Reversal of hypertension and endothelial dysfunction in deoxycorticosterone-NaCl-treated rats by high-Ca2+ diet.

We tested the effect of high-Ca2+ diet on blood pressure and responses of mesenteric arterial rings in vitro in established deoxycorticosterone (DOC)-NaCl hypertension. Ca2+ supplementation (2.5%) of Wistar rats, which was commenced 8 wk after initiation of DOC-NaCl treatment (Ca(2+)-DOC group), reversed the development of hypertension, whereas in animals ingesting a normal diet (1.

High calcium diet reduces blood pressure in exercised and nonexercised hypertensive rats.

The effects of long-term high calcium diet and physical exercise and their combined effects on the development of hypertension, plasma and tissue atrial natriuretic peptide, and arterial function were studied in spontaneously hypertensive rats with Wistar-Kyoto rats serving as normotensive controls. Hypertensive rats were made to exercise by running on a treadmill up to 900 m/day. Calcium supplementation was instituted by increasing the calcium content of the chow from 1.

Intraplatelet free calcium and calcium-regulating hormones in plasma are not related to the antihypertensive effect of nifedipine in hypertensive pregnancy.

Intracellular free calcium regulates contraction-relaxation processes in vascular smooth muscle. We compared intraplatelet free calcium ([Ca2+]i) and pH ([pH]i) in hypertensive pregnant women to those in normotensive pregnant and non-pregnant women. Plasma parathormone and vitamin D metabolite were simultaneously assessed.

Inhibition of human neutrophil function by tolfenamic acid involves inhibition of Ca2+ influx.

The present work was designed to study the pharmacological control of the receptor-mediated activation of human neutrophils by tolfenamic acid (2(-)[(3-chloro-2-methylphenyl)-amino]benzoic acid). Tolfenamic acid inhibited in a concentration-dependent manner the degranulation response and Ca2+ influx in neutrophils activated either by the chemotactic peptide fMLP (N-formyl-methionyl-leucylphenylalanine) or Ca2+ ionophore A23187 (calcimycin). When fMLP was used to activate neutrophils, tolfenamic acid (30 microM) reduced Ca2+ influx by 50% and degranulation by 20%.

Dietary calcium and magnesium supplements in spontaneously hypertensive rats and isolated arterial reactivity.

1. High calcium diet attenuates the development of hypertension but an associated undesirable effect is that Mg2+ loss to the urine is enhanced. Therefore, we studied the effects of high calcium diet alone and in combination with increased magnesium intake on blood pressure and arterial function.

Arterial function after trichlormethiazide therapy in spontaneously hypertensive rats.

Inasmuch as the long-term influences of diuretic therapy on arterial function remain largely unknown, the effects of trichlormethiazide (8 mg kg-1 day-1) on vascular responses were studied in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. The 14-week treatment attenuated the increase in blood pressure by approximately 20 mm Hg in SHR, but did not affect blood pressure in WKY rats. Responses of mesenteric arterial rings in vitro were examined at the end of the study.

Arterial smooth muscle responses in adult and moderately aged spontaneously hypertensive rats.

In order to further clarify differences between spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats as well as the effects of ageing, vascular smooth muscle responses of mesenteric arterial rings and intracellular free calcium concentration ([Ca2+]i) in platelets and lymphocytes were studied in 20-week-old and 32-week-old animals. Arterial contractile responses induced by noradrenaline and potassium chloride were comparable in 20-week-old SHR and WKY rats, whereas at 32 weeks of age maximal contractile force generation to both of these agents was clearly lower in SHR. In both age groups the calcium entry blocker nifedipine was more effective in inhibiting potassium chloride-evoked responses in SHR than in WKY rats, and arterial relaxation responses by endothelium-dependent (acetylcholine) and endothelium-independent (nitroprusside, isoprenaline) mechanisms were more pronounced in WKY rats when compared with SHR.

High calcium diet, different antihypertensive agents, and cytosolic free Ca2+ in spontaneously hypertensive rats.

Several studies have shown that increased dietary calcium decreases blood pressure (BP) in spontaneously hypertensive rats (SHR), but the underlying mechanisms are not fully understood. We compared the effects of a high calcium diet and different antihypertensive agents on BP and intracellular free Ca2+ concentration ([Ca2+]i) in lymphocytes of adult SHR. The calcium content of the normal chow was 1.

Quinapril treatment and arterial smooth muscle responses in spontaneously hypertensive rats.

1 The effects of long-term angiotensin-converting enzyme inhibition with quinapril on arterial function were studied in spontaneously hypertensive rats, Wistar-Kyoto rats serving as normotensive controls. 2 Adult hypertensive animals were treated with quinapril (10 mg kg-1 day-1) for 15 weeks, which reduced their blood pressure and the concentrations of atrial natriuretic peptide in plasma and ventricular tissue to a level comparable with that in normotensive rats. 3 Responses of mesenteric arterial rings in vitro were examined at the end of the study.

Three levels of dietary calcium-effects on blood pressure and electrolyte balance in spontaneously hypertensive rats.

The effects of three levels of calcium intake on blood pressure (BP) and electrolyte balance were studied for 12 weeks in spontaneously hypertensive rats (SHR): the chow of the SHR-1 group contained 1.1% calcium, and that of the supplemented groups 2.1% (SHR-2) and 3.

The effect of high calcium intake on intracellular free [Ca2+] and Na(+)-H+ exchange in DOC-NaCl-hypertensive rats.

The effects of calcium supplementation on blood pressure, intracellular free calcium concentration ([Ca2+]i) and rate of Na(+)-H+ exchange were studied in DOC-NaCl-hypertensive rats. All the animals were uninephrectomized and divided into two main groups: the first group received deoxycorticosterone (DOC) (25 mg/kg, s.c.

Second derivative of developed tension in classifying cardiotonics with respect to their mechanisms of action: drugs affecting cAMP metabolism.

The second derivative of developed tension (T", d2T/dt2) has not come into common use in the analysis of cardiac contractility, although it has been shown to give additional information on the myocardial contraction-relaxation cycle (CRC). In the present study a new way to use T" in the analysis of myocardial mechanics, including the time course of T", is described. Profiles of the T" of the some drugs with established cardiotonic effects are presented.

High calcium diet augments vascular potassium relaxation in hypertensive rats.

The effects of increased dietary calcium on the development of hypertension and vascular smooth muscle responses were studied in spontaneously hypertensive rats and normotensive Wistar-Kyoto rats. Both hypertensive and normotensive animals were divided into two groups; the calcium content of the normal diet was 1.1% and that of the high calcium diet 3.

The effect of high calcium intake on Ca2+ ATPase and the tissue Na:K ratio in spontaneously hypertensive rats.

The effects of oral calcium loading on the development of hypertension were studied in spontaneously hypertensive rats (SHR). Forty-eight male SHR were divided into four groups according to treatment: control, calcium, deoxycorticosterone (DOC) and DOC + calcium. Both calcium groups received ad libitum 1.

Effects of calcium supplementation and deoxycorticosterone on plasma atrial natriuretic peptide and electrolyte excretion in spontaneously hypertensive rats.

The effects of calcium and the mineralocorticoid deoxycorticosterone (DOC) on blood pressure were studied in four groups of spontaneously hypertensive rats (SHR): (1) control; (2) calcium; (3) deoxycorticosterone and; (4) deoxycorticosterone + calcium. Calcium was given as 1.5% calcium chloride in drinking fluid and deoxycorticosterone by weekly subcutaneous injections (25 mg kg-1).

Effects of a high calcium diet and deoxycorticosterone on vascular smooth muscle responses in spontaneously hypertensive rats.

The effects of calcium and deoxycorticosterone (DOC) were studied in four groups of spontaneously hypertensive rats (SHR): control, calcium, DOC and DOC + calcium. Calcium was administered in drinking fluid as 1.5% calcium chloride, and DOC was injected weekly (25 mg/kg subcutaneously).

Biochemical indicators of myocardial ischaemia during coronary artery bypass grafting.

Metabolic indicators of myocardial ischaemia were measured in coronary sinus blood in six patients undergoing coronary artery bypass grafting (CABG). Five arterial and coronary sinus blood samples were taken in each case--one before cardiopulmonary bypass (CPB), and three during and one after CPB. Moderate hypothermia with topical cardiac cooling and cold cardioplegia were used.

Effects of calcium and deoxycorticosterone on blood pressure, plasma renin activity and vascular reactivity in spontaneously hypertensive rats.

The effects of calcium and deoxycorticosterone (DOC) on blood pressure, plasma renin activity (PRA), urinary sodium excretion and aortic responses were studied in spontaneously hypertensive rats (SHR). The animals (age 9 weeks) were divided into four treatment groups: control, calcium, DOC and DOC+calcium (n = 12 and the mean systolic blood pressure 174-177 mmHg in each). Calcium was given as 1.

Deoxycorticosterone prevents the blood pressure-lowering effect of calcium in spontaneously hypertensive rats.

To study the effects of prolonged oral calcium loading on the development of hypertension in spontaneously hypertensive rats (SHR), 48 male animals (age 9 weeks) were divided into four groups according to the treatment: control, calcium, deoxycorticosterone (DOC) and calcium/DOC. Both calcium groups received 1.5% calcium chloride solution ad libitum as their drinking fluid.

Effects of non-steroidal anti-inflammatory drugs and prednisolone on synovial fluid white cells, prostaglandin E2, leukotriene B4 and cyclic AMP in patients with rheumatoid arthritis.

Altogether 53 patients (31 women, 22 men) with definite rheumatoid arthritis were randomly divided into groups of 5-6 patients and treated for one day only with one of the following non-steroidal anti-inflammatory drugs (NSAIDs): acetylsalicylic acid, carprofen, diclofenac, indomethacin, naproxen, proquazone, timegadine, tolfenamic acid or paracetamol, and with prednisolone, in recommended doses. Synovial fluid samples were collected before and after the treatment. White cell count and its differentiation as well as the concentrations of protein, cyclic adenosine-3',5'-monophosphate (cAMP), prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) were measured from the synovial fluid.

Effects of iloprost, prostaglandin E1 (PGE1) and prostacyclin (PGI2) on chemically and electrically induced seizures in mice.

The effects of iloprost (ZK 36,374), a new chemically stable analogue of prostacyclin (PGI2), on strychnine-, pentylene-tetrazol-, and maximal electroshock-induced seizures were studied in mice. The time from the beginning of the injection of the convulsant or inducing electroshock to the stage of persistent seizures was determined, and lack of tonic hindlimb extension was regarded as inhibition of convulsions. In doses of 8 micrograms--16 micrograms kg-1 iloprost already exhibited an anticonvulsant action by markedly reducing the incidence of seizures and mortality following strychnine, pentylenetetrazol or maximal electroshock.

Influence of piroxicam on the contractile action of prostaglandin E1 on the isolated rat uterus.

Influence of piroxicam on the contractile response of the isolated rat uterus to prostaglandin E1(PGE1) was studied. Piroxicam and isobutylmethylxanthine (IBMX) reduced contractions of the isolated rat uterus induced by PGE1 and decreased the contraction/relaxation velocity ratio. The results suggest that piroxicam might antagonize PGE1 effects on the isolated rat uterus by enhancing relaxation via the cyclic AMP system.