Acute desensitization of pituitary FSH response to LHRH in ovariectomized rats: further evidence that in the presence of ovarian proteins the LHRH-dependent, LH-like component of FSH release becomes apparent

1989 ◽  
Vol 123 (2) ◽  
pp. 221-226
Author(s):  
C. B. Lambalk ◽  
G. P. van Rees ◽  
J. Schoemaker ◽  
J. de Koning ◽  
J. A. M. J. van Dieten
Keyword(s):  
Body Weight ◽  
Response Curve ◽  
Ovariectomized Rats ◽  
Secretory Proteins ◽  
Dual Control ◽  
Short Term ◽  
Lh Pulsatility ◽  
Inhibitory Feedback ◽  
Lhrh Release ◽  
High Doses

ABSTRACT Pulsatile release of LHRH and short-term pituitary desensitization to LHRH in the rat are believed to be necessary for the maintenance of LH pulsatility. In contrast, FSH release is partly induced by LHRH release and is partly LHRH-independent. This LHRH-independent release of FSH is subject to inhibitory feedback control by ovarian proteins (probably inhibin), and may obscure an LHRH-induced shortterm loss of pituitary FSH responsiveness to LHRH. The object of this study was to establish whether short-term pituitary desensitization to single doses of LHRH results not only in a loss of LH response, but also of FSH response. Ovariectomized rats were used to eliminate the influence of steroid feedback. A group of ovariectomized rats was pretreated with steroid-free bovine follicular fluid (bFF) to suppress LHRH-independent FSH release, and phenobarbital to suppress LHRH-dependent FSH release respectively, 7 and 1 h before administration of LHRH. Another group received phenobarbital only. The animals were injected sequentially with either low or high doses of LHRH (1·25 or 10 ng/100 g body weight at times 0 and at 80, 120 or 180 min, and 6·25 or 50 ng/100 g at 60 min). Blood was taken for FSH measurements before and 5 and 10 min after each injection. Rats pretreated with bFF and phenobarbital showed an acute FSH response related to the dose of injected LHRH. No dose–response curve was seen in animals which had only been pretreated with phenobarbital. A significantly attenuated FSH response to LHRH injections of 1·25 or 10 ng/100 g, given 20 min after an injection of 6·25 or 50 ng LHRH/100 g body weight respectively, was observed in animals pretreated with a combination of phenobarbital and bFF, but not in those treated with phenobarbital alone. The present results confirm that FSH release is under dual control by LHRH and ovarian secretory proteins. When both LHRH-dependent FSH release and the LHRH-independent FSH release are suppressed, short-term desensitization of FSH release to exogenous LHRH can be demonstrated. It is concluded that the phenomenon of short-term pituitary desensitization to LHRH and inhibitory ovarian proteins may both play a role in the regulation of FSH release. Journal of Endocrinology (1989) 123, 221–226

scholarly journals Combination therapy with fluconazole and flucytosine in the murine model of cryptococcal meningitis.

1997 ◽  
Vol 41 (5) ◽  
pp. 1120-1123 ◽  
Author(s):  
M H Nguyen ◽  
L K Najvar ◽  
C Y Yu ◽  
J R Graybill
Keyword(s):  
Body Weight ◽  
Combination Therapy ◽  
Murine Model ◽  
Response Curve ◽  
Susceptible Strain ◽  
Treatment Groups ◽  
High Doses ◽  
Low Dosage

This study elucidates the role of combined fluconazole and flucytosine as therapy for cryptococcosis in the murine model of meningitis. Three strains of Cryptococcus neoformans for which the range of fluconazole MICs was wide--2 microg/ml (susceptible strain), 8 microg/ml (moderately susceptible strain), and 32 microg/ml (resistant strain)--were used for infection. One day postinfection, the mice were randomized into eight treatment groups: placebo; flucytosine (40 mg/kg of body weight/day); fluconazole at 3 mg/kg/day (low dosage), 10 mg/kg/day (moderate dosage), or 20 mg/kg/day (high dosage); and combined flucytosine and fluconazole at low, moderate, or high doses of fluconazole. Three major findings were demonstrated: (i) correlation between the MICs for the isolates and the in vivo effectiveness of fluconazole as assessed by the reduction in cryptococcal brain burden, (ii) a dose-response curve (a higher dose of fluconazole was significantly more efficacious than a lower dose [P < 0.001]), and (iii) synergism between fluconazole and flucytosine (therapy with a combination of fluconazole and flucytosine was superior to therapy with either agent alone [P < 0.01]).

MATURATION OF THE INHIBITORY FEEDBACK ACTION OF OESTROGEN ON FOLLICLE-STIMULATING HORMONE SECRETION IN THE IMMATURE FEMALE RAT: A ROLE FOR ALPHA-FOETOPROTEIN

1979 ◽  
Vol 81 (2) ◽  
pp. 199-208 ◽  
Author(s):  
H. M. A. MEIJS-ROELOFS ◽  
P. KRAMER
Keyword(s):  
Body Weight ◽  
Hormone Secretion ◽  
Ovariectomized Rats ◽  
Female Rat ◽  
Immature Female ◽  
Subsequent Decrease ◽  
Inhibitory Feedback ◽  
Increased Sensitivity ◽  
Constant Dose

The maturation of the inhibitory feedback action of oestrogen on FSH secretion in the immature female rat was studied from 5 days of age until after the first ovulation. To study the role of the oestrogen binding alpha-foetoprotein (AFP) which is present in the blood of young animals, the effects of various doses of oestradiol and of the synthetic oestrogen R2858 (11β-methoxy-17-ethynyl-oestradiol), which is not bound by AFP, were compared in ovariectomized rats. A rise in the serum concentration of FSH within 2 days of ovariectomy was first observed in rats ovariectomized at 8 days of age. Between 8 and 28 days of age the rise in FSH after ovariectomy could be prevented by oestrogen injections in such a way that the resulting FSH concentration amounted to 50% of that in ovariectomized control rats. This was achieved with a constant dose of 0·00015 μg R2858/100 g body weight, whereas the dose of oestradiol needed decreased from 0·05 to 0·01 μg/100 g body weight indicating an increased sensitivity to the feedback action of oestradiol. After day 28, sensitivity to the feedback action of both R2858 and oestradiol decreased progressively up to the time of the first ovulation. In contrast to results at earlier ages, none of the doses of either oestrogen was capable of maintaining near-physiological concentrations of FSH after 20 days of age. It is concluded that the apparent increase in sensitivity to the feedback action of oestradiol occurring before 28 days of age reflects the disappearance of AFP from the blood, whereas the subsequent decrease in sensitivity is independent of AFP. Moreover, it is concluded that up to about 20 days of age oestradiol could be, though not necessarily is, the sole ovarian factor involved in regulating FSH secretion, whereas at later ages additional steroids and/or factors must be involved.

scholarly journals Dosing of neuromuscular blocking agents in patients with obesity: A narrative review

2021 ◽  
pp. 0310057X2096857
Author(s):  
Brian L Erstad ◽  
Jeffrey F Barletta
Keyword(s):  
Body Weight ◽  
Ideal Body Weight ◽  
Neuromuscular Blocking ◽  
Neuromuscular Blocking Agents ◽  
Patient Specific ◽  
Lean Body Weight ◽  
Short Term ◽  
Blocking Agents ◽  
Ideal Body ◽  
Size Descriptor

There is no consensus on which weight clinicians should use for weight-based dosing of neuromuscular blocking agents (NMBAs), as exemplified by differing or absent recommendations in clinical practice guidelines. The purpose of this paper is to review studies that evaluated various size descriptors for weight-based dosing of succinylcholine and non-depolarising NMBAs, and to provide recommendations for the descriptors of choice for the weight-based dosing of these agents in patients with obesity. All of the studies conducted to date involving depolarising and non-depolarising NMBAs in patients with obesity have assessed single doses or short-term infusions conducted in perioperative settings. Recognising that any final dosing regimen must take into account patient-specific considerations, the available evidence suggests that actual body weight is the size descriptor of choice for weight-based dosing of succinylcholine and that ideal body weight, or an adjusted (or lean) body weight, is the size descriptor of choice for weight-based dosing of non-depolarising NMBAs.

scholarly journals ICI 182,780 Penetrates Brain and Hypothalamic Tissue and Has Functional Effects in the Brain after Systemic Dosing

Endocrinology ◽  
2008 ◽  
Vol 149 (10) ◽  
pp. 5219-5226 ◽  
Author(s):  
Peter D. Alfinito ◽  
Xiaohong Chen ◽  
James Atherton ◽  
Scott Cosmi ◽  
Darlene C. Deecher
Keyword(s):  
Body Weight ◽  
Skin Temperature ◽  
Ethinyl Estradiol ◽  
Ovariectomized Rats ◽  
Ici 182,780 ◽  
Hot Flush ◽  
Hypothalamic Tissue ◽  
Dependent Model ◽  
The Brain ◽  
Neuroendocrine Functions

Previous reports suggest the antiestrogen ICI 182,780 (ICI) does not cross the blood-brain barrier (BBB). However, this hypothesis has never been directly tested. In the present study, we tested whether ICI crosses the BBB, penetrates into brain and hypothalamic tissues, and affects known neuroendocrine functions in ovariectomized rats. Using HPLC with mass spectrometry, ICI (1.0 mg/kg·d, 3 d) was detected in plasma and brain and hypothalamic tissues for up to 24 h with maximum concentrations of 43.1 ng/ml, and 31.6 and 38.8 ng/g, respectively. To evaluate antiestrogenic effects of ICI in the brain after systemic dosing, we tested its ability to block the effect of 17 α-ethinyl estradiol (EE) (0.3 mg/kg, 8 d) on tail-skin temperature abatement in the morphine-dependent model of hot flush and on body weight change. In the morphine-dependent model, EE abated 64% of the naloxone-induced tail-skin temperature increase. ICI pretreatment (1.0, 3.0 mg/kg·d) dose dependently inhibited this effect. ICI (3.0 mg/kg·d) alone showed estrogenic-like actions, abating 30% the naloxone-induced flush. In body weight studies, EE-treated rats weighed 58.5 g less than vehicle-treated rats after 8 d dosing. This effect was partially blocked by ICI (3.0 mg/kg·d) pretreatment. Similar to EE treatment, rats receiving 1.0 or 3.0 mg/kg·d ICI alone showed little weight gain compared with vehicle-treated controls. Thus, ICI crosses the BBB, penetrates into brain and hypothalamic tissues, and has both antiestrogenic and estrogenic-like actions on neuroendocrine-related functions.

Short-term melatonin consumption protects the heart of obese rats independent of body weight change and visceral adiposity

2014 ◽  
Vol 57 (3) ◽  
pp. 317-332 ◽  
Author(s):  
Frederic Nduhirabandi ◽  
Barbara Huisamen ◽  
Hans Strijdom ◽  
Dee Blackhurst ◽  
Amanda Lochner
Keyword(s):  
Body Weight ◽  
Weight Change ◽  
Visceral Adiposity ◽  
Body Weight Change ◽  
Short Term ◽  
Obese Rats

Contributions of Lactobacillus plantarum PC170 administration on the recovery of gut microbiota after short-term ceftriaxone exposure in mice

2020 ◽  
Vol 11 (5) ◽  
pp. 489-509
Author(s):  
R. Cheng ◽  
H. Liang ◽  
Y. Zhang ◽  
J. Guo ◽  
Z. Miao ◽  
...  
Keyword(s):  
Body Weight ◽  
Gut Microbiota ◽  
Lactobacillus Plantarum ◽  
Antibiotic Treatment ◽  
Recovery Phase ◽  
The Body ◽  
Faecal Microbiota ◽  
Short Term ◽  
Host Animal ◽  
The Impact

This study aimed to determine the impact of Lactobacillus plantarum PC170 concurrent with antibiotic treatment and/or during the recovery phase after antibiotic treatment on the body weight, faecal bacterial composition, short-chain fatty acids (SCFAs) concentration, and splenic cytokine mRNA expression of mice. Orally administrated ceftriaxone quantitatively and significantly decreased body weight, faecal total bacteria, Akkermansia muciniphila, and Lactobacillus plantarum, and faecal SCFAs concentration. Ceftriaxone treatment also dramatically altered the faecal microbiota with an increased Chao1 index, decreased species diversities and Bacteroidetes, and more Firmicutes and Proteobacteria. After ceftriaxone intervention, these changes all gradually started to recover. However, faecal microbiota diversities were still totally different from control by significantly increased α- and β-diversities. Bacteroidetes all flourished and became dominant during the recovery process. However, mice treated with PC170 both in parallel with and after ceftriaxone treatment encouraged more Bacteroidetes, Verrucomicrobia, and Actinobacteria, and the diversity by which to make faecal microbiota was very much closer to control. Furthermore, the expression of splenic pro-inflammatory cytokine tumour necrosis factor-α mRNA in mice supplemented with PC170 during the recovery phase was significantly lower than natural recovery. These results indicated that antibiotics, such as ceftriaxone, even with short-term intervention, could dramatically damage the structure of gut microbiota and their abilities to produce SCFAs with loss of body weight. Although such damages could be partly recovered with the cessation of antibiotics, the implication of antibiotics to gut microbiota might remain even after antibiotic treatment. The selected strain PC170 might be a potential probiotic because of its contributions in helping the host animal to remodel or stabilise its gut microbiome and enhancing the anti-inflammatory response as protection from the side effects of antibiotic therapy when it was administered in parallel with and after antibiotic treatment.

Effect of short-term propionate infusion on feed intake and blood parameters in sheep

1997 ◽  
Vol 272 (6) ◽  
pp. E997-E1001 ◽  
Author(s):  
H. G. Leuvenink ◽  
E. J. Bleumer ◽  
L. J. Bongers ◽  
J. van Bruchem ◽  
D. van der Heide
Keyword(s):  
Portal Vein ◽  
Feed Intake ◽  
Blood Parameters ◽  
Feeding Pattern ◽  
Short Term ◽  
Mesenteric Vein ◽  
The Difference ◽  
High Doses

The hypothesis that propionate is a short-term feed intake-regulating agent was studied. Mature wether sheep were infused over 20 min with Na propionate into the mesenteric vein, while feed intake and feeding pattern were monitored over 1.5 h. Feed intake was reduced by infusions at 2 mmol/min, which were associated with marked increases in jugular as well as portal concentrations of insulin, glucose, and propionate. In a second experiment, animals were infused with 2 mmol/min Na propionate into the portal vein. No decrease in feed intake was observed, although there were similar increases in insulin, glucose, and propionate as found in mesenteric vein-infused animals. It is concluded that mesenteric propionate in high doses acts as a satiety factor. Possible explanations for the difference between site of infusion may be a different distribution of the infusate over the liver and/or the presence of propionate-sensitive receptors in the mesenteric/portal vein region. It seems unlikely that insulin concentrations are involved in inducing satiety in propionate-infused animals.

scholarly journals Resveratrol regulates body weight in healthy and ovariectomized rats

2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Rupali Sharma ◽  
Neel Kamal Sharma ◽  
M. Thungapathra
Keyword(s):  
Body Weight ◽  
Ovariectomized Rats

A Study of the Acid Dose-Response Curve to Small Doses of Pentagastrin in Duodenal Ulcer Patients

1972 ◽  
Vol 43 (2) ◽  
pp. 181-191
Author(s):  
J. B. Elder ◽  
G. Gillespie ◽  
E. H. G. Campbell ◽  
I. E. Gillespie ◽  
G. P. Crean ◽  
...  
Keyword(s):  
Duodenal Ulcer ◽  
Body Weight ◽  
Dose Response ◽  
Response Curve ◽  
Acid Output ◽  
Twilight Zone ◽  
Response Curves ◽  
Small Doses ◽  
Threshold Doses ◽  
Body Weight Dose

1. The acid secretory responses to a range of small doses of pentagastrin in 0·15 m-NaCl have been studied in thirty-one preoperative duodenal ulcer subjects. Acid output increased significantly above basal values when a dose of 0·064 μg h−1 kg−1 was given. 2. Control observations in sixteen duodenal ulcer patients using the saline solvent alone at identical rates of infusion showed no significant increase in acid output. 3. From the dose-response curves sub-threshold and threshold doses of pentapeptide are suggested for duodenal ulcer patients before truncal vagotomy. 4. Considerable variation in acid response was noted between patients given the same body-weight dose of pentapeptide. The results suggest that a ‘twilight zone’ of stimulation exists between the dose of pentagastrin by which few patients are stimulated and the dose by which the majority are stimulated. This may reflect some variation in the sensitivity to stimulation by pentagastrin from one patient to another.

scholarly journals Preliminary phytochemical analysis and the effect of Agave sisalana on body weight and defensive behaviours in ovariectomized rats

2017 ◽  
Vol 11 (34) ◽  
pp. 538-548 ◽  
Author(s):  
Gonçalves Carneiro Spera de Andrade Telma ◽  
Emilia Arlindo da Silva Yara ◽  
Gazoni Espinoza Diego ◽  
Mateus de Lima Leonardo ◽  
Karla de Oliveira Cezar Alessandra ◽  
...  
Keyword(s):  
Body Weight ◽  
Ovariectomized Rats ◽  
Phytochemical Analysis ◽  
Defensive Behaviours ◽  
Agave Sisalana
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