Dose-dependent cytochemical responses of the guinea pig renal cortex to femtogram quantities of bovine parathyroid hormone

1976 ◽  
Vol 22 (S1) ◽  
pp. 385-385 ◽  
Author(s):  
D. J. Chambers ◽  
J. M. Zanelli ◽  
J. Chayen ◽  
J. A. Parsons
Keyword(s):  
Parathyroid Hormone ◽  
Guinea Pig ◽  
Renal Cortex ◽  
Dose Dependent ◽  
Bovine Parathyroid Hormone

ACQUIRED RESISTANCE TO PARATHYROID HORMONE

1976 ◽  
Vol 83 (2) ◽  
pp. 321-328 ◽  
Author(s):  
Tushar K. Sinha ◽  
Sherry F. Queener ◽  
Norman H. Bell ◽  
Sarah Larson
Keyword(s):  
Parathyroid Hormone ◽  
Renal Cortex ◽  
Acquired Resistance ◽  
Terminal Portion ◽  
Short Term ◽  
Clinical Resistance ◽  
Term Administration ◽  
Parathyroid Extract ◽  
Bovine Parathyroid Hormone

ABSTRACT Studies are presented in a patient with pseudohypoparathyroidism who showed a partial response to parathyroid extract. Resistance to the extract was observed after its short-term administration for the fourth time. Serum from the patient contained antibodies of the γG globulin class which bound 125I-labelled bovine parathyroid hormone. Prior incubation of parathyroid hormone with the serum prevented the activation in vitro of adenylate cyclase from pork renal cortex. The antibodies were directed primarily toward the C-terminal portion of the molecule. Thus, clinical resistance to parathyroid hormone is attributed to specific antibodies.

scholarly journals Immunoassay of serum polypeptide hormones by using 125I-labelled anti(-immunoglobulin G) antibodies

1975 ◽  
Vol 145 (3) ◽  
pp. 607-616 ◽  
Author(s):  
P Beck ◽  
H Nicholas
Keyword(s):  
Growth Hormone ◽  
Parathyroid Hormone ◽  
Guinea Pig ◽  
Human Growth Hormone ◽  
Immunoglobulin G ◽  
Human Growth ◽  
Bovine Insulin ◽  
Polypeptide Hormone ◽  
Polypeptide Hormones ◽  
Bovine Parathyroid Hormone

1. A technique for indirectly labelling antibodies to polypeptide hormones, by combining them with radioactively labelled anti-(immunoglobulin G) is described. (a) 125I-labelled anti-(rabbit immunoglobulin G) and anti-(guinea-pig immunoglobulin G) antibodies with high specific radioactivity were prepared after purification of the antibodies on immunoadsorbents containing the respective antigens. (b) Rabbit immunoglobulin G antibodies to human growth hormone, porcine glucagon and guinea-pig immunoglobulin G antibodies to bovine insulin and bovine parathyroid hormone were combined with immunoadsorbents containing the respective polypeptide hormone antigen. (c) The immunoglobulin G antibodies to the polypeptide hormones were reacted with 125-I-labelled anti-(immunoglobulin G) antibodies directed against the appropriate species of immunoglobulin G,and the anti-hormone antibodies were combined with the hormone-containing immunoadsorbent. (d) 125I-labelled anti-(immunoglobulin G) antibodies and anti-hormone antibodies were simultaneously eluted from the hormone-containing immunoadsorbent by dilute HCl, pH 2.0. After elution the anti-(immunoglobulin G) antibodies and antihormone antibodies were allowed to recombine at pH 8.0 and 4 degrees C. 2. The resultant immunoglobulin G-anti-immunoglobulin G complex was used in immunoradiometric (labelled antibody) and two-site assays of the respective polypeptide hormone. 3. By using these immunoassays, concentrations down to 90pg of human growth hormone/ml, 100 pg of bovine insulin/ml, 80 pg of bovine parathyroid hormone/ml and 150 pg of glucagon/ml were readily detected. Assays of human plasma for growth hormone and insulin by these methods showed good agreement with results obtained by using a directly 125I-labelled anti-hormone antibody in an immunoradiometric assay of human growth hormone or by radioimmunoassay of human insulin. 4. The method described allows immunoradiometric or two-site assays to be performed starting with as little as 450 ng of polypeptide hormone-antibody protein. An additional advantage of the method is that a single iodination of the readily available antibodies to immunoglobulin G allows the establishemnt of several polypeptide hormone assays

Parathyroid hormone (PTH) fragments relax the guinea-pig trachea in vitro

1983 ◽  
Vol 61 (11) ◽  
pp. 1324-1328 ◽  
Author(s):  
Y. C. Yen ◽  
May C. M. Yang ◽  
Alexander D. Kenny ◽  
Peter K. T. Pang
Keyword(s):  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Parathyroid Hormone ◽  
Guinea Pig ◽  
Phosphodiesterase Inhibitor ◽  
Blocking Agent ◽  
No Inhibition ◽  
Per Se ◽  
Bovine Parathyroid Hormone

Synthetic bovine parathyroid hormone fragment containing the N-terminal 1 – 34 amino acids (bPTH-(1 – 34)) relaxed the guinea-pig trachea constricted with histamine in vitro. Peptides with bovine and human sequences purchased from Peninsula Laboratories and Beckman Bioproducts produced similar effects. Substitution of methionine in positions 8 and 18 by norleucine did not affect this property of bPTH-(1 – 34). However, when the methionines were oxidized by treating the peptide with hydrogen peroxide, the peptide could no longer produce relaxation in the trachea. Oxidation of the methionine-replaced analog did not affect the action of the peptide on the trachea. It seems that the methionines per se are not necessary, but once oxidized the conformation of the molecule may be sufficiently altered to affect its ability to relax the trachea. While propranolol can block the relaxing action of isoproterenol, this blocking agent produces no inhibition of the bPTH-(1 – 34) effect. This action of PTH on the trachea may be related to cAMP because isobutyryl-methylxanthine, a phosphodiesterase inhibitor, potentiates and imidazole, a phosphodiesterase stimulator, inhibits the trachea relaxing action of bPTH-(1 – 34).

Evaluation of a parathyroid hormone antagonist in an in vivo multiparameter bioassay

1987 ◽  
Vol 253 (2) ◽  
pp. E187-E192
Author(s):  
N. Horiuchi ◽  
M. Rosenblatt
Keyword(s):  
Parathyroid Hormone ◽  
Dependent Manner ◽  
Hydroxylase Activity ◽  
Dose Ratio ◽  
Hormone Analogue ◽  
Potent Antagonist ◽  
Dose Dependent ◽  
Bovine Parathyroid Hormone ◽  
Stimulation Of

The antagonist properties of a bovine parathyroid hormone analogue ([Tyr34]bPTH-(7-34] amide were quantitatively assessed in vivo in a multiparameter assay to estimate the potency of the antagonist against the major actions of PTH. The analogue inhibited PTH-stimulated urinary excretion of phosphate and adenosine 3',5'-cyclic monophosphate in vitamin D-deficient thyroparathyroidectomized rats in a dose-dependent manner. At a molar dose ratio as low as 5:1 of antagonist to PTH, partial inhibition occurred. PTH stimulates the activity of 25-hydroxyvitamin D3-1 alpha-hydroxylase in renal proximal tubules. When coinfused with PTH, this analogue completely inhibited PTH-stimulated 1 alpha-hydroxylase activity at a molar dose ratio of 25:1 of antagonist to PTH and partially inhibited the activity at a molar dose ratio of 10:1. The analogue revealed no PTH-like agonist activity for stimulation of the 1 alpha-hydroxylase. Taken together, these studies indicate that [Tyr34]bPTH-(7-34) amide is a potent antagonist of several of the parameters of PTH action in vivo and demonstrate the feasibility of designing a PTH antagonist that can interact simultaneously with all the PTH receptors responsible for the hormone's major actions in vivo.

Parathyroid hormone stimulates prostanoid formation in mouse calvarial bones

1989 ◽  
Vol 120 (3) ◽  
pp. 357-361 ◽  
Author(s):  
Östen Ljunggren ◽  
Ulf H. Lerner
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Bone Cells ◽  
Neonatal Mouse ◽  
Dose Dependent ◽  
Bovine Parathyroid Hormone

Abstract. Bovine parathyroid hormone (bPTH 1–34) caused a time- and dose-dependent enhanced formation of the two prostanoids PGE2 and 6-keto-PGF1α in cultured neonatal mouse calvarial bones, with threshold for action at 0.1 nmol/l. The PGE2 response to PTH was completely blocked by indomethacin, but insensitive to calcitonin. By contrast, indomethacin was without effect on 45Ca release induced by PTH. The PTH analogues (Nle 8, 18, Tyr 34)-bPTH (3–34) amide and (Tyr 34)-bPTH (7–34) amide, which are putative PTH antagonists, did not affect basal production of PGE2, nor did the analogues affect bPTH 1–34 induced PGE2 formation. The data show that PTH stimulates prostanoid formation in mouse bone cells and that this response is not directly linked to PTH-induced bone resorption.

Experimental parathyroid hormone deficiency produced by injection of antibodies to bovine parathyroid hormone

1968 ◽  
Vol 46 (3) ◽  
pp. 441-448 ◽  
Author(s):  
Sang Whay Kooh ◽  
Donald Fraser
Keyword(s):  
Parathyroid Hormone ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Specific Binding ◽  
Plasma Calcium ◽  
Hormone Deficiency ◽  
Similar Degree ◽  
Parathyroid Extract ◽  
Bovine Parathyroid Hormone

Antiserum to bovine parathyroid hormone (Anti-PTH) was produced in guinea pigs by repeated subcutaneous injections of purified bovine PTH with Freund's adjuvant. Specific binding of PTH with Anti-PTH was demonstrated in vitro by a two-antibody system. Anti-PTH was administered intravenously to three species of animals. Within 8 h, rats had developed a decrease in plasma calcium and an increase in plasma phosphorus concentrations, physiological changes characteristic of the PTH deficiency state. A similar degree of hypocalcemia occurred in rabbits. Some of the animals injected with Anti-PTH died within 24 h; in survivors, the hypoparathyroid state was transient and recovery occurred within 24 h. Equivalent amounts of Anti-PTH had no effect on the levels of plasma calcium in normal guinea pigs. Injections of parathyroid extract to rats, rabbits, and guinea pigs caused a hypercalcemic response. Since antibodies produced in the guinea pig to bovine PTH neutralized the physiological action of rat and rabbit PTH, but did not neutralize that of guinea pig PTH, it is concluded that bovine, rat, and rabbit PTH are immunologically similar, but that guinea pig PTH is dissimilar. However, the hormones of all four species have a common attribute that determines biological activity.

Polydatin Attenuates Carbachol-induced Contraction of Guinea Pig Gallbladder

2019 ◽  
Vol 18 (1) ◽  
pp. 34-38
Author(s):  
Chen Lei ◽  
Pan Xiang ◽  
Shen Yonggang ◽  
Song Kai ◽  
Zhong Xingguo ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Guinea Pig ◽  
Smooth Muscles ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Dependent Manner ◽  
Underlying Mechanisms ◽  
Dose Dependent

The aim of this study was to determine whether polydatin, a glucoside of resveratrol isolated from the root of Polygonum cuspidatum, warranted development as a potential therapeutic for ameliorating the pain originating from gallbladder spasm disorders and the underlying mechanisms. Guinea pig gallbladder smooth muscles were treated with polydatin and specific inhibitors to explore the mechanisms underpinning polydatin-induced relaxation of carbachol-precontracted guinea pig gallbladder. Our results shown that polydatin relaxed carbachol-induced contraction in a dose-dependent manner through the nitric oxide/cyclic guanosine monophosphate/protein kinase G and the cyclic adenosine monophosphate/protein kinase A signaling pathways as well as the myosin light chain kinase and potassium channels. Our findings suggested that there was value in further exploring the potential therapeutic use of polydatin in gallbladder spasm disorders.

Interaction between amrinone and parathyroid hormone on bone in culture

1982 ◽  
Vol 243 (6) ◽  
pp. E499-E504
Author(s):  
N. S. Krieger ◽  
P. H. Stern
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Direct Interaction ◽  
Inhibitory Effects ◽  
Dihydroxyvitamin D3 ◽  
Basal Bone ◽  
Cardiotonic Agent ◽  
Neonatal Mouse Calvaria ◽  
Dose Dependent ◽  
Stimulation Of

The cardiotonic agent amrinone has been postulated to directly affect Na-Ca exchange. Because stimulated bone resorption has been proposed to require Na-Ca exchange, we examined the effects of amrinone on bone. Amrinone inhibited release of Ca from neonatal mouse calvaria in organ culture stimulated by parathyroid hormone (PTH), 1,25-dihydroxyvitamin d3, or prostaglandin E2. Inhibition was dose dependent and maximal at 2 X 10(-4) M. The effect of amrinone differed from the inhibitory effects of calcitonin, ouabain, or nigericin in that 1) 6-h exposure to amrinone alone prevented the effect of subsequently added PTH; 2) amrinone was only partially effective if added after resorption was initiated by 24-h treatment with PTH; 3) coincubation with amrinone and PTH during the first 48 h of culture allowed for a response to PTH after amrinone was removed; no such protection by a stimulator occurred with ouabain or nigericin. Also submaximal concentrations of amrinone plus calcitonin, ouabain, or nigericin gave greater than additive inhibition of Ca release. Amrinone had no effect on basal bone cAMP or on the acute stimulation of cAMP by PTH. The results suggest that amrinone could have a more direct interaction with the pathway involved in stimulated bone resorption than the other inhibitors.

Hepatic uptake of intact glutathione S-conjugate, inhibition by organic anions, and sinusoidal catabolism

1993 ◽  
Vol 265 (3) ◽  
pp. G547-G554
Author(s):  
C. A. Hinchman ◽  
A. T. Truong ◽  
N. Ballatori
Keyword(s):  
Guinea Pig ◽  
Rat Liver ◽  
Marked Decrease ◽  
Hepatic Uptake ◽  
Half Time ◽  
High Concentrations ◽  
Rat Livers ◽  
Dose Dependent ◽  
Uptake And Metabolism ◽  
Guinea Pig Liver

To identify potential mechanisms for hepatic removal of circulating glutathione (GSH) conjugates, uptake and metabolism of S-2,4-dinitrophenylglutathione (DNP-SG) were examined in isolated perfused livers from rat and guinea pig. Guinea pig livers perfused with 5 mumol of DNP-SG in a recirculating system (50 microM initial concn) rapidly cleared the conjugate from the perfusate (half time 3.7 min), whereas clearance was considerably slower in rat liver (half time 35 min). Disappearance of DNP-SG from the perfusate was accompanied by a simultaneous appearance of DNP-SG and its metabolites in bile. Addition of acivicin, an inhibitor of gamma-glutamyltransferase (gamma-GT), to the perfusate resulted in a marked decrease in DNP-SG clearance by guinea pig liver but had no effect in rat liver, suggesting that in the guinea pig this process is largely dependent on sinusoidal gamma-GT activity. However, even in the presence of acivicin, rat and guinea pig livers removed nearly one-half of the administered DNP-SG from the recirculating perfusate over 30 min. High concentrations of DNP-SG were found in bile (up to 3.7 mM), indicating that the liver is capable of transporting the intact conjugate from the circulation. When rat livers were perfused with higher concentrations of DNP-SG (100 and 250 microM), biliary excretion of DNP-SG increased dose dependently, with concentrations in bile reaching 10 mM at the higher dose. This was accompanied by a dose-dependent choleresis.(ABSTRACT TRUNCATED AT 250 WORDS)

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