felypressin and Hypotension

The systemic and renal hemodynamic effects of PLV-2 (octapressin) were studied in patients with hypotension or decompensated cirrhosis of the liver. Low doses (0.004 to 0.02 units/min) increased renal blood flow (indicator-dilution technique), reduced renal vascular resistance, and produced a slight increase in arterial pressure and systemic vascular resistance. Higher doses (0.1 to 0.5 units/min) produced a sharp increase in arterial pressure and systemic resistance while renal resistance increased moderately and renal blood flow usually was maintained above control levels. Renal fraction was increased at all dose levels. The increased renal blood flow was accompanied by more rapid intrarenal dye transit time and slight increase in renal extraction ratio of paraaminohippurate suggesting a rise in cortical blood flow. It is concluded that PLV-2 in small doses produces renal vasodilation and in larger doses preferential extra-renal vasoconstriction resulting in redistribution of blood flow to the kidney.

Topics: Angiotensins; Blood Pressure; Cardiac Output; Felypressin; Humans; Hypotension; Norepinephrine; Renal Circulation; Vasoconstriction; Vasoconstrictor Agents; Vasodilation

Cigarette smoking is usually associated with hypertension and may modify vasoconstrictor response.. The present study aimed to analyze and compare the interaction of passive cigarette smoking and hypertension on epinephrine and felypressin blood pressure effects after intravascular injection.. 45-day male Wistar rats had the main left renal artery partially constricted and the right kidney removed (1K1C model). Rats were placed in the chamber for exposition to passive cigarette smoking (10 cigarettes) during 10 min (6 days a week). Hypertensive rats received atenolol (90 mg/kg/day) by gavage for two weeks. Hypotensive and hypertensive response, response duration and heart rate were recorded from direct blood pressure values. The significance level was 5%.. Passive cigarette smoking increased maximal hypertensive response to epinephrine in normotensive and 1K1C-atenolol treated rats and to felypressin only in 1K1C-atenolol treated rats; it also reduced epinephrine hypotensive response. Epinephrine increased heart rate in normotensive and hypertensive passive smokers or non-smoker rats. Comparing the two vasoconstrictors, epinephrine showed greater hypertensive response in normotensive smokers, 1K1C-atenolol treated smokers and non-smokers. However, in normotensive-nonsmoker rats, felypressin showed a greater and longer hypertensive effect.. Our results suggest that passive cigarette smoking may reduce epinephrine vasodilation and increase hypertensive response when compared to felypressin. Therefore, felypressin may be safe for hypertensive patients to avoid tachycardia and atenolol interaction, but for normotensive and non-smoker patients, epinephrine may be safer than felypressin.

Topics: Animals; Antihypertensive Agents; Atenolol; Blood Pressure; Dose-Response Relationship, Drug; Drug Interactions; Epinephrine; Felypressin; Heart Rate; Hypertension; Hypotension; Male; Rats, Wistar; Time Factors; Tobacco Smoke Pollution; Vasoconstrictor Agents; Vasodilation

Epinephrine is considered the gold standard vasoconstrictor for hypertensive patients, but few studies report felypressin's effects. The present study aimed to analyze and compare the effects of these two vasoconstrictors, injected by the intravenous route, on the arterial pressure of normotensive, hypertensive and atenolol-treated hypertensive rats.. The hypertension model was one-kidney-one-clip (1K1C): the main left renal artery was partially constricted and the right kidney was surgically removed in 45-day-old male Wistar rats. 1K1C hypertensive rats received atenolol (90 mg/kg/day) by gavage for 2 weeks. 28-35 days after hypertension induction, a catheter was inserted into the left carotid artery to record direct blood pressure values. The following parameters were recorded: minimal hypotensive response, maximal hypertensive response, response duration and heart rate.. Epinephrine, but not felypressin, exerted an important hypotensive action; non-treated hypertensive rats showed more pronounced vasodilation. Treated and non-treated rats showed hypertensive responses of the same magnitudes in all groups; 1K1C atenolol rats showed reduced hypertensive responses to both vasoconstrictors. Felypressin's response duration was longer than that of epinephrine in all groups. Epinephrine increased heart rate while felypressin reduced this parameter only in the normotensive group.. Our results suggest that felypressin has equipotent pressure responses when compared with epinephrine, showing a greater extent of action. Atenolol's reduction of hypertensive effects surprisingly suggests that atenolol β-blockade may also be important for felypressin's cardiovascular effect, as is widely known for epinephrine. Our data suggest that felypressin is safe for hypertensive subjects, in particular those receiving atenolol.

Topics: Animals; Atenolol; Blood Pressure; Epinephrine; Felypressin; Heart Rate; Hypertension; Hypotension; Male; Rats; Rats, Wistar; Vasoconstrictor Agents; Vasodilation

Vasoconstrictor substances, as norepinephrine and epinephrine, were mixtured to local anesthetics to decrease their toxic effects and to prolong the depth of the anesthesia. However, these catecholamines produce systolic and diastolic hypertension. The effects of felypressin, a synthetic vasoconstrictor, upon arterial blood pressure and heart are lesser than those of norepinephrine or epinephrine, but due to its effects like oxytocin these catecholamines are yet the most used vasoconstrictors in association with lidocaine or another anesthetic salt. These vasoconstrictors are contraindicated for some physician, mainly for cardiac patients. But, are the catecholamines or is the salt the most dangerous components of the local anesthetic? The effects of the salt and catecholamines are opposite, but which of these exercises their effects first when inside blood vessel? Singi et al. [Pharmacol. Res. 44 (2001)] demonstrated that the first effect is always of the salt and that norepinephrine promotes protector effects upon guinea-pig isolated heart against lidocaine action. But, is this true for in vivo animals? The present study was performed with the aiming to answer this question and to verify if felypressin can induce the same effect of the norepinephrine. Fourteen Rattus norvegicus albinus, weighing 350g on average, were used. After being anesthetized with sodic thiopental, they were tracheostomizeds and one jugular and one carotid were cannuled for application of substances and to record the blood arterial pressure, respectively. The ECG was gotten through electrodes located in the front and back paws of the animals. The animals were separated in two groups, each one with seven rats. The lidocaine hydrochloride 2% in the doses of 600 microg and 3% in the doses of 900 microg acted on the cardiovascular system reducing the arterial pressure and modifying the electrocardiogram, while the prilocaine hydrochloride, in the same doses, also reduced the arterial pressure, but did not modify the electrocardiogram. When norepinephrine was associated to lidocaine 3% hydrochloride, it was possible to observe that this salt always exercised its effect first and a protective effect against the fall of pressure produced for the lidocaine. The same protective effect did not occur when felypressin was associated with prilocaine hydrochloride 3%.

Topics: Anesthesia; Anesthetics, Local; Animals; Blood Pressure; Drug Combinations; Electrocardiography; Felypressin; Female; Heart Rate; Hypotension; Lidocaine; Male; Norepinephrine; Prilocaine; Rats; Vasoconstrictor Agents

Topics: Angiotensin II; Animals; Capillaries; Felypressin; Hypotension; Male; Microcirculation; Muscles; Norepinephrine; Rats; Regional Blood Flow; Shock, Hemorrhagic; Vasopressins

The effect of octapressin (2-phenylalanine-8-lysine vasopressin) on renal and intrarenal blood flow was studied in 11 normotensive cirrhotic patients with abnormal renal perfusion. Renal haemodynamic changes were assessed with the (133)Xenon washout technique. Of the six patients given suppressor doses of octapressin intravenously renal blood flow improved in one only. A further three patients responded to the drug in a dose which increased the mean arterial pressure by 5 or more mm Hg. The increase in mean renal blood flow was accompanied by an improvement in renal cortical perfusion. In two patients renal blood flow decreased after the administration of octapressin. These findings, in conjunction with previous reports, suggest that octapressin will only consistently improve renal perfusion in cirrhotic subjects who are hypotensive and in whom the mean arterial blood pressure is raised by the drug, but do not exclude the possibility that octapressin may have a direct renal circulatory effect in some patients.

Topics: Adult; Alkaline Phosphatase; Bilirubin; Blood Flow Velocity; Blood Pressure; Creatinine; Felypressin; Female; Humans; Hypertension, Portal; Hypotension; Kidney; Kidney Failure, Chronic; Liver Cirrhosis; Male; Middle Aged; Serum Albumin; Vasopressins; Xenon

Topics: Adolescent; Adult; Aged; Blood Pressure; Child; Child, Preschool; Felypressin; Female; Humans; Hypotension; Male; Middle Aged; Postoperative Complications; Vasopressins

Topics: Adult; Aged; Anesthesia; Animals; Blood Pressure; Felypressin; Female; Humans; Hypotension; Male; Mice; Middle Aged; Vasopressins