The present study examines the effect of carotid sinus/vagosympathetic denervation on fetal endocrine responses to prolonged reduced uterine blood flow (RUBF). Fetal sheep had vascular catheters inserted following bilateral sectioning of the carotid sinus and vagus nerves (denervated, n = 7) or sham denervation (intact, n = 7). Uterine blood flow was mechanically restricted at 126.1 +/- 0.7 days (mean +/- S.E.M.) for 24 h, decreasing arterial oxygen saturation by 47.3 +/- 2.6% (P < 0.01). Fetal plasma samples were obtained at -1, 3, 6, 12 and 24 h for subsequent analyses of arginine vasopressin (AVP), angiotensin II and catecholamines. The AVP response to prolonged RUBF was markedly attenuated in denervated fetuses (15.6 +/- 3.6 to 34.9 +/- 6.0 pg/ml) when compared with intact (10.0 +/- 1.4 to 127.3 +/- 28.4 pg/ml). In contrast, intact fetuses demonstrated no change in plasma angiotensin II concentrations with RUBF whereas denervated fetuses demonstrated a marked increase from 47.5 +/- 18.9 to 128.7 +/- 34.2 pg/ml. The norepinephrine and epinephrine responses to prolonged RUBF were attenuated in denervated fetuses (950.1 +/- 308.9 and 155.8 +/- 58.5 to 1268.3 +/- 474.6 and 290.6 +/- 160.2 pg/ml respectively) when compared with intact (1558.3 +/- 384.4 and 547.3 +/- 304.7 pg/ml to 3289.2 +/- 1219.8 and 896.8 +/- 467.8 pg/ml respectively). These results support a role for the peripheral chemoreceptors in mediating fetal endocrine responses to prolonged RUBF, which may in part lead to the altered cardiovascular responses observed in denervated fetuses under these conditions.

This article has been cited by other articles:

				K. Adachi, H. Umezaki, K. M. Kaushal, and C. A. Ducsay Long-term hypoxia alters ovine fetal endocrine and physiological responses to hypotension Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2004; 287(1): R209 - R217. [Abstract] [Full Text] [PDF]

				T. Imamura, H. Umezaki, K. M. Kaushal, and C. A. Ducsay Long-Term Hypoxia Alters Endocrine and Physiologic Responses to Umbilical Cord Occlusion in the Ovine Fetus Reproductive Sciences, April 1, 2004; 11(3): 131 - 140. [Abstract] [PDF]

				L. R. Green Programming of Endocrine Mechanisms of Cardiovascular Control and Growth Reproductive Sciences, April 1, 2001; 8(2): 57 - 68. [Abstract] [PDF]

				J. L. Segar, O. J. Smith, and A. T. Holley Mechano- and chemoreceptor modulation of renal sympathetic nerve activity at birth in fetal sheep Am J Physiol Regulatory Integrative Comp Physiol, May 1, 1999; 276(5): R1295 - R1301. [Abstract] [Full Text] [PDF]

				P. Stein, S. E. White, J. Homan, M. A. Hanson, and A. D. Bocking Altered fetal cardiovascular responses to prolonged hypoxia after sinoaortic denervation Am J Physiol Regulatory Integrative Comp Physiol, February 1, 1999; 276(2): R340 - R346. [Abstract] [Full Text] [PDF]