scholarly journals Influence of estradiol supplementation on neuropeptide Y neurotransmission in skeletal muscle arterioles of F344 rats

2012 ◽  
Vol 303 (6) ◽  
pp. R651-R657 ◽  
Author(s):  
Kirk W. Evanson ◽  
Audrey J. Stone ◽  
Enoch Samraj ◽  
Tyler Benson ◽  
Rhonda Prisby ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Neuropeptide Y ◽  
Adult Female ◽  
Treatment Phase ◽  
Physiological Saline ◽  
Vessel Diameter ◽  
Female Rats ◽  
First Order ◽  
Physiological Saline Solution

The effects of estradiol on neuropeptide Y (NPY) neurotransmission in skeletal muscle resistance vessels have not been described. The purpose of this study was to determine the effects of long-term estradiol supplementation on NPY overflow, degradation, and vasoconstriction in gastrocnemius first-order arterioles of adult female rats. Female rats (4 mo; n = 34) were ovariectomized (OVX) with a subset ( n = 17) receiving an estradiol pellet (OVE; 17β-estradiol, 4 μg/day). After conclusion of the treatment phase (8 wk), arterioles were excised, placed in a physiological saline solution (PSS) bath, and cannulated with micropipettes connected to albumin reservoirs. NPY-mediated vasoconstriction via a Y1-agonist [Leu31Pro34]NPY decreased vessel diameter 44.54 ± 3.95% compared with baseline; however, there were no group differences in EC50(OVE: −8.75 ± 0.18; OVX: −8.63 ± 0.10 log M [Leu31Pro34]NPY) or slope (OVE: −1.11 ± 0.25; OVX: −1.65 ± 0.34% baseline/log M [Leu31Pro34]NPY). NPY did not potentiate norepinephrine-mediated vasoconstriction. NPY overflow experienced a slight increase following field stimulation and significantly increased ( P < 0.05) over control conditions in the presence of a DPPIV inhibitor (diprotin A). Estradiol status did not affect DPPIV activity. These data suggest that NPY can induce a moderate decrease in vessel diameter in skeletal muscle first-order arterioles, and DPPIV is active in mitigating NPY overflow in young adult female rats. Long-term estradiol supplementation did not influence NPY vasoconstriction, overflow, or its enzymatic breakdown in skeletal muscle first-order arterioles.

Regrowth of atrophied skeletal muscle in adult rats after ending immobilization

1978 ◽  
Vol 44 (2) ◽  
pp. 225-230 ◽  
Author(s):  
F. W. Booth
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Adult Female ◽  
Total Protein ◽  
Recovery Time ◽  
Time Course ◽  
Citrate Synthase ◽  
Female Rats ◽  
Adult Rats ◽  
Wet Weight

The recovery time course of muscle atrophied by immobilization was followed after removal of hindlimb casts from adult female rats. Increases of only 9% in body weight, 4% in gastrocnemius weight, and 10% in soleus weight occurred in controls during the 78-day duration of the experiment. There were no increases in the amounts of total protein or of citrate synthase activities in gastrocnemius or soleus during the first 3 days after removal of hindlimb casts; thereafter, there were increases in these paramters. Citrate synthase activities per mg of gastrocnemius protein were significantly higher at the 16th and 50th day of recovery. No significant differences for citrate synthase activity per mg of soleus occurred during recovery. Until the 50th day of recovery, no significant differences for total protein in soleus and for total protein and wet weight of gastrocnemius were observed between control and recovery values. However, the wet weight of the soleus returned rapidly during recovery and was not significantly different from control during recovery.

Estrogen modulates the contribution of neuropeptide Y to baseline hindlimb blood flow control in female Sprague-Dawley rats

2010 ◽  
Vol 298 (5) ◽  
pp. R1351-R1357 ◽  
Author(s):  
Dwayne N. Jackson ◽  
Christopher G. Ellis ◽  
J. Kevin Shoemaker
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Flow Control ◽  
Neuropeptide Y ◽  
Female Rats ◽  
Vastus Lateralis Muscle ◽  
Peptidase Activity ◽  
Vascular Conductance ◽  
Ovx Rats ◽  
Blood Flow Control

The purpose of this study was to determine the role of estrogen in neuropeptide Y (NPY) and Y1 receptor (Y1R)-mediated vascular responses in female rats. Based on earlier work from our laboratory that female rats lacked an NPY contribution to hindlimb vascular conductance relative to males, we tested the hypothesis that estrogen modulates Y1R-mediated hindlimb blood flow control. Thus it was expected that ovariectomy would: 1) increase skeletal muscle Y1R expression, 2) decrease skeletal muscle Y2 receptor (Y2R) expression, 3) decrease peptidase activity, and/or 4) increase overall skeletal muscle NPY concentration. Separate groups of control (CTL), ovariectomized (OVX), and OVX + 17β-estradiol replacement (OVX + E2; 21-day pellet) rats were studied. Animals were anesthetized and given localized hindlimb delivery of BIBP-3226 (Y1R antagonist), while femoral artery blood flow and blood pressure were recorded. Tissue samples from the white and red vastus lateralis muscle were extracted to examine Y1R and Y2R expression, peptidase activity, and NPY concentration. We found that Y1R blockade resulted in increased baseline hindlimb blood flow and vascular conductance in OVX rats, whereas no change was noted in CTL or OVX + E2 groups ( P < 0.05). This enhanced functional effect in the OVX group aligned with greater skeletal muscle Y1R expression in white vastus muscle and a substantial increase in NPY concentration in both white and red vastus muscle compared with CTL and OVX + E2 groups. There was no change in Y2R expression or peptidase activity among the groups. These data support the hypothesis that estrogen blunts Y1R activation in the rat hindlimb through an effect on Y1R expression and NPY concentration.

scholarly journals Neuropeptide Y and neurovascular control in skeletal muscle and skin

2009 ◽  
Vol 297 (3) ◽  
pp. R546-R555 ◽  
Author(s):  
Gary J. Hodges ◽  
Dwayne N. Jackson ◽  
Louis Mattar ◽  
John M. Johnson ◽  
J. Kevin Shoemaker
Keyword(s):  
Skeletal Muscle ◽  
Neuropeptide Y ◽  
Receptor Activation ◽  
Female Rats ◽  
Whole Body ◽  
Vasomotor Tone ◽  
Local Cooling ◽  
Vascular Conductance ◽  
Vasoactive Agent

Neuropeptide Y (NPY) is a ubiquitous peptide with multiple effects on energy metabolism, reproduction, neurogenesis, and emotion. In addition, NPY is an important sympathetic neurotransmitter involved in neurovascular regulation. Although early studies suggested that the vasoactive effects of NPY were limited to periods of high stress, there is growing evidence for the involvement of NPY on baseline vasomotor tone and sympathetically evoked vasoconstriction in vivo in both skeletal muscle and the cutaneous circulation. In Sprague-Dawley rat skeletal muscle, Y1-receptor activation appears to play an important role in the regulation of basal vascular conductance, and this effect is similar in magnitude to the α1-receptor contribution. Furthermore, under baseline conditions, agonist and receptor-based mechanisms for Y1-receptor-dependent control of vascular conductance in skeletal muscle are greater in male than female rats. In skin, there is Y1-receptor-mediated vasoconstriction during whole body, but not local, cooling. As with the NPY system in muscle, this neural effect in skin differs between males and females and in addition, declines with aging. Intriguingly, skin vasodilation to local heating also requires NPY and is currently thought to be acting via a nitric oxide pathway. These studies are establishing further interest in the role of NPY as an important vasoactive agent in muscle and skin, adding to the complexity of neurovascular regulation in these tissues. In this review, we focus on the role of NPY on baseline vasomotor tone in skeletal muscle and skin and how NPY modulates vasomotor tone in response to stress, with the aim of compiling what is currently known, while highlighting some of the more pertinent questions yet to be answered.

IMPAIRMENT OF THE CONTROL OF GONADOTROPHIN SECRETION AFTER OESTROGEN ADMINISTRATION TO ADULT FEMALE RATS

1977 ◽  
Vol 73 (3) ◽  
pp. 497-505 ◽  
Author(s):  
K. BROWN-GRANT ◽  
M. B. TER HAAR
Keyword(s):  
Adult Female ◽  
Female Rats ◽  
Postnatal Life ◽  
Normal Female ◽  
Control Mechanisms ◽  
Plasma Prolactin ◽  
Gonadotrophin Secretion ◽  
Significant Impairment ◽  
Long Acting

SUMMARY The possible occurrence of long-term changes in gonadotrophin control mechanisms following the administration of oestrogen to adult female rats has been studied. Administration of 2·5 mg oestradiol benzoate (OB) to normal female rats at 60 days of age did not result in failure of ovulation at 120 days of age but significant impairment of the LH and FSH responses to progesterone after ovariectomy and oestrogen priming was observed at 160–180 days of age. Treatment with the same dose of OB at 60 days of rats injected with 10 μg testosterone propionate on Day 4 of postnatal life resulted in an increased incidence of failure of ovulation at 120 though not at 150 days of age but did not further impair the already reduced gonadotrophin response to progesterone at 160–180 days of age. Removal of the ovaries at 60 days of age did not modify the effects of oestrogen given at 60 days of age in either group nor did ovariectomy at 60 days improve the response of neonatally androgen-treated rats to progesterone at 160–180 days of age. The increases in plasma prolactin and TSH levels in response to oestrogen priming after ovariectomy were not affected in any of the experimental groups. The administration of a long-acting oestrogen preparation (oestradiol cyclopentyl propionate, 2·5 mg at 60 days of age) to normal female rats suppressed ovulation and depressed plasma LH and FSH concentrations for at least 90 days; anterior pituitary weights were greatly increased and plasma prolactin concentrations were very high.

Long-term exercise of young and adult female rats: Effect on femoral neck biomechanical competence and bone structure

2009 ◽  
Vol 9 (3) ◽  
pp. 409-416 ◽  
Author(s):  
Charlotte H. Søgaard ◽  
Carl Christian Danielsen ◽  
Eivind B. Thorling ◽  
Lis Mosekilde
Keyword(s):  
Femoral Neck ◽  
Adult Female ◽  
Bone Structure ◽  
Female Rats

scholarly journals 3-Methylhistidine turnover in the whole body, and the contribution of skeletal muscle and intestine to urinary 3-methylhistidine excretion in the adult rat

1983 ◽  
Vol 214 (2) ◽  
pp. 607-615 ◽  
Author(s):  
D J Millward ◽  
P C Bates
Keyword(s):  
Skeletal Muscle ◽  
Urinary Excretion ◽  
Adult Female ◽  
Turnover Rate ◽  
Female Rats ◽  
Whole Body ◽  
Synthesis Rate ◽  
Turnover Rates ◽  
Adult Rat

The tissue origin of 3-methylhistidine (N tau-methylhistidine) was investigated in adult female rats. The decay of labelling of urinary 3-methylhistidine was compared with the labelling of protein-bound 3-methylhistidine in skeletal muscle and intestine after the injection of [methyl-14C]methionine. The decay curve for urinary 3-methylhistidine was much steeper than that in muscle or intestine, falling to values lower than those in either tissue after 30 days. The lack of decay of labelling in muscle during the first 30 days is shown to result from the persistence of label in the precursor S-adenosylmethionine. The relative labelling of urinary, skeletal-muscle and intestinal 3-methylhistidine cannot be explained in terms of skeletal muscle accounting for a major proportion of urinary 3-methylhistidine. Measurements were also made of the steady-state synthesis rate of protein-bound 3-methylhistidine in intestinal smooth muscle in vivo in adult female rats. This involved measurement of the overall rate of protein synthesis and measurement of the relative rates of synthesis of 3-methylhistidine and of mixed protein. The synthesis rate of 3-methylhistidine was 29.1%/day, compared with the overall rate of 77.1%/day for mixed, non-mucosal intestinal protein. Measurement of the amount of 3-methylhistidine in skeletal muscle (0.632 +/- 0.024 mumol/g) and in the whole body (0.332 +/- 0.013 mumol/g) indicate that, although the muscle pool is 86% of the total, because of its slow turnover rate of 1.1-1.6%/day, it only accounts for 38-52% of the observed excretion. Measurements of the mass of the intestine (9.95 g/250 g body wt.) and protein-bound 3-methylhistidine content (0.160 mumol/g of tissue) indicate a pool size of 1.59 mumol/250 micrograms rat. Thus 463 nmol of the urinary excretion/day would originate from the intestine, 22% of the total. The tissue source of the remaining urinary excretion is not identified, but other non-muscle sources constituting about 10% of the whole-body pool could account for this with turnover rates of only 6%/day, a much lower value than the turnover rate in the intestine.

scholarly journals Long-term silk peptide intake promotes skeletal muscle mass, reduces inflammation, and modulates gut microbiota in middle-aged female rats

2021 ◽  
Vol 137 ◽  
pp. 111415
Author(s):  
Sunmin Park ◽  
Heng Yuan ◽  
Ting Zhang ◽  
Xuangao Wu ◽  
Shao Kai Huang ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Gut Microbiota ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Female Rats ◽  
Middle Aged ◽  
Silk Peptide

scholarly journals IN VITRO EFFECTS OF ISOQUERCITRIN ON SELECTED VITALITY MARKERS OF BOVINE SPERMATOZOA

2019 ◽  
Vol 1 (2) ◽  
pp. 18-23
Author(s):  
Filip Benko ◽  
Hana Greifová ◽  
Eva Tvrdá
Keyword(s):  
Physiological Saline ◽  
Biological Properties ◽  
Computer Assisted ◽  
Movement Activity ◽  
Spermatozoa Motility ◽  
Physiological Saline Solution ◽  
Bovine Spermatozoa ◽  
In Vitro Effects

The aim of this study was to evaluate the dose- and time-dependent in vitroeffects of isoquercitrin (ISO), a natural flavonoid with numerous biological properties on bovine spermatozoa during three different time periods (0 h, 2 h, 24 h). Bovine semen samples were diluted and cultivated in physiological saline solution containing 0.5% DMSO together with 200, 100, 50, 10, 5 and 1 μmol/L ISO. Spermatozoa motility was measured using the HTM IVOS CASA (Computer Assisted Semen Analyzer) system. The viability of spermatozoa was assessed by the metabolic (MTT) assay, production of superoxide radicals was quantified using the nitroblue tetrazolium (NBT) test, and chemiluminescence was used to evaluate the generation of reactive oxygen species (ROS). The results of the movement activity showed a significant increase in the motility during long term cultivation in case of concentrationsranging between 5 and 50 μmol/L ISO (P<0.05; 24 h). At the same time, supplementation of several concentrations of ISO led to a significant preservation of the cell viability (P<0.05 in the case of 50 μmol/L, P<0.01 with respect to 1 and 5 μmol/L, and P<0.001 in relation to 10 μmol/L; 24 h). ISO addition at 10 and 50 μmol/L also provided a significantly higher protection against superoxide (P<0.05) and ROS (P<0.001) overgeneration after a 24 h cultivation. We may suggest that supplementation of ISO to bovine spermatozoa, particularly at concentrations ranging between 10 and 50 μmol/L, may offer protection to the motility, viability and oxidative status of the sperm cells, particularly notable at 24 h.

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