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Biomedical subjects

O L Pedersen

Publications and source records attributed to O L Pedersen.

85 records · Page 5Linked to original sources
PubMed1978

The effect of nifedipine on isolated human peripheral vessels.

Isometric tension was recorded in ring preparations of human peripherial arteries and veins contracted by potassium (127mM) and noradrenaline (1.8 X 10(-5)M). In the veins, nifedipine had a marked relaxing effect on contractions induced by both agents, and also reduced the contractile amplitude when added prior to stimulation. The inhibiting effect of nifedipine was more marked on the potassium than on the noradrenaline-evoked responses. This was in contrast to verapamil, which inhibited the noradrenaline-induced contractions significantly more, than those produced by potassium. After immersion of the vein preparations in calcium-free medium for 30 min., the potassium contracture decreased to 26+/2.0% (mean +/ S.E.M.) of the response in normal Krebs solution, and the noradrenaline-evoked to 7.1+/0.8%. The responses to both agents were completely restored when the calcium concentration was increased from 0 to 4 mM. Nifedipine (1.5X10(-7)M) depressed the potassium contracture in calcium-free solution to 7.3+/1.6%, and the noradrenaline response to 5.5+/1.6%; on addition of calcium, the response elicited by potassium increased to 16+/1.7%, and that by noradrenaline to 56+/8.6%. Compared with its actions on the veins, the effect of nifedipine on the arterial preparations was less pronounced. In the arteries, too, the inhibiting effect of nifedipine was significantly more pronounced on the potassium than on the noradrenaline-induced contraction. Immersion for 30 min. in calcium-free medium reduced the response to potassium to 61+/6.0% and that to noradrenaline to 68+/5.6% of the control in normal Krebs. Nifedipine (2.9X10(-7)M) further reduced the potassium contraction to 20+/4.0%; the response to noradrenaline was unaffected, being 74+/6.4% of the control.

Adolescent↗
PubMed1976

Comparison of metoprolol as hydrochlorothiazide and antihypertensive agents.

A crossover comparison of metoprolol and hydrochlorothiazide has been performed in 20 patients with mild hypertension. Both drugs caused almost identical statistically significant reduction in blood pressure of about 20 mm Hg systolic and 15 mm Hg diastolic. The side effects during active therapy were few and mild, but 5 patients experienced subjective symptoms during the first few days following abrupt withdrawal of metoprolol, namely general malaise, palpitations, headache, sweating and tremor. The symptoms were more pronounced in the standing position and disappeared at once on resumption of beta-blocker therapy, or gradually over 5 - 7 days when placebo tablets were given. In 11 of the 20 patients hydrochlorothiazide produced subnormal serum potassium levels and potassium supplements were given. The serum uric acid level was also significantly increased during hydrochlorothiazide treatment.

Adult↗
PubMedDate not supplied

Spontaneous afternoon plasma cortisol in depression.

Spontaneous plasma cortisol was measured in the interval from 15.00-18.00 h 74 hospitalized depressed patients (56 endogenously and 18 non-endogenously depressed according to the Newcastle index). The cortisol value at the individual time points correlated well with the mean cortisol concentration with the best correlation in the interval between 16.00 and 17.00 h (RHO = 0.89-0.92). For most patients maximum cortisol concentration was found early in the sampling period. Plasma cortisol was high during depression and was reduced after recovery in both diagnostic groups. Correlation between plasma cortisol during depression and type of depression or degree of depression was poor indicating that spontaneous plasma cortisol might have only a limited diagnostic value. However, among the endogenously depressed patients those not responding to treatment with cyclic antidepressants alone had significantly higher cortisol levels prior to treatment than responders. Afternoon plasma cortisol thus may be used as a predictor of the outcome of treatment with cyclic antidepressants.

Adolescent↗
PubMedDate not supplied

Cardiac mass and peripheral vascular structure in hydralazine-treated spontaneously hypertensive rats.

We have examined the effect of antihypertensive treatment on heart weight and on structural and functional characteristics of isolated mesenteric resistance vessels (internal diameter 170-220 micron) in spontaneously hypertensive rats (SHR) and in Wistar-Kyoto rats (WKY). The SHR and WKY were treated with hydralazine from the age of 4 weeks and were examined at ages 12 to 14 weeks and 23 to 27 weeks. Treated SHR had a mean blood pressure as much as 29% below that of control WKY, which in turn was 25 to 40% less than that of control SHR. In 12- to 14-week-old rats the heart to body weight ratio (which in control SHR was 13% greater than of WKY) was unaffected by treatment. Thereafter, the heart to body weight ratio of treated SHR did not increase as much as usual. At both ages, the media thickness and contractile response of the resistance vessels of the SHR (which were, respectively, 37% and 30% greater than those of vessels of WKY) were unaffected by treatment. However, because treatment caused a small (8%) increase in the lumen diameter of the vessels of the SHR, treatment did cause small, but possibly physiologically important, decreases both in the media to lumen ratio (11%) and in the pressure against which these vessels would have been able to contract (10%). Treatment had little effect on the pharmacological characteristics of vessels of either SHR or WKY. The results suggest that the increased heart weight, media thickness, and contractile response in mesenteric resistance vessels of SHR up to ages 23 to 27 weeks are due primarily to factors other than increased pressure.

Aging↗