Gender-Related Differences of Tachykinin NK Receptor Expression and Activity in Human Colonic Smooth Muscle.

The tachykinin NK receptor plays a key role in gastrointestinal motor function. Enteric neurons release neurokinin A (NKA), which activates NK receptors on gastrointestinal smooth muscle, leading to contraction and increased motility. In patients with diarrhea-predominant irritable bowel syndrome, the NK receptor antagonist ibodutant had a greater therapeutic effect in females than males.

Obesity up-regulates intermediate conductance calcium-activated potassium channels and myoendothelial gap junctions to maintain endothelial vasodilator function.

The mechanisms involved in altered endothelial function in obesity-related cardiovascular disease are poorly understood. This study investigates the effect of chronic obesity on endothelium-dependent vasodilation and the relative contribution of nitric oxide (NO), calcium-activated potassium channels (K(Ca)), and myoendothelial gap junctions (MEGJs) in the rat saphenous artery. Obesity was induced by feeding rats a cafeteria-style diet (∼30 kJ as fat) for 16 to 20 weeks, with this model reflecting human dietary obesity etiology.