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Regulation of the vasomotor activity of lymph microvessels by nitric oxide and prostaglandins.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Mizuno, Risuke Koller, Annick Kaley, Gabor |
| Copyright Year | 1998 |
| Abstract | It was shown previously that the presence of endothelium modulates spontaneous vasomotion of small lymphatic vessels. In the present study, we aimed to elucidate the nature of endothelium-derived factors, produced in basal conditions and in response to agonists, that affect the smooth muscle tone of lymph microvessels in vitro. Afferent lymph microvessels were isolated from rat iliac lymph nodes, cannulated with glass micropipettes, and pressurized (6 cmH2O), and changes in their diameter were investigated with video microscopy. In resting conditions, isolated lymph vessels exhibited spontaneous constrictions and dilations. The maximum and minimum diameters (Dmax and Dmin) were 149.8 +/- 2.9 and 85.8 +/- 3.6 microns, respectively. Acetylcholine (ACh, 10(-7) to 10(-5) M) and sodium nitroprusside (SNP, 10(-8) to 10(-6) M) temporarily abolished diameter oscillations, increasing the diameter of lymphatics dose dependently. For example, 10(-5) M ACh and 10(-6) M SNP increased the diameter (Dmax) by 15.2 +/- 2.2 and 25.0 +/- 2.7 microns, respectively. Treatment of vessels with NG-nitro-L-arginine (10(-4) M) significantly reduced the amplitude of diameter oscillations and nearly completely eliminated ACh-induced dilation of lymph microvessels, whereas SNP (10(-6) M) elicited a significantly greater dilation (55.6 +/- 7.5 microns). Arachidonic acid (AA, 10(-8) to 10(-6) M) constricted (up to 50 microns), whereas prostaglandin E2 (PGE2, 10(-9) to 10(-7) M) dilated (up to 40 microns), lymphatic vessels. Indomethacin (10(-5) M) increased both Dmax and Dmin and completely inhibited AA-induced constrictions, but did not affect PGE2-induced dilations of lymph microvessels. AA-induced constrictions of lymphatics were converted into dilations after treatment with SQ-29,548, a selective PGH2-thromboxane A2 (PGH2-TxA2, 10(-6) M) receptor antagonist, whereas PGE2-induced dilations were not affected. We conclude that endothelial nitric oxide and prostaglandins are important modulators of lymphatic vasomotion, hence pumping activity of lymph microvessels in vivo. |
| Starting Page | 1 |
| Ending Page | 8 |
| Page Count | 8 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://ajpregu.physiology.org/content/ajpregu/274/3/R790.full.pdf |
| Alternate Webpage(s) | http://ajpregu.physiology.org/content/ajpregu/274/3/r790.full.pdf |
| PubMed reference number | 9530247v1 |
| Volume Number | 274 |
| Issue Number | 3 |
| Part | 2 |
| Journal | The American journal of physiology |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Acetylcholine Amino Acids Arachidonic Acid Arginine Blood Vessel Bone structure of ilium Centimeters of Water Common iliac lymph node Constriction procedure Diameter (qualifier value) Dilate procedure Dinoprostone In Vitro [Publication Type] Indomethacin Lymphadenopathy Lymphatic System Lymphatic vessel Micron Microscopy, Video Microvessels Muscle Tonus NG-Nitroarginine Methyl Ester Nitric Oxide Nitroarginine Nitroprusside Pathological Dilatation Prostaglandins Rest Smooth muscle (tissue) lymph nodes pump (device) vasomotion |
| Content Type | Text |
| Resource Type | Article |
