OBJECTIVE: Cerebral vessels, such as intracerebral perforating arterioles isolated from rat brain, have been widely used as an ex vivo model to study the cerebrovascular function associated with cerebrovascular disorders and the therapeutic effects of various pharmacological agents. These perforating arterioles, however, have demonstrated differences in the vascular architecture and reactivity compared with a larger leptomeningeal artery which has been commonly implicated in cerebrovascular disease. In this study, therefore, we developed the method for studying cerebrovascular function utilizing the olfactory artery isolated from the mouse brain. METHODS: The olfactory artery (OA) was isolated from the C57/BL6 wild-type mouse brain. After removing connective tissues, one side of the isolated vessel segment (approximately -500 microm in length) was cannulated and the opposite end of the vessel was completely sealed while being viewed with an inverted microscope. After verifying the absence of pressure leakage, we examined the vascular reactivity to various vasoactive agents under the fixed intravascular pressure (60 mm Hg). RESULTS: We found that the isolated mouse OAs were able to constrict in response to vasoconstrictors, including KCl, phenylephrine, endothelin-1, and prostaglandin PGH2. Moreover, this isolated vessel demonstrated vasodilation in a dose-dependent manner when vasodilatory agents, acetylcholine and bradykinin, were applied. CONCLUSION: Our findings suggest that the isolated olfactory artery would provide as a useful ex vivo model to study the molecular and cellular mechanisms of vascular function underlying cerebrovascular disorders and the direct effects of such disease-modifying pathways on cerebrovascular function utilizing pharmacological agents and genetically modified mouse models.
Animals ; Arteries* ; Arterioles ; Bradykinin ; Brain ; Cerebral Arteries ; Cerebrovascular Disorders ; Cholinergic Agents ; Connective Tissue ; Endothelin-1 ; Mice* ; Phenylephrine ; Prostaglandin H2 ; Rats ; Vasoconstriction ; Vasoconstrictor Agents ; Vasodilation

OBJECTIVES: Biofilm formation is critical to dental caries initiation and development. The aim of this study was to investigate the effects of nicotine exposure on Streptococcus mutans (S. mutans) biofilm formation concomitantly with the inhibitory effects of sodium chloride (NaCl), potassium chloride (KCl) and potassium iodide (KI) salts. This study examined bacterial growth with varying concentrations of NaCl, KCl, and KI salts and nicotine levels consistent with primary levels of nicotine exposure. MATERIALS AND METHODS: A preliminary screening experiment was performed to investigate the appropriate concentrations of NaCl, KCl, and KI to use with nicotine. With the data, a S. mutans biofilm growth assay was conducted using nicotine (0–32 mg/mL) in Tryptic Soy broth supplemented with 1% sucrose with and without 0.45 M of NaCl, 0.23 M of KCl, and 0.113 M of KI. The biofilm was stained with crystal violet dye and the absorbance measured to determine biofilm formation. RESULTS: The presence of 0.45 M of NaCl, 0.23 M of KCl, and 0.113 M of KI significantly inhibited (p < 0.05) nicotine-induced S. mutans biofilm formation by 52%, 79.7%, and 64.1%, respectively. CONCLUSIONS: The results provide additional evidence regarding the biofilm-enhancing effects of nicotine and demonstrate the inhibitory influence of these salts in reducing the nicotine-induced biofilm formation. A short-term exposure to these salts may inhibit S. mutans biofilm formation.
Biofilms ; Dental Caries ; Gentian Violet ; Mass Screening ; Nicotine ; Potassium Chloride ; Potassium Iodide ; Salts ; Sodium Chloride ; Streptococcus mutans ; Streptococcus ; Sucrose

Although spermatozoa are formed during spermatogenesis in the testis, testicular spermatozoa are immature and cannot swim or fertilize. These critical spermatozoal functions are acquired in the epididymis where a specific luminal environment is created by the blood-epididymal barrier; proteins secreted by epididymal principal cells bind to maturing spermatozoa and regulate the maturational process of the spermatozoa. In the epididymis, epithelial cell-cell interactions are mediated by adhering junctions, necessary for cell adhesion, and by tight junctions, which form the blood-epididymal barrier. The regulation of these cellular junctions is thought to represent a key determinant in the process of sperm maturation within the epididymis. Tight junctions between adjacent principal cells permit the formation of a specific microenvironment in the lumen of the epididymis that is essential for sperm maturation. Although we have made significant progress in understanding epididymal function and the blood-epididymal barrier, using animal models, there is limited information on the human epididymis. If we are to understand the normal and pathological conditions attributable to human epididymal function, we must clearly establish the physiological, cellular and molecular regulation of the human epididymis, develop tools to characterize these functions and develop clinical strategies that will use epididymal functions to improve treatment of infertility.
Animals ; Blood-Testis Barrier ; physiology ; Cadherins ; metabolism ; Cell Adhesion ; Epididymis ; blood supply ; physiology ; Humans ; Male ; Membrane Proteins ; metabolism ; Occludin ; Rats ; Spermatozoa ; physiology ; Tight Junctions ; physiology

AIM: This study was aimed at evaluating the anti-diabetic activity of the ethanol and aqueous extracts of the leaf material of Barringtonia acutangula in a diabetic animal model. METHODS: The ethanolic and aqueous extracts (250 and 500 mg·kg(-1) body weight) of the leaves of B. acutangula were assessed for antidiabetic activity in a streptozotocin (STZ)-induced diabetes animal model following 21 days of treatment. Glibenclamide (0.6 mg·kg(-1) p.o.) was used as a positive control. The hematological parameters, such as blood glucose level, urea, creatinin, cholesterol, HDL-C, and LDL-C levels were examined. RESULTS: An acute toxicity study (5 000 mg·kg(-1), p.o.) did not produce any symptoms of toxicity. Significant reductions in blood glucose level, and serum total cholesterol and triglyceride levels were noted in animals treated with the extract. The high density lipoprotein-cholesterol (HDLC) level was found to increase as compared with the diabetic control group. CONCLUSION These results suggest that the leaf aqueous and ethanolic extracts of B. acutangula have anti-diabetic effects. The aqueous extract of B. acutangula produced a similar effect when compared with the ethanol extract. It is proposed that consumption of B. acutangula in some form like tea may help the management of diabetes.
Animals ; Barringtonia ; Blood Glucose ; metabolism ; Cholesterol ; blood ; Cholesterol, HDL ; blood ; Diabetes Mellitus, Experimental ; blood ; drug therapy ; Hypoglycemic Agents ; pharmacology ; therapeutic use ; Lipids ; blood ; Male ; Phytotherapy ; Plant Extracts ; pharmacology ; therapeutic use ; Plant Leaves ; Rats ; Rats, Wistar ; Triglycerides ; blood