We have shown previously that treatment with pegylated leptin peptide receptor antagonist 2 (PEG-LPrA2) reduced the expression of vascular endothelial growth factor (VEGF), type (VEGFR2) and 4T1-breast cancer (BC) in syngeneic mice. In this investigation, PEG-LPrA2 was used to evaluate whether inhibition signaling has differential impact on pro-angiogenic pro-proliferative molecules human estrogen receptor-positive (ER+) receptor-negative (ER-) BC xenografts hosted by immunodeficient mice.To...

We determined developmental changes in circulating levels of the soluble leptin receptor (sOB-R), leptin, and gonadal hormones human subjects. In both sexes rise with age was associated a decline sOB-R, age-related parameters preceded pubertal hormones. Leptin above 10 ng/ml were strong predictor sOB-R concentrations, but this predictive value decreased as declined. young subjects there no gender differences serum boys had higher levels. adults neither nor changed age, lower women than men....

Leptin-deficient (ob/ob) male mice are morbidly obese and exhibit impaired reproductive function. The objective of this study was to assess the effect a leptin deficiency on testicular morphology, germ cell development, apoptotic activity within cells, expression levels apoptosis-related genes in testis. Sixteen week-old ob/ob (n = 8) controls were killed, their organs weighed. Testes processed for either histomorphological analysis (hematoxylin eosin [H&E] staining), apoptosis assessment...

It appears from the evidence documented in this Commentary that neonatal period is another critical stage process of sexual, behavioural and immune system development maturation primates. Interference with normal brain-pituitary-gonadal function during (e.g. a GnRH analogue monkeys) to impact adversely on subsequent reproductive, immunological function. These data further emphasize importance fully understanding regulatory mechanisms govern gonadal primate, if we are eliminate, control or...

ABSTRACT: We have investigated the effect of acute immobilization (3 hours) stress on testicular steroidogenesis in adult rat. Immobilization did not alter plasma luteinizing hormone (LH) levels, but testosterone (T) levels were reduced by 82%. Plasma corticosterone stressed rats elevated more than ninefold over control levels. After 3 hours stress, progesterone 33%, and 17α‐hydroxyprogesterone T 47% 37%, respectively, compared to controls. for had no association or dissociation rate...

The objective of this study was to examine the effect blockade neonatal activation pituitary-testicular axis, using a GnRH agonist, on sexual development in male rhesus monkeys. Monkeys were treated with either agonist (10 micrograms/day; n = 8) or vehicle (n 9) for 112 days osmotic minipumps beginning at 10-13 age. In control monkeys serum LH and testosterone concentrations during first 3 postnatal months similar those adults; they then declined very low levels. administration caused an...

Fibrates, the ligands of peroxisome proliferator-activated receptor- α, have been shown to a renal protective action in diabetic models disease, but mechanisms underlying this effect are unknown. In present study, we sought investigate greater detail fenofibrate and its mechanism on inflammation tubulointerstitial fibrosis an animal model type 2 diabetes mellitus. Twelve-week-old non-diabetic Zucker lean (ZL) fatty (ZD) rats were treated with vehicle or for 10 weeks. mRNA protein analyses...

The role of estrogen and progesterone in facilitating the proestrous release LH was examined 4-day cyclic rats. Ovariectomy at 1000 hr diestrous day 2 eliminated expected plasma surge. Administration either 1.0, 10.0 or 50 μg estradiol benzoate (EB)/100 g body wt (1000 2) re-established gonadotropin these animals, with intermediate dosage being most effective. However, peak concentrations did not approach normal levels, rates were abnormally slow more sustained. On other hand, 17β-estradiol...

Leptin purportedly plays an important role in pubertal development a number of mammalian species. Adult leptin-deficient (ob/ob) female mice are infertile, but the mechanisms responsible for reproductive failure have not been fully elucidated. The major objective current study was to assess effects leptin deficiency on ovarian folliculogenesis and apoptosis. Beginning at 4 wk age, control (n = 8) ob/ob 7) were weighed examined daily vaginal opening. After 3 killed, organs weighed. Ovaries...

Five adult male rhesus monkeys were continuously infused for 56 dayswith 25 μg/day of GnRH agonist (Wy- 40972; Ag) using an implanted osmotic pump. Bioassayable serum levels LH elevated 8-fold on the second day Agtreatment and then declined precipitously to below pretreatment by 15.Serum testosterone (T) changed similarly during Ag treatment, except that fall in preceded decline levelsof T at least 2 days. administration also eliminated diurnal variation inserum T. (50 μg) induced a 13-...

<i>Background/Aims:</i> Studies have shown that kidney injury molecule-1 (KIM-1) is upregulated in damaged renal proximal tubules. In this study, we examined KIM-1 expression glomerular epithelial cells diabetic glomerulopathy. <i>Methods:</i> Renal histology, immunostaining and Western blot for protein level, real-time PCR mRNA of podocyte markers were evaluated untreated or losartan-treated Zucker lean (Fa/+) fatty (Fa/Fa) rats. <i>Results:</i> The rats...

We have examined the effect of 3 hr immobilization stress on plasma luteinizing hormone, testosterone, and corticosterone levels, activity 3β-hydroxysteroid dehydrogenase (3β-HSD) in microsomal mitochondrial fractions testis from adult rats. Immobilization for increased reduced testosterone concentrations by 57%. Plasma hormone levels were lower, although not significantly (P = 0.093) so, stressed animals. (3 hr) Vmax values 3β-HSD mitochondria fraction 40% 34%, respectively, but had no Km...

In a 5-year longitudinal study, we examined the effect of disrupting neonatal activity pituitary-testicular axis on sexual development male rhesus monkeys. Animals in social group under natural lighting conditions were treated with GnRH antagonist (antide), antide and androgen, or both vehicles, from birth until 4 months age. antide-treated neonates, serum LH testosterone near below limits detection throughout period. Antide + androgen-treated neonates had subnormal LH, but above normal...

This study examined the potential use of GnRH agonist-treated female monkey as a model for bone loss after medical oophorectomy or onset menopause in women. Three rhesus monkeys (13–16 yr age) were treated continuously 10 months with 25 μg/day agonist using osmostic minipumps. All three animals exhibited normal menstrual cycles before treatment. Within 5 weeks beginning treatment, serum progesterone and estradiol concentrations had fallen to low values did not rise significantly during...

Male rhesus monkeys treated continuously with a GnRH agonist for the first 4 months of postnatal life exhibited delay in onset puberty and an attenuated peripubertal rise testosterone (T) secretion. The objectives current study were to determine whether these effects on sexual development permanent hypothalamic-pituitary-testicular axis was functioning normally animals as adults. Neonatal treatment delays but does not permanently block maturation male monkeys. Treated that did show pubertal...

Electroejaculation of 17 rhesus monkeys was performed at intervals during a 15-month period using both penile and rectal probe stimulation. The semen quality compared for the two stimulation methods. Both methods were effective in approximately 90% attempts, there no difference fertilizing capacity sperm. A seasonal detected, samples recovered by showed higher sperm count.

In this study we have demonstrated that acute adrenalectomy (1000 hr proestrus) has no effect on the release of LH proestrous afternoon. However, chronic results in loss some factor responsible for synchronizing preovulatory surge. Since investigator shown previously (15) progesterone can influence timing ovariectomized and ovariectomized-adrenalectomized animals, it is most likely adrenal involved event.

The objective of this study was to examine longitudinal changes in serum leptin concentrations during development and correlate those with sexual male rhesus monkeys housed under natural environmental conditions. Blood samples were drawn from 8 control animals approximately every other month 10 30 mo age thereafter monthly through 80 age. Leptin levels declined the juvenile period until onset puberty negatively correlated body weight. Seven eight became sexually mature breeding season their...