Baicalin relieves neuropathic pain by regulating α2-adrenoceptor levels in rats following spinal nerve injury

In the present study, the ability of baicalin to relieve neuropathic pain due to spinal nerve ligation in rats was explored, and the relationship between baicalin and α₂-adrenoceptors (α₂-AR) was determined. The neuropathic pain model was established by ligating the L5-L6 spinal nerves in Sprague-Dawley rats. Several α₂-AR antagonists were injected into the intramedullary sheath to evaluate the role of baicalin in neuropathic pain. The antagonists included nonselective α₂-AR antagonist idazoxan, α_2a-AR antagonist BRL 44408, α_2b-AR antagonist ARC 239 and α_2c-AR antagonist JP 1302. The rats were divided into an untreated control group, saline group, baicalin group and baicalin + α₂-AR antagonist groups. Paw withdrawal threshold (PWT) was tested to assess the level of pain felt by the rats. The levels of α₂-AR mRNA were tested by reverse transcription-quantitative PCR. Inflammatory factors, including tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-17 and IL-1β, were analyzed by ELISA. The histopathological changes were assessed by hematoxylin and eosin staining. Flow cytometry was used to examine the percentage of CD4⁺ peripheral blood mononuclear cells (PBMCs). Compared with the saline group, the PWT value increased after treating with baicalin. However, intrathecal injection of α₂-AR antagonist reversed the antinociceptive effects of baicalin. Compared with the saline group, the expression of α_2a-AR and α_2c-AR mRNA was upregulated significantly in the baicalin group (P<0.05). Levels of α₂-AR mRNA were also decreased in the baicalin + idazoxan group compared with the baicalin group (P<0.05). The levels of TNF-α, IL-6, IL-17 and IL-1β were raised after treatment with baicalin. In addition, baicalin treatment ameliorated the histological damage in the spinal cord. The percentage of CD4⁺ PBMCs was increased in the saline group compared with the control group (P<0.05). Compared with the baicalin group, the percentage of CD4+ PBMCs was raised after treatment with the α₂-AR antagonists. In conclusion, intrathecal injection of baicalin produced an antiallodynic effect in a spinal nerve ligation-induced neuropathic pain model. The mechanism may be related to the regulation of a₂-AR expression.

Effect of a 12-Week Aerobic Exercise Training on Serum Fetuin-A and Adipocytokine Levels in Type 2 Diabetes

OBJECTIVE

We aimed to evaluate the effect of 12-week aerobic exercise training on fetuin-A levels in type 2 diabetes mellitus and examine the relationships between fetuin-A and adipocytokine levels and cardiovascular risk factors.

METHODS

The study included 32 patients with type 2 diabetes mellitus who were assigned to an exercise or a control group. The exercise group underwent 12 weeks of exercise (consisting of a 5-min warm-up, 60-min aerobic bicycle training performed at 70% of the maximal heart rate, a cool-down period, 5 times/week). Adiponectin, resistin, and fetuin-A serum levels were measured using enzyme-linked immunosorbent assay. Leptin serum levels were measured by a radioimmunoassay.

RESULTS

Exercise for 12 weeks significantly reduced serum fetuin-A (643.1±109.4 to 448.7±92.5 μg/mL, P<0.05), leptin (11.9±7.2 to 8.6±5.7 ng/dL, P<0.05), and resistin (3.2±1.5 to 2.2±1.4 ng/mL, P<0.05) levels, but increased adiponectin (6.9±1.9 to 8.1±1.7 µg/mL, P<0.05) levels. In the exercise group, Δfetuin-A positively correlated with differences in weight (r=0.654, P=0.046), body mass index (r=0.725, P=0.002), waist circumference (r=0.898, P=0.013), and adiponectin levels (r=0.662, P=0.035).

CONCLUSIONS

Aerobic exercise significantly decreased serum fetuin-A levels in type 2 diabetes mellitus, which can be attributed to weight loss and related to increased adiponectin levels.

Fine structure of the acinar and duct cell components in the parotid and submandibular salivary glands of the rat: a TEM, SEM, and HRSEM study

Parenchymal and stromal components of the rat parotid and submandibular glands were examined by conventional and high resolution scanning electron microscopy (HRSEM). Freeze-fractured specimens were subjected to HCl and NaOH extraction procedures to better differentiate connective tissue and cellular components. In addition, the internal three-dimensional morphology of the secretory acinar cells and duct cells was revealed by maceration with a dilute osmium tetroxide solution to selectively remove some of the cytoplasmic components. SEM and HRSEM examination of the HCl-treated samples of both glands revealed a fine filamentous network immediately surrounding each acinus. Coarser bundles of collagen that linked neighboring acini were also observed. NaOH-extracted samples selectively removed the cellular components and showed more clearly the three-dimensional structure of the connective-tissue stroma. A dense-collagenous network surrounded each lobule while more internal regions consisted of a honeycomb-like pattern of evacuated spaces previously occupied by secretory acini. These spaces were smoothened in appearance and often interconnected. Apically-located secretory granules and profiles of the rough endoplasmic reticulum and Golgi apparatus in perinuclear regions were encountered in the acinar and duct cells of macerated samples by HRSEM. In addition, a phenylephrine-induced experimental condition performed in some rats resulted in a significant increase in secretory granule size and density of the serous cells.

Ultracytochemical study of trimetaphosphatase activity during acrosomal formation in the mouse testis

The localization of Trimetaphosphatase (TMPase) activity during the acrosomal formation in the mouse testis was enzyme cytochemically investigated by the cerium-salt method. In addition to the lysosomes of the Sertoli cells and the spermatogenic cells in the seminiferous tubules, positive TMPase activity was detected in the Golgi complex and in the acrosomal vesicles of the spermatids, as well as in the acrosomes of both spermatids and spermatozoa. In the Golgi complex of the spermatids, TMPase activity was observed in the first one or two lamellae of the trans-face and in the small vesicles in the vicinity of the Golgi complex. TMPase positive reaction was also detected in the acrosomes of the spermatozoa in the lumina of both the seminiferous tubules and the epididymal duct. The localization of this enzyme activity was compared with that of acid phosphatase (ACPase), as detected by the cerium-based method, using beta-glycerophosphate as substrate: ACPase activity was completely absent from the Golgi complex, small vesicles, acrosomal vesicle and acrosome throughout the entire process of acrosomal formation. TMPase is thought to become one of the acrosomal components, and may be involved in the acrosomal reaction during fertilization.