Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UNIPROT:P01189 (
beta-endorphin
)
21,003
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Naloxone has been used as a pharmacological tool to investigate the role of endorphins and opiate receptors in the cardiovascular pathophysiology of shock. It would appear that endorphins act on opiate receptors to contribute to the abnormalities found and that naloxone improves survival as well as cardiovascular function in shock. Preliminary studies in humans and the subhuman primate create cautious optimism regarding the clinical application of this information. Naloxone has served us well as a key to unlock the involvement of endorphins and opiate receptors in shock. However, further advances in our understanding may depend on the development and use of opiate receptor agonists and antagonists specific for the different opiate receptors described, each subserving different functions. Naloxone's disadvantage of increasing pain awareness may limit its clinical usefulness but might be overcome by using drugs that reverse the behavioral and neuroendocrine changes produced by
beta-endorphin
without altering pain relief. Thyrotropin-releasing hormone (TRH) is just such a "physiological" opiate antagonist which has been shown to increase
MAP
in experimental endotoxic and hemorrhagic shock [32].
...
PMID:Naloxone in endotoxic shock: experimental models and clinical perspective. 630 74
Previous studies established that naloxone reverses hypotension in endotoxin, hemorrhagic, and spinal shock. We studied endotoxin shock in hypophysectomized (Hx) rats, which have little circulating
beta-endorphin
. Hx or intact rats received surgically implanted jugular catheters for drug injection and aortic catheters for arterial blood pressure (
MAP
) recording. On the second day after implantation, rats were pretreated with either naloxone or saline. Two minutes later each rat received endotoxin. Following endotoxin, all rats showed a brief biphasic hypertensive-hypotensive response followed by stabilization of
MAP
near baseline. Within 20 min, all Hx rats, regardless of pretreatment, and the saline-treated intact rats, showed progressive hypotension (P less than 0.005). Only the naloxone-pretreated intact rats maintained a stable
MAP
. Plasma endorphin measured at 20 min was undetectable in Hx rats in contrast to intact rats (P less than 0.001); plasma corticosterone levels were likewise suppressed in the Hx rats (P less than 0.01). Thus (1) naloxone protected only the rats with an intact pituitary-adrenal-sympathetic system, and (2) pituitary endorphin is not required to generate endotoxin shock in hypophysectomized rats.
...
PMID:Endotoxin shock: prevented by naloxone in intact but not hypophysectomized rats. 632 Feb 13
We have successfully established normal neonatal and adult human melanocyte cultures in a growth medium containing the physiologic mitogens basic fibroblast growth factor (bFGF; 0.6 ng/ml), endothelin-1 (endo-1; 10 nM), and alpha-melanocyte stimulating hormone (
alpha-MSH
; 10 nM). The latter two factors replaced the commonly used mitogens 12-O-tetradecanoylphorbol 13-acetate (TPA) and bovine pituitary extract (BPE), respectively. Basic FGF alone maintained the viability but did not induce the proliferation of melanocytes. The addition of endo-1 to the bFGF-containing medium resulted in reduction of tyrosinase activity without enhancement of proliferation. However, the addition of
alpha-MSH
to the bFGF-containing medium potentiated melanocyte proliferation and tyrosinase activity. The concomitant addition of endo-1,
alpha-MSH
, and bFGF significantly increased the entry of melanocytes into S phase and potentiated their proliferation. Melanocytes maintained under these conditions had the same tyrosinase activity as those maintained in a medium containing
alpha-MSH
and bFGF. The signal transduction pathway induced by either endo-1 or bFGF, but not
alpha-MSH
, includes the activation of the mitogen-activated (
MAP
) kinase pathway. The addition of both endo-1 and bFGF had more than an additive effect on the MAP kinase extracellular signal-regulated kinase 2 (ERK2). This effect was further increased by the addition of
alpha-MSH
to these two growth factors. In summary, we have devised a growth medium for human melanocytes based on the use of physiologic mitogens that substituted for routinely used artificial and undefined growth factors. The resulting cultures should be desirable for clinical uses and permissive for the expression of in vivo relevant responses to regulatory factors.
...
PMID:Long-term proliferation of human melanocytes is supported by the physiologic mitogens alpha-melanotropin, endothelin-1, and basic fibroblast growth factor. 769 46
The present study examined the association between hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-ovarian axes. HPA activity determined by plasma levels of
adrenocorticotropin
(ACTH) and corticosterone (B) was assessed in intact female rats as a function of oestrous cycle stage under resting conditions and after exposure to a 20 min restraint stress. To delineate the roles of oestradiol and progesterone in HPA axis modulation, plasma concentrations of ACTH and B were determined in ovariectomised (OVX) animals treated with oestradiol and/or progesterone under resting conditions and during exposure to the stress of a novel environment. The effects of these steroid treatments on the transcription and/or binding properties of the two corticosteroid receptors, the mineralocorticoid (MR) and glucocorticoid (GR) receptors, were also examined in hippocampal tissue, (i) Fluctuations in basal and stress-induced plasma ACTH and B concentrations were found during the oestrous cycle with highest levels at late pro-oestrus. (ii) In OVX steroid-replaced animals, basal and stress-induced activity was enhanced in oestradiol and oestradiol plus progesterone-treated animals compared with OVX controls. (iii) Cytosol binding assays revealed an oestradiol-induced decrease in hippocampal MR capacity. This decrease appears to be due to an effect of the steroid on MR transcription as in situ hybridisation analysis of MR mRNA showed an oestradiol-induced decrease in MR transcript in all hippocampal subfields. (iv) Treatment of oestradiol-primed animals with progesterone reversed the oestradiol-induced decrease in hippocampal MR capacity. Data from MR mRNA hybridisation in situ experiments indicate that this reversal may be due to an antagonism of the oestradiol effect on MR transcription. (v)
Progesterone
treatment with or without prior oestradiol-priming induced a significant decrease in the apparent binding affinity of hippocampal MR. We show that progesterone and its 11 beta-hydroxylated derivative have a high affinity for the hippocampal MR. (vi) Neither oestradiol nor progesterone affected GR binding parameters in the hippocampus. In conclusion, we find that sex steroids modulate HPA activity and suggest that the observed effects of these steroids on hippocampal MR may underlie their concerted mechanism of action in inducing an enhanced activity at the period of late pro-oestrus.
...
PMID:The influence of ovarian steroids on hypothalamic-pituitary-adrenal regulation in the female rat. 770 84
The goal of this study was to test the hypothesis that increasing or decreasing the load on baroreceptors in the right heart influenced the secretion of arginine vasopressin (AVP),
adrenocorticotropic hormone (ACTH)
, and renin during a state of sustained arterial hypotension. The hypothesis was tested in chronically instrumented conscious dogs prepared with inflatable cuffs around the pulmonary artery (PA) and the thoracic inferior vena cava (IVC). In one protocol (n = 5), mean arterial pressure was reduced 10 or 20% below control by constriction of the PA, a maneuver that caused a fall in left atrial pressure (LAP) and an increase in right atrial pressure (RAP). Plasma AVP, ACTH, atrial natriuretic peptide (ANP), and plasma renin activity (PRA) all increased (P < 0.05) in response to constriction of the PA. Reducing RAP to control by constriction of the IVC during maintained constriction of the PA had no effect on
MAP
, LAP, plasma AVP, ACTH, or PRA, but plasma ANP fell significantly. In a separate protocol (n = 4), constriction of the IVC was used to reduce
MAP
10 or 20% below control, and this led to significant decreases in both LAP and RAP and increases in plasma AVP, ACTH, and PRA. RAP was then increased above control by constriction of the PA without altering either
MAP
or LAP. Raising RAP from a level that was 6.3 +/- 1.3 mmHg below control to 3.5 +/- 1.0 mmHg above control had no effect on plasma AVP, ACTH, or PRA.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Effect of loading right atrial and ventricular receptors on stimulated AVP, ACTH, and renin secretion in awake dogs. 773 89
Dynamic changes of immunoreactive
beta-endorphin
(ir-beta-EP) in perfusates collected from hypothalamic paraventricular nuclei at different times after burn, and the effects of intrahypothalamic paraventricular microinjection of
beta-endorphin
or its antiserum on various cardiac indices (
MAP
, dP/dtmax, Lvsp and HR) and survival time, were observed in anesthetized SD rats after third degree burn of 20% total body surface area. The results showed a significant increase of ir-
beta-endorphin
contents in the perfusate with the appearance of two peaks. According to the cardiac indices and mean survival time, the condition of the burned animals were improved by injection of anti-
beta-endorphin
serum, while injection of
beta-endorphin
did the reverse. The above results suggest that massive accumulation of
beta-endorphin
in the paraventricular nucleus appears to be one of the important factors detrimental to burn shock.
...
PMID:[Effect of hypothalamic paraventricular beta-endorphin on burn shock in rats]. 778 94
Ovarian steroids exert feedback effects at the level of both the hypothalamus and anterior pituitary to regulate the secretion of gonadotrophins. Oestradiol decreases the activity of mRNA encoding the alpha and beta subunits of gonadotrophins. In the late follicular phase, oestradiol exerts a positive feedback control over pituitary luteinizing hormone (LH) release and a negative control over follicle stimulating hormone (FSH). Oestradiol also induces a pre-ovulatory increase of gonadotrophin releasing hormone (GnRH) secretion which is continuous rather than episodic. Such a GnRH rise may not be required to produce the LH surge.
Progesterone
exerts its major effect at the hypothalamic level and decreases GnRH pulse frequency by inducing the release of
beta-endorphin
. However, the hypothalamus is not the exclusive target of progesterone action, for its facilitatory action on gonadotrophin release may be at the level of the pituitary gland. This positive feedback effect was studied in women with hypothalamic gonadotrophin deficiency treated with pulsatile GnRH. In physiological doses, progesterone had a stimulatory effect on LH secretion at the pituitary level. Finally, regarding the effect of androgens upon gonadotrophin secretion, the administration of a non-steroidal pure anti-androgen (Flutamide) for 12 months in 10 normally cycling women did not change significantly the mean levels, frequency, or amplitude of LH pulses or the LH and FSH responsiveness to GnRH. Androgens (apart from their aromatization to oestrogens) do not directly play a physiological role in gonadotrophin regulation in normal women.
...
PMID:The control of gonadotrophin secretion by ovarian steroids. 827 77
Effects of the GABAergic drug diazepam (0.15 mg kg-1, i.v.) on cardiovascular and endocrine responses to 50 degrees head-up tilt were evaluated in seven men. During the initial phase of tilt (normotensive phase), increases in heart rate (HR) and total peripheral resistance (TPR) and decreases in cardiac output were unaffected by diazepam. Also the associated increase in plasma noradrenaline did not change, while response in plasma ACTH was diminished and in plasma cortisol abolished by diazepam (F(1,10) = 6.45; P < 0.03). After 42 +/- 4 min of sustained tilt with saline (control) and 47 +/- 6 min (n.s.) after diazepam, presyncopal symptoms appeared (hypotensive phase) associated with decreases in HR,
MAP
, and TPR (P < 0.01). This episode induced a 2-3-fold increase in plasma ACTH,
beta-endorphin
, prolactin, cortisol (< 0.01), and a moderate increase in plasma adrenaline (P < 0.05). Diazepam did not significantly change cardiovascular and endocrine responses to the hypotensive phase of tilt. Results indicate that diazepam attenuates the cortisol part of pituitary-adrenal responses to moderate, but not to severe, central hypovolaemia in humans with no effect on cardiovascular tolerance.
...
PMID:Effect of diazepam on endocrine and cardiovascular responses to head-up tilt in humans. 835 26
We have investigated the role of the gonadal steroids testosterone (T) and progesterone in modulating: (1) the onset and severity of adjuvant-induced arthritis (AA), (2) the response of the hypothalamo-pituitary-adrenal (HPA) axis, and (3) the levels of plasma prolactin and anterior pituitary prolactin messenger ribonucleic acid (mRNA) in the rat. Male rats were castrated (CSX) and received either no T, low T or high T delivered using silastic implants. In a second study experimental groups comprised CSX/AA, CSX/AA + progesterone or CSX/AA + progesterone + T. The time of onset was sooner and the severity of AA was greater in CSX rats. Inflammation was prevented by T replacement. Endogenous plasma T levels were decreased in AA rats. In control animals with AA there was an increase in
pro-opiomelanocortin (POMC)
mRNA in the anterior pituitary and of plasma corticosterone, and a decrease in corticotrophin-releasing factor (CRF) mRNA. These changes in the HPA axis of AA and CSX/AA rats were reversed by T replacement. These data suggest that T has an important protective effect on the progress and severity of AA. This was reflected by a reversal of the neuroendocrine changes of the HPA axis.
Progesterone
treatment alone had no effect on the severity of the disease. Prolactin mRNA in the anterior pituitary was decreased in the CSX and in the CSX/AA group but was not altered by AA. Plasma prolactin was raised in AA but T replacement did not reduce these elevated levels despite the absence of disease. Thus, prolactin provides a poor indicator of inflammation, suggesting that it may not be a potent pro-inflammatory compound in AA.
...
PMID:A protective role for testosterone in adjuvant-induced arthritis. 860 51
Progesterone
(P) stimulates prolactin secretion through a neural mechanism in estrogen (E)-primed female monkeys. Several peptides, including
beta-endorphin
(BE), oxytocin (OT), substance P (SP) and vasoactive intestinal polypeptide (VIP) are potential prolactin stimulatory factors and could mediate the effect of P. We hypothesized that the antagonism of a pivotal peptidergic neural system would block P-induced prolactin secretion and that the function of a pivotal peptidergic system would be altered by changes in gonadal steroid concentrations. Therefore it was of interest (1) to examine the effect of infusion of antagonists to these peptides on P-induced prolactin secretion, and (2) to determine BE, OT, SP and VIP levels in the hypothalamus of monkeys of various reproductive states. For the antagonist studies, female monkeys (n = 8) were spayed, adapted to a vest and tether remote sampling system and catheterized prior to antagonist challenges. E-primed monkeys received P injections 48 h prior to antagonist administration. Prolactin increased within 36-48 h of P injection. All antagonist challenges were administered in varying doses during the P-induced prolactin elevation and blood samples were collected every 10 min for prolactin determinations. The opiate antagonist, naloxone (n = 5), reduced serum prolactin in a dose-related manner with a mean IC50 of 1.5 +/- 0.6 micrograms/kg/min. The OT (n = 4), SP (n = 4) or VIP (n = 4) antagonists did not reduce serum prolactin in a dose-related manner. We previously reported that the hypothalamic content of OT is increased by ovarian hormones. To determine whether the hypothalamic content of BE, SP or VIP was related to gonadal status, the peptide levels in 4 hypothalamic regions of monkeys in various physiological states were measured. BE (ng/mg protein) in the medial basal hypothalamus (MBH) was significantly greater in adult females (17.7 +/- 6.9; n = 6) as compared to spayed females (0.6 +/- 0.2; n = 3) and juvenile females (1.8 +/- 1.1; n = 3). Hypothalamic content of SP in the preoptic area and mammillary bodies, but not the MBH, was significantly greater in gonadal intact females than spayed females. VIP content (pg/mg protein) was not significantly different between adult, spayed and juvenile females nor between adult and juvenile males in any hypothalamic area. Taken together these results support a pivotal role for BE in the neural regulation of P-induced prolactin secretion. The involvement of OT, SP, and VIP in a specific manner at the pituitary level is not indicated.
...
PMID:Beta-endorphin, but not oxytocin, substance P or vasoactive-intestinal polypeptide, contributes to progesterone-induced prolactin secretion in monkeys. 879 99
<< Previous
1
2
3
4
5
6
Next >>