Circadian variation of thyrotrophin, determined by ultrasensitive immunoradiometric assay, and the effect of low dose nocturnal dopamine infusion

1987 ◽  
Vol 72 (6) ◽  
pp. 737-741 ◽  
Author(s):  
D. J. Kerr ◽  
V. K. Singh ◽  
M. G. McConway ◽  
G. H. Beastall ◽  
J. M. C. Connell ◽  
...  
Keyword(s):  
Low Dose ◽  
Circadian Variation ◽  
Random Order ◽  
Serum Prolactin ◽  
Healthy Male ◽  
Short Term ◽  
Dopamine Infusion ◽  
Maximal Peak ◽  
Late Evening ◽  
Serum Tsh

1. The effect of low dose dopamine infusion on the circadian rhythm of thyrotrophin (TSH), prolactin and Cortisol in a group of six healthy male volunteers is reported. Subjects were infused in random order with either saline (154 mmol/l NaCl solution; control) or dopamine (0.1 and 1 μg min−1 kg−1) between 21.00 and 01.00 hours, in random order. 2. The serum TSH profile was characterized by a maximal peak occurring at 23.00 hours and higher nocturnal than diurnal values. Superimposed on this are short term oscillations in serum TSH levels, typical of an ultradian rhythm. 3. The maximal peak in TSH, occurring at 23.00 hours, was abolished by dopamine infused at a rate of 1 μg min−1 kg−1, and was unaffected by the lower rate of dopamine infusion (0.1 μg min−1 kg−1). 4. The serum prolactin profile was characterized by a peak occurring soon after the onset of sleep (23.30–00.30 hours), which fell during the morning, and began to rise in late evening. 5. Low dose dopamine (0.1 μg min−1 kg−1) had a slight but insignificant effect with decreased prolactin levels at the end of the infusion whereas the higher dopamine dose was associated with significantly lower prolactin levels during and throughout the infusion. There was a rebound to levels significantly higher than control on cessation of the infusion. Cortisol levels were unaffected by dopamine.

The effect of Low-Dose Dopamine Infusion on Anterior Pituitary Hormone Secretion in Normal Female Subjects

1984 ◽  
Vol 67 (2) ◽  
pp. 219-223 ◽  
Author(s):  
J. M. C. Connell ◽  
S. G. Ball ◽  
G. C. Inglis ◽  
G. H. Beastall ◽  
D. L. Davies
Keyword(s):  
Anterior Pituitary ◽  
Low Dose ◽  
Hormone Secretion ◽  
Serum Prolactin ◽  
Control Group ◽  
Pituitary Hormone ◽  
Normal Female ◽  
Dopamine Infusion ◽  
Anterior Pituitary Hormone ◽  
Female Subjects

1. The effect of low-dose dopamine infusion on anterior pituitary hormone secretion in a group of seven healthy female subjects is reported. Subjects were infused with NaCl solution (154 mmol/l) (control) or dopamine (0.01 and 0.1 μg min−1 kg−1 for 120 min at each rate) on separate days in the early follicular phase of consecutive menstrual cycles. 2. Serum prolactin decreased during infusion of dopamine at 0.01 μg min−1 kg−1 but a similar fall was found in the control group. 3. When the rate of dopamine infusion was increased to 0.1 μg min−1 kg−1 a further substantial decrease in prolactin concentration occurred, whereas prolactin in the control group showed no change. At the end of the period of dopamine infusion at 0.1 μg min−1 kg−1 serum prolactin remained significantly (P<0.025) lower than in the control group (85 ± 12 vs 180 ± 21 m-units/l). 4. No change in thyrotrophin (TSH), growth hormone (GH) or luteinizing hormone (LH) was seen during either rate of dopamine infusion compared with control. 5. While dopamine infusion at 0.1 μg min−1 kg−1 caused significant inhibition of prolactin secretion in normal female subjects, other pituitary hormone secretion was not affected: it is suggested that under the conditions of this study dopamine in hypophysial portal blood is not of primary importance in the control of basal TSH, GH and LH release.

Short-Term Serum Prolactin Concentrations in Goldfish (Carassius auratus) Subjected to Serial Sampling and Restraint

1976 ◽  
Vol 33 (1) ◽  
pp. 183-186 ◽  
Author(s):  
Richard E. Spieler ◽  
Albert H. Meier
Keyword(s):  
Carassius Auratus ◽  
Marked Decrease ◽  
Circadian Variation ◽  
Serum Prolactin ◽  
Short Term ◽  
Goldfish Carassius Auratus ◽  
Serial Sampling ◽  
The Times ◽  
Initial Capture

Serum prolactin concentrations in serially sampled goldfish (Carassius auratus) did not vary significantly between 30 s and 3 min after initial capture. A marked decrease in prolactin concentration was noted 9–17 min after initial capture followed by a recovery at 30–48 min. Although there was a circadian variation in prolactin concentration, the pattern of response to capture and sampling did not vary significantly among the times tested.

Short-term, low-dose ACTH therapy in West syndrome

2005 ◽  
Vol 36 (02) ◽  
Author(s):  
G Ramantani ◽  
M Tzitiridou ◽  
C Panteliadis
Keyword(s):  
Low Dose ◽  
West Syndrome ◽  
Short Term ◽  
Acth Therapy

Pituitary responses to a dopamine antagonist at different times of the day in normal women

1982 ◽  
Vol 100 (4) ◽  
pp. 481-485 ◽  
Author(s):  
F. R. Pérez-López ◽  
C. M. González-Moreno ◽  
M. D. Abós ◽  
J. A. Andonegui ◽  
R. H. Corvo
Keyword(s):  
Serum Prolactin ◽  
Dopamine Antagonist ◽  
Hormonal Changes ◽  
Healthy Women ◽  
Serum Lh ◽  
Normal Women ◽  
The Times ◽  
Serum Tsh

Abstract. In order to determine whether or not pituitary responsiveness to the dopaminergic antagonist clebopride changes during the nyctohemeral cycle, 10 healthy women with regular cycles were given 1 mg of clebopride orally at 09.00 h and 24.00 h with at least a 5 day interval between each test. In addition, 5 of the women were given a placebo instead of clebopride at midnight to evaluate the spontaneous hormonal changes. During the 24.00 h test the women had significantly higher P < 0.05) mean TSH basal levels. Serum prolactin (Prl) increased significantly (P < 0.001) after clebopride administration while these changes did not occur when placebo was used instead of clebopride at midnight. The Prl response to clebopride was qualitatively similar at 09.00 h and at 24.00 h. Clebopride given at midnight induced a significant increase (P < 0.05) in serum TSH while this change did not occur when the drug was given at 09.00 h or when placebo was given at midnight. The administration of clebopride resulted in no discernible alterations in serum LH, FSH or GH in either the 09.00 h or the 24.00 h tests. Thus, Prl responses to clebopride were similar in the morning and at midnight, TSH significantly increased after clebopride at midnight whereas this did not occur when the drug was given in the morning, and no significant changes were induced in LH, FSH or GH at the times studied.

Bioactive Peptides Sensitize Cells to Anticancer Effects of Oxaliplatin in Human Colorectal Cancer Xenografts in Nude Mice

2019 ◽  
Vol 26 (7) ◽  
pp. 512-522
Author(s):  
Xian Li ◽  
Long Xia ◽  
Xiaohui Ouyang ◽  
Qimuge Suyila ◽  
Liya Su ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Colorectal Cancer ◽  
Nude Mice ◽  
Low Dose ◽  
Bioactive Peptides ◽  
Human Colorectal Cancer ◽  
Short Term ◽  
Hct 116

<P>Background: Despite new agent development and short-term benefits in patients with Colorectal Cancer (CRC), metastatic CRC cure rates have not improved due to high rates of oxaliplatin resistance and toxicity. There is an urgent need for effective tools to prevent and treat CRC and reduce morbidity and mortality of CRC patients. Exploring the effects of bioactive peptides on the antitumor to CRC was of vital importance to the clinical application. </P><P> Objective: This study aimed to investigate the therapeutic impact of Anticancer Bioactive Peptides (ACBP) on anticancer effect of oxaliplatin (LOHP) in human colorectal cancer xenografts models in nude mice. </P><P> Methods: HCT-116 cells were cultured in vitro via CCK-8 assays and the absorbance was measured at 450 nm. Apoptosis and cell cycle were assessed by Flow Cytometry (FCM) in vitro. HCT-116 human colorectal cancer cells inoculated subcutaneously in nude mice of treatment with PBS (GG), ACBP, LOHP, ACBP+LOHP (A+L) in vivo. The quality of life was assessed by dietary amount of nude mice, the weight of nude mice, inhibition rates, tumor weight and tumor volume. Immunohistochemistry and RT-qPCR method was conducted to determine the levels of apoptosisregulating proteins/genes in transplanted tumors. </P><P> Results: ACBP induced substantial reductions in viable cell numbers and apoptosis of HCT116 cells in combined with LOHP in vitro. Compared with the control GG group, ACBP combined low dose oxaliplatin (U) group demonstrated significantly different tumor volume, the rate of apoptosis, the expression levels of Cyt-C, caspase-3,8,9 proteins and corresponding RNAs (P<0.05). The expression of pro-apoptotic proteins in the cytoplasm around the nucleus was significantly enhanced by ACBP. Short term intermittent use of ACBP alone indicted a certain inhibitory effect on tumor growth, and improve the quality of life of tumor bearing nude mice. </P><P> Conclusion: ACBP significantly increased the anti-cancer responses of low dose oxaliplatin (L-LOHP), thus, significantly improving the quality of life of tumor-bearing nude mice.</P>

Specific impairments in visuospatial working and short-term memory following low-dose scopolamine challenge in healthy older adults

2008 ◽  
Vol 46 (10) ◽  
pp. 2476-2484 ◽  
Author(s):  
Elizabeth Thomas ◽  
Peter J. Snyder ◽  
Robert H. Pietrzak ◽  
Colleen E. Jackson ◽  
Martin Bednar ◽  
...  
Keyword(s):  
Older Adults ◽  
Low Dose ◽  
Short Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Healthy Older Adults

Effect of Low-Dose Dopamine Infusion on Prolactin and Thyrotropin Secretion in Preterm Infants with Hyaline Membrane Disease

Neonatology ◽  
1985 ◽  
Vol 47 (6) ◽  
pp. 317-322 ◽  
Author(s):  
I. Sen ◽  
T. Tulassay ◽  
J. Kiszel ◽  
F. Ruppert ◽  
E. Sulyok ◽  
...  
Keyword(s):  
Preterm Infants ◽  
Low Dose ◽  
Hyaline Membrane Disease ◽  
Dopamine Infusion ◽  
Hyaline Membrane
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