The implications of the purinergic signaling throughout pregnancy.

Purinergic signaling is a necessary mechanism to trigger or even amplify cell communication. Its ligands, notably adenosine triphosphate (ATP) and adenosine, modulate specific membrane-bound receptors in virtually all human cells. Regardless of the stage of the pregnancy, cellular communication between maternal, placental, and fetal cells is the paramount mechanism to sustain its optimal status. In this review, we describe the crucial role of purinergic signaling on the regulation of the maternal-fetal trophic exchanges, immune control, and endocrine exchanges throughout pregnancy. The nature of the modulation of both ATP and adenosine on the embryo-maternal interface, going through placental invasion until birth delivery depends on the general maternal-fetal health state and consequently on the selective activation of their specific receptors. In addition, an increasing number of studies have been demonstrating the pivotal role of ATP and adenosine in modulating deleterious effects of suboptimal conditions of pregnancy. Here, we discuss the role of purinergic signaling on the balance that coordinates the embryo-maternal exchanges and a promising therapeutic venue in the context of pregnancy disorders.

Testosterone replacement maintains smooth muscle content in the corpus cavernosum of orchiectomized rats.

OBJECTIVE: To evaluate the effects of testosterone (T) on the maintenance of corpus cavernosum (CC) structure and apoptosis. METHODS: Animals were divided into three groups: sham operation group (n = 8) underwent sham operation; Orchiectomized (Orchiec)+ oily vehicle group (n = 8) underwent bilateral orchiectomy and received a single dose of oily vehicle by intramuscular injection (i.m.) 30 days after orchiectomy; and Orchiec + T group (n = 8) underwent bilateral orchiectomy and received a single dose of T undecanoate 100 mg/kg i.m. 30 days after the surgery. Animals were euthanized 60 days after the beginning of the experiment with an anesthetic overdose of ketamine and xylazine. Blood samples and penile tissue were collected on euthanasia. Azan's trichrome staining was used to evaluate smooth muscle, Weigert's Fucsin-Resorcin staining was used to evaluate elastic fibers and Picrosirius red staining was used to evaluate collagen. Apoptosis was evaluated using TUNEL technique. RESULTS: T levels decreased in Orchiec + oily vehicle when compared to sham operation and Orchiec + T groups (p < 0.001). T deprivation reduced trabecular smooth muscle content and penile diameter and T replacement maintained both parameters (p = 0.005 and p = 0.001, respectively). No difference was observed in the content of sinusoidal space (p = 0.207), elastic fibers (p = 0.849), collagen (p = 0.216) and in apoptosis (p = 0.095). CONCLUSION: Normal testosterone levels maintain CC smooth muscle content and do not influence elastic fibers, collagen content and apoptotic index. Further studies should be performed in order to investigate the mechanisms by which androgen mediates its effects on CC structure.