Effects of different vasopressors on the contraction of the superior mesenteric artery and uterine artery in rats during late pregnancy

Salt Restriction and Angiotensin-Converting Enzyme Inhibitor Improve the Responsiveness of the Small Artery in Salt-Sensitive Hypertension

For salt-sensitive hypertension (SSH), salt restriction and angiotensin-converting enzyme (ACE) inhibitors are essential treatments, but their effect on the function of resistance arteries is unclear. Here, we present an intravital study to detect the effect of salt restriction and ACE inhibitors on the function of the mesenteric small artery (MSA) in SSH. Dahl salt-sensitive rats were randomized into the following groups: ACE inhibitor gavage, salt restriction, ACE inhibitor combined with salt restriction, and high-salt diet. After a 12-week intervention, the mesenteric vessels maintained their perfusion in vivo, and the changes in the diameter and blood perfusion of the MSAs to norepinephrine (NE) and acetylcholine (ACh) were detected. Switching from a high-salt diet to a low-salt diet (i.e., salt restriction) attenuated the vasoconstriction of the MSAs to NE and promoted the vasodilatation to ACh, while ACE inhibitor improved the vasodilatation more obviously. Pathologically, changes in local ACE, AT1R, and eNOS expression were involved in these processes induced by a high-salt diet. Our study suggests that salt restriction and ACE inhibitor treatment improve high salt intake-induced MSA dysfunction in SSH, and salt restriction is a feasible and effective treatment. Our findings may provide a scientific basis for the treatment of hypertension.

Resuscitation of the Obstetric Patient

Pregnancy is a time of tremendous physiologic change and vulnerability. At any point, symptoms and complications can prompt the need for emergency care, and these can range from minor to life-threatening. Emergency physicians must be prepared to treat any of these complications, in addition to rescucitating the critically ill and injured pregnant patient. To optimally care for these patients, it is paramount to be aware of the unique physiologic changes that occur during pregnancy. The focus of this review is to discuss illnesses unique to pregnancy and additional aspects of resuscitation that must be considered when caring for a critically ill pregnant patient.