Growth Hormone Secretion Patterns in German Landrace (DL) Fetuses and Piglets Compared to DL Piglets with Inherited 1,25-Dihydroxyvitamin D3 Deficiency.

The regulation of growth hormone (GH) release during prenatal development and during early postnatal life is not entirely clarified. In this study plasma GH concentrations in pigs with inherited pseudo vitamin D deficiency type I (PDDR-I), which regularly show growth retardation, were compared during ontogeny with unaffected pigs of the same breed (German Landrace, DL) as control. Plasma GH concentrations were measured in plasma of chronically catheterized fetuses (beginning on day 101 after mating or after artificial insemination) and in piglets (day 37 postpartum (p.

Maternal low-protein diet affects epigenetic regulation of hepatic mitochondrial DNA transcription in a sex-specific manner in newborn piglets associated with GR binding to its promoter.

Mitochondrial oxidative phosphorylation (OXPHOS) plays an important role in energy homeostasis by controlling electron transfer and ATP generation. Maternal malnutrition during pregnancy affects mitochondrial (mt) DNA-encoded OXPHOS activity in offspring, yet it is unknown whether epigenetic mechanism is involved in the transcriptional regulation of mtDNA-encoded OXPHOS genes. In this study, 14 primiparous purebred Meishan sows were fed either standard- (SP, 12% crude protein) or low-protein (LP; 6% crude protein) diets throughout gestation, and the hepatic expression and transcriptional regulation of mtDNA-encoded OXPHOS genes were analyzed in newborn piglets.

Paternal fenvalerate exposure influences reproductive functions in the offspring.

Fenvalerate (Fen), a synthetic pyrethroid insecticide, has been shown to have adverse effects on male reproductive system. Thus, the aim of the present study was to elucidate whether these adverse effects are passed from exposed male mice to their offspring. Adult male mice received Fen (10 mg/kg) daily for 30 days and mated with untreated females to produce offspring.

Maternal low-protein diet induces gender-dependent changes in epigenetic regulation of the glucose-6-phosphatase gene in newborn piglet liver.

Glucose-6-phosphatase (G6PC) plays an important role in glucose homeostasis because it catalyzes the final steps of gluconeogenesis and glycogenolysis. Maternal malnutrition during pregnancy affects G6PC activity, yet it is unknown whether epigenetic regulations of the G6PC gene are also affected. In this study, we fed primiparous, purebred Meishan sows either standard-protein (SP; 12% crude protein) or low-protein (LP; 6% crude protein) diets throughout gestation and analyzed hepatic G6PC expression in both male and female newborn piglets.

Maternal low-protein diet causes epigenetic deregulation of HMGCR and CYP7α1 in the liver of weaning piglets.

To investigate the effect of maternal dietary protein on hepatic cholesterol metabolism in offspring pigs and to detect underlying epigenetic mechanisms, 14 primiparous purebred Meishan sows were fed standard-protein (SP, n=7) or low-protein (LP, 50% of SP, n=7) diets during pregnancy and lactation, respectively. LP piglets showed significantly lower body weight and liver weight at weaning, associated with decreased liver and serum cholesterol content. Hepatic SREBP2, HMGCR and CYP7α1 mRNA expressions were all up-regulated in LP piglets, as well as SREBP2 protein content and HMGCR enzyme activity, compared to SP piglets, while the mRNA expression of LDLR, FXR, LXR and CYP27α1 was not altered.

Visualization of immunoreactive growth hormone in cultured peripheral bovine lymphocytes.

Growth hormone (GH) has been shown to be released by immune cells in vitro. Thus, the intracellular confinement of GH immunoreactivity was investigated in cultured bovine lymphocytes using con-focal microscopy. Peripheral blood lymphocytes from cows in early pregnancy (10-20 days post insemination; pi) or during mid-pregnancy (day 110-140 pi) were harvested and cultured for 48 h in presence of phytohemagglutinin-M (PHA-M) or served as controls.

Effect of glucocorticoids pretreatment on steroidogenic capacity of adrenocortical cells isolated from Meishan piglets.

The present in vitro experiment was designed to test whether 48 h of pretreatment with glucocorticoids, cortisol, or dexamethasone (DEX), would affect basal and corticotrophin (ACTH) stimulated (24 h) cortisol secretion from primary cultures of pig adrenocortical cells. Cells were divided into six groups: control pretreatment with or without ACTH challenge, cortisol pretreatment with or without ACTH challenge, and DEX pretreatment with or without ACTH. The culture medium and cells were collected at the end of treatment.

Long-term effects of intermittent equine parathyroid hormone fragment (ePTH-1-37) administration on bone metabolism in healthy horses.

Intermittent administration of parathyroid hormone (PTH) is an anabolic therapy for osteoporotic conditions in humans. This study evaluated the effects of equine PTH fragment (ePTH-1-37) administration on bone metabolism in 12 healthy horses. Six horses each were treated once daily for 120days with subcutaneous injections of 0.

Effects of age and altrenogest treatment on conceptus development and secretion of LH, progesterone and eCG in early-pregnant mares.

The treatment of early pregnant mares with a history of repeated early embryonic loss with the progestin altrenogest has become routine; however no controlled studies on the efficiency of altrenogest to prevent embryonic losses are available so far. In the present study, we have investigated effects of altrenogest treatment in mares on conceptus development and the secretion of LH, progesterone, and eCG until day 100 of pregnancy. In addition, differences related to age of mares were assessed.

Up-regulation of lymphocytic growth hormone secretion during the luteal phase of cycle and early pregnancy.

Growth hormone (GH) has been shown to be produced and secreted by peripheral immune cells. Therefore, we studied the release of GH by lymphocytes, during various stages of pregnancy and estrous cycle in the cow. The effect of leptin on the lymphocytic GH release was also investigated.

Involvement of opioids and catecholamines in stress modulation of LH secretion in the male pig.

The effects of different acute stressors on LH secretion and their possible interactions with opioidergic and catecholaminergic-modulation of LH secretion were investigated using gonadectomized male miniature pigs. Nose-snare (NS) or high intensity cracker blast (CB) or ACTH (1 iu/kg BW) was administered 3h after start of blood sampling. Animals also received either naloxone (Nal; 1 mg/kg BW) or propranolol-a beta-adrenergic antagonist (Pro; 0.

Age-dependent role of steroids in the regulation of growth of the hen follicular wall.

Background: The ovaries are the primary targets of senescence effects in mammalian and avian species. In the present study, relationships between reproductive aging, sex steroids and the growth pattern of the pre-ovulatory follicle wall were investigated using young hens with long clutch (YLC), old hens with long clutch (OLC), old hens with short clutch (OSC), and old hens with interrupted long clutch (OILC).

Methods: Experiment 1: Hens were sacrificed 1.

Diminished expression of ACTH signaling proteins and steroidogenic limiting factors in adrenocortical cells isolated from halothane nn pigs.

Previous studies demonstrated significantly lower plasma cortisol level in homozygous halothane-positive (Hal nn) pigs, as compared with homozygous halothane-negative (Hal NN) pigs. To determine whether such difference is attributed to the fundamental alterations in adrenocortical function, F1 offsprings from Pietrain (Hal nn)xErhualian (Hal NN) were intercrossed to produce F2 sibling pigs with segregated genotypes. Adrenocortical cells were isolated from the Hal nn and Hal NN F2 pigs, respectively, and cultured with or without ACTH challenge.

Ovulatory cycle-related alterations in the thecal growth and membrane protein content of thecal tissue of hen preovulatory follicles.

In the hen ovary, each preovulatory follicle in the hierarchy, irrespective of its size and the level of its maturity is exposed to the preovulatory LH surge in each ovulatory cycle of an egg laying sequence. In the present study, the thecal weight and membrane protein content of theca layers at different stages of hen ovulatory cycle were assessed. Hens were killed 2 h (stage I), 9 h (stage II), 16 h (stage III), and 23 h (stage IV) after oviposition.

Characterization of growth hormone binding sites in granulosa and theca layers at different stages of follicular maturation and ovulatory cycle in the domestic hen.

The currently available evidence points to a possible influence of growth hormone (GH) on avian folliculogenesis, which can be mediated by both hepatic- and ovarian-derived IGF-I. Therefore, the purpose of the present study was to reveal GH-binding sites in granulosa and theca layers of preovulatory follicles and to determine the binding characteristics depending on the degree of follicular maturation and the stage of the ovulatory cycle in the hen. Hens were killed 2 h (stage I), 9 h (stage II), 16 h (stage III), and 23 h (stage IV) after oviposition, and the five largest yellow follicles (from F1 to F5) were removed.

Leptin induces growth hormone secretion from peripheral blood mononuclear cells via a protein kinase C- and nitric oxide-dependent mechanism.

Leptin is a key mediator of signals regulating food intake and energy expenditure and exerts potent immunomodulatory effects. We investigated the mechanisms mediating the action of leptin on GH secretion from peripheral blood mononuclear cells (PBMCs). Using immunofluorescence microscopy, we demonstrated a polarized expression pattern of leptin receptor protein on the surface of mononuclear cells and constitutive expression of GH in PBMCs.

Somatostatin treatment affects testicular function in stallions.

This study investigated the regulation of growth hormone (GH) release in stallions and tested the hypothesis that the somatotrophic axis influences testicular function. Basal plasma GH concentrations, effects of an experimental decrease of GH release on testicular function and an opioidergic regulation of GH release were investigated in Shetland stallions (n=6). No seasonal variations in plasma GH concentrations were found over a 12-month period.