Search

The present study was designed to assess the responsiveness of hypothalamic–pituitary–gonadal axis to kisspeptin administration with increasing age in men. Human kisspeptin‐10 was administered in single iv bolus dose (1 µg/kg BW) to healthy adult, middle and advanced age men. Serial blood samples were collected for 30 min pre‐ and 120 min post‐kisspeptin injection periods at 30‐min interval. Analysis of plasma LH by ELISA showed a significant (p < 0.05) increase after kisspeptin‐10 administration in all groups, whereas plasma testosterone concentration was significantly elevated (p < 0.05) after kisspeptin‐10 injection only in the adult men group. Present results suggest that in men, central hypothalamic–pituitary axis remains active and shows responsiveness to kisspeptin stimulation across life. However, Leydig cell responsiveness to kisspeptin‐induced LH decreases with age in men. [ABSTRACT FROM AUTHOR]

Kisspeptin is a powerful regulator of the hypothalamic-pituitary-gonadal axis. It acts through its receptor GPR54 to regulate sexual maturation, oogenesis, spermatogenesis and fertilization. The present research was implemented to evaluate the presence of kisspeptin receptor on various regions of buffalo bull spermatozoa and to decipher its relationship with different motility parameters of the fresh spermatozoa. Standard swim-up protocol was performed on fresh ejaculates from Nili-Ravi buffalo bulls to obtain three hypothetical layers, having spermatozoa with enhanced motility and normal morphology. The progressive sperm motility was measured in each layer by using phase contrast microscopy. Methanol fixed sperm smears from each layer were processed for standard immunocytochemistry procedure for the detection of kisspeptin receptor using specific antibodies. Maximum GPR54 immunoreactivity was observed in the upper regions (head, neck/midpiece) and moderate immunoreactivity was seen in the lower region (tail) of the spermatozoa in all the three layers. No significant difference in total GPR54 expression was observed in the spermatozoa from three layers and no relationship was observed between percentage motility and GPR54 like ir. Present findings suggest that the buffalo sperm motility is not influenced by GPR54 expression on different regions of the sperm. However, robust GPR54 expression in dorsal areas of buffalo sperm, would raise possibility of a covert function of kisspeptin in the bubaline sperm biology. [ABSTRACT FROM AUTHOR]

This study was designed to determine possible effects of human kisspeptin-10 (KP-10) on motility spectrum of buffalo bull spermatozoa. Semen was collected from three adult Nili-Ravi buffalo bulls twice a week for three-weeks, split into five aliquots and diluted with different doses (0, 0.2, 2.0, 20.0 and 40.0 pM) of KP-10 in 0.1% BSA-PBS. The aliquots were incubated for 2, 6, 12 and 24 min at 37°C and evaluated through Computer-Assisted Sperm Analysis (CASA) system for sperm motility parameters. Ethanol fixed smears were processed for immuno-cytochemical detection of KP. Results showed that KP-10 exposure (mostly at 20.0 and 40.0 pM) for different incubation time-points significantly (P<0.05) improved CASA sperm motilities, velocities, and rapid subpopulation than control. Furthermore, buffalo bull spermatozoa showed KP-10 expression in their tail region. This study identified the stimulatory effect of human KP-10 on buffalo bull sperm motility parameters during in vitro incubation. Thus, human KP-10 can be potentially used to enhance quality of buffalo bull sperm during incubation at 37°C in vitro. [ABSTRACT FROM AUTHOR]

The problem of low efficiency of organic solar cells can be solved by improving the charge mobility and open circuit voltage of these cells. The current research aims to present the role of π-linkers, having extended conjugation, between the donor and acceptor moieties of indacenodithiophene core-based A-π-D-π-A type SJ-IC molecule to improve the photovoltaic performance of pre-existing SJ-IC. Several crucial photovoltaic parameters of SJ-IC and seven newly proposed molecules were studied using density functional theory. Surprisingly, this theoretical framework manifested that the tailoring of SJ-IC by replacing its π-linker with linkers having extended π-conjugation gives a redshift in maximum absorption coefficient in the range of 731.69-1112.86 nm in a solvent. In addition, newly designed molecules exhibited significantly narrower bandgaps (ranging from 1.33 eV to 1.93 eV) than SJ-IC having a bandgap of 2.01 eV. Similarly, newly designed molecules show significantly less excitation energy in gaseous and solvent phases than SJ-IC. Furthermore, the reorganization energies of DL1-DL7 are much lower than that of SJ-IC, indicating high charge mobility in these molecules. DL6 and DL7 have shown considerably improved open circuit voltage ( V OC ), reaching 1.49 eV and 1.48 eV, respectively. Thus, the modification strategy employed herein has been fruitful with productive effects, including better tuning of the energy levels, lower bandgaps, broader absorption, improved charge mobility, and increased V OC . Based on these results, it can be suggested that these newly presented molecules can be considered for practical applications in the future., Competing Interests: Authors have no conflict of interest., (This journal is © The Royal Society of Chemistry.)