Potential neuroprotective effect of nanomicellar curcumin on learning and memory functions following subacute exposure to bisphenol A in adult male rats.

Bisphenol A (BPA) is an endocrine-disrupting chemical commonly utilized in the manufacture of plastics, which may cause damage to brain tissue. Curcumin is a phytochemical with protective effects against neurological and mental diseases. The purpose of this research was to evaluate whether nanomicellar curcumin (NmCur) might protect rats against BPA-induced learning and memory deficits. After determining the proper dose of BPA, the animals were randomly divided into 8 groups (8 rats in each group) receiving dextrose 5% (as vehicle of NmCur) (Dex), sesame oil (as vehicle of BPA) (Sea), Sea plus Dex, NmCur (50 mg/kg), BPA (50 mg/kg), and 50 mg/kg BPA plus 10, 25, and 50 mg/kg NmCur groups, respectively. Behavioral tests performed using passive avoidance training (PAT), open-field (OF), and Morris water maze (MWM) tests. The expression of oxidative stress markers, proinflammatory cytokines, oxidative stress-scavenging enzymes, glutamate receptors, and MAPK and memory-related proteins was measured in rat hippocampus and cortical tissues. BPA up-regulated ROS, MDA, TNF-α, IL-6, IL-1ß, SOD, GST, p-P38, and p-JNK levels; however, it down-regulated GSH, GPx, GR, CAT, p-AKT, p-ERK1/2, p-NR1, p-NR2A, p-NR2B, p-GluA1, p-CREB, and BDNF levels. BPA decreased step-through latency (STL) and peripheral and total, but not central, locomotor activity. It increased the time to find the hidden platform, the mean of escape latency time, and the traveled distance in the target quadrant, but decreased the time spent in the target quadrant. The combination of BPA (50 mg/kg) and NmCur (25 and 50 mg/kg) reversed all of BPA's adverse effects. Therefore, NmCur exhibited neuroprotective effects against subacute BPA-caused learning and memory impairment.

Maternal diabetes decreases the expression of α2-adrenergic and M2 muscarinic receptors in the visual cortex of male rat neonates.

AIMS: This study investigates the impact of maternal diabetes on the expression of α2-adrenergic and M2 muscarinic receptors in the primary visual cortex of male offspring born to diabetic rats. MAIN METHODS: In adult female rats, a single dose of intraperitoneal streptozotocin (STZ) was used to induce diabetes (Diabetic group). Diabetes was controlled with insulin in the Insulin-treated group. Female rats in the control group received normal saline instead of STZ. Male newborns were euthanized at P0, P7, and P14, and the expression of α2-adrenergic and M2 muscarinic receptors in the primary visual cortex was determined using immunohistochemistry (IHC). KEY FINDINGS: The study showed that α2-adrenergic and M2 muscarinic receptors were significantly suppressed in all layers of the primary visual cortex of male neonates born to diabetic rats at P0, P7, and P14 compared to the control group. The highest expression was for the Con group at P14 and the lowest one was in the Dia group at P0 for both receptors. The insulin treatment in diabetic mothers modulated the expression of these receptors to normal levels in their newborns. SIGNIFICANCE: The results demonstrate maternal diabetes decreases the expression of α2-adrenergic and M2 muscarinic receptors in the primary visual cortex of male offspring born to diabetic rats. Insulin treatment can offset these effects of diabetes.

Increased Apoptosis in Subcortical Regions of The Visual Pathway in Offspring Born to Diabetic Rats.

OBJECTIVE: Diabetes in pregnancy is a prevalent disease that can affect the central nervous system of the fetus by hyperglycemia. This study aimed to investigate the impact of maternal diabetes on neuronal apoptosis in the superior colliculus (SC) and the lateral geniculate nucleus (LGN) in male neonates born to diabetic mothers. MATERIALS AND METHODS: In this experimental study, female adult rats were separated into three groups: control, diabetic (induced using an intraperitoneal injection of streptozotocin), and insulin-treated diabetic [diabetes controlled by subcutaneous neutral protamine hagedorn (NPH)-insulin injection]. Male neonates from each group were euthanized on 0, 7, and 14 postnatal days (P0, P7, and P14, respectively), and apoptotic cells were identified using TUNEL staining. RESULTS: The numerical density per unit area (NA) of apoptotic cells was significantly higher in SC and the dorsal LGN (dLGN) in neonates born to the diabetic rats compared to the control group at P0, P7, and P14. However, insulin treatment normalized the number of apoptotic cells. CONCLUSION: This study demonstrated that maternal diabetes increased apoptosis in dLGN and SC of male neonates at P0, P7, and P14.

Expression of GABAAα1, GABAB1, and mGluR2 receptors in the lateral geniculate body of male neonates born to diabetic rats.

Objectives: Diabetes during gestation is one of the most common pregnancy complications and has adverse effects on offspring, including a negative impact on the offspring's central nervous system (CNS). Diabetes is a metabolic disease associated with visual impairment. Due to the importance of the lateral geniculate body (LGB) in the visual pathway, the present study examined the effect of maternal diabetes on the expression of gamma-aminobutyric acid (GABAAα1 and GABAB1) and metabotropic Glutamate (mGlu2) receptors in the LGB of male neonates of diabetic rats. Materials and Methods: Diabetes was induced in female adult rats by a single intraperitoneal dose of streptozotocin (STZ) 65 (mg/kg). In the Insulin-treated diabetic rats, diabetes was controlled by subcutaneous NPH-insulin injection daily. After mating and delivery, male offspring were killed by carbon dioxide gas inhalation at P0, P7, and P14 (postnatal days 0, 7, and 14). The expression of GABAAα1, GABAB1, and mGluR2 in the LGB of male neonates was determined using the immunohistochemistry (IHC) method. Results: The expression of GABAAα1 and GABAB1 was significantly reduced, whereas the expression of mGluR2 was markedly increased in the diabetic group compared with the control and insulin-treated groups at P0, P7, and P14. Conclusion: The results of the present study showed that induction of diabetes altered the expression of GABAAα1, GABAB1, and mGluR2 in the LGB of male neonates born to diabetic rats at P0, P7, and P14. Moreover, insulin treatment could reverse these effects of diabetes.

Maternal diabetes decreases the expression of GABAAα1, GABAB1, and mGlu2 receptors in the visual cortex of male rat neonates.

AIMS: This study examines the impact of maternal diabetes on the expression of GABAB1, GABAAα1, and mGlu2 receptors in the primary visual cortex layers of male rat newborns. MAIN METHODS: In diabetic group (Dia), diabetes was induced in adult female rats using an intraperitoneal dose of Streptozotocin (STZ) 65 (mg/kg). Diabetes was managed by daily subcutaneous injection of NPH insulin in insulin-treated diabetic group (Ins). Control group (Con) received normal saline intraperitoneally rather than STZ. Male offspring born to each group of female rats were euthanized via CO2 inhalation at P0, P7, and P14 days after delivery and the expression of GABAB1, GABAAα1, and mGlu2 receptors in their primary visual cortex was determined using immunohistochemistry (IHC). KEY FINDINGS: The expression of GABAB1, GABAAα1, and mGlu2 receptors increased gradually with age in the male offspring born to Con group while the highest expression was detected in layer IV of the primary visual cortex. In Dia group newborns, the expression of these receptors was significantly reduced in all layers of the primary visual cortex at every three days. Insulin treatment in diabetic mothers restored the expression of these receptors to normal levels in their newborns. SIGNIFICANCE: The study indicates that diabetes reduces the expression of GABAB1, GABAAα1, and mGlu2 receptors in the primary visual cortex of male offspring born to diabetic rats at P0, P7, and P14. However, insulin treatment can counteract these effects.

The distribution pattern of M2 and Adrenergicα2 receptors on inferior colliculi in male newborns of diabetic rats.

AIMS: Despite the high prevalence of diabetes in the world, its possible effects throughut pregnancy on neonatal auditory nervous system development are still unknown. In the present research, maternal diabetes' impact on the M2 and Adrenergicα2 receptors expression in the inferior colliculus (IC) of male newborn rats was investigated. MAIN METHODS: Female rats were grouped into three: sham, insulin-treated diabetic, and diabetic. Diabetes was induced through streptozotocin (STZ) injection as one dose intraperitoneally (65 mg/kg). After mating and delivery, male rats were euthanized on P0, P7, and P14. Immunohistochemistry (IHC) was used to study the distribution pattern of receptors. KEY FINDINGS: The present study indicated that the expression of M2 receptors in the diabetic group was significantly increased in pairwise comparisons in the sham and diabetic treated with insulin groups (P < 0.001, each). The highest M2 expression was for the diabetic group on P14 and the lowest one was for the sham group on P0. The Adrenergicα2a receptors expression in the diabetic group was significantly reduced in pairwise comparisons in the sham and diabetic treated with insulin groups (P < 0.001, each). The highest Adrenergicα2a expression was for the sham group on P14 and the lowest one was for the diabetic group on P0. There was no significant difference between the sham and insulin groups regarding all receptors expression. SIGNIFICANCE: This study demonstrated a time-dependent significant decrease in Adrenergicα2a but a time-dependent significant increase in M2 receptors expression.

Different Protocols of Combined Application of Photobiomodulation In Vitro and In Vivo Plus Adipose-Derived Stem Cells Improve the Healing of Bones in Critical Size Defects in Rat Models.

Introduction: Long bone segmental deficiencies are challenging complications to treat. Hereby, the effects of the scaffold derived from the human demineralized bone matrix (hDBMS) plus human adipose stem cells (hADSs) plus photobiomodulation (PBM) (in vitro and or in vivo) on the catabolic step of femoral bone repair in rats with critical size femoral defects (CDFDs) were evaluated with stereology and high stress load (HSL) assessment methods. Methods: hADSs were exposed to PBM in vitro; then, the mixed influences of hDBMS+hADS+PBM on CSFDs were evaluated. CSFDs were made on both femurs; then hDBMSs were engrafted into both CSFDs of all rats. There were 6 groups (G)s: G1 was the control; in G2 (hADS), hADSs only were engrafted into hDBMS of CSFD; in G3 (PBM) only PBM therapy for CSFD was provided; in G4 (hADS+PBM in vivo), seeded hADSs on hDBMS of CSFDs were radiated with a laser in vivo; in G5 (hADSs+PBM under in vitro condition), hADSs in a culture system were radiated with a laser, then transferred on hDBMS of CSFDs; and in G6 (hADS+PBM in conditions of in vivo and in vitro), laser-exposed hADSs were transplanted on hDBMS of CSFDs, and then CSFDs were exposed to a laser in vivo. Results: Groups 4, 5, and 6 meaningfully improved HSLs of CSFD in comparison with groups 3, 1, and 2 (all, P=0.001). HSL of G5 was significantly more than G4 and G6 (both, P=0.000). Gs 6 and 4 significantly increased new bone volumes of CSFD compared to Gs 2 (all, P=0.000) and 1 (P=0.001 & P=0.003 respectively). HSL of G 1 was significantly lower than G5 (P=0.026). Conclusion: HSLs of CSFD in rats that received treatments of hDBMS plus hADS plus PBM were significantly higher than treatments with hADS and PBM alone and control groups.

Developmental regulation and lateralization of N-methyl-d-aspartate (NMDA) receptors in the rat hippocampus.

N-methyl-d-aspartate receptors (NMDARs) are expressed abundantly in the brain and play a crucial role in the regulation of central nervous system (CNS) development, learning, and memory. During early neuronal development, NMDARs modulate neurogenesis, neuronal differentiation and migration, and synaptogenesis. The present study aimed to examine the developmental expression of NMDARs subunits, NR1 and NR2B, in the developing hippocampus of neonatal rats during the first two postnatal weeks. Fifty-four male offspring were randomly divided into three age groups, postnatal days (P) 0, 7, and 14. Real-time-PCR, western blotting, and immunohistochemistry (IHC) analyses were employed to examine and compare the hippocampal expression of the NMDA receptor subunits. The highest mRNA expression of NR1 and NR2B subunits was observed at P7, regardless of its laterality. The mRNA expression of both subunits in the right hippocampus was significantly higher than that of the left one at P0 and P7. Similarly, the highest protein level expression of NR1 and NR2B subunits was also observed at P7 in both sides hippocampi. Although the protein expression of NR1 was significantly higher on the right side in all studied days, the NR2B was significantly higher in the right hippocampus only at P7. The analysis of optical density (OD) has shown a marked increase in the distribution pattern of the NR1 and NR2B subunits at P7 in all hippocampal subregions. In conclusion, there is a marked right-left asymmetry in the expression of NR1 and NR2B subunits in the developing rat hippocampus, which might be considered as a probable mechanism for the lateral differences in the structure and function of the hippocampus in rats.

Preconditioning adipose-derived stem cells with photobiomodulation significantly increased bone healing in a critical size femoral defect in rats.

We assessed the combined impacts of human demineralized bone matrix (hDBM) scaffold, adipose-derived stem cells (hADS), and photobiomodulation (PBM) on bone repair of a critical size femoral defect (CSFD) in 72 rats. The rats were divided into six groups: control (group 1); ADS (group 2 - ADS transplanted into hDBM); PBM (group 3 - PBM-treated CSFDs); ADS + PBM in vivo (group 4 - ADS transplanted into hDBM and the CSFDs were treated with PBM in vivo); ADS + PBM in vitro (group 5 - ADS were treated with PBM in vitro, then seeded into hDBM); and ADS + PBM in vitro+in vivo (group 6 - PBM-treated ADS were seeded into hDBM, and the CSFDs were treated with PBM in vivo. At the anabolic phase (2 weeks after surgery), bone strength parameters of the groups 5, 6, and 4 were statistically greater than the control, ADS, and PBM in vivo groups (all, p = 0.000). Computed tomography (CT) scans during the catabolic phase (6 weeks after surgery) of bone healing revealed that the Hounsfield unit (HU) of CSFD in the groups 2 (p = 0.000) and 5 (p = 0.019) groups were statistically greater than the control group. The groups 5, 4, and 6 had significantly increased bone strength parameters compared with the PBM in vivo, control, and ADS groups (all, p = 0.000). The group 5 was statistically better than the groups 4, and 6 (both, p = 0.000). In vitro preconditioned of hADS with PBM significantly increased bone repair in a rat model of CSFD in vivo.

Improvement in viability and mineralization of osteoporotic bone marrow mesenchymal stem cell through combined application of photobiomodulation therapy and oxytocin.

The probable positive effects of photobiomodulation therapy (PBMT) and oxytocin (OT) treatments together or alone were evaluated on cell viability along with the changes in the gene expression of Osteocalcin (OC), Osteoprotegerin (OPG), and Runt-related transcription factor 2 (Runx2) levels of sham (healthy)-Bone marrow mesenchymal stem cell(BMMSC) and ovariectomy-induced osteoporosis (OVX)-BMMSC. BMMSC was harvested from healthy and OVX rats and was cultured in osteogenic induction medium (OIM). There were five groups of BMMSCs: (1) sham -BMMSCs; (2) control -OVX-BMMSCs; (3) OT-treated-OVX-BMMSCs; (4) PBMT-treated-OVX-BMMSCs, and (5) OT + PBMT-OVX-BMMSCs. In all 5 groups, BMMSC viability and proliferation as well as gene expression of OC, OPG, and RUNX2 were evaluated. PBMT and PBMT + OT treatments showed a promising effect on the increased viability of OVX-BMMSC (ANOVA test; LSD test, p = 0.01, p = 0.002). The results of gene expression analysis revealed that the sham- BMMSCs responded optimally to OT treatment. It was also found that OVX-BMMSCs responded optimally to PBMT + OT and PBMT treatments at early and middle stages of osteogenic induction process. Nevertheless, they responded optimally to PBMT + OT and OT especially at the late stage of osteogenic induction process. PBMT and PBMT + OT treatments significantly increased viability of OVX-BMMSC in OIM in vitro. Both PBMT and PBMT + OT treatments could promote mineralization of OVX-BMMSC in the culture medium at early and middle stages of osteogenic induction process. Both OT and PBMT + OT treatments could promote mineralization of OVX-BMMSC in vitro at late stages of osteogenic induction process.

Photobiomodulation with 630 plus 810 nm wavelengths induce more in vitro cell viability of human adipose stem cells than human bone marrow-derived stem cells.

The goal of the current experiment is to explore the influence of combined and/or single applications of red and near infrared (NIR) photobiomodulation (PBM) at different wavelengths, energy densities and times on cell viability, population doubling time (PDT), and apoptosis of in vitro cultures of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) and h adipose-derived stem cells (hASCs). Both in vitro hBM-MSCs and hASCs were irradiated with 36 protocols using two different laser types (helium­neon [He-Ne] and diodes), four different laser wavelengths (HeNe laser, 630 nm, 810 nm, 630 + 810 nm); three different energy densities (0.6 J/cm2, 1.2 J/cm2, 2.4 J/cm2); and three different PBM times (1, 2, and 3). One-way ANOVA analysis showed that PBM with the 630 nm red laser significantly stimulated cellular viability of both hBM-MSCs and hASCs. The 630 nm red laser significantly decreased PDT of hBM-MSCs. One-way ANOVA demonstrated that the 630 + 810 laser significantly stimulated cellular viability, and significantly decreased PDT and apoptosis of hBM-MSCs and hASCs. Two-way ANOVA analysis showed that PBM with the 630 nm red laser and 630 + 810 nm laser significantly stimulated cellular viability of hASCs compared to the control hASCs, and experimental and control hBM-MSCs. Our study demonstrated that PBM with the combined 630 + 810 nm lasers significantly stimulated cell viability, and significantly decreased PDT and apoptosis of hBM-MSCs and hASCs in vitro. We reported new in vitro evidence where PBM administered at 630 nm (one and two times, 0.6 and 1.2 J/cm2) and 630 + 810 nm (three times, 2.4 J/cm2) significantly increased hASC cell viability compared to its control and the PBM-treated hBM-MSC groups.

Photobiomodulation improved stereological parameters and sperm analysis factors in streptozotocin-induced type 1 diabetes mellitus.

The aim of this study was to evaluate the effect of photobiomodulation (PBM) on testicular tissues and fresh sperm analysis factors in streptozotocin (STZ)-induced type one diabetes mellitus (T1DM) mice. T1DM was induced in 15 male Syrian mice by injection of 200 mg/kg STZ. After one month, mice were divided randomly into three groups, harboring 5 mice each: 1, control group; 2, first laser group (890 nm, 80 Hz, 0.03 J/cm2) and 3, second laser group (0.2 J/cm2). Then the mice were euthanized and testicles were dissected for stereological studies, and both epididymis and vas deferens were removed for fresh sperm analysis. Data were analyzed by statistical methods. A significant increase was observed in the Sertoli cell count in both PBM groups, compared to the control group. In addition, the second PBM group shows a significant increase in the Sertoli cell count, compared to the first PBM group. Both PBM groups show significant increase in the Leydig cell count, compared to the control group. There were significant increases of the length in the seminiferous tubules in both PBM groups, compared to the control group. In addition, the second PBM group showed a significant increase of the length in the seminiferous tubules, compared to the first PBM group. The second PBM group showed a significant increase in the sperm count, compared to the control, and first PBM groups. The first PBM group showed a significant increase in sperm count, compared to the control group. The sperm motility and count were significantly increased in the second PBM group, compared to the control and first PBM groups. The sperm motility was significantly increased in the first PBM group, compared to the control group. PBM with 0.2 J/cm2 and 0.03 J/cm2 energy densities significantly improved the stereological parameters and fresh sperm analysis factors, compared to the control group in STZ-induced T1DM in mice. Moreover, the PBM with 0.2 J/cm2 energy density was statistically more effective, compared to the 0.03 J/cm2.

Combined effects of photobiomodulation and alendronate on viability of osteoporotic bone marrow-derived mesenchymal stem cells.

Osteoporotic bone marrow mesenchymal stem cells (BMMSCs) are involved in the pathogenesis of osteoporosis (OP). Photobiomodulation (PBM) has positive effects on healthy BMMSCs. The goal of current experiment was to evaluate the combined influence of photobiomodulation PBM and alendronate (ALN) incubation on ovariectomized induced osteoporosis(OVX)- BMMSC viability in vitro. 15 female adult Wistar rats were distributed into the 2 groups: (1) 3 healthy (sham)control rats, (2) 12 OVX- rats. All OVX rats underwent ovariectomy. After 3.5 months sham and OVX rats were euthanized and their MSC harvested and cultured in a complete osteogenic incubation medium (OM). As the next step, in sham and OVX groups flowcytometry and osteogenic differentiation assays were performed. OVX- rats were divided into (2) OVX-control, (3) OVX- PBM (HeNe laser, 623.8 nm, 1.2 J/cm2, one time), (4) OVX-ALN (10-8 M, three times incubations), and (5) OVX-PBM + ALN, Finally BMMSC viability of all five groups were evaluated using MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide) assay. Based on our observations, PBM significantly increased optical density of OVX-BMMSCs (2.15 ±â€¯0.11) compared to control -OVX-BMMSCs (1.55 ±â€¯0.10) and healthy -BMMSCs (1.65 ±â€¯0.10)(LSD test, both p < 0.05). Further, we found that both ALN, and ALN + PBM significantly increased optical densities of OVX-BMMSCs (24 h:2.40 ±â€¯0.03;48 h:2.06 ±â€¯0.00[ALN],both p < 0.01) and 1.88 ±â€¯0.05[ALN + PBM], p < 0.05 compared to control -OVX-BMMSCs (24 h: 1.46 ±â€¯0.01; 48 h: 1.83 ±â€¯0.00 and 1.57 ±â€¯0.08). It was concluded that PBM significantly increased cell viability of OVX-BMMSCs compared to control -OVX-BMMSCs and healthy -BMMSCs.

Effect of low-level laser therapy and oxytocin on osteoporotic bone marrow-derived mesenchymal stem cells.

Postmenopausal osteoporosis (OP) is a major concern for public health. Low-level laser therapy (LLLT) has a positive effect on the health of bone marrow mesenchymal stem cells (BMMSCs). The purpose of this study is to evaluate the influence of LLLT and oxytocin (OT) incubation-individually and in combination-on osteoporotic BMMSCs in ovariectomized rats. Twelve female rats were randomized into two groups to undergo either a sham surgery (sham group) or ovariectomy-induced osteoporosis (OVX group). MSCs harvested from the BM of healthy and OVX rats underwent culture expansion. There were five groups. In Groups one (sham-BMMSC) and two (OVX-BMMSC) the cells were held in osteogenic condition medium without any intervention. In the group three (OT), OT incubation with optimum dose was performed for 48 h (two times, 10-12 molar). In Group four, laser-treated-OVX-BMMSCs were treated with optimum protocol of LLLT (one time, 1.2 J/cm2 ). In Group five (laser + OT group), the OT incubation plus the laser irradiation was performed. The biostimulatory effect of LLLT is demonstrated by a significant increase in the viability of OVX-BMMSCs, cell cycle, and extracellular levels of Transforming growth factor beta (TGF-ß), insulin-like growth factor-I (IGF-I), and Alkaline phosphatase (ALP) compared to control OVX-BMMSCs and/or the sham group. OT incubation and laser + OT incubation have a positive effect on OVX-BMMSCs. However, LLLT is more effective statistically. We conclude that LLLT significantly improved cell viability, enhanced the osteogenic potential of the OVX-BMMSCs, and increased the extracellular levels of the TGF-ß, IGF-I, and ALP.

Low-level laser therapy with helium-neon laser improved viability of osteoporotic bone marrow-derived mesenchymal stem cells from ovariectomy-induced osteoporotic rats.

The purpose of this study was to evaluate the influences of helium­neon (He­Ne) and infrared (IR) lasers on the viability and proliferation rate of healthy and ovariectomy-induced osteoporotic (OVX) bone marrow mesenchymal stem cells (BMMSCs) in vitro. MSCs harvested from the BM of healthy and OVX rats were culture expanded. He­Ne and IR lasers were applied three times at energy densities of 0.6, 1.2, and 2.4??J/cm2 for BMMSCs. BMMSCs viability and proliferation rate were evaluated by MTT assay on days 2, 4, 6, 14, and 21. The results showed that healthy BMMSCs responded optimally to 0.6??J/cm2 using an IR laser after three times of laser radiation. Moreover, it was found that OVX-BMMSCs responded optimally to 0.6??J/cm2 with He­Ne laser and one-time laser radiation. It is concluded that the low-level laser therapy (LLLT) effect depends on the physiological state of the BMMSCs, type of the laser, wavelength, and number of laser sessions. The biostimulation efficiency of LLLT also depends on the delivered energy density. LLLT can enhance the viability and proliferation rate of healthy and especially osteoporotic autologous BMMSCs, which could be very useful in regenerative medicine.

Evaluation of the effects of pulsed wave LLLT on tibial diaphysis in two rat models of experimental osteoporosis, as examined by stereological and real-time PCR gene expression analyses.

Osteoporosis (OP) and osteoporotic fracture are major public health issues for society; the burden for the affected individual is also high. Previous studies have shown that pulsed wave low-level laser therapy (PW LLLT) has osteogenic effects. This study intended to evaluate the impacts of PW LLLT on the cortical bone of osteoporotic rats' tibias in two experimental models, ovariectomized and dexamethasone-treated. We divided the rats into four ovariectomized induced OP (OVX-d) and four dexamethasone-treated (glucocorticoid-induced OP, GIOP) groups. A healthy (H) group of rats was considered for baseline evaluations. At 14 weeks following ovariectomy, we subdivided the OVX-d rats into the following groups: (i) control which had OP, (ii) OVX-d rats treated with alendronate (1 mg/kg), (iii) OVX-d rats treated with LLLT, and (iv) OVX-d rats treated with alendronate and PW LLLT. The remaining rats received dexamethasone over a 5-week period and were also subdivided into four groups: (i) control rats treated with intramuscular (i.m.) injections of distilled water (vehicle), (ii) rats treated with subcutaneous alendronate injections (1 mg/kg), (iii) laser-treated rats, and (iv) rats simultaneously treated with laser and alendronate. The rats received alendronate for 30 days and underwent PW LLLT (890 nm, 80 Hz, 0.972 J/cm(2)) three times per week during 8 weeks. Then, the right tibias were extracted and underwent a stereological analysis of histological parameters and real-time polymerase chain reaction (RT-PCR). A significant increase in cortical bone volume (mm(3)) existed in all study groups compared to the healthy rats. There were significant decreases in trabecular bone volume (mm(3)) in all study groups compared to the group of healthy rats. The control rats with OP and rats from the vehicle group showed significantly increased osteoclast numbers compared to most other groups. Alendronate significantly decreased osteoclast numbers in osteoporotic rats. Concurrent treatments (compounded by PW LLLT and alendronate) produce the same effect on osteoporotic bone.