Mechanistic insight of cyclin-dependent kinase 5 in modulating lung cancer growth G. M. Shazzad Hossain Prince, Tsung-Ying Yang, Ho Lin, Mei-Chih Chen Chinese Journal of Physiology 2019 62(6):231-240 Lung harbors the growth of primary and secondary tumors. Even though numerous factors regulate the complex signal transduction and cytoskeletal remodeling toward the progression of lung cancer, cyclin-dependent kinase 5 (Cdk5), a previously known kinase in the central nervous system, has raised much attention in the recent years. Patients with aberrant Cdk5 expression also lead to poor survival. Cdk5 has already been employed in various cellular processes which shape the fate of cancer. In lung cancer, Cdk5 mainly regulates tumor suppressor genes, carcinogenesis, cytoskeletal remodeling, and immune checkpoints. Inhibiting Cdk5 by using drugs, siRNA or CRISP-Cas9 system has rendered crucial therapeutic advantage in the combat against lung cancer. Thus, the relation of Cdk5 to lung cancer needs to be addressed in detail. In this review, we will discuss various cellular events modulated by Cdk5 and we will go further into their underlying mechanism in lung cancer.

Identification of the force–velocity curve on dynamic resistance exercise for rats Hugo A. P. Santana, Hamilton Miotto, Keemilyn K. S. Silva, Rodolfo A Dellagrana, Jeeser A Almeida Chinese Journal of Physiology 2019 62(6):241-244 The aim of this study was to identify force–velocity and power–velocity curves in climbing activity protocols, used as dynamic resistance exercise in rats. Eighteen 45-day-old male Wistar rats (weight = 211.9 ± 5.2 g) were evaluated. After familiarization to the climbing procedure, the animals performed an incremental climbing test (load relative to 75% of the body mass at first stage, followed by 30 g increments with and 120 s recovery between climbs) to determine the maximum carrying capacity (MCC). After this, the animals climbed with different loads (without load, 10%, 20%, 30%, 40%, 50%, 75%, 90%, and 100% of MCC) with 120 s recovery between climbs. Time for each climb was recorded to calculate the mechanical power. The peak power was reached at 30% of MCC. For the force–velocity curve, an inversely proportional relation was observed between force and velocity, as expected, greater forces were expressed in lower velocities. Therefore, our results suggest that training at 30% of MCC should be encouraged aiming the target for greater power output and 90%–100% of MCC should be the load aiming for strength training in climbing activities for rats.

Sex differences and the modulating effects of gonad intactness on behavioral conformity in a mouse model Chianfang G Cherng, Lung Yu Chinese Journal of Physiology 2019 62(6):245-255 Although gender differences in conformity are noticed in human studies, cultural norms and psychosocial factors inevitably affect such differences. Biological factors, especially the gonadal hormones and the brain regions involved, contributing to the sex differences in behavioral conformity remained scarcely explored. To prevent psychosocial and cultural norm confounds, intact and gonadectomized male and female mice were used to assess the modulating effects of gonadal hormones on behavioral conformity and such conformity-related brain regions using an approach of choice paradigm. Intact and gonadectomized mice' choices for the nonrewarded runway were assessed when these experimental mice were alone versus with a group, consisting of three same-sex noncagemates choosing the respective experimental mice' nonrewarded runway, in a double-J-shaped maze test. Although male and female mice exhibited comparable rewarded runway choices at the conclusion of the operant training procedures and in the test individually, male mice demonstrated greater conformity index as compared to female mice when group tested. Gonadectomy, done at their 4 or 9 weeks of age, decreased males' conformity index but did not affect females' when both sexes were group tested. Such gonadectomy did not affect the conditioning or conformity index when tested individually in either sex. Female mice had higher serum corticosterone (CORT) levels when group tested as compared to the female mice tested individually and male mice. Finally, the number of FOS-staining cells in high conformity-displaying mice was found less than it in the low conformity-performing mice in the nucleus accumbens. Taken together, we conclude that testis-derived hormones, at least, play a role in enhancing behavioral conformity in male mice. CORT and nucleus accumbal neuronal activity deserve further investigation for their involvement in behavioral conformity.

Changes in the microvasculature and hemostatic system in rats after insonation Yuliya Bondarchuk, Marina Nosova, Igor Shakhmatov Chinese Journal of Physiology 2019 62(6):256-260 Ultrasound, one of the most physically impactful factors of the modern human living environment, can cause hemodynamic changes in the microvasculature and the hemostatic system. Such shifts can be considered as possible predictors of cardiovascular diseases and their complications. This study aimed to examine the effect of 7-day in-air insonation on the microvasculature and hemostatic system of rats. The study included 28 male Wistar rats. A group of study animals was insonated over 7 days at a frequency of 25 kHz. The emitters were installed in a vertical position at a distance of 10 cm from both the sidewalls of a coarse wire cage. The sound pressure was 89.0 dB and power flux density was 7.73 ± 0.03 W/cm2. The microvasculature values of the study rats obtained by laser Doppler flowmetry were compared to those of control animals. To evaluate the hemostatic system, an integral research method, thromboelastography, was used. In the study rats, in response to 7-day insonation, statistically significant decreases in the active and passive factors of blood circulation modulation were observed compared to the control animals: microcirculation, flux, amplitude of endothelial and vasomotor vibrations, and amplitude of respiratory and pulse waves. According to the thromboelastography data, prolonged coagulation time at the initial stage and inhibited fibrinolytic activity were recorded. Thus, the study animals showed signs of a stress reaction based on changes in their microcirculatory parameters confirmed by increased serum concentrations of adrenocorticotropic hormone and cortisol and analysis of behavioral reactions in the open-field test.

Sex Differences in antiaging response to short- and long-term high-intensity interval exercise in rat cardiac muscle: Telomerase activity, total antioxidant/oxidant status Marziyeh Saghebjoo, Saber Sadeghi-Tabas, Iman Saffari, Azin Ghane, Ivan Dimauro Chinese Journal of Physiology 2019 62(6):261-266 Cardiovascular disease prevails with age which varies according to sex. Telomere length plays an important role in aging. Despite the great benefits of high-intensity interval training (HIIT), the acute responses to HIIT with different intervals have not been elucidated in different sexes. This study was conducted to investigate the sex-dependent responses of telomerase enzyme activity, total oxidant status (TOS), total antioxidant capacity (TAC), and the ratio of TAC/TOS to short- and long-term high-intensity interval exercise (HIIE) in cardiac muscle of male and female rats. Forty adult Wistar rats were randomly allocated to six groups: male and female HIIE with short-term intervals (MHIIESh and FHIIESh, respectively), male and female HIIE with long-term intervals (MHIIEL and FHIIEL, respectively), and controls groups. Telomerase activity, TAC, and TOS levels were examined immediately after exercise in the cardiac muscle. The level of telomerase enzyme activity, TOS level, and the ratio of TAC/TOS did not change after HIIE with short-term interval and HIIE with long-term interval (HIIEL) in male and female rats (P = 0.52, 0.69, and 0.08, respectively). There was a statistically significant decrease in the TAC level in the MHIIESh group (P = 0.04). Furthermore, a significant decrease was observed in the HIIEL in both male and female rats (P = 0.03 and 0.04, respectively). Acute exposure to HIIE with short- and long-term intervals would not result in a significant change in some indicators of biological aging. However, due to gender-specific biological differences, further studies will provide evidence regarding the roles of HIIE at different times of intervals, which contribute to aging prevention.

Contrasting actions of ginsenosides Rb1 and Rg1 on glucose tolerance in rats Rungchai Chaunchaiyakul, Naruemon Leelayuwat, Jin-Fu Wu, Chih-Yang Huang, Chia-Hua Kuo Chinese Journal of Physiology 2019 62(6):267-272 Ginsenoside profile of Panax ginseng is changing with season and cultivated soil. Yet, dose-response relationship of main ginsenosides on metabolic measures has not been documented in vivo. Here, we examined glucose and insulin responses after an oral glucose challenge (0.5 g/kg body weight) at various doses (0.01, 0.1, 1, and 10 mg/kg of body weight) under acute and chronic Rb1 and Rg1 supplemented conditions. The results show that Rb1 (0.01 and 0.1 mg/kg body weight) increased, whereas Rg1 (0.01 mg/kg body weight) decreased postprandial glucose levels compared with the Vehicle group (P < 0.05). This contrasting effect reduced as dose increased. Both Rb1 and Rg1 decreased the mitochondrial enzyme citrate synthase activity (P < 0.05) together with decreases in glycogen content in red gastrocnemius muscle and body temperature at low doses (P < 0.05), compared with the Vehicle group. These differences also diminished as dosage increases. For reliable ginseng research, dose standardization on Rg1 and Rb1 is essential based on their opposing action and peculiar dose-response relationship. Both major ginsenosides may influence dynamics of mitochondria turnover and alter muscle metabolism.

The impact of high-intensity laser therapy on oxidative stress, lysosomal enzymes, and protease inhibitor in athletes Łukasz Sielski, Paweł Sutkowy, Pawlak-Osińska Katarzyna, Alina Woźniak, Agnieszka Skopkowska, Bartosz Woźniak, Jolanta Czuczejko Chinese Journal of Physiology 2019 62(6):273-278 The aim of the study was to assess the effect of one session of high-intensity laser therapy (HILT) on the levels of selected oxidative stress parameters, lysosomal hydrolases, and anti-inflammatory serine protease inhibitor in the peripheral blood of amateur athletes with torn or pulled tendons of the ankle or the knee joint. The group of injured athletes comprised 16 males and females aged 16.3 ± 1.3 years, while the control group of 14 healthy, noninjured amateur athletes of both sexes (controls; age 17.4 ± 4.6 years). Material for the study was peripheral blood taken at three study time points: Immediately before, 30 min after, and 24 h after HILT intervention. In plasma and erythrocytes, thiobarbituric acid reactive substances (TBARSpl and TBARSer, respectively) were determined. In erythrocytes, the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were measured. In serum, the activity of acid phosphatase (AcP), arylsulfatase (ASA), cathepsin D (CTS D), and α1-antitrypsin (AAT) were determined. Among oxidative stress parameters, only the CAT activity significantly decreased 24 h after HILT compared to measurement 30 min after the treatment in the injured individuals (P < 0.01), while the GPx activity in that group was meaningfully higher 30 min after HILT compared to controls (P < 0.05). Thirty min after the intervention, the activities of AcP and ASA were lower in the injured participants compared to the uninjured ones (P < 0.01 and P < 0.05, respectively). The CTS D activity was lower 30 min and 24 h after HILT in both groups (P < 0.001) and did not differ significantly between them (P > 0.05). Moreover, the study showed statistically significant linear relationships between the TBARSer concentration and the SOD activity before HILT in the healthy participants (r = -0.6, P = 0.021) and 24 h after HILT in the injured ones (r = 0.6, P = 0.025). In the noninjured athletes before HILT, the CTS D activity linearly correlated with the AAT activity (r = -0.70, P = 0.005), and 30 min after the treatment, with the AcP activity (r = 0.5, P = 0.041). 24 h after the HILT intervention, the CTS D and AcP activities were also correlated in the injured athletes (r = 0.8, P = 0.002). The study suggests that one HILT intervention does not significantly influence the redox equilibrium but stabilizes lysosomal membranes.

Blood dopamine level enhanced by caffeine in men after treadmill running Jeong-Beom Lee, Hye-Jin Lee, Seung-Jea Lee, Tae-Wook Kim Chinese Journal of Physiology 2019 62(6):279-284 The aim of this study was to investigate the plasma dopamine and serum serotonin levels in humans with and without caffeine (CAFF) ingestion during treadmill running exercise. Thirty male volunteers participated in the randomized experiment involving two groups: CON (n = 15, 200 mL of tap water) versus CAFF (n = 15, 3 mg/kg CAFF and 200 mL tap water). After treadmill running, the dopamine level was significantly increased in the CAFF group (P < 0.01) and was significantly higher than in the CON group (P < 0.01). Serotonin was significantly increased in both groups after treadmill running (P < 0.05). However, serotonin levels showed no significant statistical difference between the groups. Prolactin and cortisol were significantly increased in both groups after treadmill running (P < 0.01). However, there was no significant statistical difference between groups. β-endorphin level was significantly increased in the CAFF group at after treadmill running (P < 0.01) and was significantly higher than in CON after treadmill running (P < 0.01). In conclusion, 3 mg/kg CAFF ingestion before treadmill running stimulated dopamine release without inhibiting serotonin, which may reduce central fatigue.

Corrigendum: Action of citral on the substantia gelatinosa neurons of the trigeminal subnucleus caudalis in juvenile mice Chinese Journal of Physiology 2019 62(6):285-285

Author Index for Volume 62 Chinese Journal of Physiology 2019 62(6):0-0