Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
 
Articles by G. A Laine
Total Records ( 8 ) for G. A Laine
  J Yang , Y Park , H Zhang , X Xu , G. A Laine , K. C Dellsperger and C. Zhang
 

We hypothesized that the interaction between tumor necrosis factor- (TNF-)/nuclear factor-B (NF-B) via the activation of IKK-β may amplify one another, resulting in the evolution of vascular disease and insulin resistance associated with diabetes. To test this hypothesis, endothelium-dependent (ACh) and -independent (sodium nitroprusside) vasodilation of isolated, pressurized coronary arterioles from mLeprdb (heterozygote, normal), Leprdb (homozygote, diabetic), and Leprdb mice null for TNF- (dbTNF–/dbTNF–) were examined. Although the dilation of vessels to sodium nitroprusside was not different between Leprdb and mLeprdb mice, the dilation to ACh was reduced in Leprdb mice. The NF-B antagonist MG-132 or the IKK-β inhibitor sodium salicylate (NaSal) partially restored nitric oxide-mediated endothelium-dependent coronary arteriolar dilation in Leprdb mice, but the responses in mLeprdb mice were unaffected. The protein expression of IKK- and IKK-β were higher in Leprdb than in mLeprdb mice; the expression of IKK-β, but not the expression of IKK-, was attenuated by MG-132, the antioxidant apocynin, or the genetic deletion of TNF- in diabetic mice. Leprdb mice showed an increased insulin resistance, but NaSal improved insulin sensitivity. The protein expression of TNF- and NF-B and the protein modification of phosphorylated (p)-IKK-β and p-JNK were greater in Leprdb mice, but NaSal attenuated TNF-, NF-B, p-IKK-β, and p-JNK in Leprdb mice. The ratio of p-insulin receptor substrate (IRS)-1 at Ser307 to IRS-1 was elevated in Leprdb compared with mLeprdb mice; both NaSal and the JNK inhibitor SP-600125 reduced the p-IRS-1-to-IRS-1 ratio in Leprdb mice. MG-132 or the neutralization of TNF- reduced superoxide production in Leprdb mice. In conclusion, our results indicate that the interaction between NF-B and TNF- signaling induces the activation of IKK-β and amplifies oxidative stress, leading to endothelial dysfunction in type 2 diabetes.

  R. M Dongaonkar , R. H Stewart , G. A Laine , M. J Davis , D. C Zawieja and C. M. Quick
 

In skin, it is believed that lymph must be pumped by intrinsic contraction of lymphatic muscle, since investigators have not considered that cyclical dilation of venules could compress adjacent lymphatic microvessels. Because lymphatic vessels are sensitive to stretch, we hypothesized that venomotion not only can cause extrinsic pumping of lymph in nearby lymphatic vessels, but also can stimulate intrinsic contractions. Bat wing venules have pronounced venomotion and are in close proximity to lymphatic microvessels, and can be studied noninvasively without the confounding effects of anesthesia, surgical trauma, or contrast agents. Therefore, the interaction between venules and their paired lymphatic vessels in unanesthetized Pallid bats (n = 8) was evaluated by recording the diameters of both vessels. Four sets of observations suggested that lymphatic and venous contractions were partially coupled. First, venous dilation and contraction produced a significant change in lymphatic microvascular cross-sectional area. Second, lymphatic microvascular contractions were immediately preceded by a change in venular diameter. Third, venular and lymphatic vessel contraction frequencies were positively correlated (r = 0.75). Fourth, time delays between peak venular systole and onset of lymphatic microvascular contraction were negatively correlated with venomotion magnitude (r = –0.55) and velocity (r = –0.64). In a separate experiment, inhibiting venomotion resulted in a 54.3 ± 20.0% (n = 8) decrease in lymphatic contraction frequency. Furthermore, 85.7% (n = 56) of lymphatic vessels switch sides and lie adjacent to arterioles when venules were too small to exhibit venomotion. These results are consistent with both extrinsic pumping of lymph and stretch-induced lymphatic contraction and imply that intrinsic and extrinsic pumping can be coupled.

 
 
 
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility