background : magnesium is the second most abundant intracellular cation. it plays an important role in insulin homeostasis and glucose metabolism through multiple enzymatic reactions. with increasing data on magnesium deficiency in diabetic patients and epidemiological studies demonstrating magnesium deficiency as a risk factor for diabetes, it is logical to search for its possible beneficial e...

Cardiovascular responses to graded iv infusions of norepinephrine were observed in 24 dogs that had been treated for 1 week with either placebo, dexamethasone, or deoxycorticosterone. Eight dogs served as control and received daily iv injections of placebo; eight dogs received the mineralocorticoid, deoxycorticosterone; and eight received the glucocorticoid, dexamethasone. The three groups did ...

ramadan is considered as holy month of muslims worldwide. during this month, most able-bodied muslim adults refrain from foods, drinks, smoking, and medications from dawn until sunset. in islamic rules, patients and those for whom fasting may have major health risks are exempted from fasting during ramadan. there is still no consensus regarding the effects of ramadan fasting, as a unique opport...

Studies examined the role of angiotensin (ANG) AT1a receptors in cardiovascular autonomic control by measuring arterial pressure (AP) and heart rate (HR) variability and the effect of autonomic blockade in mice lacking AT1a receptors (AT1a -/-). Using radiotelemetry in conscious AT1a +/+ and AT1a -/- mice, we determined 1) AP and pulse interval (PI) variability in time and frequency (spectral a...

Hourly measurements of the transient mydriasis and intraocular pressure decrease after right cervical ganglionectomy and left cervical sympathotomy were simultaneously performed in conscious rabbits. The times of onset of these phenomena after the denervation were 14.51 0.21 hr. (n = 8) and 18.71 ± 0.78 hr. (n = 7), respectively. Their duration values were 18.01 ± 0.89 hr. (n = 8) and 18.81 ± 1...

The "push-pull" effect denotes the reduced tolerance to +Gz (hypergravity) when +Gz stress is preceded by exposure to hypogravity, i.e., fractional, zero, or negative Gz. Previous studies have implicated autonomic reflexes as a mechanism contributing to the push-pull effect. The purpose of this study was to test the hypothesis that nonautonomic mechanisms can cause a push-pull effect, by using ...

The role of nitric oxide (NO) in the regulation of O2 consumption was studied in chronically instrumented conscious dogs. A specific NO synthesis inhibitor, nitro-L-arginine (NLA, 30 mg/kg i.v.), significantly increased mean arterial pressure from 100 +/- 4 to 134 +/- 5 mm Hg (mean +/- SEM) and total peripheral resistance by 157 +/- 16% and reduced cardiac output by 47 +/- 3% and heart rate by ...

The intra-venous (i.v.) hypotensive action of the final aqueous fraction of Pimenta dioica was studied in Spontaneously Hypertensive Rats (SHR). The rats were anaesthetized (sodium pentobarbital 50 mg/kg), the trachea, right carotid artery and jugular vein were cannulated for adequate ventilation, direct blood pressure measurement and intra-venous administration of extracts, solutions and drugs...

Using the radioactive microsphere technique, we studied the systemic and regional hemodynamic effects of ketanserin in conscious renal hypertensive rabbits. To characterize the hypotensive mechanism of the compound, we evaluated its antagonism toward 5-hydroxytryptamine2 and alpha 1-adrenergic receptors at hypotensive doses and compared the cardiovascular profile of ketanserin with that of the ...