Feeding Reduces Serum Concentration of Endogenous  Bioactive (1-84), but Not Total Intact Parathyroid  Hormone in Female Sprague-Dawley Rats

1. Hypertension induced by treatment with deoxycorticosterone acetate and sodium chloride was studied in male Sprague-Dawley rats and related to parathyroid hormone secretion. 2. Lack of parathyroid hormone (due to parathyroidectomy) or decreased parathormone secretion (due to a high-calcium diet) partially inhibited the development of arterial hypertension. 3. In contrast, in thyroparathyroidectomized rats supplemented with thyroxine, the administration of parathyroid hormone rapidly elevated arterial blood pressure. 4. Maintaining a physiological concentration of serum calcium in the absence of parathyroid hormone (by feeding a high-calcium diet to parathyroidectomized rats) was not sufficient to establish mineralocorticoid hypertension. 5. These results show that parathyroid hormone is necessary for the complete development of mineralocorticoid hypertension.

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Mechanism of dopamine inhibition of renal phosphate transport.

Journal of the American Society of Nephrology ◽

10.1681/asn.v2111601 ◽

1992 ◽

Vol 2 (11) ◽

pp. 1601-1607

Author(s):

J Isaac ◽

R P Glahn ◽

M M Appel ◽

M Onsgard ◽

T P Dousa ◽

...

Keyword(s):

Parathyroid Hormone ◽

Brush Border Membrane ◽

Phosphate Transport ◽

Constant Infusion ◽

Saline Control ◽

Control Group ◽

Sprague Dawley ◽

Pi Transport ◽

Sprague Dawley Rats ◽

Dependent Transport

Dopamine (DA) is natriuretic and phosphaturic. However, whether the effect of DA on Pi reabsorption is a consequence of its effect on sodium transport is not known. Therefore, this study was performed to determine the effect of DA on the maximal transport of phosphate (TmPi), and upon the capacity of renal proximal brush border membrane (BBM) for (Naextra-vesicular greater than Naintravesicular)-gradient-dependent transport of Pi, as compared with the transport of other solutes. Graded infusions of Pi (0, 1, 2, and 3 mumols/min) were given to thyroparathyroidectomized male Sprague-Dawley rats in the presence of vehicle (0.9% NaCl; N = 5), DA 15 micrograms/kg/min; N = 6), or parathyroid hormone ((PTH); 1 U/kg/min; N = 5). The TmPi for rats infused with DA (3.3 +/- 0.3 mumol/mL) was significantly less than the TmPi for saline control rats (4.4 +/- 0.2 mumol/mL). Rats infused with PTH exhibited the lowest TmPi (1.8 +/- 0.3 mumol/mL). No differences in sodium excretion were observed among any of the groups. Na-dependent Pi transport was studied in BBM vesicles (BBMV) prepared from rats fed a low-phosphate diet for 2 days that were anesthetized, acutely thyroparathyroidectomized, and systemically infused with DA (350 micrograms bolus, plus 35 micrograms/kg/min; N = 8), PTH (33 U/kg bolus, followed by a continuous infusion of 1 U/kg/min; N = 6), or vehicle (1 mL/kg bolus, plus 2 mL/h constant infusion of 0.9% NaCl; N = 8) for 90 min. DA significantly inhibited the Na cotransport of Pi by 22.4 +/- 4.1% (P less than 0.01) as compared with the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

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Phosphaturic effect of L-NMMA in the presence of parathyroid hormone

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1996.271.6.r1477 ◽

1996 ◽

Vol 271 (6) ◽

pp. R1477-R1480

Author(s):

M. J. Onsgard-Meyer ◽

R. J. Kerrigan ◽

M. Collins ◽

A. A. Khraibi ◽

F. G. Knox

Keyword(s):

Parathyroid Hormone ◽

Fractional Excretion ◽

Parathyroid Glands ◽

Constant Infusion ◽

Sprague Dawley ◽

Phosphate Excretion ◽

Sprague Dawley Rats ◽

Additional Group ◽

Renal Clearances ◽

Intact Rats

The objective of this study was to examine the effect of NG-monomethyl-L-arginine (L-NMMA) on phosphate excretion in the presence and absence of parathyroid hormone (PTH). Renal clearances were obtained before and during infusion of L-NMMA (15 mg/kg bolus and 500 micrograms.kg-1.min-1 infusion) in Sprague-Dawley rats with intact parathyroid glands (n = 6), in thyroparathyroidectomized (TPTX) rats receiving a constant infusion of PTH-(1-34) (0.01-0.03 U.kg-1.min-1) (n = 11) throughout the experiment, or in TPTX rats, that received an acute infusion of PTH-(1-34) (33 U/kg bolus and 1 U.kg-1.min-1 infusion) after L-NMMA infusion alone (n = 7). In rats with intact parathyroid glands, L-NMMA increased the fractional excretions of phosphate (FEPi) and sodium (FENa) and mean arterial pressure (MAP) (delta 8.6 +/- 1.5%, delta 0.62 +/- 0.1%, and delta 26.7 +/- 4.9 mmHg, respectively; P < 0.05). In TPTX rats receiving a constant infusion of PTH, L-NMMA again increased FEPi, FENa, and MAP (delta 9.5 +/- 3.6%, delta 1.1 +/- 0.4%, and delta 28.4 +/- 4.5 mmHg, respectively; P < 0.05). However, in TPTX rats, L-NMMA alone did not increase FEPi (delta 0.9 +/- 0.3%), whereas the subsequent infusion of PTH with L-NMMA increased FEPi (delta 15.6 +/- 3.1%; P < 0.05). In an additional group of intact and TPTX rats, the fractional excretion of lithium (FELi) was measured as an index of proximal reabsorption. L-NMMA increased FELi in intact rats (delta 13.2 +/- 2.6%; P < 0.05), but not in TPTX rats (delta 4.2 +/- 3.3%). In conclusion, L-NMMA increases phosphate excretion in association with increases in MAP and FENa, and this phosphaturic effect is dependent on the presence of PTH.

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Calcium intake by rats: influence of parathyroid hormone, calcitonin, and 1,25-dihydroxyvitamin D

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1998.274.1.r214 ◽

1998 ◽

Vol 274 (1) ◽

pp. R214-R231 ◽

Cited By ~ 4

Author(s):

Michael G. Tordoff ◽

Rebecca L. Hughes ◽

Diane M. Pilchak

Keyword(s):

Parathyroid Hormone ◽

Calcium Intake ◽

Plasma Calcium ◽

Sprague Dawley ◽

Dihydroxyvitamin D ◽

1,25 Dihydroxyvitamin D ◽

Sprague Dawley Rats ◽

Sustained Effect ◽

Individual Actions ◽

High Doses

We examined the contribution of the primary hormones of calcium homeostasis to the control of calcium intake in the rat. Male Sprague-Dawley rats with 50 mM CaCl2 solution as their only source of calcium received subcutaneous hormone infusions for 13 days. Parathyroid hormone (PTH; 40, 80, or 160 ng/h) produced sustained dose-related decreases in CaCl2intake. High doses of calcitonin (CT; 32 or 64 ng/h) increased CaCl2 intake transiently, and low doses (4, 8, or 16 ng/h) had no effect. 1,25-Dihydroxyvitamin D [1,25(OH)2D] in doses >1 ng/h initially increased CaCl2 intake, but the effects of moderate doses (2 or 4 ng/h) tended to dissipate, and the sustained effect of high doses (8 or 16 ng/h) was to reduce CaCl2 intake. Infusions of combinations of the hormones had effects consistent with their individual actions: there was no evidence for synergy. Based on changes in plasma hormone concentrations, it appeared that most of the infusions had effects within the physiological range. Consistent with hypotheses that calcium appetite is mediated by circulating calcium, PTH and CT infusions produced reciprocal changes in plasma calcium concentrations and CaCl2 intake. However, the finding that 1,25(OH)2D elevated both plasma calcium concentrations and CaCl2intake raises the possibility that one or more of the hormones may mediate calcium appetite directly.

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Linezolid Inhibited Synthesis of ATP in Mitochondria: Based on GC-MS Metabolomics and HPLC Method

BioMed Research International ◽

10.1155/2018/3128270 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Xuemei Ye ◽

Aifang Huang ◽

Xianqin Wang ◽

Congcong Wen ◽

Lufeng Hu ◽

...

Keyword(s):

Serum Concentration ◽

High Performance ◽

Multidrug Resistant ◽

Hplc Method ◽

Control Group ◽

Sprague Dawley ◽

High Group ◽

Atp Concentration ◽

Sprague Dawley Rats ◽

Serious Infections

Linezolid has been widely used in serious infections for its effective inhibiting effect against multidrug-resistant gram-positive pathogens. However, linezolid caused severe adverse reactions, such as thrombocytopenia, anaemia, optic neuropathy, and near-fatal serotonin syndrome. In order to investigate the toxicity of linezolid, twenty-four Sprague-Dawley rats were randomly divided into: control group (n=7), low-group (n=8), and high-group (n=9). The rats of low-group and high-group were given by gavage with linezolid 60 and 120 mg/kg/day for 7 days, respectively. The serum concentration of linezolid was determined by high performance liquid chromatography (HPLC); blood metabolic change was analyzed by gas chromatography-mass spectrometer (GC-MS). Adenosine triphosphate (ATP) concentration in HepG2-C3A after being cultured with linezolid was determined by HPLC. The results showed that there were six metabolites and nine metabolites had statistical differences in low-group and high-group (P<0.05). The trimethyl phosphate was the most significant indicator in those changed metabolites. Except for d-glucose which was slightly increased in low-group, octadecanoic acid, cholest-5-ene, hexadecanoic acid, α-linolenic acid, eicosapentaenoic acid, 9,12-Octadecadienoic acid, and docosahexaenoic acid were all decreased in low-group and high-group. ATP concentration was decreased in HepG2-C3A after cultured with linezolid. In conclusion, the toxicity of linezolid is related to its serum concentration. Linezolid may inhibit the synthesis of ATP and fatty acid.

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ANTINOCICEPTION VERSUS SERUM CONCENTRATION RELATIONSHIPS FOLLOWING ACUTE ADMINISTRATION OF INTRAVENOUS MORPHINE IN MALE AND FEMALE SPRAGUE-DAWLEY RATS: DIFFERENCES BETWEEN THE TAIL FLICK AND HOT PLATE NOCICEPTIVE TESTS

Clinical and Experimental Pharmacology and Physiology ◽

10.1111/j.1440-1681.2008.05019.x ◽

2009 ◽

Vol 36 (1) ◽

pp. 20-28 ◽

Cited By ~ 24

Author(s):

Samantha M South ◽

Stephen R Edwards ◽

Maree T Smith

Keyword(s):

Serum Concentration ◽

Tail Flick ◽

Acute Administration ◽

Sprague Dawley ◽

Hot Plate ◽

Male And Female ◽

Sprague Dawley Rats ◽

Intravenous Morphine

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Parathyroid hormone contributes to volume expansion-induced inhibition of proximal reabsorption

AJP Renal Physiology ◽

10.1152/ajprenal.1985.248.1.f100 ◽

1985 ◽

Vol 248 (1) ◽

pp. F100-F103 ◽

Cited By ~ 2

Author(s):

O. Mercier ◽

M. Bichara ◽

M. Paillard ◽

J. P. Gardin ◽

F. Leviel

Keyword(s):

Parathyroid Hormone ◽

Volume Expansion ◽

Sprague Dawley ◽

Nacl Transport ◽

Free Expansion ◽

Group Iii ◽

Group I ◽

Sprague Dawley Rats ◽

Stimulation Of ◽

Intact Rats

Volume expansion inhibits the proximal reabsorption of water, bicarbonate, and chloride. The present work tested a hypothetical role of parathyroid hormone (PTH) in the expansion effect. We studied 19 Sprague-Dawley rats during a plasma-replete euvolemic state and following 10% body wt colloid-free expansion. In group I, six intact rats, volume expansion decreased plasma ionized calcium concentration ([Ca2+]P) from 2.28 +/- 0.06 to 2.11 +/- 0.04 meq/liter and increased nephrogenous cAMP (NcAMP) from 29 +/- 5 to 66 +/- 10 pmol X min-1 X g kidney wt-1. In group II, six acutely thyroparathyroidectomized (TPTX) rats, [Ca2+]P also fell from 2.18 +/- 0.08 to 1.80 +/- 0.08 meq/liter but NcAMP did not rise significantly (9 +/- 3 vs. 17 +/- 5 pmol X min-1 X g kidney wt-1). These data strongly suggest that stimulation of PTH activity occurred during expansion in intact animals. In group III, seven TPTX rats, volume expansion inhibited proximal reabsorption of total CO2 by 11%, of chloride by 24%, and of water by 19%. Volume expansion-induced reduction in bicarbonate, chloride, and water reabsorption was smaller in TPTX than in intact rats previously studied. We conclude that volume expansion inhibits proximal reabsorption in part by decreasing the active transcellular NaHCO3 and NaCl transport secondary to stimulation of PTH activity.

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Parathyroïdes et hypertension artérielle à l'acétate de désoxycorticostérone chez le rat

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y79-024 ◽

1979 ◽

Vol 57 (2) ◽

pp. 157-162 ◽

Cited By ~ 6

Author(s):

A. Berthelot ◽

R. Schleiffer ◽

A. Gairard

Keyword(s):

Blood Pressure ◽

Parathyroid Hormone ◽

Arterial Hypertension ◽

Mechanism Of Action ◽

Parathyroid Glands ◽

Sprague Dawley ◽

Deoxycorticosterone Acetate ◽

Hypertension Artérielle ◽

Sprague Dawley Rats

We studied the importance of parathyroids in the development of mineralocorticoid hypertension in male Sprague–Dawley rats. Ablation of the parathyroids 1 week before deoxycorticosterone acetate (DOCA) + NaCl administration prevented development of hypertension (for 1 year). But ablation of parathyroids 2 weeks after the start of treatment has no effect on the development of arterial hypertension. Autotransplantation of parathyroids in thyroidectomized rats caused a recurrence of mineralocorticoid hypertension, which was completed after DL-thyroxine supplementation: blood pressure levels were nearly the same as in DOCA sham rats. We conclude that parathyroid glands favor the establishment of mineralocorticoid hypertension in the rat. These results raise the question of the mechanism of action of parathyroid hormone in the hypertensive process.

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Propranolol restores phosphaturic effect of PTH in short-term phosphate deprivation

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1990.258.1.r120 ◽

1990 ◽

Vol 258 (1) ◽

pp. R120-R123

Author(s):

A. Rybczynska ◽

A. Hoppe ◽

F. G. Knox

Keyword(s):

Parathyroid Hormone ◽

Fractional Excretion ◽

Adrenergic System ◽

Sprague Dawley ◽

Short Term ◽

Phosphate Deprivation ◽

Sprague Dawley Rats ◽

Complete Resistance ◽

Fractional Excretion Of Phosphate

Phosphate deprivation causes a resistance to the phosphaturic effect of parathyroid hormone (PTH). The present study evaluated the role of the beta-adrenergic system in this resistance phenomenon. In clearance experiments performed on acutely thyroparathyroidectomized male Sprague-Dawley rats, the phosphaturic response to PTH was determined in the presence and absence of propranolol in rats fed a low-phosphate diet (LPD) for 0.5, 1, 2, 3, or 4 days. Fractional excretion of phosphate (FEPi) in control rats fed a normal-phosphate diet (NPD) increased from 4.37 +/- 1.6 to 38.5 +/- 3.4% in response to PTH infusion. Propranolol did not change FEPi in NPD animals in the absence or in the presence of PTH (2.0 +/- 1.1 vs. 36.7 +/- 1.6%). LPD resulted in a gradual decrease in the phosphaturic response to PTH infusion as compared with NPD animals. PTH increased FEPi to 24.2 +/- 6.0% after one-half day of LPD, but when the infusion was supplemented with propranolol, PTH increased FEPi to 38.0 +/- 4.7%, similar to that in NPD animals. In the group fed LPD for one day, PTH increased FEPi to 16.9 +/- 4.3%, whereas in the presence of propranolol FEPi was restored to a similar level as in the NPD group (36.0 +/- 5.9%). Two days of LPD markedly decreased FEPi in response to PTH to 7.9 +/- 3.8% as compared with NPD rats, and propranolol infusion did not change this value significantly. Three and 4 days of LPD induced complete resistance to the phosphaturic effect of PTH in the presence as well as in the absence of propranolol.(ABSTRACT TRUNCATED AT 250 WORDS)

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