bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of pituitary adenylate cyclase-activating polypeptide 38 on growth hormone and prolactin expression
Authors: Velkeniers B , Zheng L , Kazemzadeh M , Robberecht P , Vanhaelst L , Hooghe-Peters E L 
Published: December 2008

Abstract
Time- and dose-dependent effects of pituitary adenylate cyclase-activating polypeptide (PACAP) on prolactin (PRL) and growth hormone (GH) release were examined in static and dynamic rat pituitary cell incubations and on different pituitary cell (sub)populations separated according to their density on a discontinuous Percoll gradient. Quantitative in situ hybridization histochemistry allowed us to examine in parallel the effects of PACAP on PRL and GH gene expression. PACAP did not alter GH or PRL secretion in a dynamic superfusion system, in any cell population tested. Static incubations (30 min, 2–36 h) with PACAP 38 resulted in a significant increase in GH release and stimulated GH synthesis, as measured by the cytoplasmic accumulation of GH mRNA in the somatotrophs. These effects on synthesis and release were also observed after the enrichment of GH cells on Percoll gradients. PRL release was not altered by longer periods of incubation. Although no significant changes were observed in PRL secretion after 38 h, accumulation of cytoplasmic PRL mRNA was significantly stimulated in total pituitary cell suspension. After fractioning lactotrophs on Percoll gradients, the stimulatory effect of PACAP on PRL synthesis was lost.
These results suggest that PACAP stimulates GH release and synthesis, and that it may act as a physiological regulator of this cell type. The PRL cell is not the most likely target cell type for PACAP. Effects observed on PRL synthesis in the total cell population may involve paracrine action of other hormone- or non-hormone-secreting cell types.
Journal of Endocrinology (1994) 143, 1–11
Regulation of gonadotrophin-releasing hormone receptor mRNA expression in the sheep
Authors: Brooks J , McNeilly A S 
Published: December 2008

Abstract
To investigate the regulation of the sheep gonadotrophin-releasing hormone receptor (GnRH-R) gene expression, two different treatment regimes were used. Experiment 1 examined the effects of twice daily injections of ovine follicular fluid (oFF, 15 ml s.c.) as a source of inhibin, and daily GnRH antagonist injections (Nal-Glu.HOAc, 2 mg s.c.) on days 9–12 of the oestrous cycle. Luteolysis was induced on day 12 with prostaglandin (PG) and the ewes killed at two different stages; day 12 (luteal) and 18 h after PG injection. Experiment 2 examined the effect of a single injection of oestradiol benzoate (100 μg i.m.) 18 h before death in luteal phase ewes and ewes chronically implanted with the GnRH agonist, buserelin. In both experiments, pituitaries were removed at death for determination of pituitary GnRH binding, LH content and levels of GnRH-R and LHβ mRNA. In addition in experiment 1, follicles ≥2·5 mm were dissected from the ovaries for determination of oestradiol content.
In experiment 1, oFF treatment during the luteal phase completely inhibited follicle oestradiol production but was without effect on the other parameters measured. After cessation of oFF treatment and induction of luteolysis, a significant (P<0·05) increase in plasma LH occurred but the normal follicular increase in both GnRH-R mRNA levels and GnRH binding seen in control ewes was prevented. GnRH antagonist treatment alone or in combination with oFF also inhibited follicle oestradiol production, prevented the increase in GnRH-R mRNA, completely inhibited GnRH binding and significantly decreased LHβ mRNA levels. Pituitary LH content was unaffected by any treatment. In experiment 2, oestradiol treatment did not affect GnRH-R mRNA levels, GnRH binding, LHβ mRNA or pituitary LH content in luteal phase ewes, whilst chronic GnRH agonist treatment acted to decrease these parameters dramatically. A single injection of oestradiol in the GnRH agonist treated ewes significantly (P<0·05) increased GnRH-R mRNA levels and completely restored GnRH binding to luteal levels, without any effect on LHβ mRNA or pituitary LH content.
These results suggest that the control of GnRH receptor expression in the sheep is directly related to oestradiol and not to the action of GnRH itself.
Journal of Endocrinology (1994) 143, 175–182
Differential regulation of insulin-like growth factor binding protein-2 and -4 mRNA in muscle tissues and liver by diabetes or fasting
Authors: Chen Y , Arnqvist H J 
Published: December 2008

Abstract
The present study was undertaken to investigate the metabolic regulation of insulin-like growth factor binding proteins (IGFBPs) gene expression in muscles from diabetic or fasted rat. The messenger RNA (mRNA) levels for IGFBP-2 and -4 were analysed by solution hybridization in heart, skeletal and smooth muscle and liver from fasted (3 days) and refed (6, 12, 24, 72 h) rats and rats made diabetic with streptozotocin. In aortic intima-media, the mRNA levels for IGFBP-2 and -4 were decreased by diabetes or fasting and were restored gradually by refeeding. The response of IGFBP-4 mRNA to diabetes appeared two days after injection of streptozotocin, while a significant decrease of IGFBP-2 mRNA was found after a diabetes duration of two weeks. Both diabetes and fasting decreased IGFBP-4 mRNA levels in heart muscle and skeletal muscle and refeeding restored mRNA for IGFBP-4 to normal level. IGFBP-2 mRNA was undetectable in heart muscle and skeletal muscle. In liver IGFBP-4 mRNA was abundantly expressed. It was slightly but significantly decreased by fasting and approached normality with refeeding, while no change was found in diabetic liver. In contrast, liver IGFBP-2 mRNA was much lower in amount than IGF-I mRNA and IGFBP-4 mRNA and was sharply elevated by fasting, and decreased by refeeding. In conclusion, 1) both IGFBP-2 and -4 mRNA in various tissues are regulated by diabetes or fasting; 2) the mRNA for IGFBP-2 is metabolically regulated in a discordant, organ-specific manner.
Journal of Endocrinology (1994) 143, 235–242
CELLS CULTURED FROM THE GROWING TIP OF RED DEER ANTLER EXPRESS ALKALINE PHOSPHATASE AND PROLIFERATE IN RESPONSE TO INSULIN-LIKE GROWTH FACTOR-I
Authors: Price Joanna S. , Oyajobi Babatunde O. , Oreffo Richard O. C. , Russell R. Graham G. 
Published: December 2008

ABSTRACT
Deer antler growth provides a unique natural model of rapid and complete bone regeneration. In this study, the distal antler tips of male red deer (Cervus elaphus) were collected post-mortem during the annual growth period (April-August), and an in vitro system established for the culture of cells from three regions; the inner layer of the perichondrium, the reserve mesenchyme and the cartilage zone. Alkaline phosphatase (ALP) expression by cultured cells, as demonstrated by enzyme histochemistry and biochemical assay, reflected the stage of cellular differentiation. ALP activity was highest in cells cultured from the hypertrophic cartilage region (3.6 ± 0.2 μmol/μg cell protein/minute), and lowest in undifferentiated mesenchymal cells (0.3 ± 0.01 μmol/μg cell protein/minute). ALP expression was lost with passage in culture. Levels of ALP activity in cultured cells correlated with the pattern and extent of enzyme expression in tissue sections as demonstrated by histochemical staining. Insulin-like growth factor (IGF)-I (10−9M-10−7M) was found to be mitogenic for cultured cells from all three zones as shown by increased incorporation of [3H]thymidine into DNA. These results demonstrate that cells from three different regions of the antler tip can be maintained in culture, and that antler cells share certain phenotypic characteristics of growth plate chondrocytes. These data provide further evidence of a role for IGF-1 in the regulation of antler growth. Antler regrowth is a potentially useful model for the study of the factors that regulate bone formation.
Tissue distribution of 131I-labelled epidermal growth factor in the pig visualized by dynamic scintigraphy
Authors: Vinter-Jensen L , Frøkiær J , Jørgensen P E , Marqversen J , Rehling M , Dajani E Z , Nexø E 
Published: December 2008

Abstract
We visualized the metabolism of intravenously injected 131I-labelled epidermal growth factor in the pig using dynamic scintigraphy combined with repetitive samplings of blood, urine and bile. The labelled peptide was recognized in the samples by means of immunoprecipitation and high pressure liquid chromatography. The plasma elimination was extremely rapid, and it was described with a triexponential equation, C(t)=A*e −α*t+B*e −β*t+ C*e −γ*t. The first two exponentials denoted the distribution phase, and the third the elimination phase. T1/2α ranged from 0·4–0·7 min, T1/2β from 2·0–2·2 min and T1/2γ from 53·3–97·6 min. Concomitant with the rapidly declining plasma concentration, the gamma camera visualized the uptake by the liver and the kidneys. The liver was the principal organ for clearance and degradation of the labelled peptide, but only 0·12–0·30% of the injected dose was excreted into the bile. The renal uptake and the urinary excretion accounted for 6·6–13·0 and 2·5–4·9% of the given dose, respectively.
Journal of Endocrinology (1995) 144, 5–12
Differential expression of hepatic oestrogen, phenol and dehydroepiandrosterone sulphotransferases in genetically obese diabetic (ob/ob) male and female mice
Authors: Borthwick E B , Burchell A , Coughtrie M W H 
Published: December 2008

Abstract
Sulphotransferases (STs) are a family of closely related enzymes playing a key role in regulation of the bioavailability and activity of important endogenous molecules such as steroid hormones. A relationship between the expression of steroid STs and the diabetic state has been demonstrated in various laboratory animal models, and steroid sulphates such as dehydroepiandrosterone sulphate are known to have anti-diabetic properties. In order to further our understanding of the molecular basis for the association of steroid hormone sulphation and diabetes, we have examined the expression of oestrogen, phenol and dehydroepiandrosterone (DHEA) STs in mice carrying the obesity mutation (ob), which in the homozygous state (ob/ob) produces mice which are obese and diabetic. Our data show that, in male mice, ST activities towards oestrone (E1), oestriol (E3), DHEA and the xenobiotic 1-naphthol are elevated in ob/ob mice, whereas in female mice, only the oestrogen ST activities were elevated, with the DHEA and 1-naphthol ST activities reduced. Using antibodies directed against oestrogen ST, it was demonstrated that the induction of E1 and E3 ST activity in ob/ob mice correlated with the expression of an ST isoenzyme not constitutively expressed in control mouse liver.
Journal of Endocrinology (1995) 144, 31–37
Recombinant FSH (Org32489) induces follicle growth and ovulation in the adult cyclic rat
Authors: van Cappellen W A , Meijs-Roelofs H M A , Kramer P , van Leeuwen E C M , de Leeuw R , de Jong F H 
Published: December 2008

Abstract
The effects of a single injection of recombinant human FSH (rhFSH; Org32489) on ovulation rate and timing and on antral follicle growth were studied in adult 5-day cyclic rats. Rats injected at 1700 h on dioestrus-2 with a dose of 10 IU rhFSH showed, on average, no increase in ovulation rate on the day of expected oestrus. However, an additional, precocious ovulation resulting in a normal number of corpora lutea 13·3±0·4, n=6) was found to take place on the night after injection, i.e. dioestrus-3. No mating behaviour, as shown by the absence of vaginal plugs the next morning, was observed at this ovulation. Follicle counts showed a loss of large antral follicles due to ovulation and increased numbers of healthy small antral follicles at 17 and 41 h after injection, indicating a decrease of atresia of growing follicles as well as additional recruitment of new antral follicles. The endogenous serum FSH concentration on the subsequent day of oestrus (65 h after the rhFSH injection) as well as recruitment of small antral follicles were lower in the rhFSH-treated rats than in saline-treated controls. The ovulation at oestrus, 48 h after the precocious, rhFSH-induced ovulation showed large differences in the number of oocytes between the rats in one treatment group.
Similar results in terms of immediate ovulation induction were obtained by using a highly purified human urinary FSH preparation (i.e. metrodin). Furthermore, the direct induction of ovulation by rhFSH or metrodin could not be prevented by the injection of an LHRH antagonist.
It was concluded that rhFSH can induce acute ovulation in rats, and stimulates follicular development directly or indirectly through increased FSH levels after ovulation. It induces antral follicle growth and decreases early atresia in small antral follicles.
Journal of Endocrinology (1995) 144, 39–47
Continuous 14 day infusion of IGF-II increases the growth of normal female rats, but exhibits a lower potency than IGF-I
Authors: Conlon M A , Francis G L , Tomas F M , Wallace J C , Howarth G S , Ballard F J 
Published: December 2008

Abstract
The effects of continuous 14 day infusion of recombinant human IGF-I (104 or 260 μg/day) or IGF-II (104, 260 or 650 μg/day) via s.c. implanted osmotic pumps were compared in young female rats in order to establish the relative efficacies of these two growth factors.
Significant increases in body weight gain and feed conversion efficiency were achieved by 260 of IGF-I or 650 μg/day of IGF-II. These treatments were associated with increased nitrogen retention and increases in the fractional weights of kidneys, spleen, total gut and individual gut regions. There was an increase in the size of villi and muscularis lining the jejunum, suggesting an increased absorptive capacity of the gut. However there was no significant change in the amount of faecal nitrogen excretion when expressed as a percentage of nitrogen intake. Interestingly, IGF-II was at least as potent as IGF-I in increasing the depth of jejunal crypts. Infusion of equivalent doses of either IGF-I or IGF-II resulted in similar increases in circulating concentrations of the respective peptides, though IGF-II infusion dosedependently decreased plasma IGF-I concentrations from those of the controls. Plasma IGF-binding protein levels were increased by both IGF-I and IGF-II treatments, though IGF-I elicited greater responses.
In summary, IGF-II can promote the growth of young female rats, although generally less potently than IGF-I.
Journal of Endocrinology (1995) 144, 91–98
Pharmacokinetics and bioactivity of intact versus truncated IGF-I during a 24-h infusion into lactating goats
Authors: Prosser C G , Davis S R , Hodgkinson S C , Mohler M A 
Published: December 2008

Abstract
The aim of this study was to compare the plasma concentration profile, mammary blood flow response and transfer into milk of intact IGF-I with that of its truncated analogue, des(1–3)IGF-I (des-IGF-I). Each peptide was infused for 24 h into the pudic artery supplying one mammary gland of lactating goats (n=5). Concentrations of IGF-I in plasma (from the jugular vein) rose rapidly during infusion of IGF-I or des-IGF-I to reach 510±62 and 640±32 ng/ml (mean ± s.e.m.) respectively, compared with 262±35 ng/ml after a similar infusion of saline. Ligand blotting analysis indicated a significant increase in the intensity of [125I]IGF-I binding to the 40–43 kDa doublet (binding protein-3 (BP-3), P<0·01) and the band at 31 kDa (P<0·05) during infusion of either IGF-I or des-IGF-I, as compared with saline. Furthermore des-IGF-I induced a significant increase in intensity of binding to the 35 and 24 kDa bands, but IGF-I did not. Whereas [125I]IGF-I was distributed between BP-3 and the other binding proteins, [125I]des-IGF-I bound exclusively to BP-3.
Mammary blood flow (MBF) increased 48±6% after 12 h of infusion of des-IGF-I, compared with an increase of 22±6% during IGF-I. The difference in response was significant at P<0·05. In addition, more IGF-I was secreted into the milk of the infused than the non-infused gland during either infusion of IGF-I or des-IGF-I. This difference between glands was greater (P<0·05) during des-IGF-I compared with IGF-I infusion, suggesting greater uptake of des-IGF-I by the gland compared with IGF-I, when infused locally. These findings indicate a greater bioactivity of des-IGF-I compared with IGF-I when infused locally into the mammary gland and may be explained by the different pattern of association of the two peptides with different binding proteins. The similar plasma profile and pharmacokinetics for IGF-I and desIGF-I during their 24-h continuous infusion of des-IGF-I or IGF-I is in contrast to results reported for a single injection of the peptides, probably relating to the ability of des-IGF-I to induce and bind to BP-3.
Journal of Endocrinology (1995) 144, 99–107
Pituitary adenylate cyclase activating polypeptide can regulate testicular germ cell protein synthesis in vitro
Authors: West A P , McKinnell C , Sharpe R M , Saunders P T K 
Published: December 2008

Abstract
The aim of this study was to explore whether pituitary adenylate cyclase activating polypeptide (PACAP) could regulate protein synthesis by enriched preparations of spermatocytes and spermatids from the adult rat testis. Spermatocytes and spermatids were incubated for 8 h or 24 h in the absence (control) or presence of PACAP-27, PACAP-38, vasoactive intestinal peptide (VIP) or dibutyryl adenosine-3′,5′-cyclic monophosphate (db-cAMP). Total synthesis of intracellular and secreted proteins, during the incubation periods, was assessed and selected samples were analysed by 2-D SDS-PAGE. PACAP-38 (200 nm), VIP (200 nm) and db-cAMP (1 mm) significantly increased the synthesis of spermatocyte-secreted and intracellular proteins by 8 h and 24 h. Synthesis of both intracellular and secreted proteins by spermatids was significantly inhibited at 8 h and 24 h with PACAP, VIP and db-cAMP. The abundance of four germ cell-secreted proteins (GSP1, GSP2, GSP3 and phosphatidyethanolamine-binding protein (PEBP)), which can be identified in both spermatocyte and spermatid culture medium, and β-actin, which can only be identified in spermatid culture medium, was analysed. PACAP-38 and db-cAMP significantly increased the incorporation of label into GSP1, GSP2, GSP3 and PEBP, derived from spermatocyte culture medium, at 8 h and 24 h. In contrast PACAP-38 inhibited the incorporation of label into GSP1 and β-actin, derived from spermatid culture medium, at 24 h. The results show that PACAP can regulate synthesis of both secreted and intracellular proteins by spermatids and spermatocytes in vitro. This effect is mimicked with high doses of db-cAMP (>1 mm), suggesting that PACAP may act via a pathway that involves changes in cyclic AMP concentration in the germ cells.
Journal of Endocrinology (1995) 144, 215–223
Neurophysin stimulates prolactin release from primary cultured rat pituitary cells
Authors: Shin S H , Heisler R L , Lee C S-S 
Published: December 2008

Abstract
The neurohypophysial hormones, oxytocin and vasopressin, are present as non-covalently bound complexes with their designated neurophysin in the secretory granules of the posterior pituitary. The neurophysins are generally considered to be biologically inert carrier proteins for oxytocin and vasopressin. We have examined the actions of bovine neurophysin-I (bNP-I), bovine neurophysin-II (bNP-II), rat neurophysin (rat NP) and oxytocin on prolactin release using primary cultured rat pituitary cells. A dynamic perifusion system was chosen to test their stimulatory actions. The rat NP and bNP-II stimulated prolactin release. It is a new observation that rat NP and bNP-II stimulate prolactin release from primary cultured rat pituitary cells. The maximum sensitivities, the lowest concentration which stimulate prolactin release, of rat NP, bNP-II, bNP-I and oxytocin in primary cultured cells were 1 nmol/l, 1 nmol/l, 1000 nmol/l and 1 nmol/l respectively. The maximum sensitivities of rat NP and bNP-II were within the physiologically relevant concentrations.
Journal of Endocrinology (1995) 144, 225–231
Effects of neuroleptic treatment on cortisol and 3-methoxy-4-hydroxyphenylethyl glycol levels in blood
Authors: Wik G 
Published: December 2008

Abstract
Plasma cortisol and serum 3-methoxy-4-hydroxyphenylethyl glycol (MHPG) were determined before and after 5–6 weeks of neuroleptic treatment in patients with schizophrenia. Following drug treatment both plasma cortisol and serum MHPG levels in patients decreased and plasma cortisol levels were also lower than in unmedicated healthy controls. Indications of a relationship between the reduction of cortisol and MHPG levels were found. The data show that neuroleptic drug treatment inhibits cortisol secretion. It is speculated that this inhibition could be related to reduced noradrenergic activity.
Journal of Endocrinology (1995) 144, 425–429
Do vasopressin and oxytocin have synergistic renal effects in the conscious rat?
Authors: Windle R J , Judah J M , Forsling M L 
Published: December 2008

Abstract
The renal effects of arginine vasopressin and oxytocin were studied in the conscious unrestrained rat infused with 0·077 m NaCl. Peptides were infused at rates of 24 and 160 pmol/min (vasopressin) or 30 and 200 pmol/min (oxytocin) either alone or as a combination of the two lower or two higher doses. The rates of infusion were selected to give ratios of oxytocin:vasopressin similar to those seen in the plasma of euhydrated and dehydrated rats.
Vasopressin produced dose-dependent antidiuretic and natriuretic responses, the natriuresis commencing after 15–30 min infusion. Oxytocin produced dose-dependent diuretic and natriuretic responses, the natriuresis commencing within the first 15 min of infusion. Combined infusion of vasopressin and oxytocin produced dose-dependent antidiuretic responses which were comparable to those seen with vasopressin alone. The natriuretic response from combined infusion at the higher rate appeared to have the greater magnitude for individual 15-min periods of the vasopressin response combined with the longer duration of the oxytocin response. Although the total natriuretic response was therefore greater, this difference failed to reach significance.
Only the higher rates of infusion of vasopressin and oxytocin significantly increased the clearance of sodium, by 53 ± 23 and 62 ± 18% and glomerular filtration rate (GFR) by 23 ± 4 and 23 ± 4% respectively. The clearance of sodium during the combined hormone infusion was significantly greater (109 ± 21%), while the rise in GFR at 23 ± 5% was comparable to that seen when each hormone was given separately. Both fractional excretion of sodium and potassium excretion were also significantly elevated by this combined infusion, suggesting an additional tubular component to the response. Although no synergistic effect of neurohypophysial hormones on the antidiuresis was found in the conscious rat, they may act together to promote sodium excretion
Journal of Endocrinology (1995) 144, 441–448