Changes in Gastric Smooth Muscle Cell Contraction during Pregnancy: Effect of Estrogen

Synthesis, Regulatory Factors, and Signaling Pathways of Estrogen in the Ovary

New insights have been thrown for understanding the significant role of estrogen on various systems of humans. Increasing evidences have determined the significant roles of estrogen in female reproductive system. So, the normal synthesis and secretion of estrogen play important roles in maintaining the function of tissues and organs. The ovaries are the main synthetic organs of estrogen. In this review, we summarized the current knowledge of the estrogen synthesis in the ovaries. A series of factors and signaling pathways that regulate the synthesis of estrogen are expounded in detail. Understanding the regulating factors and potential mechanism related to estrogen synthesis will be beneficial for understanding estrogen disorder related diseases and may provide novel therapeutic targets.

Progesterone Inhibitory Role on Gastrointestinal Motility

Progesterone is a steroidal hormone that is produced from the corpus luteum of the ovaries and from the placenta. The main function of progesterone is to promote the secretory differentiation in the endometrium of the uterus and to maintain pregnancy by inhibiting uterine contractions throughout pregnancy. Progesterone performs its actions by activating the classical progesterone nuclear receptors that affect gene transcription and by the non-classical activation of cell surface membrane receptors that accounts for the rapid actions of progesterone. Besides the reproductive roles of progesterone, it exerts functions in many tissues and systems such as the nervous system, the bone, the vascular system, and the gastrointestinal (GI) tract. This review will summarize the recent literature that investigated the role of progesterone in GI tract motility. Most literature indicates that progesterone exerts an inhibitory role on gut smooth muscle cells in part by elevating nitric oxide synthesis, which induces relaxation in smooth muscle. Moreover, progesterone inhibits the signaling pathways that lead to contraction such as Rho kinase inhibition. These data serve as a quick resource for the future directions of progesterone research that could lead to better understanding and more effective treatment of gender-related GI tract motility disorders.

The therapeutic effect of bromocriptine as mesylate and estradiol valerate on serum and blood biochemistry of common quails

Hematology and serum biochemistry study may provide antique knowledge about the physical status of individuals, making them a valuable tool to differentiate healthy animals from affected animals. We aimed to investigate Steroid safety levels in birds through ex-situ studies at regular therapeutic doses. A total of 100 birds were used for hematology and serum biochemistry. This study was designed into 2 trials over the summer and winter, each comprised 5, 10, 15, and 20 d. Each study group was based on 5 control group birds and 20 experimental group birds. A sum of 2 groups representing 2 different steroids trial groups was treated with therapeutic doses to the stretch of 5, 10, 15, and 20 d each season. A therapeutic dose of each of the steroids was given at the rate of 3 drops 2 times a day to each bird. Analysis of data reveals that steroids had severe effects on bird's (Coturnix coturnix) hematological parameters. In most trials, the hematological effects of bromocriptine as mesylate showed an increase in red blood cell count and white blood cell count. On the other hand, steroid estradiol valerate showed a decrease in these parameters. Effect of steroids on serum biochemistry profile indicate acute damage to vital organs, especially to liver and kidney, indicating an increase in cholesterol, total protein, albumin, urea, and uric acid. The overall effect of steroids on the bird's serum and biochemistry of quails were nearly similar but different only in their intensity.

Calcium and potassium channels are involved in curcumin relaxant effect on tracheal smooth muscles

Context: Curcumin, the active component of Curcuma longa L. (Zingiberaceae), exhibits a wide variety of biological activities including vasodilation and anti-inflammation.Objective: The relaxant effect of curcumin in tracheal smooth muscle (TSM) was not examined so far, thus, this study was designed to assess the relaxant effect of curcumin on rat TSM and examine the underlying mechanism(s) responsible for this effect.Materials and methods: TSM was contracted by KCl (60 mM) or methacholine (10 μM), and cumulative concentrations of curcumin (12.5, 25, 50, and 100 mg/mL) or theophylline (0.2, 0.4, 0.6, and 0.8 mM, as positive control) were added to organ bath. The relaxant effect of curcumin was examined in non-incubated or incubated tissues with atropine (1 μM), chlorpheniramine (1 μM), indomethacin (1 μM), and papaverine (100 μM).Results: In non-incubated TSM, curcumin showed significant relaxant effects on KCl-induced contraction in a concentration-dependent manner (p < 0.001 for all concentrations). The relaxant effects of curcumin 12.5, 25, and 50 mg/mL were significantly lower in atropine-incubated tissue compared to non-incubated TSM (p < 0.05 to p < 0.001). A significant difference was observed in EC₅₀ between atropine-incubated (48.10 ± 2.55) and non-incubated (41.65 ± 1.81) tissues (p < 0.05). Theophylline showed a significant relaxant effect on both KCl and methacholine-induced contraction in a concentration-dependent manner (p < 0.001 for all cases).Conclusions: The results indicated a relatively potent relaxant effect of curcumin on TSM, which was less marked than the effect of theophylline. Calcium channel blocking and/or potassium channel opening properties of curcumin may be responsible for TSM relaxation.