scholarly journals PO-139 Effects of Exercise During Pregnancy on CaV1.2 Channel in Mesenteric Artery from SHR Offspring

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Shan Shan Li ◽  
Fan Xing Zeng ◽  
Li Jun Shi
Keyword(s):  
Blood Pressure ◽  
Protein Expression ◽  
Isometric Contraction ◽  
Mesenteric Artery ◽  
Exercise Group ◽  
Mesenteric Arteries ◽  
Sedentary Group ◽  
Pressor Responses ◽  
Significant Difference ◽  
Exercise During Pregnancy

Objective To investigate the effect of exercise during pregnancy on L-type Ca2+ (CaV1.2) channel in mesenteric artery from spontaneously hypertensive rats (SHR) offspring. Methods Female (11 weeks old) and male (12 weeks old) SHR, female (11 weeks old) and male (12 weeks old) WKY rats were selected to use for breeding. The day when the vaginal bolt was found was considered day 1 of gestation. The pregnant rats were randomly divided into four groups: WKY sedentary group (WKY-SED), WKY exercise group (WKY-EX), SHR sedentary group (SHR-SED) and SHR exercise group (SHR-EX). The exercise groups were subjected to swimming at the first day of pregnancy, 1h/d，6 days/week for 3 weeks. The 6-month-old male offspring were operated with femoral arterial and venous cannulation, and the blood pressure after intravenous (i.v.) injection of CaV1.2 channel opener BayK8644 and blocker nifedipine were monitored in vivo. In vitro study, the mesenteric arteries were removed and used for isometric contraction studies. The non-selective NOS inhibitor Nω-nitro-L-arginine methyl ester (L-NAME, 100 μM) was added after 60mM KCl measurement. To investigate the contribution of CaV1.2 channels in vascular tone regulation, the vascular responses to nifedipine (10−9–10−5M) were examined. Western blot was applied to examine the protein expression levels of CaV1.2 channel. Results (1) The mean arterial pressure(MAP) were higher in the 6M offspring of SHR-SED group than that of WKY-SED group (P＜0.01), but there was no significant difference between the 6M offspring of SED and Ex groups. (2) The pressor responses induced by i.v. injection of BayK8644（0.1mg/Kg）were increased in the 6M offspring of SHR-SED group (P＜0.05) compared with the WKY-SED group. Exercise during pregnancy markedly decreased the pressor responses in 6M offspring of SHR-EX group (P＜0.05). (3) Compared with the 6M offspring of WKY-SED group, the depressor responses induced by i.v. injection of nifedipine（1mg/Kg）were increased in the 6M offspring of SHR-SED group (P＜0.01). Exercise during pregnancy markedly attenuated the depressor responses in 6M offspring of SHR-EX group (P＜0.05). (4) The isometric contraction study revealed that nifedipine induced concentration-dependent vasorelaxation in mesenteric artery precontracted with noradrenaline. The sensitivity of tissues to nifedipine in 6M offspring of SHR-SED group was significantly higher than that of WKY-SED group (P＜0.01). Exercise during pregnancy normalized the increased sensitivity of tissues to nifedipine in 6M offspring of SHR (P＜0.05). (5) Compared with the 6M offspring of WKY-SED group, the protein expression of CaV1.2α1C was significantly increased in SHR-SED group(P＜0.01). Exercise during pregnancy markedly inhibited the expression of CaV1.2α1C in 6M offspring of SHR-EX group (P＜0.05). Conclusions Pregnancy exercise has no significant effect on basic blood pressure in 6M offspring of SHR; but the increased function and protein expression of CaV1.2 channel in 6M offspring of SHR may be normalized by exercise during pregnancy.

Endothelin-1 and -3 cause endothelium-dependent hyperpolarization in the rat mesenteric artery

1993 ◽  
Vol 265 (6) ◽  
pp. H2137-H2141 ◽  
Author(s):  
M. Nakashima ◽  
P. M. Vanhoutte
Keyword(s):  
Mesenteric Artery ◽  
Mesenteric Arteries ◽  
Receptor Subtype ◽  
Spontaneously Hypertensive ◽  
Rat Mesenteric Artery ◽  
Significant Difference ◽  
Eta Receptor ◽  
Etb Receptor ◽  
Wistar Kyoto ◽  
Eta Receptor Antagonist

The present study was designed to determine whether endothelin (ET) induces endothelium-dependent hyperpolarization in the isolated rat mesenteric artery and, if so, to identify the receptor subtype involved. Main superior mesenteric arteries of Wistar-Kyoto and spontaneously hypertensive rats were used for the measurement of electrical responses of smooth muscle cells, using glass microelectrode. In tissues with endothelium of both strains, ET-1 (10(-8) M) caused an initial transient hyperpolarization followed by a sustained depolarization. In tissues without endothelium, only depolarization was observed. ET-3 (10(-8) M) produced transient hyperpolarizations only in preparations with endothelium. There was no significant difference in maximal amplitude of hyperpolarization between the two strains. BQ-123 (selective ETA-receptor antagonist) blocked the depolarization to ET-1 but did not inhibit hyperpolarizing responses to either isopeptide. IRL-1620 (specific ETB-receptor agonist) produced transient membrane hyperpolarizations in tissues with endothelium. The hyperpolarizations induced by ET were not affected by NG-nitro-L-arginine. These data suggest that both ET-1 and ET-3 can cause endothelium-dependent hyperpolarization in the rat mesenteric artery and that the endothelial receptor involved may belong to ETB subtype.

scholarly journals PO-152 The effects of 4 weeks training mediates apelin on the p-AMPK(Thr172)/AMPK ratio in skeletal muscle of mice

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Tieying Li ◽  
Ying Zhang
Keyword(s):  
Skeletal Muscle ◽  
Protein Expression ◽  
Exercise Group ◽  
Treadmill Running ◽  
Exercise Session ◽  
Control Group ◽  
Wild Type ◽  
Protein Activity ◽  
Sedentary Group ◽  
Injection Control

Objective To investigate the effects of 4 weeks aerobic exercise mediates apelin on the p-AMPK(Thr172)/AMPK ratio in skeletal muscle of mice. Methods The C57BL/6J wild type mice(n=40) were randomly divided into four groups: control group (WC), exercise group (WE), apelin injection control group (AC) and apelin injection exercise group (AE), with 10 mice in each group. Apelin injection group mice were intraperitoneally injected with apelin (0.1 μmol/kg/day) for 4 weeks. At the same time, the exercise groups mice underwent 60min/day treadmill running with a slope of  5°at the speed of 15m/min for 2 weeks, and the speed was adjusted to 20m/min in the later 2 weeks. 48 h after the final exercise session quadriceps muscles were harvest. The protein expression of apelin, APJ, AMPKα and p-AMPKα (Thr172) in skeletal muscle was determined by Western Blot. Results (1) Compared with WC group, the protein expression of apelin , APJ and p-AMPKα (Thr172)/AMPKα ratio  in AC group skeletal muscle of mice were increased; (2) Compared with WE group , the p-AMPKα (Thr172) / AMPKα ratio in AE group skeletal muscle of mice were  increased. Conclusions Apelin supplementation for 4 weeks can up-regulate AMPK protein activity in skeletal muscle both in sedentary group and exercise group.

Norepinephrine and renin content in arterial tissue from different vascular beds

1969 ◽  
Vol 47 (1) ◽  
pp. 87-91 ◽  
Author(s):  
J. Genest ◽  
S. Simard ◽  
J. Rosenthal ◽  
R. Boucher
Keyword(s):  
Mesenteric Artery ◽  
Hind Limb ◽  
Rectus Abdominis ◽  
Mesenteric Arteries ◽  
Mesenteric Vein ◽  
Significant Difference ◽  
Arterial Tissue ◽  
Norepinephrine Content ◽  
Vascular Beds ◽  
Renin Content

Norepinephrine and renin contents in arterial tissues from different vascular territories in mongrel dogs were measured simultaneously. A significantly greater concentration of these two substances was found in the branches of the superior and inferior mesenteric arteries in contrast to arterial tissue taken from the aorta and from carotid, renal, femoral, and hind limb arteries of similar diameter. Norepinephrine and renin were undetectable in the rectus abdominis artery. There was no significant difference in the norepinephrine content of branches of mesenteric vein when compared with similar branches of mesenteric artery.

Cromakalim and pinacidil dilate small mesenteric arteries but not small cerebral arteries

1991 ◽  
Vol 261 (2) ◽  
pp. H287-H291 ◽  
Author(s):  
J. G. McCarron ◽  
J. M. Quayle ◽  
W. Halpern ◽  
M. T. Nelson
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Mesenteric Artery ◽  
Cerebral Arteries ◽  
Mesenteric Arteries ◽  
Membrane Hyperpolarization ◽  
K Channels ◽  
Muscle Types ◽  
External K

Small elevations in external K+ hyperpolarize and dilate small cerebral arteries. The hyperpolarization and dilation to K+ are blocked by barium (less than 0.1 mM). Since membrane hyperpolarization appears to be an important mechanism for dilation of these small cerebral arteries, we investigated the effects of the hyperpolarizing vasodilators, cromakalim and pinacidil, on isolated pressurized rat cerebral arteries (diameter of 158 +/- 5 microns at 50% of the systolic blood pressure). Cromakalim and pinacidil, which are potent relaxants of a variety of muscle types, were without effect on posterior cerebral arteries at concentrations that completely dilate similarly sized rat mesenteric arteries (diameter 134 +/- 6 microns at 50% of the systolic blood pressure). The mesenteric artery dilation to cromakalim and pinacidil was reversed by glibenclamide. However, unlike the cerebral arteries, mesenteric arteries did not exhibit a barium-sensitive dilation to external K+. Thus it appears that there may be differences in the types of K+ channels that are activated by dilating mechanisms in small cerebral and mesenteric arteries.

scholarly journals Effects of Exercise Combined with Finasteride on Hormone and Ovarian Function in Polycystic Ovary Syndrome Rats

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Chuyan Wu ◽  
Feng Jiang ◽  
Ke Wei ◽  
Feng Lin ◽  
Zhongli Jiang
Keyword(s):  
Polycystic Ovary Syndrome ◽  
Polycystic Ovary ◽  
Fasting Blood Glucose ◽  
Serum Levels ◽  
Exercise Group ◽  
Female Rats ◽  
Total Testosterone ◽  
Ovary Syndrome ◽  
Sedentary Group ◽  
Significant Difference

Exercise can reduce androgen and insulin levels in polycystic ovary syndrome (PCOS) patients. Finasteride is also presumed to improve the developing follicle environment. Therefore, the aim of this study was to observe the effects of the combination of exercise and finasteride therapy on hormone levels and ovarian morphology in rats with polycystic ovary syndrome. Forty female rats were randomly divided into five groups (n=8 each group): the PCOS sedentary group (P-Sed), PCOS exercise group (P-Ex), PCOS finasteride and sedentary group (P-FSed), and PCOS finasteride and exercise group (P-FEx), and healthy, age-matched rats were used as controls (CO). The results indicated that the levels of FINS in the P-FEx group were significantly lower than those in the P-Sed and P-FSed groups, while the ratio of fasting blood glucose (FBG)/fasting serum levels of insulin (FINS) in the P-FEx group was significantly higher than that in the P-Sed and P-FSed groups. Compared to the P-FEx group, serum levels of TT (total testosterone) in the P-Sed and P-FSed groups were significantly increased. The thickness of the follicular membrane and the number of atresia follicles in the P-FEx and CO groups were significantly lower than those in the P-Sed group, but there was no significant difference between the P-Ex and P-Sed groups. These results show that the combined usage of exercise and finasteride does not alter the effects of exercise on increasing insulin sensitivity and reducing androgen levels. There is also a synergistic effect of exercise and finasteride on the morphology of the ovary, including a reduced number of atresia follicles and thickness of the follicular membrane.

Late-gestation betamethasone enhances coronary artery responsiveness to angiotensin II in fetal sheep

2004 ◽  
Vol 286 (1) ◽  
pp. R80-R88 ◽  
Author(s):  
Robert D. Roghair ◽  
Fred S. Lamb ◽  
Kurt A. Bedell ◽  
Oliva M. Smith ◽  
Thomas D. Scholz ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Protein Expression ◽  
Late Gestation ◽  
Mesenteric Arteries ◽  
Receptor Protein ◽  
Maximal Response ◽  
Ang Ii ◽  
Fetal Sheep ◽  
Arterial Blood ◽  
Significant Difference

Antenatal glucocorticoids are used to promote the maturation of fetuses at risk for preterm delivery. While perinatal glucocorticoid exposure has clear immediate benefits to cardiorespiratory function, there is emerging evidence of adverse long-term effects. To determine if antenatal betamethasone alters vascular reactivity, we examined isometric contraction of endothelium-intact coronary and mesenteric arteries isolated from twin fetal sheep at 121-124 days gestation (term being 145 days). One twin received betamethasone (10 μg/h iv) while the second twin received vehicle (0.9% NaCl) for 48 h immediately before the final physiological measurements and tissue harvesting. Fetuses that received betamethasone had higher mean arterial blood pressures than the saline-treated twin controls (53 ± 1 vs. 48 ± 1 mmHg, P < 0.05). Coronary vessels from betamethasone-treated fetuses exhibited enhanced peak responses to ANG II (72 ± 17 vs. 23 ± 6% of the maximal response to 120 mM KCl, P < 0.05). There was no significant difference in response of the coronary arteries to other vasoactive compounds [KCl, U-46619, sodium nitroprusside, 8-bromo-cGMP (8-BrcGMP), isoproterenol, and forskolin]. Contractile responses to ANG II were similar in betamethasone and control mesenteric arteries (48 ± 17 vs. 36 ± 12% of the maximal response to 10-6 M U-46619). Western blot analysis revealed AT1 receptor protein expression was increased by betamethasone in coronary but not in mesenteric arteries. These findings demonstrate that antenatal betamethasone exposure enhances coronary but not mesenteric artery vasoconstriction to ANG II by selectively upregulating coronary artery AT1 receptor protein expression.

scholarly journals Effects of different vasopressors on the contraction of the superior mesenteric artery and uterine artery in rats during late pregnancy

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tingting Wang ◽  
Limei Liao ◽  
Xiaohui Tang ◽  
Bin Li ◽  
Shaoqiang Huang
Keyword(s):  
Caesarean Section ◽  
Blood Vessels ◽  
Mesenteric Artery ◽  
Uterine Artery ◽  
Contractile Response ◽  
Mesenteric Arteries ◽  
Response Curves ◽  
Pregnant Rats ◽  
Neuraxial Anaesthesia ◽  
Significant Difference

Abstract Background Hypotension after neuraxial anaesthesia is one of the most common complications during caesarean section. Vasopressors are the most effective method to improve hypotension, but which of these drugs is best for caesarean section is not clear. We assessed the effects of vasopressors on the contractile response of uterine arteries and superior mesenteric arteries in pregnant rats to identify a drug that increases the blood pressure of the systemic circulation while minimally affecting the uterine and placental circulation. Methods Isolated ring segments from the uterine and superior mesenteric arteries of pregnant rats were mounted in organ baths, and the contractile responses to several vasopressor agents were studied. Concentration-response curves for norepinephrine, phenylephrine, metaraminol and vasopressin were constructed. Results The contractile response of the mesenteric artery to norepinephrine, as measured by the pEC50 of the drug, was stronger than the uterine artery (5.617 ± 0.11 vs. 4.493 ± 1.35, p = 0.009), and the contractile response of the uterine artery to metaraminol was stronger than the mesenteric artery (pEC50: 5.084 ± 0.17 vs. 4.92 ± 0.10, p = 0.007). There was no statistically significant difference in the pEC50 of phenylephrine or vasopressin between the two blood vessels. Conclusions In vitro experiments showed that norepinephrine contracts peripheral blood vessels more strongly and had the least effect on uterine artery contraction. These findings support the use of norepinephrine in mothers between the time of neuraxial anaesthesia and the delivery of the foetus.

scholarly journals Upregulation of Na+/Ca2+ exchanger and TRPC6 contributes to abnormal Ca2+ homeostasis in arterial smooth muscle cells from Milan hypertensive rats

2010 ◽  
Vol 299 (3) ◽  
pp. H624-H633 ◽  
Author(s):  
Alessandra Zulian ◽  
Sergey G. Baryshnikov ◽  
Cristina I. Linde ◽  
John M. Hamlyn ◽  
Patrizia Ferrari ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Plasma Membrane ◽  
Smooth Muscle Cells ◽  
Mesenteric Artery ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Muscle Cells ◽  
Mesenteric Arteries ◽  
Membrane Microdomains

The Milan hypertensive strain (MHS) of rats is a model for hypertension in humans. Inherited defects in renal function have been well studied in MHS rats, but the mechanisms that underlie the elevated vascular resistance are unclear. Altered Ca2+ signaling plays a key role in the vascular dysfunction associated with arterial hypertension. Here we compared Ca2+ signaling in mesenteric artery smooth muscle cells from MHS rats and its normotensive counterpart (MNS). Systolic blood pressure was higher in MHS than in MNS rats (144 ± 2 vs. 113 ± 1 mmHg, P < 0.05). Resting cytosolic free Ca2+ concentration (measured with fura-2) and ATP-induced Ca2+ transients were augmented in freshly dissociated arterial myocytes from MHS rats. Ba2+ entry activated by the diacylglycerol analog 1-oleoyl-2-acetyl- sn-glycerol (a measure of receptor-operated channel activity) was much greater in MHS than MNS arterial myocytes. This correlated with a threefold upregulation of transient receptor potential canonical 6 (TRPC6) protein. TRPC3, the other component of receptor-operated channels, was marginally, but not significantly, upregulated. The expression of TRPC1/5, components of store-operated channels, was not altered in MHS mesenteric artery smooth muscle. Immunoblots also revealed that the Na+/Ca2+ exchanger-1 (NCX1) was greatly upregulated in MHS mesenteric artery (by ∼13-fold), whereas the expression of plasma membrane Ca2+-ATPase was not altered. Ca2+ entry via the reverse mode of NCX1 evoked by the removal of extracellular Na+ induced a rapid increase in cytosolic free Ca2+ concentration that was significantly larger in MHS arterial myocytes. The expression of α1/α2 Na+ pumps in MHS mesenteric arteries was not changed. Immunocytochemical observations showed that NCX1 and TRPC6 are clustered in plasma membrane microdomains adjacent to the underlying sarcoplasmic reticulum. In summary, MHS arteries exhibit upregulated TRPC6 and NCX1 and augmented Ca2+ signaling. We suggest that the increased Ca2+ signaling contributes to the enhanced vasoconstriction and elevated blood pressure in MHS rats.

scholarly journals Effects of different vasopressors on the contraction of the superior mesenteric artery and uterine artery in rats during late pregnancy

2021 ◽  
Author(s):  
Tingting Wang ◽  
Limei Liao ◽  
Xiaohui Tang ◽  
Bin Li ◽  
Shaoqiang Huang
Keyword(s):  
Caesarean Section ◽  
Mesenteric Artery ◽  
Uterine Artery ◽  
Contractile Response ◽  
Mesenteric Arteries ◽  
Response Curves ◽  
Pregnant Rats ◽  
Neuraxial Anaesthesia ◽  
Significant Difference

Abstract Background：Hypotension after neuraxial anaesthesia is one of the most common complications during caesarean section. Vasopressors are generally agreed to be the most effective way to improve hypotension, but it is unclear which of these drugs is best for caesarean section. We assessed the effects of vasopressors on the contractile response of uterine arteries and superior mesenteric arteries in pregnant rats, with the goal of identifying a drug that raises the blood pressure of the systemic circulation while minimally affecting the uterine and placental circulation. Methods： Isolated ring segments from the uterine and superior mesenteric arteries of pregnant rats were mounted in organ baths, and their contractile responses to several vasopressor agents were studied. Concentration-response curves for norepinephrine, phenylephrine, metaraminol and vasopressin were constructed. Results：The experimental results showed that the contractile response of the mesenteric artery to norepinephrine, as measured by the pEC50 of the drug, was stronger than that of the uterine artery (5.617 ± 0.11 vs. 4.493 ± 1.35, p=0.009), and the contractile response of the uterine artery to metaraminol was stronger than that of the mesenteric artery (pEC50: 5.084±0.17 vs 4.92±0.10, p=0.007). There was no statistically significant difference in the pEC50 of phenylephrine or vasopressin between the two blood vessels. Conclusion： In vitro experiments show that compared with phenylephrine, metaraminol , vasopressin, norepinephrine can contract peripheral blood vessel more strongly, while having the least effect on the contraction of uterine artery. These findings provide some support for the use of norepinephrine in mothers between the time of neuraxial anaesthesia and the delivery of the foetus.

scholarly journals Myocardial load at 30% and 50% of Maximal Voluntary Isometric Contraction in healthy individuals with Active and Sedentary Lifestyle

2020 ◽  
Vol 4 (1) ◽  
pp. 7-11
Author(s):  
Samrudhi Singh ◽  
◽  
Mariya Jiandani ◽  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Isometric Contraction ◽  
Sedentary Lifestyle ◽  
Rate Pressure Product ◽  
Care Hospital ◽  
Hemodynamic Parameters ◽  
Maximal Voluntary Isometric Contraction ◽  
Significant Difference

Background: Activities of daily living consists of isometric & isotonic contraction. Isometric contraction is a static contraction that exerts pressure overload on the heart. Studies have been carried out demonstrating hemodynamic effects of isotonic exercises however limited studies are available on myocardial load with isometric exercises. Aims and Objectives: To study the myocardial load at 30% and 50% of maximal voluntary isometric contraction (MVIC) in individuals with active and sedentary lifestyle. Study design and setting: Observational cross-sectional study was carried out in a tertiary care hospital. Materials and Methods: 140 healthy subjects (70 each in active & sedentary group) were recruited for the study. Baseline demographics of both groups were comparable. Hemodynamic parameters were taken at rest. Subject performed 30% and 50% MVIC and hemodynamic parameters were recorded during and post contraction. Statistical Analysis: Paired t test was used to compare the myocardial load between 30% and 50% MVIC in both groups. Repeated measures ANOVA was used to compare the myocardial load between active & sedentary groups at 30% and 50% MVIC. Result: There was a statistically significant difference in heart rate, systolic blood pressure &rate pressure product between 30% and 50% in active as well as sedentary groups. There was statistically no significant difference in heart rate, systolic blood pressure & rate pressure product between active & sedentary groups at 30% and 50% MVIC. Conclusion: The myocardial load during activities at submaximal intensities (<50%) is within the physiological limits and can be performed safely in individuals with active and sedentary lifestyle.

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