{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,11]],"date-time":"2026-05-11T13:08:45Z","timestamp":1778504925565,"version":"3.51.4"},"reference-count":23,"publisher":"American Physiological Society","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["American Journal of Physiology-Heart and Circulatory Physiology"],"published-print":{"date-parts":[[2005,4]]},"abstract":"<jats:p> This study compared the vasodilatory responses to magnesium sulfate (MgSO<jats:sub>4<\/jats:sub>) of cerebral and mesenteric resistance arteries and determined whether the responses varied between different gestational groups. Third-order branches (&lt;200 \u03bcm) of the posterior cerebral (PCA) and mesenteric arteries (MA) were dissected from nonpregnant (NP; n = 6), late pregnant (LP; day 19, n = 6), and postpartum (PP; day 3, n = 6) Sprague-Dawley rats. A concentration-response curve was performed by replacing the low-MgSO<jats:sub>4<\/jats:sub> (1.2 mM) HEPES buffer solution with increasing concentrations of MgSO<jats:sub>4<\/jats:sub> (4, 6, 8, 16, and 32 mM) and measuring lumen diameter at each concentration. All groups exhibited concentration-dependent dilation to MgSO<jats:sub>4<\/jats:sub>, decreasing the amount of tone in the vessels. However, MA were significantly more sensitive to MgSO<jats:sub>4<\/jats:sub> than PCA. Whereas there was no difference in the response between different gestational groups in MA, the PCA from the LP and PP groups showed a significantly diminished response to MgSO<jats:sub>4<\/jats:sub>. The percent dilation at 32 mM MgSO<jats:sub>4<\/jats:sub> for PCA versus MA in NP, LP, and PP animals was 36 \u00b1 2 vs. 51 \u00b1 7% ( P &lt; 0.05), 19 \u00b1 9 vs. 54 \u00b1 6% ( P &lt; 0.01 vs. PCA and NP), and 12 \u00b1 5 vs. 52 \u00b1 11% ( P &lt; 0.01 vs. PCA and NP). These results demonstrate that MgSO<jats:sub>4<\/jats:sub> is a vasodilator of small resistance arteries in the cerebral and mesenteric vascular beds. The refractory responses of the PCA in LP and PP groups demonstrate changes in the cerebrovascular vasodilatory mechanisms with gestation. The greater sensitivity of the MA to MgSO<jats:sub>4<\/jats:sub>-induced vasodilation suggests that the prophylactic effect of MgSO<jats:sub>4<\/jats:sub> on eclamptic seizures may be more closely related to the lowering of systemic blood pressure than to an effect on cerebral blood flow. <\/jats:p>","DOI":"10.1152\/ajpheart.00994.2004","type":"journal-article","created":{"date-parts":[[2004,12,3]],"date-time":"2004-12-03T01:19:00Z","timestamp":1102036740000},"page":"H1521-H1525","source":"Crossref","is-referenced-by-count":37,"title":["Resistance artery vasodilation to magnesium sulfate during pregnancy and the postpartum state"],"prefix":"10.1152","volume":"288","author":[{"given":"Anna G.","family":"Euser","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marilyn J.","family":"Cipolla","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"24","reference":[{"key":"R1","doi-asserted-by":"publisher","DOI":"10.1093\/cvr\/27.9.1629"},{"key":"R2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa021180"},{"key":"R3","doi-asserted-by":"publisher","DOI":"10.1016\/S0002-9378(11)91567-1"},{"key":"R4","doi-asserted-by":"publisher","DOI":"10.3109\/00016349309058156"},{"key":"R5","doi-asserted-by":"publisher","DOI":"10.1067\/mob.2002.125241"},{"key":"R6","doi-asserted-by":"publisher","DOI":"10.1161\/01.STR.29.6.1223"},{"key":"R7","doi-asserted-by":"publisher","DOI":"10.1152\/ajpheart.01154.2003"},{"key":"R8","doi-asserted-by":"publisher","DOI":"10.1007\/s002340000439"},{"key":"R9","doi-asserted-by":"publisher","DOI":"10.1097\/00004872-199501000-00002"},{"key":"R10","doi-asserted-by":"publisher","DOI":"10.1097\/00127893-200111000-00005"},{"key":"R11","doi-asserted-by":"publisher","DOI":"10.1139\/y01-046"},{"key":"R12","unstructured":"Ku DN and Zhu C. The mechanical environment of the artery. In: Hemodynamic Forces and Vascular Cell Biology, edited by Sumpio BE. Austin, TX: Landes, 1993, chapt. 1, p. 1\u201323."},{"key":"R13","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199403033300907"},{"key":"R14","doi-asserted-by":"publisher","DOI":"10.1067\/mob.2001.112587"},{"key":"R15","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199507273330401"},{"key":"R16","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(02)08778-0"},{"key":"R17","unstructured":"Manfredi M, Beltramello A, Bongiovanni LG, Polo A, Pistoia L, and Rizzuto N. Eclamptic encephalopathy: imaging and pathogenetic considerations. Acta Neurol Scand 96: 277\u2013282, 1997."},{"key":"R18","doi-asserted-by":"crossref","unstructured":"Perales AJ, Torregrosa G, Salom JB, Miranda FJ, Alabadi JA, Monleon J, and Alborch E. In vivo and in vitro effects of magnesium sulfate in the cerebrovascular bed of the goat. Am J Obstet Gynecol 165: 1534\u20131538, 1991.","DOI":"10.1016\/S0002-9378(12)90795-4"},{"key":"R19","doi-asserted-by":"publisher","DOI":"10.1161\/01.HYP.0000054981.03589.E9"},{"key":"R20","doi-asserted-by":"publisher","DOI":"10.1042\/cs0960313"},{"key":"R21","doi-asserted-by":"publisher","DOI":"10.1203\/00006450-199606000-00029"},{"key":"R22","doi-asserted-by":"crossref","unstructured":"Witlin AG and Sibai BM. Magnesium sulfate therapy in preeclampsia and eclampsia. Obstet Gynecol 92: 883\u2013889, 1998.","DOI":"10.1097\/00006250-199811000-00028"},{"key":"R23","unstructured":"Wityk RJ and Pessin MS. Hypertensive encephalopathy. In: Cerebrovascular Disease, edited by Batjer HH. Philadelphia, PA: Lippencott-Raven, 1997, chapt. 8, p. 97\u2013102."}],"container-title":["American Journal of Physiology-Heart and Circulatory Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.physiology.org\/doi\/pdf\/10.1152\/ajpheart.00994.2004","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,9,8]],"date-time":"2019-09-08T19:10:49Z","timestamp":1567969849000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.physiology.org\/doi\/10.1152\/ajpheart.00994.2004"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2005,4]]},"references-count":23,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2005,4]]}},"alternative-id":["10.1152\/ajpheart.00994.2004"],"URL":"https:\/\/doi.org\/10.1152\/ajpheart.00994.2004","relation":{},"ISSN":["0363-6135","1522-1539"],"issn-type":[{"value":"0363-6135","type":"print"},{"value":"1522-1539","type":"electronic"}],"subject":[],"published":{"date-parts":[[2005,4]]}}}