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Pulse waveform analysis on temporal changes in ocular blood flow due to caffeine intake: a comparative study between habitual and non-habitual groups

Ismail A, Bhatti MS, Faye I, Lu CK, Laude A, Tang TB

Graefes Arch Clin Exp Ophthalmol, 2018 Sep;256(9):1711-1721.
PMID: 29876732 DOI: 10.1007/s00417-018-4030-9

PURPOSE: To evaluate and compare the temporal changes in pulse waveform parameters of ocular blood flow (OBF) between non-habitual and habitual groups due to caffeine intake.
METHOD: This study was conducted on 19 healthy subjects (non-habitual 8; habitual 11), non-smoking and between 21 and 30 years of age. Using laser speckle flowgraphy (LSFG), three areas of optical nerve head were analyzed which are vessel, tissue, and overall, each with ten pulse waveform parameters, namely mean blur rate (MBR), fluctuation, skew, blowout score (BOS), blowout time (BOT), rising rate, falling rate, flow acceleration index (FAI), acceleration time index (ATI), and resistive index (RI). Two-way mixed ANOVA was used to determine the difference between every two groups where p

Matched MeSH terms: Regional Blood Flow/drug effects*
The potential for evaluating the effects of intensified antithrombotic therapy using retinal optical coherence tomography angiography

Aik Kah T

Med Hypotheses, 2018 Jun;115:54-57.
PMID: 29685198 DOI: 10.1016/j.mehy.2018.03.022

Oral anticoagulants are widely used in the treatment and prevention of both venous and arterial thromboembolism. They are classified into vitamin K anticoagulants (VKAs) and non-vitamin K antagonist oral anticoagulants (NOACs). The main advantage of NOACs over VKAs is the absence of the need for continuous monitoring. However, there are concerns about their effectiveness and safety in certain clinical situations. In this manuscript, I discussed the possibility of using optical coherence tomography angiography [OCTA] in the monitoring of the activity of NOACs. The rapid development of OCTA technology is very promising. Further research and development will extend its use beyond the realm of ophthalmology.

Matched MeSH terms: Regional Blood Flow/drug effects
Streptokinase infusion for asparaginase-induced arterial thrombosis

Omar KZ, Ariffin H, Abdullah WA, Chan LL, Lin HP

Med. Pediatr. Oncol., 2000 May;34(5):377-8.
PMID: 10797367
Matched MeSH terms: Regional Blood Flow/drug effects
The effects of tempol on renal function and hemodynamics in cyclosporine-induced renal insufficiency rats

Chia TY, Sattar MA, Abdulla MH, Rathore HA, Ahmad Fu, Kaur G, et al.

Ren Fail, 2013 Aug;35(7):978-88.
PMID: 23822648 DOI: 10.3109/0886022X.2013.809563

This study investigated the effects of tempol, a superoxide dismutase (SOD) mimetic and L-NAME, a nitric oxide (NO) synthase inhibitor on the renal function and hemodynamics in cyclosporine A (CsA) induced renal insufficiency rats. Male Sprague-Dawley rats were treated with either vehicle (C), tempol (T, 1 mmol/L in drinking fluid), L-NAME (L, 1 mmol/L in drinking fluid), CsA (Cs, 25 mg/kg/day via gavage), CsA plus tempol (TCs), CsA plus L-NAME (LCs) or CsA plus a combination of tempol and L-NAME (TLCs) for 21 consecutive days. At the end of treatment regimen, the renal responses to noradrenaline (NA), phenylephrine (PE), methoxamine and angiotensin II (Ang II) were determined. Cs and LCs rats had lower creatinine clearance (0.7 ± 0.1 and 0.6 ± 0.5 vs. 1.3 ± 0.2 mL/min/kg) and fractional excretion of sodium (0.12 ± 0.02 and 0.17 ± 0.01 vs. 0.67 ± 0.04%) but higher systolic blood pressure (145 ± 2 and 178 ± 4 vs. 116 ± 2) compared to the control (all p blood pressure and improved creatinine clearance and sodium excretion compared to untreated Cs. The renal vasoconstriction in Cs or LCs to NA, PE and Ang II were lower than control by ∼35-48% (all p

Matched MeSH terms: Regional Blood Flow/drug effects
Chronic treatment with losartan and carvedilol differentially modulates renal vascular responses to sympathomimetics compared to treatment with individual agents in normal Wistar Kyoto and spontaneously hypertensive rats

Abdulla MH, Sattar MA, Abdullah NA, Khan MA, Abdallah HH, Johns EJ

Eur J Pharmacol, 2009 Jun 10;612(1-3):69-74.
PMID: 19356722 DOI: 10.1016/j.ejphar.2009.03.064

This study set out to investigate the impact of chronic cumulative blockade of angiotensin II and adrenoceptors in WKY and SHR and to explore how the renovascular responses to adrenergic and angiotensin II receptor agonists may be interdependent. Rats were treated with either losartan, carvedilol or losartan+carvedilol for 7 days and on day eight, animals were pentobarbitone anaesthetized and prepared for renal haemodynamic study. Dose-response relationships were determined in terms of reduction/elevation in the magnitude of renal blood flow in response to intrarenal arterial injection of dopamine, phenylephrine and isoprenaline. Renal vascular responses were blunted in WKY and SHR treated with either losartan or carvedilol as compared to their untreated counterparts (P<0.05). In the combined treated rats, the vascular responses to isoprenaline and phenylephrine were restored to levels observed in the untreated rats, but the renal vasoconstrictor responses to dopamine decreased (P<0.05) in both WKY and SHR. There was a reduction of (P<0.05) in the magnitude of the isoprenaline induced renal vasodilation in all SHR as compared to WKY groups. The data obtained showed that the renal vascular action of dopamine, phenylephrine and isoprenaline depended on an intact renin-angiotensin system (RAS) in WKY and SHR. Treatment with losartan or carvedilol blunted the renal vasoconstrictor/vasodilator responses to sympathomimetics which was attenuated with the combined treatment. These observations using chronic blockade of adrenergic and angiotensin receptors demonstrated that there was a long standing interdependency between the RAS and sympathetic nervous system (SNS) in determining the responsiveness of the renal vasculature of normal and hypertensive rats.

Matched MeSH terms: Regional Blood Flow/drug effects
Fulltext Effect of TGF-beta1 antisense oligodeoxynucleotide on renal function in chronic renal failure rats

Hiong LC, Voon KL, Abdullah NA, Sattar MA, Rahman NA, Khan AH, et al.

Acta Pharmacol Sin, 2008 Apr;29(4):451-7.
PMID: 18358091 DOI: 10.1111/j.1745-7254.2008.00772.x

The aim of the present study was to investigate the effectiveness of transforming growth factor (TGF)-beta1 antisense oligodeoxynucleotides (ODN) in ameliorating deteriorated kidney function in rats with puromycin-induced chronic renal failure (CRF).

Matched MeSH terms: Regional Blood Flow/drug effects
The contribution of α1B-adrenoceptor subtype in the renal vasculature of fructose-fed Sprague-Dawley rats

Abdulla MH, Sattar MA, Abdullah NA, Hye Khan MA, Anand Swarup KR, Johns EJ

Eur J Nutr, 2011 Jun;50(4):251-60.
PMID: 20882287 DOI: 10.1007/s00394-010-0133-8

PURPOSE: Fructose feeding induces a moderate increase in blood pressure, insulin resistance, and hyperinsulinemia. This study investigated the role of α(1B)-adrenoceptor subtype in the control of renal hemodynamic responses to exogenously administered angiotensin II (Ang II) and a set of adrenergic agonists in a model of high fructose-fed rats.
METHODS: Sprague-Dawley rats were fed for 8 weeks with 20% fructose in drinking water (FFR). The renal cortical vasoconstriction to noradrenaline (NA), phenylephrine (PE), methoxamine (ME) and Ang II in the presence and absence of chloroethylclonidine (CEC) (α(1B)-adrenoceptor antagonist) was determined. Data, mean ± SEM or SD were subjected to ANOVA with significance at p blood pressure, plasma glucose, and insulin levels when compared to control. FFR expressed reduced renal cortical vascular sensitivity to NA, PE, ME, and Ang II. Furthermore, renal cortical vasoconstriction response to NA, PE, ME, and Ang II was blunted in the presence of CEC in control. While in FFR, renal cortical vasoconstriction to NA, PE, and ME was enhanced by CEC. Renal cortical vasoconstriction to Ang II in FFR was reduced in the presence of CEC.
CONCLUSIONS: In the presence of a hyperinsulinemic state resulting from chronic and high fructose feeding, an attenuated AT(1) and α(1)-adrenoceptors response to Ang II and adrenergic stimuli respectively, is expected. In addition, α(1B)-adrenoceptor is the functional subtype that mediates renal cortical vasoconstriction in control rat, while high fructose feeding did influence the functionality of α(1B)-adrenoceptor in mediating the renal cortical hemodynamic changes.

Matched MeSH terms: Regional Blood Flow/drug effects