BACKGROUND/AIMS Circulating fibrocytes (CFs) have been placed at the center of a number of fibrosing conditions. Recently, attention has been drawn to the non-anticoagulant activities of low molecular weight heparin (LH), especially its anti-fibrotic effects. The purpose of this study was to investigate the effects of LH on CFs differentiation and possible underlying mechanisms. METHODS/RESUL...

Skipping reproduction is often observed in long-lived organisms, but proximate mechanisms remain poorly understood. Since young and/or very old snow petrels (Pagodroma nivea) commonly skip breeding, we tested whether they are physiologically able to breed during the pre-laying stage. To do so, we measured the ability of known-age (11-45 years old) petrels to release luteinizing hormone (LH, a c...

Luteinizing hormone as other glycoprotein hormones is characterized by a heterodimeric structure composed a common α-subunit noncovalently linked to a specific β-subunit. The correct conformation of the heterodimer is important for efficient secretion, hormonal-specific post-translational modifications, receptor binding and signal transduction. To determine whether αand βsubunits can be synthes...

BACKGROUND In comparison to short-term gonad heat exposure, little is known about the molecular mechanisms that regulate testicular steroidogenesis during long-term whole body heat acclimation. MATERIAL AND METHODS Testicular slices from neonatal (NHA) and adult (AHA) heat-acclimated Wistar rats were analysed in vitro to assess the mRNA expression and enzymatic activity of steroidogenic enzym...

Lysyl hydroxylase 3 (LH3) is a multifunctional enzyme possessing lysyl hydroxylase (LH), hydroxylysyl galactosyltransferase (GT) and galactosylhydroxylysyl glucosyltransferase (GGT) activities in vitro. To investigate the in vivo importance of LH3-catalyzed lysine hydroxylation and hydroxylysine-linked glycosylations, three different LH3-manipulated mouse lines were generated. Mice with a mutat...

It is known that continuous stimulation with LHRH induces a biphasic release of LH. The two pools theory is generally accepted in interpreting this phenomenon. The present study was conducted in order to elicit qualitative differences in LH included in the two pools. Five hundred micrograms synthetic LHRH was infused for 2h in 10 women in various phases of the menstrual cycle and 5 h blood samp...

Nigella sativa (black seed) is an important medicinal herb with folkloric use in wide range of diseases. It is well studied for its biological activities. However, there is limited information regarding its effect on the male reproductive system. This study describes the effect of the aqueous extract of N. sativa (NSE) on testicular steroidogenesis from mice Leydig cells in vitro . Mice tes...

Pituitary adenylate cyclase-activating polypeptide (PACAP) releases LH and FSH from anterior pituitary cells. Although this effect is relatively weak, it has a strong sensitizing action on GnRH-induced gonadotropin secretion. Here we investigated the possibility that ovarian steroids, which are well-known modulators of LH secretion, interact with PACAP and GnRH in pituitary gonadotrophs. Rat pi...

We develop, implement, and test a feedback and feedforward biomathematical construct of the male hypothalamic [gonadotropin-releasing hormone (GnRH)]-pituitary [luteinizing hormone (LH)]-gonadal [testosterone (Te)] axis. This stochastic differential equation formulation consists of a nonstationary stochastic point process responsible for generating episodic release of GnRH, which is modulated n...

Clarification of the nature of the proteins involved in the cleavage of C3b and C4b is of great interest because these complement fragments are opsonins and, in addition, they modulate the activities of several key enzymes of the complement cascade. When these complement peptides are in solution, proteolysis by a serum enzyme, C3binactivator (C3bINA), 1 requires cofactors: f l lH in the case of...