Passage of leptin across the blood-testis barrier

1999 ◽  
Vol 276 (6) ◽  
pp. E1099-E1104 ◽  
Author(s):  
William A. Banks ◽  
Robert N. McLay ◽  
Abba J. Kastin ◽  
Ulla Sarmiento ◽  
Sheila Scully
Keyword(s):  
Central Nervous System ◽  
Sertoli Cells ◽  
Leydig Cells ◽  
Reproductive Function ◽  
Multiple Time ◽  
Testicular Function ◽  
Leptin Receptors ◽  
The Central Nervous System ◽  
Significant Expression ◽  
Blood Testis Barrier

Leptin is a 17-kDa protein, secreted by fat, that controls adiposity and has been proposed to have numerous effects on reproduction in the mouse. To assess whether the effects of leptin on testicular function are direct, we determined whether leptin can cross the murine blood-testis barrier. Multiple time regression analysis showed that a small amount of blood-borne leptin is able to enter the testis but does so by a nonsaturable process. In addition, no significant expression of leptin receptors was found at the Leydig cells or Sertoli cells of the testis. This compares with the presence of a saturable transport system for leptin at the blood-brain barrier and abundant receptors for leptin at the leptomeninges, neurons, and choroid plexus of the central nervous system (CNS). These results support the hypothesis that the effects of leptin on reproductive function are not mediated at the level of the testis but indirectly, probably through the CNS.

scholarly journals Testicular expression of NGF, TrkA and p75 during seasonal spermatogenesis of the wild ground squirrel (Citellus dauricus Brandt)

2015 ◽  
Vol 59 (3) ◽  
Author(s):  
H. Zhang ◽  
Y. Wang ◽  
J. Zhang ◽  
L. Wang ◽  
Q. Li ◽  
...  
Keyword(s):  
Breeding Season ◽  
Sertoli Cells ◽  
Seasonal Changes ◽  
Ground Squirrel ◽  
Leydig Cells ◽  
Testicular Function ◽  
Nonbreeding Season ◽  
Function Change ◽  
The Mean ◽  
Neuronal Systems

The nerve growth factor (NGF) not only has an essential effect on the nervous system, but also plays an important role in a variety of non-neuronal systems, such as the reproductive system. The aim of this study was to investigate the seasonal changes in<strong> </strong>expression of NGF and its receptors (TrkA and p75) in testes of the wild ground squirrel during the breeding and nonbreeding seasons.<strong> </strong>Immunolocalization for NGF was detected mainly in Leydig cells and Sertoli cells in testes of the breeding and nonbreeding seasons. The immunoreactivity of TrkA was highest in the elongated spermatids, whereas p75 in spermatogonia and spermatocytes in testes of the breeding season. In the nonbreeding season testes, TrkA showed positive immunostainings in Leydig cells, spermatogonia and primary spermatocytes, while p75 showed positive signals in spermatogonia and primary spermatocytes. Consistent with the immunohistochemical results, the mean mRNA and protein level of NGF and TrkA were higher in the testes of the breeding season, and then decreased to a relatively low level in the nonbreeding season. In addition, the concentration of plasma gonadotropins and testosterone were assayed by radioimmunoassay (RIA), and the results showed a significant seasonal change between the breeding and nonbreeding seasons. To conclude, these results of this study provide the first evidence on the potential involvement of NGF and its receptor, TrkA and p75 in the seasonal spermatogenesis and testicular function change of the wild ground squirrel.

Analysis of Testicular Toxicity of Solanine in Mice

2011 ◽  
Vol 282-283 ◽  
pp. 195-200
Author(s):  
Yu Bin Ji ◽  
Jing Chao Sun ◽  
Lang Lang
Keyword(s):  
Sertoli Cells ◽  
Leydig Cells ◽  
Pathological Change ◽  
Reproductive Toxicity ◽  
Reproductive Function ◽  
Control Group ◽  
Testicular Toxicity ◽  
Male Reproductive Function ◽  
Testicular Weight ◽  
Test Concentration

Solanine is one of chemicalcomponents in the tuber and the sprout of the potato which is toxic to human. Some studies on the toxicity of solanine on humans and animals have been reported, little is known about the mechanism of its testicular toxicity. In present study, the toxicity of solanine on male reproductive function was investigated in adult male Kunming mice. Compared with the control group, there was an obvious pathological change in testis, and the expression levels of 3β-HSD and vimentin decreased when the test concentration of solanine was at 21 mg/kg/day. Meanwhile, there was a significant dose- and duration-dependent reduction in the testicular weight and organ coefficient. However, no changes have been detected about the level of testosterone and there was a dramatic increase in the expression of LH in Leydig cells. Results of this study suggested that solanine leaded to male reproductive toxicity influencing the functions of Sertoli cells and Leydig cells.

Immunodetection of inhibin in the human testis and epididymis during normal development and in non-tumoural testicular lesions

2010 ◽  
Vol 22 (3) ◽  
pp. 558 ◽  
Author(s):  
Manuel Nistal ◽  
Pilar González-Peramato ◽  
Maria P. De Miguel
Keyword(s):  
Sertoli Cells ◽  
Leydig Cells ◽  
Staining Pattern ◽  
Hormonal Treatment ◽  
Human Testis ◽  
Seminiferous Tubules ◽  
Secretory Cells ◽  
Testicular Function ◽  
Human Epididymis ◽  
Efferent Ducts

Plasma concentrations of inhibin are correlated with spermatogenetic function. Inhibin is secreted mainly by the Sertoli and Leydig cells of the testis. In the human epididymis, the location and function of inhibin are contentious. Thus, the aim of the present study was to determine the location of inhibin in the human epididymis. Investigations were performed in samples with normal testicular function at different stages of development, as well as in samples in which testicular function or the testicular–epididymal connection were altered. In fetal, newborn and infant testes, Sertoli and Leydig cells stained positive for inhibin, whereas no such staining was detected in the epididymides. Inhibin was located in both the Sertoli and Leydig cells, as well as in the epididymis, in the apical pole of mainly secretory cells in the efferent ducts. This staining pattern was not correlated with the staining pattern for macrophages. The main duct of the epididymis was negative for inhibin staining. In ischaemic atrophic testes, the few tubules in which Sertoli cells were present stained positive for inhibin, whereas the epididymides stained negative. In paediatric cryptorchidism, Sertoli and Leydig cells stained positive for inhibin, whereas the epididymides were negative. In adult cryptorchidism, Sertoli and Leydig cells stained positive for inhibin, even in tubules containing Sertoli cells only. Interestingly, inhibin was absent from the efferent ducts. In three cases undergoing hormonal treatment prior to subsequent gender change, Sertoli and Leydig cells stained positive for inhibin. In contrast, the efferent ducts were negative or only faintly positive in cases of shorter hormonal treatment. In all cases studied, the presence of inhibin in the efferent ducts was associated with its production in the testis, suggesting that the epididymis is not responsible for the production of inhibin in men. The pattern of inhibin staining does not correlate with that of macrophages, suggesting that inhibin is not degraded in the human epididymis. The data suggest that, in humans, inhibin is secreted by Sertoli cells into the seminiferous tubules and then travels towards the efferent ducts, where it is reabsorbed into the bloodstream.

scholarly journals Leptin participation in the processes of nervous impulse transmission and its influence on the formation of neuro-mental development of children

2022 ◽  
pp. 21-25
Author(s):  
G. O. Momot ◽  
E. V. Krukovich ◽  
T. N. Surovenko
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Lipid Metabolism ◽  
Cognitive Development ◽  
Cognitive Functions ◽  
Cognitive Abilities ◽  
Nervous Impulse ◽  
Leptin Receptors ◽  
The Central Nervous System ◽  
Functional Features

Review of publications on the functional features of leptin in the central nervous system in children. The participation of leptin mechanisms in the transmission of nerve impulses, the effect of leptin on cognitive functions in children. The article reveals the general mechanisms of maturation of the central nervous system in children, the participation of leptin and leptin receptors in the formation of cognitive abilities in children. Possible interrelationships of impairments in cognitive development and lipid metabolism including obesity are revealed.

Testicular function and sexual activity in senescent mice

1984 ◽  
Vol 247 (5) ◽  
pp. E569-E573 ◽  
Author(s):  
C. Chubb ◽  
C. Desjardins
Keyword(s):  
Central Nervous System ◽  
Sexual Activity ◽  
Reproductive Performance ◽  
Young Male ◽  
Testicular Function ◽  
Male Mice ◽  
Testicular Steroidogenesis ◽  
The Central Nervous System ◽  
Old Mice

The steroidogenic potentials of testes from 6-mo-old and approximately 28-mo-old CB6F1 mice were compared by measuring the secretion rate of 11 steroids produced by testes perfused in vitro. Testes from 6- and 28- to 30-mo-old mice secreted similar amounts of testosterone, but marked differences in the secretion of testosterone biosynthetic intermediates were discovered. Testes of old mice produced significantly more (P less than 0.01) delta 5-steroids than young male mouse testes. The presence or absence of sexual activity among old male mice was not correlated with changes in testicular steroidogenesis or plasma steroid levels. The results suggest that selected alterations in androgen biosynthesis occur during aging, but that the decline in reproductive performance among old mice is not attributable to deficits in testicular steroidogenesis. Rather, age-associated losses in sexual activity may be mediated by disturbances in the central nervous system.

Male Reproductive Function

2011 ◽  
Author(s):  
William J. Kovacs
Keyword(s):  
Tight Junctions ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Leydig Cells ◽  
Reproductive Function ◽  
Rete Testis ◽  
Seminiferous Tubules ◽  
Male Reproductive Function ◽  
Peritubular Tissue

The testes are the source of both germ cells and hormones essential for male reproductive function. The production of both sperm and steroid hormones is under complex feedback control by the hypothalamic-pituitary system. The testis consists of a network of tubules for the production and transport of sperm to the excretory ducts and a system of interstitial cells (called Leydig cells) that express the enzymes required for the synthesis of androgens. The spermatogenic or seminiferous tubules are lined by a columnar epithelium composed of the germ cells themselves as well as supporting Sertoli cells surrounded by peritubular tissue made up of collagen, elastic fibers, and myofibrillar cells. Tight junctions between Sertoli cells at a site between the spermatogonia and the primary spermatocyte form a diffusion barrier that divides the testis into two functional compartments, basal and adluminal. The basal compartment consists of the Leydig cells surrounding the tubule, the peritubular tissue, and the outer layer of the tubule containing the spermatogonia. The adluminal compartment consists of the inner two-thirds of the tubules containing primary spermatocytes and germ cells in more advanced stages of development. The base of the Sertoli cell is adjacent to the basement membrane of the spermatogenic tubule, with the inner portion of the cell engulfing the developing germ cells so that spermatogenesis actually takes place within a network of Sertoli cell cytoplasm. The mechanism by which spermatogonia pass through the tight junctions between Sertoli cells to begin spermatogenesis is unknown. The close proximity of the Leydig cell to the Sertoli cell with its embedded germ cells is thought to be critical for normal male reproductive function. The seminiferous tubules empty into a network of ducts termed the rete testis. Sperm are then transported into a single duct, the epididymis. Anatomically, the epididymis can be divided into the caput, the corpus, and the cauda regions. The caput epididymidis consists of 8 to 12 ductuli efferentes, which have a larger lumen tapering to a narrower diameter at the junction of the ductus epididymidis.

Effects of leptin administration on lactational infertility in food-restricted rats depend on milk delivery

2004 ◽  
Vol 286 (1) ◽  
pp. R217-R225 ◽  
Author(s):  
Alfonso Abizaid ◽  
Diana Kyriazis ◽  
Barbara Woodside
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Milk Production ◽  
Food Deprivation ◽  
Food Restriction ◽  
Reproductive Function ◽  
Time Period ◽  
Lactating Females ◽  
The Central Nervous System ◽  
Direct Binding

Leptin administration has been shown to prevent the disruptive effects of acute food deprivation on reproductive function in cycling females and lactating females. We examined the ability of intracerebroventricular leptin administration to ameliorate the effects of food restriction for the first 2 wk postpartum on length of lactational infertility. Leptin administration did not reduce the effects of food restriction on reproductive function at either time period ( days 8-15 and 15-22 postpartum) or dose (1 and 10 μg/day) administered. Because of the sharp contrast between these results and the ability of leptin to offset the effects of acute food deprivation in lactating rats, the remaining studies investigated the possible causes of this difference. Both central and peripheral leptin administration eliminated food deprivation-induced prolongation of lactational infertility, suggesting that neither route of administration nor dose was a factor. However, we noticed that, whereas chronically food-restricted females continue to deliver milk to their young, acutely food-deprived females do not. To test the hypothesis that the continued energetic drain of milk production and delivery might prevent the ability of exogenous leptin administration to eliminate the effects of undernutrition, leptin was administered to food-restricted, lactating rats prevented from delivering milk. In this situation intracerebroventricular leptin treatment completely eliminated the effects of food restriction on lactational infertility, suggesting that leptin contributes to the maintenance of reproductive function via two pathways: direct binding in the central nervous system and through increasing the availability of oxidizable metabolic fuels.

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