bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation and characterization of a cytostatic histone H2B-like protein from fetal lungs of non-diabetic and diabetic rats
Authors: Conliffe P. R. , Bennett H. P. J. , Mulay S. 
Published: December 2008

ABSTRACT
It was observed in the course of other studies that rat fetal lung extracts inhibited proliferation of fetal lung cells in culture. The purpose of the present study was to isolate and characterize this cytostatic factor. It was found that fetal lungs contained a 16 kDa cytostatic factor and its concentration was twofold greater in fetal lungs of diabetic rats compared with control rats. This fetal lung cytostatic protein (FLCP) was purified by reversed-phase, heparin-affinity and gel filtration high-performance liquid chromatography and SDS-PAGE. The purified protein was electroblotted onto polyvinylidene difluoride membrane and subjected to sequence analysis. The amino-terminal sequence of this fetal lung cytostatic protein was PEPAKSAPAPXKGIGKQXXKAX XKA... and showed significant homology with histone H2B; however, the amino acid composition of FLCP suggested that it may be structurally distinct from histone H2B. Ion-spray mass spectrometry suggested that FLCP was made up of at least two species of the protein with molecular weights of 13 776·1 and 14 007·3 and was different from the molecular weight of rat histone H2B predicted by its cDNA sequence. The concentration of FLCP, based on amino acid compositions, was 0·32 nmol/g and 0·83 nmol/g wet fetal lung from non-diabetic and diabetic rats respectively. These findings suggest that the fetal rat lung produces a regulatory factor bearing considerable homology with but possibly different from histone H2B and that fetal lung immaturity during diabetic pregnancy might be contributed to by an increase in this factor.
Journal of Endocrinology (1993) 139, 97–105
Localization, characterization and activity of pituitary adenylate cyclase-activating polypeptide in the frog adrenal gland
Authors: Yon L. , Feuilloley M. , Chartrel N. , Arimura A. , Fournier A. , Vaudry H. 
Published: December 2008

ABSTRACT
Pituitary adenylate cyclase-activating polypeptide (PACAP) has recently been isolated from the frog brain and the sequence of the peptide appears to be strikingly similar to that of mammalian PACAP. In the present study, we have investigated the localization of PACAP in the frog interrenal (adrenal) gland by immunocytochemistry using antisera directed against PACAP 38 or PACAP 27. Two types of PACAP-immunoreactive fibres were observed: thick varicose fibres coursing between adrenal cells and thin processes located in the walls of blood vessels irrigating the gland. Bilateral transection of the splanchnic nerves did not affect the intensity and distribution of PACAP immunoreactivity. The mean ± s.e.m. concentration of PACAP, measured by radioimmunoassay in crude adrenal extracts, was 0·65 ± 0·16 nmol/g wet tissue. Two molecular forms of PACAP in the adrenal gland were characterized by reversed phase high-performance liquid chromatography combined with radioimmunoassay quantification. The elution profiles revealed the existence of two peaks exhibiting the same retention times as synthetic frog PACAP 38 (fPACAP 38) and PACAP 27, the predominant form being PACAP 38. The possible involvement of PACAP in the regulation of adrenal steroidogenesis was investigated in vitro using a perifusion system for frog adrenal slices. Graded doses of fPACAP 38 (0·1–10 μmol/l) increased the secretion of both corticosterone and aldosterone in a dose-dependent manner. Administration of repeated pulses of fPACAP 38 (1 μmol/l), at 120-min intervals, led to a reproducible stimulation of corticosteroid secretion without any tachyphylaxis. Prolonged infusion (2 h) of the peptide induced a rapid increase in corticosterone and aldosterone output, followed by a gradual decline in the secretion rate, suggesting the occurrence of a desensitization phenomenon. Synthetic porcine vasoactive intestinal peptide, which is structurally related to PACAP, was about ten times less potent than fPACAP 38 in stimulating steroidogenesis while the [Des-His1]-fPACAP 38 analogue was 100 times less effective. These results demonstrate that a peptide closely related to fPACAP 38 is present in fibres innervating the frog adrenal gland and could participate in the regulation of corticosteroid secretion, particularly during neurogenic stress.
Journal of Endocrinology (1993) 139, 183–194
Urinary epidermal growth factor is excreted from the rat isolated perfused kidney in the absence of plasma
Authors: Jørgensen P. E. , Hilchey S. D. , Nexø E. , Poulsen S. S. , Quilley C. P. 
Published: December 2008

ABSTRACT
Large amounts of epidermal growth factor (EGF) are excreted in urine and the majority of this urinary EGF appears to be of renal origin. EGF is synthesized in the kidneys as a membrane-bound 160 kDa precursor, in the thick ascending limb of Henle and in the early part of the distal convoluted tubule. Very little is known about how EGF is released from cell membranes into urine but proteolytic cleavage of the membrane-bound EGF precursor seems likely. The purpose of this study was to examine whether plasma constituents are necessary for urinary excretion of EGF. In the rat isolated kidney perfused at a pressure of 90 mmHg with a modified Krebs–Henseleit buffer containing oncotic agents, the quantity of EGF excreted into the ureteral effluent was 67% of the amount excreted by the rat kidney in vivo. The EGF excreted by the isolated kidney behaved like urinary EGF upon gel filtration. Administration of the proteinase inhibitor aprotinin reduced urinary EGF excretion from the rat isolated perfused kidney by approximately 50%.
In conclusion, the rat isolated perfused kidney excreted significant amounts of urinary EGF without having access to plasma, and EGF excretion was reduced by aprotinin. This is further evidence suggesting an intrarenal source of urinary EGF and suggests that the EGF precursor in the rat kidney is processed by enzyme(s) of renal origin.
Journal of Endocrinology (1993) 139, 227–234
A novel angiotensin I isolated from an elasmobranch fish
Authors: Takei Y. , Hasegawa Y. , Watanabe T. X. , Nakajima K. , Hazon N. 
Published: December 2008

ABSTRACT
It is believed that the renin-angiotensin system evolved initially in primitive bony fishes and is absent from elasmobranchs. We have isolated angiotensin I from the incubates of plasma and kidney extracts of an elasmobranch fish, Triakis scyllia, using eel vasopressor activity as an assay system. Its sequence was determined to be H-Asn-Arg-Pro-Tyr-Ile-His-ProPhe-Gln-Leu-OH. Dogfish angiotensin I is teleost-like because of an asparagine residue at position 1 but it is mammalian-like because of an isoleucine residue at position 5. The unique and most important substitution in dogfish angiotensin I is a proline residue at position 3 which may cause significant changes in its tertiary structure. A glutamine residue at position 9 is also unique among all angiotensin Is sequenced to date. Dogfish angiotensin I is more potent than rat angiotensin I in its vasopressor activity in the dogfish but the relationship is reversed in the rat. Thus angiotensin receptors as well as the hormone molecules appear to have evolved during vertebrate phylogeny. Our findings establish the elasmobranch renin-angiotensin system and support the hypothesis that the renin-angiotensin system is a phylogenetically old hormonal system which plays important roles in cardiovascular and fluid homeostasis.
Journal of Endocrinology (1993) 139, 281–285
Effect of fasting on serum insulin-like growth factor-I (IGF-I) levels and IGF-I-binding activity in cockerels
Authors: Morishita D. , Sasaki K. , Wakita M. , Hoshino S. 
Published: December 2008

ABSTRACT
White Leghorn male chicks of 40 days of age were fasted for 5 days and then refed. Blood samples were collected from these chicks before, during and after fasting and serum levels of GH and insulin-like growth factor-I (IGF-I) and serum IGF-I-binding activity were determined. The fasting-induced reduction in body weight was accompanied by a significant rise in circulating GH and fall in IGF-I, coupled with increased serum IGF-I-binding activity. When pooled serum was chromatographed under neutral conditions, IGF-I binding activity and IGF-I immunoreactivity were mainly associated with a large (Mr= 150 000) and a small protein (Mr=30 000). Fasting induced a marked increase in the IGF-I-binding activity of the 30 kDa IGF-I-binding protein (IGFBP) and refeeding restored activity to the normal levels seen before fasting. Ligand blotting of serumbinding proteins with 125I-labelled IGF-I, after first subjecting the samples to polyacrylamide gel electrophoresis and transfer to nitrocellulose, revealed that four IGFBPs (Mr=20 000, 30 000, 35 900 and 41 000) were present in chicken serum, and that the 125I-labelled IGF-I binding of the 30 kDa monomer was increased by fasting and restored to normal by refeeding in agreement with gel filtration profiles of IGF-Ibinding activity. Western blot analysis suggested that the 30 kDa IGFBP is homologous to IGFBP-2 found in mammalian blood plasma. The results show that IGFBPs in chicken serum and their responses to fasting are similar to those in mammals.
Journal of Endocrinology (1993) 139, 363–370
Prolactin receptor expression in the gastrointestinal tract: characterization of the prolactin receptor of gastric mucosa
Authors: Lobie P. E. , García-Aragón J. , Waters M. J. 
Published: December 2008

ABSTRACT
There is evidence that prolactin (PRL) influences gastrointestinal function. However, the sites at which prolactin exerts these effects are not known. A monoclonal antibody was therefore generated against the rabbit mammary gland prolactin receptor (MAb 218) and used to study the distribution of the prolactin receptor in the rabbit gastrointestinal tract (GIT) by immunohistochemistry. MAb 218 is an IgG 1 κprecipitating antibody which precipitates major affinity cross-linked mammary gland prolactin receptor subunits of molecular masses 45 and 80 kDa. It has an affinity of 0·8 × 109 mol/l for the prolactin receptor and does not react with GH or insulin receptors in precipitation assays. MAb 218 immunoreactivity was observed in classical prolactin target cells such as mammary gland epithelium, and this immunoreactivity was abolished by preincubation of MAb 218 with purified prolactin receptor but not by preincubation with purified GH receptor.
In the GIT, the most intense immunoreactivity was associated with the oesophageal epithelium, chief (zymogenic) cells of the fundic mucosa, pancreatic islets of Langerhans and surface epithelial cells of the duodenum and jejunum. Other specific elements of the GIT were immunoreactive at lower levels or were immunonegative. No immunoreactivity was observed in these locations with a control monoclonal antibody (MAb 50·8) of identical isotype to 218.
To support the immunohistochemical findings, rabbit gastric mucosal membranes were used to show the presence of lactogen-specific binding. Scatchard analysis of 125I-labelled human GH binding to the gastric mucosal membranes with rat prolactin as displacing ligand yielded an affinity constant (Ka) of 1·0 ± 0·2 × 109 mol/l with a capacity of 3·5 ± 0·4 fmol/mg protein. Affinity cross-linking and sodium dodecyl sulphate-polyacrylamide gel electrophoresis of the gastric receptor revealed lactogenic hormone-binding subunits of molecular masses 43, 68 and 83 kDa. The 68 kDa subunit was not seen in rabbit mammary gland or ovarian tissue, and may be unique to gastric mucosa.
In conclusion, we have demonstrated the presence of a high affinity lactogenic receptor in specific epithelial cell subpopulations of the GIT. This localization of the prolactin receptor in the GIT will assist in further functional assignment of prolactin to gastrointestinal physiology.
Journal of Endocrinology (1993) 139, 371–382
The role of nitric oxide derived from l-arginine in the control of steroidogenesis, and perfusion medium flow rate in the isolated perfused rat adrenal gland
Authors: Cameron L. A. , Hinson J. P. 
Published: December 2008

ABSTRACT
The present studies were designed to investigate the role of nitric oxide (NO) in the regulation of adrenocortical function, using the intact rat adrenal gland in situ, perfused with medium (Hank's balanced salt solution) containing a range of concentrations of l-arginine, the substrate for NO production. In addition, the effects of NG-nitro-l-arginine methylester (l-NAME), an inhibitor of NO production, were investigated. Results showed that l-arginine caused a dose-dependent increase in the flow rate of the perfusion medium through the adrenal gland. This effect was specific, as neither d-arginine nor l-lysine had an effect. The presence of l-NAME (5 mmol/l) in perfusion medium containing l-arginine caused a decrease in flow rate to levels seen in the absence of l-arginine. In the presence of concentrations of l-arginine up to 500 μmol/l, corticosterone secretion rates were also stimulated in a dose-dependent manner. Further studies, investigating the effect of l-arginine on the response to ACTH(1–24) stimulation, found that the percentage increase in flow rate, aldosterone secretion and corticosterone secretion caused by ACTH were not significantly different using media containing 230 μmol l-arginine/l or in the absence of l-arginine.
These results suggest a role for NO derived from l-arginine in the regulation of basal levels of adrenal vascular tone in the rat isolated adrenal gland preparation. They do not suggest an obligatory role for NO in either the vascular or steroidogenic response to ACTH stimulation.
Journal of Endocrinology (1993) 139, 415–423
Thyrotrophin-dependent desensitization by Chinese hamster ovary cells that express the recombinant human thyrotrophin receptor
Authors: Haraguchi K. , Peng X. , Kaneshige M. , Anzai E. , Endo T. , Onaya T. 
Published: December 2008

ABSTRACT
To determine whether thyrotrophin (TSH)-induced desensitization requires a thyroid-specific factor(s), the human TSH (hTSH) receptor was expressed in Chinese hamster ovary cells. The first incubation of the cells with TSH decreased the subsequent response of adenosine 3′,5′-cyclic monophosphate to freshly added TSH in the second incubation. This homologous desensitization was observed as early as after 3 h of the first incubation. The lowest dose of TSH that elicited desensitization was 0·1 nmol/l. The desensitization was not overcome by adding higher doses of TSH in the second incubation. A 125I-labelled TSH-binding study revealed a decrease in the number of high-affinity binding sites but not in that of low-affinity binding sites. The data suggest that TSH-induced desensitization in hTSH receptor-transfected cells is caused, at least in part, by a decrease in the number of TSH receptors on the cell surface. The evidence demonstrates, contrary to an earlier report, that a thyroid-specific factor(s) is not required for hTSH receptor desensitization.
Journal of Endocrinology (1993) 139, 425–429
Pharmacokinetic and galactopoietic response to recombinant variants of bovine growth hormone
Authors: Eppard P. J. , White T. C. , Birmingham B. K. , Hintz R. L. , Bentle L. A. , Wood D. C. , Salsgiver W. J. , Rowold E. , Miller M. A. , Ganguli S. , Hale M. D. , Krivi G. G. , Collier R. J. , Lanza G. M. 
Published: December 2008

ABSTRACT
Two studies were designed to examine the pharmacokinetic and galactopoietic potency of three molecular variants of recombinant-derived bovine GH (rbGH): [Met1, Leu127]-bGH, [Ala1, Val127]-bGH and [Ala1, Val127, His133]-bGH. Histidine substitution for arginine at residue 133 of rbGH was shown to impart thrombin resistance. In a Latin square design, nine lactating Holstein cows received a 25 mg rbGH bolus infusion via the jugular vein followed by frequent blood sampling over the next 12 h. The serum GH concentration data were found to fit to a two-compartment open model. Neither primary nor secondary kinetic parameter estimates differed significantly (P>0·05) among the three rbGH variants. Thus, the disposition of GH concentration at time t was described by the equation C(t)=(1295·5 μg/l) (e−(0·11/min)(t)) + (317·3 μg/l)(e−(0·03/min)(t)). Overall averages were: area under the curve=27·1 mg · min per 1, clearance=0·15 litres/min per 100 kg and volume of distribution of the central compartment =2·59 litres/100 kg. The t1/2 for the two compartments averaged 8·2 and 29·1 min. In the second study, 36 lactating Holstein cows received i.m. injections of one of four oil-based formulation treatments: control vehicle or 500 mg of one of the three rbGH variants every 14 days for 42 days. Average and maximum serum GH concentrations and area under the curve estimates were increased by approximately 3–6 μg/l, 5–15 μg/l and 40–90 μg · day per 1 respectively. Ala1, Val127 rbGH treatments elicited greater blood GH concentrations than [Met1, Leu127]-bGH when administered in an oil-based formulation. Blood GH responses did not directly translate into milk response differences, possibly due to differences in biopotency or receptor availability. Thrombin resistance resulting from substitution of histidine at position 127 of rbGH did not affect blood GH pharmacokinetic parameters or milk response over other rbGH variants.
Journal of Endocrinology (1993) 139, 441–450
Role of adenylate cyclase-cyclic AMP-dependent signal transduction in the ACTH-induced biphasic growth effect of rat adrenocortical cells in primary culture
Authors: Arola J. , Heikkilä P. , Voutilainen R. , Kahri A. I. 
Published: December 2008

ABSTRACT
ACTH has a biphasic effect on the proliferation of fetal rat adrenocortical cells in primary culture. Dramatic changes occurred during the first 72 h of ACTH stimulation, when incorporation of bromodeoxyuridine was used as an indicator of proliferation. The primary effect of ACTH was the inhibition of proliferation during the first 24 h, which was followed by an intense stimulatory phase during the third day of ACTH treatment. Cycloheximide (a protein synthesis inhibitor) prevented both the inhibitory and the stimulatory effects of ACTH, but did not affect the basal proliferation of unstimulated zona glomerulosa-like cells. Although adrenocortical cells stimulated with cyclic AMP (cAMP) derivatives, 8-bromo cAMP (8-Br cAMP) or dibutyryl cAMP ((Bu)2cAMP), differentiated morphologically into fasciculata-like cells, and secreted corticosterone and 18-OH-deoxycorticosterone, as did ACTH-stimulated cells, neither of the derivatives inhibited proliferation during the first 24 h of treatment. In contrast to ACTH, (Bu)2cAMP had a stimulatory effect on bromodeoxyuridine incorporation during the first 24 h of treatment. 8-Br cAMP did not change proliferation during the 24 h of treatment, but had a stimulatory effect after 72 h, which was not seen with (Bu)2cAMP.
Thus, these results suggest that (1) differentiation, steroid hormone synthesis and the mitogenic effect of ACTH are transduced through the cAMP-mediated system, (2) the antimitogenic effect of ACTH is transduced via a cAMP-independent pathway and (3) both antimitogenic and mitogenic effects of ACTH are dependent on protein synthesis.
Journal of Endocrinology (1993) 139, 451–461
Maternal vitamin D status has no effect on the ontogeny of calcium-binding proteins in the duodenum, kidney and cerebellum of fetal mice
Authors: Shamley D. R. , Buffenstein R. , Veale G. , Pettifor J. M. 
Published: December 2008

ABSTRACT
The effects of vitamin D3 deficiency on the ontogeny of calcium-binding proteins (CaBPs) and the vitamin D receptor in the duodenum, kidney and cerebellum of the mouse were examined. Maternal vitamin D status did not affect the time of appearance of the fetal 28 kDa CaBP (CaBP-D28k) in the cerebellum, kidney and duodenum, and the 9 kDa CaBP (CaBP-D9k) in the intestine and kidney. Vitamin D receptor was undetectable in all fetal tissues, regardless of maternal vitamin D status, at all stages of gestation examined. Thus it appears that maternal vitamin D status does not affect the ontogeny of CaBP-D9k or CaBP-D28k in the mouse fetus. The factors that influence the appearance of calbindins in the fetus are unclear.
Journal of Endocrinology (1993) 139, 473–478
Testrosterone-induced compared with oestradiol-induced immunosuppression against Plasmodium chabaudi malaria
Authors: Benten W. P. M. , Wunderlich F. , Herrmann R. , Kühn-Velten W. N. 
Published: December 2008

ABSTRACT
Testosterone suppresses immunity against malaria caused by Plasmodium chabaudi in B10 mice. Since this effect is probably not mediated through the classical androgen-receptor response, we investigated whether testosterone might act, after aromatization to oestradiol (OE2), through the oestrogen receptor (ER). Indeed, OE2 was found to act immunosuppressively when used at only about 1% of the immunosuppressive dose of testosterone. This becomes evident as an OE2-induced suppression of self-healing of P. chabaudi infections in female and castrated male B10 mice. The immunosuppressive OE2 effect is associated with a 16-fold increase in the circulating level of OE2 and can be prevented by ER blockers such as tamoxifen and clomifene. In contrast, the immunosuppressive effect of testosterone, which is not associated with any changes in the level of OE2, cannot be abolished by ER blockers or by aromatase inhibitors, such as atamestane and drofazar hydrochloride. Moreover, OE2 and testosterone act differently on spleen cells; OE2 induces a decrease in CD4+-T-cells, whereas testosterone causes an increase in CD8+-T-cells and a decrease in total nucleated spleen cells. The immunosuppressive effect of testosterone, but not that of OE2, can be adoptively transferred to syngeneic mice by nucleated spleen cells, predominantly T-cells. Our data show that the immunosuppressive activity of testosterone, in contrast to OE2, is not mediated through the ER. The immunosuppressive action of testosterone is therefore thought to be primarily mediated through a non-genomic mechanism.
Journal of Endocrinology (1993) 139, 487–494
Immunological activities of highly purified isoforms of human FSH correlate with in vitro bioactivities
Authors: Burgon P. G. , Robertson D. M. , Stanton P. G. , Hearn M. T. W. 
Published: December 2008

ABSTRACT
In a recent study, a five- to eightfold range in human FSH radioreceptor activity (RRA) was documented for highly purified isoforms of FSH when the data were expressed on an FSH protein content basis as determined by amino acid analysis. This study examined the FSH in vitro bioactivity and immunoactivity of these preparations. FSH in vitro biological activity showed a five- to eightfold range in activity with a high correlation with the RRA values (r=0·82). A similar five- to eightfold range of values was obtained with a specific FSH radioimmunoassay and an FSH two-site immunoassay with high correlations again observed between each other, between each immunoassay and with either the in vitro bioassay or the RRA method (r=0·77–0·995). Although there was overall a close correlation between these assays, significant differences in ratios of activities between the in vitro bioassay and other methods were observed with highly purified FSH isoform preparations from different pI regions.
The high correlation between in vitro bioassay/RRA methods and immunoassay methods over a wide range of isoform specific activities suggests that these methods are detecting similar structural features on each isoform. It is thus concluded that these immunoassays are not solely measuring hormone mass based entirely on amino acid composition. This conclusion raises questions about ratio measurements of FSH, where immunoassay methods are presumed to measure total protein content, and their application in physiological situations and clinical practice.
Journal of Endocrinology (1993) 139, 511–518