Search results for "endocrine"

Distribution of corticotropin-releasing factor-immunoreactive neurons in the central nervous system of the domestic chicken and Japanese quail

2004

In birds, as in mammals, corticotropin-releasing factor (CRF) is present in a number of extrahypothalamic brain regions, indicating that CRF may play a role in physiological and behavioral responses other than the control of adrenocorticotropin hormone release by the pituitary. To provide a foundation for investigation of the roles of CRF in the control of avian behavior, the distribution of CRF immunoreactivity was determined throughout the central nervous system of the domestic chicken (Gallus domesticus) and Japanese quail (Coturnix japonica). The distribution of CRF-immunoreactive (-ir) perikarya and fibers in the chicken and quail brain was found to be more extensive than previously re…

Role of glutathione in Thiobencarb resistance in the European eel Anguilla anguilla.

2000

Glutathione-dependent defense against xenobiotic toxicity is a multifaceted phenomenon that has been well characterized in mammals. In the present study, eels of species Anguilla anguilla were exposed to 15 ppm of the herbicide thiobencarb (S-4-chlorobenzyl diethylthiocarbamate) for 96 h. Eels exposed to the pesticide were grouped in 24-h intervals according to their time of death, while surviving intoxicated eels constituted another group (live animals). Glutathione content (GSx, GSH, GSSG) was determined in liver and muscle tissues of the dead and live (intoxicated) animals and compared to control values (nonexposed eels). The fish that died before 96 h of exposure were considered suscept…

Development of day-night rhythmicity in "synaptic" ribbon numbers in the pinealocytes of posthatch chicks kept under either natural photoperiodic con…

1991

: Pineal synaptic ribbons (SR) undergo characteristic changes over a period of 24 hr under natural photoperiodic conditions in various vertebrates, being low in number during daytime and elevated at night. During posthatch development of chicks, the rhythmicity of SR numbers is reported to appear at the age of about 2 weeks. Because the influence of external light during the growth phase of chicks on the development of day-night rhythmicity in SR numbers is unknown, we studied day-night differences in SR numbers in the pinealocytes of chicks at the posthatch ages of 15, 17, and 19 days; chicks had previously been kept under natural photoperiodic conditions or continuous illumination. Under …

Human Oviductal Gonadotropin-Releasing Hormone: Possible Implications in Fertilization, Early Embryonic Development, and Implantation1

2000

The oviduct is host to gametes and early embryos at a critical point in their lives. It is clear that the interactions of gametes/early embryo with the maternal oviduct in an autocrine and paracrine manner provide a microenvironment that enhances fertilization, early embryonic development, and implantation. Moreover, there is considerable evidence that an extrahypothalamic GnRH may play a substantial role as a molecular autocrine/paracrine regulator in these events. Gametes and preimplantation embryos express GnRH and GnRH receptor at both messenger ribonucleic acid (mRNA) and protein levels. However, whether GnRH is produced by the human oviduct has not yet been demonstrated. We used RT-PC…

2015

The melanocortin system is one of the most important neuronal pathways involved in the regulation of food intake and is probably the best characterized. Agouti-related peptide (AgRP) and proopiomelanocortin (POMC) expressing neurons located in the arcuate nucleus of the hypothalamus are the key elements of this system. These two neuronal populations are sensitive to circulating molecules and receive many excitatory and inhibitory inputs from various brain areas. According to sensory and metabolic information they integrate, these neurons control different aspects of feeding behavior and orchestrate autonomic responses aimed at maintaining energy homeostasis. Interestingly, composition and a…

Respiratory Parameters after Systemic Corticotropin-Releasing Hormone Administration

1991

Neuroanatomical studies on the distribution of corticotropin-releasing hormone (CRH) and its receptors (7) as well as physiological data suggest a regulatory function of endogenous CRH in hypothalamic and extrahypothalamic brain areas [1, 4]. Endogenous CRH acts within the endocrine hypothalamo-pituitary-adrenal axis and affects cardiovascular regulation and respiration through extrahypothalamic pathways. CRH also stimulates gluconeogenesis and release of plasma-catecholamines. Our experiments in humans also demonstrate an influence on respiration and on heart rate activity after systemic application of CRH. Respiratory parameters and heart rate were analyzed during steady-state conditions …

HGH secretion after oral application of l-Dopa and l-Carbiodopa

1976

The stimulatory effect of L-Dopa and L-Carbidopa (Nacom) on HGH secretion was determined in 12 children of normal height aged from 6 to 14 years. Each child received a standard dose of 250 mg L-Dopa and 25 mg L-Carbidopa p.o. HGH concentration in the serum was determined at standard intervals. All subjects showed a sufficient increase of HGH. The mean value was 19.6 ng/ml. According to the maximum values of the HGH concentration the sample can be divided into two groups; the first group reached the highest values after 20--40 min, the second one after 60--90 min. On evaluation of the curve of the mean values it appears that 2 blood samples taken 40 and 90 min after the ingestion of L-Dopa a…

Endokrinologische Vorhersage der Therapieansprechbarkeit depressiver Patienten auf Lofepramin

1979

In a pilot study of 15 depressive patients of the neurotic and endogenous type we could show that some neuroendocrinological parameters are apt to predict the thymoleptic efficacy of lofepramine. These parameters, which were measured with a simple global stimulation test (insulin hypoglycaemia combined with injection of TRH and LHRH), were as follows: high basal blood glucose; high hypoglycaemic blood glucose; high decrease of blood glucose in comparison to the basal level; low basal TSH; low increase of HGH and low increase of cortisol after hypoglycemia. A synopsis of these parameters allowed a correct classification of 14 out of 15 patients according to therapy response and therapy resis…

Simultaneous stimulation of growth hormone, adrenocorticotropin and cortisol with L‐dopa/L‐carbidopa and propranolol in children of short stature

2000

In 59 otherwise healthy children of short stature, the simultaneous response of growth hormone, cortisol and plasma adrenocorticotropin (ACTH) to L-dopa/L-carbidopa and propranolol at 45 and 90 min after administration were investigated. A growth hormone response of 10 microg/l or higher was considered positive. The definition of a positive cortisol response included either a hormone increase of at least 193 nmol/l or a peak hormone level of at least 497 nmol/l. The ACTH increase had to be fourfold above 11 pmol/l to be considered positive. In the 59 investigated children, the median basal growth hormone levels increased from 1.35 microg/l to 18.05 microg/l and 10.15 microg/l at 45 and 90 m…

Hypothalamic-Pituitary-Adrenal Dysfunction in the Polycystic Ovary Syndrome

2007

Between 20 and 30% of patients with polycystic ovary syndrome (PCOS) demonstrate adrenal androgen (AA) excess, detectable primarily by elevated dehydroepiandrosterone sulfate (DHEAS) levels. Generalized adrenocortical hyperresponsivity to adrenocorticotropic hormone (ACTH) stimulation is also observed and may be the principal mechanism determining AA excess in PCOS. The causes of this abnormality are unclear, but increased peripheral metabolism of cortisol, altered factors regulating glucose-mediated glucose disposal, and perhaps ovarian sex steroids may in different ways contribute to the AA excess in PCOS. Additionally, DHEAS levels and the response of AAs to ACTH are relatively constant …