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Query: UNIPROT:P61278 (
somatostatin
)
22,083
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The effects of treatment with a
somatostatin
analog (Sandostatin, SMS201-995) were investigated in female rats with dimethylbenzanthracene (DMBA)-induced rat mammary tumors. A 3-week treatment was performed using sandostatin, the
LHRH
-agonist buserelin alone, or buserelin in combination with sandostatin. Twice daily sandostatin treatment was performed with dosages of 0.05 microgram, 0.2 microgram, 1 microgram, 5 micrograms, and 20 micrograms. Buserelin was used in a 2 x 5 micrograms/day dosage. The combined results from six different experiments show that the various dosages of sandostatin caused no tumor growth inhibition.
Somatostatin
receptors could not be demonstrated in these mammary tumors. Sandostatin treatment by daily injections did not suppress levels of growth hormone, prolactin, or epidermal growth factor-like activities. Estrogen (ER) and progesterone (PgR) receptor contents of the mammary tumors were not changed. In contrast, buserelin treatment caused highly significant tumor remission. The combined treatment with sandostatin and buserelin did not alter the treatment results obtained after treatment with buserelin alone. In conclusion, sandostatin treatment in this tumor model had no direct growth inhibitory effect and did not cause an endocrine inhibition of mammary tumor growth. However, these results do not exclude antitumor effects in human breast cancer in view of the presence of
somatostatin
receptors in approximately 20-45% of human tumors, besides possible different endocrine effects.
...
PMID:The somatostatin analog Sandostatin (SMS201-995) in treatment of DMBA-induced rat mammary tumors. 196 5
To determine the effects of prepubertal ethanol (ETOH) exposure on hypothalamic and pituitary hormones known to be involved in the onset of female puberty, we have chronically exposed female rats to either a liquid-diet containing ETOH or an isocaloric control liquid-diet. An additional set of controls consisted of animals maintained on Lab Chow, and water provided ad lib. Our results indicate that the feeding regimen employed produced no differences with regard to body and reproductive organ weights, as well as any of the hormones measured between the two control groups. Conversely, ETOH-treated animals showed significantly lower body and reproductive organ weights than the control animals and although no differences were detected between ETOH-treated and control animals with regard to the hypothalamic content of
somatostatin
(SRIF), there was a significant increase in the hypothalamic content of growth hormone releasing hormone (GHRH), with a concomitant and significant decrease in the serum concentration of growth hormone (GH). Furthermore, the ETOH-treated animals showed a significant increase in the hypothalamic content of
luteinizing hormone releasing hormone (LHRH)
with a significant decrease in the serum concentration of luteinizing hormone (LH), but not follicle stimulating hormone (FSH). These results demonstrate for the first time that chronic, prepubertal ETOH administration alters the concentrations of specific hypothalamic and pituitary hormones which are known to be involved in the female pubertal process.
...
PMID:Actions of ethanol on hypothalamic and pituitary hormones in prepubertal female rats. 196 48
Dopaminergic and peptidergic nerve fibers were simultaneously demonstrated with a double-labeling technique at the ultrastructural level. The first antibody, raised against tyrosine hydroxylase, was applied during the preembedding phase and visualized with the peroxidase method. The second antibody, raised against one of the peptides met-enkephalin,
somatostatin
or
gonadotropin-releasing hormone
(GnRH), was applied to the ultrathin sections and visualized with gold-labeled goat anti-rabbit IgG. The fibers of both categories were present in the zona externa of the median eminence, frequently contacting the basal lamina of the portal vessels. In addition, topographical relationships between different types of nerve fibers were observed in the perivascular areas, although there were no morphological signs of synaptic specializations. Using serial sections, it could be established that one GnRH-fiber contacted both a dopaminergic fiber and a fiber immunoreactive for met-enkephalin. The observations support earlier physiological data concerning the regulation of the hypothalamo-hypophyseal axis, with special emphasis on the release of neurohormones in the median eminence of the newt.
...
PMID:Topographical relationships between catecholamine- and neuropeptide-containing fibers in the median eminence of the newt, Triturus alpestris. An ultrastructural immunocytochemical study. 196 31
To elucidate the role of growth hormone (GH)-releasing hormone (
GRH
) and
somatostatin
(SRIH) in the regulation of the growth hormone (GH) secretory pattern, we collected portal blood from five unanesthetized ovariectomized ewes for repeated measurements of
GRH
and SRIH simultaneous with those of peripheral GH. Hormones were measured at 10-min intervals for 5.5 h and their interrelationships analyzed. Mean portal
GRH
was 20.4 +/- 6.7 (SD) pg/ml and the estimated overall secretion rate was 13 pg/min.
GRH
secretion was pulsatile with peaks of 25-40 pg/ml and a mean pulse interval of 71 min. Mean portal SRIH was 72 +/- 33 pg/ml and the estimated overall secretion rate was 32 pg/min. SRIH secretion was also pulsatile with peaks of 65-160 pg/ml and a mean pulse interval of 54 min. The GH pulse interval was 62 min. A significant association was present between
GRH
and GH secretory peaks though not between
GRH
and SRIH or SRIH and GH. Insulin hypoglycemia resulted in a rapid and brief stimulation of SRIH secretion followed by a decline in GH levels. No effect was observed on
GRH
secretion until 90 min, when a slight increase occurred. The results suggest (a) the presence of an independent neural rhythmicity of
GRH
and SRIH secretion with a primary role of
GRH
in determining pulsatile
GRH
secretion, and (b) that the inhibitory effects of insulin hypoglycemia on GH in this species are attributable to a combination of enhanced SRIH secretion and possibly other factors, though without significant inhibition of
GRH
.
...
PMID:Measurement of growth hormone-releasing hormone and somatostatin in hypothalamic-portal plasma of unanesthetized sheep. Spontaneous secretion and response to insulin-induced hypoglycemia. 197 73
Changes in the structure and function of five neuropeptide families during evolution are considered. The families of
gonadotropin-releasing hormone
(GnRH), corticotropin-releasing factor (CRF), growth hormone-releasing hormone (GH-RH),
somatostatin
(SS), and vasopressin/oxytocin (VP/Oxy) are used as models to illustrate the importance of a phylogenetic approach in understanding neuropeptide structure/activity relationships, precursors, processing, gene duplication, novel locations and functions, and gene-associated peptides.
...
PMID:Neuropeptide families: an evolutionary perspective. 197 5
Glutathione content and glutamyl transpeptidase activity in different regions of adult female rat brain were determined at 10 and 30 min following intraventricular injection of
LHRH
and
somatostatin
. Hypothalamic glutathione levels were significantly elevated at 10 and 30 min after a single injection of a 0.1 micrograms dose of
LHRH
. On the contrary, glutathione levels significantly decreased in the hypothalamus, cerebral cortex and cerebellum at 10 and 30 min after 0.5 or 1 microgram dose. However, significant decrease in brain stem glutathione was evident at 30 min after 0.5 microgram and 10 min after the 1 microgram dose.
Somatostatin
at doses of 0.5 microgram and 1 microgram significantly decreased glutathione levels in all four brain regions both at 10 and 30 min following injection into the 3rd ventricle. Gamma-glutamyl transpeptidase activity in the hypothalamus and cerebral cortex was significantly elevated after intraventricular injection of
LHRH
. However, a significant increase in gamma-glutamyl transpeptidase activity in cerebellum and brain stem was seen only with 0.5 and 1 micrograms doses of
LHRH
.
Somatostatin
also significantly increased gamma-glutamyl transpeptidase activity in hypothalamus, cerebral cortex, brain stem and cerebellum. The decrease in glutathione levels with corresponding increase in gamma-glutamyl transpeptidase activity after intraventricular administration of
LHRH
and
somatostatin
suggests a possible interaction between glutathione and hypothalamic peptides.
...
PMID:Glutathione and gamma-glutamyl transpeptidase in the adult female rat brain after intraventricular injection of LHRH and somatostatin. 197 5
Newly developed
somatostatin
analogues may be useful agents in the treatment of breast and prostate cancer. Potential mechanisms of antitumor action include suppression of circulating levels of trophic hormones and growth factors as well as direct effects at the tumor level, potentially involving autocrine/paracrine mechanisms. Pilot clinical trials conducted in heavily pretreated women with advanced breast cancer indicate that SMS 201-995 (Sandostatin R) has minimal toxicity and moderately suppresses stimulated growth hormone secretion and basal somatomedin-C level.
Somatostatin
analogues have also been found to retard the growth of experimental prostate cancer, particularly when used in combination with
LHRH
analogues. The therapeutic efficacy of these compounds used alone or in combination with other agents in the treatment of breast and prostate cancer remains to be established in larger clinical trials involving less heavily pretreated patients.
...
PMID:Somatostatin analogues in the treatment of breast and prostate cancer. 198 Oct 12
To date, the effects of long-term growth hormone (GH)-releasing hormone [GHRH(1-29)-NH2] treatment on the plasma concentrations of
somatostatin
-like immunoreactivity (SLI) remain undefined. In the present study, the effect of GHRH(1-29)-NH2 therapy on plasma SLI levels has been studied in 11 non-GH-deficient children. The pattern of administration was 5 micrograms/kg body weight, given subcutaneously once every day. There was no significant change in plasma SLI levels after bolus injection of GHRH(1-29)-NH2 before and during GHRH(1-29)-NH2 therapy. However, plasma SLI rose in basal plasma and nocturnal sleep after 3 months of GHRH(1-29)-NH2 therapy and remained the same during 6 months of treatment with GHRH(1-29)-NH2. The reason for this finding is uncertain, but an increase in SLI release from the enteroinsular axis is a possible explanation. The association of our findings with the role of the circulating SLI on nutrient homeostasis and the effects of
GNRH
on growth velocity is discussed.
...
PMID:Plasma somatostatin-like immunoreactivity during growth-hormone-releasing hormone therapy in non-growth-hormone-deficient children. 198 47
Specific polyclonal antibodies raised against synthetic thyrotropin-releasing hormone (TRH) infused intracerebroventricularly (ICV) significantly decreased gastric lesions induced by cold restraint stress. The antiulcer effect of immunologic blockade of brain TRH was specific. Normal rabbit serum or antibodies raised against
somatostatin
, alpha-MSH, Leu-enkephalin,
gonadotropin-releasing hormone
and atrial natriuretic factor were ineffective. These findings suggest that brain TRH may play an important role in experimental stress ulcer formation.
...
PMID:Evidence for a role of brain thyrotropin-releasing hormone (TRH) on stress gastric lesion formation in rats. 211 18
This study evaluated the effect of ACTH and several ACTH fragments on the development of gastric glandular lesions induced by cold-restraint stress in rats. Intracerebroventricular administration of ACTH1-39 dose-dependently (0.1-10 micrograms) inhibited stress gastric lesion formation. Studies with smaller molecular weight forms of ACTH (in a dose equimolar to 10 micrograms of ACTH1-39) revealed that ACTH1-13 and ACTH1-10 were also protective. The ACTH fragments ACTH5-10, ACTH34-39 and ACTH1-17 were without effect. Immunoneutralization of endogenous brain ACTH1-39 significantly increased stress gastric lesion severity. Antisera raised against synthetic
somatostatin
,
gonadotropin-releasing hormone
, and L-enkephalin were ineffective. These results with ACTH coupled with our previous demonstration of a protective effect of beta-endorphin suggest that specific brain pro-opiomelanocortin gene products modulate gastric mucosal integrity in response to stress.
...
PMID:Brain ACTH prevents stress gastric lesions in rats. 217 16
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