Abstract
Microcirculatory observations and measurements were made by in vivo microscopy in 35 germfree and 26 conventional rats. The rate of vasomotor activity, "vasomotion," of precapillary arterioles was found markedly decreased in the germfree animals. All precapillary vessels in the germfree rats were markedly hyporeactive to the catecholamines, epinephrine and norepinephrine, as compared to similar vessels of conventional rats. The vessels in the germfree animals were also less responsive to vasopressin but not angiotensin. A greater lumen:wall ratio of primary arterioles, but not of secondary arterioles and metarterioles, found in germfree animals is related to change in vessel lumen alone without concomitant change in wall thickness. The germfree rat is characterized by possessing a hypotonic, catecholamine-refractory mesoappendix microvasculature.
Full Text
The Full Text of this article is available as a PDF (628.3 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BAEZ S. Response characteristics of perfused microvessels to pressure and vasoactive stimuli. Angiology. 1961 Oct;12:452–461. doi: 10.1177/000331976101201004. [DOI] [PubMed] [Google Scholar]
- Baez S. Bayliss response in the microcirculation. Fed Proc. 1968 Nov-Dec;27(6):1410–1415. [PubMed] [Google Scholar]
- Baez S. Recording of microvascular dimensions with an image-splitter television microscope. J Appl Physiol. 1966 Jan;21(1):299–301. doi: 10.1152/jappl.1966.21.1.299. [DOI] [PubMed] [Google Scholar]
- Baez S. Simultaneous measurements of radii and wall thickness of microvessels in the anesthetized rat. Circ Res. 1969 Sep;25(3):315–329. doi: 10.1161/01.res.25.3.315. [DOI] [PubMed] [Google Scholar]
- GORDON H. A., WOSTMANN B. S., BRUCKNER-KARDOSS E. EFFECTS OF MICROBIAL FLORA ON CARDIAC OUTPUT AND OTHER ELEMENTS OF BLOOD CIRCULATION. Proc Soc Exp Biol Med. 1963 Nov;114:301–304. doi: 10.3181/00379727-114-28658. [DOI] [PubMed] [Google Scholar]
- Gordon H. A., Kokas E. A bioactive pigment ("alpha pigment") in cecal contents of germ-free animals. Biochem Pharmacol. 1968 Nov;17(11):2333–2337. doi: 10.1016/0006-2952(68)90041-5. [DOI] [PubMed] [Google Scholar]
- Heneghan J. B., Peuler M., Costrini A., Cohn I., Jr Hemorrhagic shock in cecectomized germfree rats. Surg Forum. 1970;21:232–233. [PubMed] [Google Scholar]
- SHORR E., ZWEIFACH B. W., FURCHGOTT R. F., BAEZ S. Hepatorenal factors in circulatory homeostasis. IV. Tissue origins of the vasotropic principles, VEM and VDM, which appear during evolution of hemorrhagi and tourniquet shock. Circulation. 1951 Jan;3(1):42–79. doi: 10.1161/01.cir.3.1.42. [DOI] [PubMed] [Google Scholar]
- Strandberg K., Sedvall G., Midtvedt T., Gustafsson B. Effect of some biologically active amines on the cecum wall of germfree rats. Proc Soc Exp Biol Med. 1966 Mar;121(3):699–702. doi: 10.3181/00379727-121-30864. [DOI] [PubMed] [Google Scholar]
- TREXLER P. C., REYNOLDS L. I. Flexible film apparatus for the rearing and use of germfree animals. Appl Microbiol. 1957 Nov;5(6):406–412. doi: 10.1128/am.5.6.406-412.1957. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WOSTMANN B. S., KNIGHT P. L., KEELEY L. L., KAN D. F. Metabolism and function of thiamine and naphthoquinones in germfree and conventional rats. Fed Proc. 1963 Jan-Feb;22:120–124. [PubMed] [Google Scholar]
- WOSTMANN B. S. Nutrition of the germfree mammal. Ann N Y Acad Sci. 1959 May 8;78:175–182. doi: 10.1111/j.1749-6632.1959.tb53102.x. [DOI] [PubMed] [Google Scholar]
- Wostmann B. S., Bruckner-Kardoss E., Knight P. L., Jr Cecal enlargement, cardiac output, and O2 consumption in germfree rats. Proc Soc Exp Biol Med. 1968 May;128(1):137–141. doi: 10.3181/00379727-128-32962. [DOI] [PubMed] [Google Scholar]
- ZWEIFACH B. W., GORDON H. A., WAGNER M., REYNIERS J. A. Irreversible hemorrhagic shock in germfree rats. J Exp Med. 1958 Mar 1;107(3):437–450. doi: 10.1084/jem.107.3.437. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ZWEIFACH B. W. Hemorrhagic shock in germfree rats. Ann N Y Acad Sci. 1959 May 8;78:315–320. doi: 10.1111/j.1749-6632.1959.tb53116.x. [DOI] [PubMed] [Google Scholar]