Pioglitazone enhances small-sized adipocyte proliferation in subcutaneous adipose tissue.

The possibility that mature adipocytes proliferate has not been fully investigated. In this study, we demonstrate that adipocytes can proliferate. 5-bromo-2'-deoxyuridine (BrdU)-labeled adipocyte like cells, most of which were less than 30 µm in diameter, were observed in adipose tissue. Proliferating cell nuclear antigen (PCNA) was simultaneously detected in BrdU-labeled nuclei. Observation of individual mature adipocytes of smeared specimens on glass slides revealed that small sized adipocytes more frequently incorporated BrdU. Cultured mature adipocytes using the ceiling-cultured method showed clustering of proliferating cells in small-sized adipocytes. These small cultured adipocytes, but not large ones, extensively incorporated BrdU. Quantified analysis of BrdU incorporation demonstrated that mature visceral adipocytes, including epididymal, mesenteric and perirenal adipocytes, proliferated more actively than subcutaneous ones. On the other hand, treatment with pioglitazone (Pio), a ligand of peroxisome proliferator-activated receptor γ, containing food for 2w, elevated BrdU incorporation and expression of PCNA in mature adipocytes isolated from subcutaneous, but not visceral adipose tissue. Moreover, Pio induced increased BrdU-labeled small-sized subcutaneous adipocytes, which was associated with an increased number of total small adipocytes in subcutaneous adipose tissue. In conclusion, mature adipocytes have a subgroup representing the potential to replicate, and this proliferation is more active in visceral adipocytes. Treatment with Pio increases proliferation in subcutaneous adipocytes. These results may explain the mechanism of Pio-induced hyperplasia especially in subcutaneous adipocytes.

Effect of royal jelly ingestion for six months on healthy volunteers.

BACKGROUND: Royal jelly is a widely ingested supplement for health, but its effects on humans are not well known. The objective was to evaluate the effects of long-term royal jelly ingestion on humans. METHODS: We conducted a randomized placebo-controlled, double-blind trial. A total of 61 healthy volunteers aged 42-83 years were enrolled and were randomly divided into a royal jelly group (n = 31) and a control group (n = 30). Three thousand mg of royal jelly (RJ) or a placebo in 100 ml liquid/day were ingested for 6 months. The primary outcomes were changes in anthropometric measurements and biochemical indexes from baseline to 6 months after intervention. RESULTS: Thirty subjects in the RJ group and 26 in the control group were included in the analysis of endpoints. In an adjusted mean change of the variables from the baseline, significant differences between the two groups could be found in red blood cell counts (+0.16x106/µL for the RJ group vs. -0.01x106/µL for the control group, P = 0.0134), hematocrit (+0.9% vs. -0.8%, P = 0.0251), log (fasting plasma glucose) (+0.01 ± 0.01 log mg/dL vs. +0.05 ± 0.01 log mg/dL, P = 0.0297), log (insulinogenic index) (+0.25 vs. -0.13, P = 0.0319), log dehydroepiandrosterone sulfate (DHEA-S) (+0.08 log µg/dL vs. +0.20 log µg/dL, P = 0.0483), log testosterone (T) (+0.12 ± 0.04 log ng/mL vs. -0.02 ± 0.05 log ng/mL, P = 0.0416), log T/DHEA-S ratio (+0.05 ± 0.05 vs. -0.23 ± 0.59, P = 0.0015), and in one of the SF-36 subscale scores, mental health (MH) (+4 vs. -7, P = 0.0276). CONCLUSIONS: Six-month ingestion of RJ in humans improved erythropoiesis, glucose tolerance and mental health. Acceleration of conversion from DHEA-S to T by RJ may have been observed among these favorable effects.

Lindera strychnifolia is protective against post-ischemic myocardial dysfunction through scavenging hydroxyl radicals and opening the mitochondrial KATP channels in isolated rat hearts.

Lindera strychnifolia (tendai-uyaku), a medicinal plant, has long been used for the treatment of cardiac, renal and rheumatic diseases in Japan. We aim to clarify (1) whether L. strychnifolia is protective against post-ischemic myocardial dysfunction, and (2) whether its effect is related to scavenging hydroxyl radicals and opening the mitochondrial KATP channels in isolated rat hearts. Male Sprague-Dawley rats were orally given 1 ml/day of L. strychnifolia, which was extracted from 0.75 and 1.5 g/kg of roots of L. strychnifolia for 4 days. The rat hearts were excised and perfused on a Langendorff apparatus with Krebs-Henseleit solution with a gas mixture of 95% O2 and 5% CO2. The hearts were paced at 320 beats/min except during ischemia. Left ventricular developed pressure (LVDP, mmHg), +/- dP/dt (mmHg/sec) and coronary flow (ml/min) were continuously monitored. All hearts were perfused for a total of 120 minutes consisting of a 30-minute pre-ischemic period followed by 30 minutes of global ischemia and 60 minutes of reperfusion with or without 5-HD, a mitochondrial KATP channel blocker. The levels of lactate, LDH and 2,5-DHBA, an indicator of hydroxyl radicals, in the perfusate during reperfusion period were also measured. Treatment with L. strychnifolia significantly improved LVDP and +/- dP/dt without altering coronary flow during reperfusion. The 100 microM of 5-HD in Krebs-Henseleit solution was perfused during the 10 minutes of pre-ischemic periods. Pretreatment with 5-HD abolished the improvement of LVDP and +/- dP/dt by L. strychnifolia. L. strychnifolia significantly attenuated the levels of lactate, LDH and 2,5-DHBA during reperfusion, and which were restored by pretreatment with 5-HD. In conclusion, L. strychnifolia is protective against post-ischemic left ventricular dysfunction through scavenging hydroxyl radicals and opening the KATP channels in the isolated rat heart.

Acceleration of the healing process and myocardial regeneration may be important as a mechanism of improvement of cardiac function and remodeling by postinfarction granulocyte colony-stimulating factor treatment.

BACKGROUND: We investigated whether the improvement of cardiac function and remodeling after myocardial infarction (MI) by granulocyte colony-stimulating factor (G-CSF) relates to acceleration of the healing process, in addition to myocardial regeneration. METHODS AND RESULTS: In a 30-minute coronary occlusion and reperfusion rabbit model, saline (S) or 10 microg x kg(-1) x d(-1) of human recombinant G-CSF (G) was injected subcutaneously from 1 to 5 days after MI. Smaller left ventricular (LV) dimension, increased LV ejection fraction, and thicker infarct-LV wall were seen in G at 3 months after MI. At 2, 7, and 14 days and 3 months after MI, necrotic tissue areas were 14.2+/-1.5/13.4+/-1.1, 0.4+/-0.1/1.8+/-0.5*, 0/0, and 0/0 mm2 x slice(-1) x kg(-1), granulation areas 0/0, 4.0+/-0.7/8.5+/-1.0*, 3.9+/-0.8/5.7+/-0.7,* and 0/0 mm2 x slice(-1) x kg(-1), and scar areas 0/0, 0/0, 0/0, and 4.2+/-0.5/7.9+/-0.9* mm2 x slice(-1) x kg(-1) in G and S, respectively (*P<0.05, G versus S). Clear increases of macrophages and of matrix metalloproteinases (MMP) 1 and 9 were seen in G at 7 days after MI. This suggests that G accelerates absorption of necrotic tissues via increase of macrophages and reduces granulation and scar tissues via expression of MMPs. Meanwhile, surviving myocardial tissue areas within the risk areas were significantly increased in G despite there being no difference in LV weight, LV wall area, or cardiomyocyte size between G and S. Confocal microscopy revealed significant increases of cardiomyocytes with positive 3,3,3',3'-tetramethylindocarbocyanine perchlorate and positive troponin I in G, suggesting enhanced myocardial regeneration by G. CONCLUSIONS: The acceleration of the healing process and myocardial regeneration may play an important role for the beneficial effect of post-MI G-CSF treatment.

Up-regulation of cochlear aquaporin-3 mRNA expression after intra-endolymphatic sac application of dexamethasone.

The final aim of the present study is to see if the endolymphatic sac is really available as a drug delivery system to have effect on the inner ear organs. In the present study, we examined effects of a single insertion of dexamethasone into the rat unilateral endolymphatic sac on mRNA expression of the inner ear aquaporin (AQP) family, transmembrane water transporters and putative endolymphatic fluid modulators, by means of real-time quantitative PCR. Only AQP-3 mRNA expression in the ipsilateral cochlea was significantly up-regulated in comparison with controls and the up-regulation was demonstrated both in dose-dependent and time-dependent manners. These findings suggest that the intra-endolymphatic sac steroids could make regulatory effects on the inner ear AQP-3 expression via vestibular aqueduct and modulate the homeostasis of endolymphatic fluids, encouraging the possibility that the endolymphatic sac could be a therapeutic window for the inner ear disease.

The role of serotonin in ischemic cellular damage and the infarct size-reducing effect of sarpogrelate, a 5-hydroxytryptamine-2 receptor blocker, in rabbit hearts.

OBJECTIVE: We aimed to clarify the relation between sarpogrelate (SG), a 5-hydroxytryptamine (5-HT)-2 receptor blocker, and myocardial interstitial serotonin or infarct size during ischemia and reperfusion. BACKGROUND: In cardiac tissues serotonin is rich in vascular platelets, mast cells, sympathetic nerve endings, and the receptors are present in platelets and cardiomyocytes. METHODS: The myocardial interstitial serotonin levels were measured using a microdialysis technique during 30-min ischemia with and without SG in in vivo as well as isolated rabbit hearts. Other rabbits underwent 30 min of ischemia and 48 h of reperfusion, and the effect of SG on the infarct size was investigated in the absence and presence of a selective protein kinase C (PKC) inhibitor, chelerythrine (5 mg/kg, intravenously), or a mitochondrial adenosine triphosphate sensitive potassium (KATP) channel blocker, 5-hydroxydecanoate (5-HD) (5 mg/kg, intravenously). In another series, the effect of SG on PKC isoforms in cytosol and membrane fraction was assessed after a 20-min global ischemia in isolated rabbit hearts. RESULTS: Interstitial serotonin levels were markedly increased during 30-min ischemia in in vivo and isolated hearts, and the increases were inhibited by SG in each. The infarct size was reduced by SG (27 +/- 2% vs. 40 +/- 3% of control). This effect was blocked by chelerythrine and 5-HD, respectively. Sarpogrelate further enhanced the ischemia-induced translocation of PKC-epsilon to the membrane fraction. CONCLUSIONS: Sarpogrelate reduces the myocardial infarct size by inhibiting the serotonin release followed by enhancement of PKC-epsilon translocation and opening of the mitochondrial KATP channel in ischemic myocytes.

Sheng-Mai-San is protective against post-ischemic myocardial dysfunction in rats through its opening of the mitochondrial KATP channels.

The present study used isolated rat hearts to investigate whether (1) Sheng-Mei-San (SMS), a traditional Chinese formulation comprising Radix Ginseng, Radix Ophiopogonis and Fructus Schisandrae, is protective against post-ischemic myocardial dysfunction, and (2) whether the cardioprotective effect of SMS is related to scavenging of hydroxyl radicals and opening the mitochondrial KATP channels. The excised hearts of male Sprague-Dawley rats were perfused on a Langendorff apparatus with Krebs-Henseleit solution with a gas mixture of 95% O2 and 5% CO2. Left ventricular end-diastolic pressure (LVEDP, mmHg), left ventricular developed pressure (LVDP, mmHg), +/-dP/dt (mmHg/s) and coronary flow (ml/min) were continuously monitored. All hearts were perfused for a total of 120 min consisting of a 30-min pre-ischemic period followed by a 30-min global ischemia and 60-min reperfusion. Lactate, lactate dehydrogenase (LDH) and 2,5-dihydroxybenzoic acid (2,5-DHBA) concentrations in the effluent were measured during reperfusion. Three days' treatment with SMS (1.67 ml/kg per day) inhibited the rise in LVEDP and improved the post-ischemic LVDP and +/-dP/dt significantly better than in the untreated control hearts during reperfusion. SMS increased the coronary flow at baseline, and during reperfusion. Pretreatment with 5-hydroxydecanoic acid (5-HD), a mitochondrial KATP channel blocker, abolished the inhibition of the rise in LVEDP, the increase in coronary flow and the improvement in LVDP and +/-dP/dt induced by SMS. SMS significantly attenuated the concentrations of lactate, LDH and 2,5-DHBA during reperfusion, but the pretreatment with 5-HD restored them; 5-HD alone did not affect the concentrations. SMS improved the post-ischemic myocardial dysfunction through opening the mitochondrial KATP channels.