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. 1988 Jun;400:29–44. doi: 10.1113/jphysiol.1988.sp017108

Direct observations of effects of baroreceptor stimulation on mesenteric circulation of the rat.

M T Hébert 1, J M Marshall 1
PMCID: PMC1191795  PMID: 3418527

Abstract

1. In anaesthetized rats, supramaximal baroreceptor stimulation by carotid sinus inflation evoked a reflex fall in systemic arterial pressure and an increase in gross mesenteric vascular conductance, but no significant change in gross mesenteric blood flow. 2. Principal arteries (80-350 microns internal diameter (i.d.)) which supply the intestine and mesentery, small arteries (30-40 microns) and some terminal arterioles (18-30 microns) of the mesentery showed a diameter increase beginning with the fall in arterial pressure, but remaining terminal arterioles and precapillary arterioles (10-18 microns) showed a diameter increase beginning when arterial pressure neared its lowest level. 3. Application of phentolamine to the mesentery abolished diameter increases that began with the reflex fall in arterial pressure. Thereafter, 50% of small arteries and terminal and precapillary arterioles showed diameter increases that began when the fall in arterial pressure neared its zenith. 4. It is proposed that the proximal arterial vessels, which are known to be sympathetically innervated, predominantly showed dilatation mediated by reflex inhibition of sympathetic tone, while more distal arterioles showed myogenic dilatation secondary to the fall in systemic arterial pressure. 5. Small veins (30-50 microns) of the mesentery and principal veins (100-560 microns) that drain mesentery and intestine also showed a diameter increase beginning with the reflex fall in systemic arterial pressure. Since they are known to have a sympathetic noradrenergic supply, and in the absence of changes in mesenteric blood flow likely to cause passive changes in venous diameter, they apparently showed dilatation due to inhibition of sympathetic tone. 6. The above responses are all compatible with, and so suggest underlying mechanisms for, changes in blood flow, regional blood volume, and capillary filtration evoked by baroreceptor stimulation in studies of whole mesenteric circulation, i.e. intestine as well as mesentery.

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Selected References

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

  1. Bohlen H. G., Gore R. W. Comparison of microvascular pressures and diameters in the innervated and denervated rat intestine. Microvasc Res. 1977 Nov;14(3):251–264. doi: 10.1016/0026-2862(77)90024-3. [DOI] [PubMed] [Google Scholar]
  2. Brooksby G. A., Donald D. E. Dynamic changes in splanchnic blood flow and blood volume in dogs during activation of sympathetic nerves. Circ Res. 1971 Sep;29(3):227–238. doi: 10.1161/01.res.29.3.227. [DOI] [PubMed] [Google Scholar]
  3. Burrows M. E., Johnson P. C. Arteriolar responses to elevation of venous and arterial pressures in cat mesentery. Am J Physiol. 1983 Nov;245(5 Pt 1):H796–H807. doi: 10.1152/ajpheart.1983.245.5.H796. [DOI] [PubMed] [Google Scholar]
  4. Burrows M. E., Johnson P. C. Diameter, wall tension, and flow in mesenteric arterioles during autoregulation. Am J Physiol. 1981 Dec;241(6):H829–H837. doi: 10.1152/ajpheart.1981.241.6.H829. [DOI] [PubMed] [Google Scholar]
  5. Cardinal D. C., Higgs G. A. A photometric device for measuring blood vessel diameter in the microcirculation. J Pharmacol Methods. 1980 Sep;4(2):109–114. doi: 10.1016/0160-5402(80)90030-3. [DOI] [PubMed] [Google Scholar]
  6. FOLKOW B., LEWIS D. H., LUNDGREN O., MELLANDER S., WALLENTIN I. THE EFFECT OF GRADED VASOCONSTRICTOR FIBRE STIMULATION ON THE INTESTINAL RESISTANCE AND CAPACITANCE VESSELS. Acta Physiol Scand. 1964 Aug;61:445–457. [PubMed] [Google Scholar]
  7. Furness J. B., Marshall J. M. Correlation of the directly observed responses of mesenteric vessles of the rat to nerve stimulation and noradrenaline with the distribution of adrenergic nerves. J Physiol. 1974 May;239(1):75–88. doi: 10.1113/jphysiol.1974.sp010556. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Gaehtgens P., Uekermann U. The distensibility of mesenteric venous microvessels. Pflugers Arch. 1971;330(3):206–216. doi: 10.1007/BF00588612. [DOI] [PubMed] [Google Scholar]
  9. Gore R. W. Fluid exchange across single capillaries in rat intestinal muscle. Am J Physiol. 1982 Feb;242(2):H268–H287. doi: 10.1152/ajpheart.1982.242.2.H268. [DOI] [PubMed] [Google Scholar]
  10. Hainsworth R., Karim F. Responses of abdominal vascular capacitance in the anaesthetized dog to changes in carotid sinus pressure. J Physiol. 1976 Nov;262(3):659–677. doi: 10.1113/jphysiol.1976.sp011614. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Hébert M. T., Marshall J. M. Direct observations of responses of mesenteric microcirculation of the rat to circulating noradrenaline. J Physiol. 1985 Nov;368:393–407. doi: 10.1113/jphysiol.1985.sp015864. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Hébert M. T., Marshall J. M. Direct observations of the effects of baroreceptor stimulation on skeletal muscle circulation of the rat. J Physiol. 1988 Jun;400:45–59. doi: 10.1113/jphysiol.1988.sp017109. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Kirchheim H. R. Systemic arterial baroreceptor reflexes. Physiol Rev. 1976 Jan;56(1):100–177. doi: 10.1152/physrev.1976.56.1.100. [DOI] [PubMed] [Google Scholar]
  14. Nosaka S., Wang S. C. Carotid sinus baroceptor functions in the spontaneously hypertensive rat. Am J Physiol. 1972 May;222(5):1079–1084. doi: 10.1152/ajplegacy.1972.222.5.1079. [DOI] [PubMed] [Google Scholar]
  15. Oberg B. The relationship between active constriction and passive recoil of the veins at various distending pressures. Acta Physiol Scand. 1967 Oct-Nov;71(2):233–247. doi: 10.1111/j.1748-1716.1967.tb03729.x. [DOI] [PubMed] [Google Scholar]
  16. Resnicoff S. A., Harris J. P., Hampsey J. P., Schwartz S. I. Effects of sinus nerve stimulation on arterial resistance and flow patterns of specific vascular beds. Surgery. 1969 Oct;66(4):755–761. [PubMed] [Google Scholar]
  17. Vatner S. F., Franklin D., Braunwald E. Effects of anesthesia and sleep on circulatory response to carotid sinus nerve stimulation. Am J Physiol. 1971 May;220(5):1249–1255. doi: 10.1152/ajplegacy.1971.220.5.1249. [DOI] [PubMed] [Google Scholar]

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