hogan R. P., 3rd, Kotchen T. A., Boyd A. E., 3rd, Hartley L. H. Effect of altitude on renin-aldosterone system and metabolism of water and electrolytes. J Appl Physiol. 1973 Sep;35(3):385–390. doi: 10.1152/jappl.1973.35.3.385. [DOI] [PubMed] [Google Scholar]
  12. Hébert F., Fouron J. C., Boileau J. C., Biron P. Pulmonary fate of vasoactive peptides in fetal, newborn, and adult sheep. Am J Physiol. 1972 Jul;223(1):20–23. doi: 10.1152/ajplegacy.1972.223.1.20. [DOI] [PubMed] [Google Scholar]
  13. Johnson J. A., Davis J. O., Witty R. T. Effects of catecholamines and renal nerve stimulation on renin release in the nonfiltering kidney. Circ Res. 1971 Dec;29(6):646–653. doi: 10.1161/01.res.29.6.646. [DOI] [PubMed] [Google Scholar]
  14. Kleinman L. I., Lubbe R. J. Factors affecting the maturation of glomerular filtration rate and renal plasma flow in the new-born dog. J Physiol. 1972 Jun;223(2):395–409. doi: 10.1113/jphysiol.1972.sp009854. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Lever A. F., Robertson J. I., Tree M. The estimation of renin in plasma by an enzyme kinetic technique. Biochem J. 1964 May;91(2):346–352. doi: 10.1042/bj0910346. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. McKenzie J. K., Lee M. R., Cook W. F. Effect of hemorrhage on arterial plasma renin activity in the rabbit. Circ Res. 1966 Aug;19(2):269–273. doi: 10.1161/01.res.19.2.269. [DOI] [PubMed] [Google Scholar]
  17. McKenzie J. K., Ryan J. W., Lee M. R. Effect of laparotomy on plasma renin activity in the rabbit. Nature. 1967 Jul 29;215(5100):542–543. doi: 10.1038/215542b0. [DOI] [PubMed] [Google Scholar]
  18. Mellor D. J., Slater J. S. Daily changes in amniotic and allantoic fluid during the last three months of pregnancy in conscious, unstressed ewes, with catheters in their foetal fluid sacs. J Physiol. 1971 Sep;217(3):573–604. doi: 10.1113/jphysiol.1971.sp009587. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Ng K. K., Vane J. R. Conversion of angiotensin I to angiotensin II. Nature. 1967 Nov 25;216(5117):762–766. doi: 10.1038/216762a0. [DOI] [PubMed] [Google Scholar]
  20. Rudolph A. M., Heymann M. A. Circulatory changes during growth in the fetal lamb. Circ Res. 1970 Mar;26(3):289–299. doi: 10.1161/01.res.26.3.289. [DOI] [PubMed] [Google Scholar]
  21. Skinner S. L. Improved assay methods for renin "concentration" and "activity" in human plasma. Methods using selective denaturation of renin substrate. Circ Res. 1967 Apr;20(4):391–402. doi: 10.1161/01.res.20.4.391. [DOI] [PubMed] [Google Scholar]
  22. Skinner S. L., Lumbers E. R., Symonds E. M. Analysis of changes in the renin-angiotensin system during pregnancy. Clin Sci. 1972 Apr;42(4):479–488. doi: 10.1042/cs0420479. [DOI] [PubMed] [Google Scholar]
  23. Trimper C. E., Lumbers E. R. The renin-angiotensin system in foetal lambs. Pflugers Arch. 1972;336(1):1–10. doi: 10.1007/BF00589136. [DOI] [PubMed] [Google Scholar]
  24. Vander A. J., Carlson J. Mechanism of the effects of furosemide on renin secretion in anesthetized dogs. Circ Res. 1969 Aug;25(2):145–152. doi: 10.1161/01.res.25.2.145. [DOI] [PubMed] [Google Scholar]
  25. Vander A. J. Control of renin release. Physiol Rev. 1967 Jul;47(3):359–382. doi: 10.1152/physrev.1967.47.3.359. [DOI] [PubMed] [Google Scholar]
  26. Vander A. J. Direct effects of potassium on renin secretion and renal function. Am J Physiol. 1970 Aug;219(2):455–459. doi: 10.1152/ajplegacy.1970.219.2.455. [DOI] [PubMed] [Google Scholar]
  27. Vander A. J. Effect of catecholamines and the renal nerves on renin secretion in anesthetized dogs. Am J Physiol. 1965 Sep;209(3):659–662. doi: 10.1152/ajplegacy.1965.209.3.659. [DOI] [PubMed] [Google Scholar]
  28. Vander A. J., Geelhoed G. W. Inhibition of renin secretion by angiotensin. II. Proc Soc Exp Biol Med. 1965 Nov;120(2):399–403. doi: 10.3181/00379727-120-30547. [DOI] [PubMed] [Google Scholar]
  29. Vandongen R., Peart W. S., Boyd G. W. Andrenergic stimulation of renin secretion in the isolated perfused rat kidney. Circ Res. 1973 Feb;32(2):290–296. doi: 10.1161/01.res.32.2.290. [DOI] [PubMed] [Google Scholar]

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