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Biomedical subjects

I Oye

Publications and source records attributed to I Oye.

At least 55 records · Page 3Linked to original sources
PubMed1976

Pseudohypoparathyroidism: a difficult diagnosis in early childhood.

We have studied one adult and three children with pseudohypoparathyroidism and observed that the physical character of short metacarpal bones is not evident in the first 4-5 years of life, that hypocalcaemia and hyperphosphataemia may be absent in the first years of life, but that the renal unresponsiveness to parathyroid hormone can still be demonstrated. Our data confirm earlier observation that in evaluating the renal responsiveness to parathyroid hormone, urinary cyclic AMP is a better parameter than urinary phosphorus. Thus in early childhood, it may be difficult to differentiate between a normal child, a child with pseudohypoparathyroidism and a child with pseudo-pseudohypoparathyroidism unless the renal parathyroid hormone responsiveness is studied.

Adult↗
PubMed1976

Basal and hormone-induced urinary cyclic AMP in children with renal disorders.

The excretion of cyclic AMP in urine has been examined in normal children and in children with nephrogenic diabetes insipidus or moderate renal failure (predominantly defective concentrating ability) under basal conditions and in response to antidiuretic hormone (ADH) and parathyroid hormone (PTH). In contrast to other reported data, we could not confirm an ADH- and (PTH-unresponsiveness in hereditary, congenital nephrogenic diabetes insipidus, but our patients with structural renal disorders characterized by a defective urine concentrating ability did have reduced hormonal responses. It seems necessary to define nephrogenic diabetes insipidus very carefully, and until more data are collected, there appears to be no value in the measurement of urinary cyclic AMP level in the individual patient in the differential diagnosis of disorders due to renal concentrating defects.

Adolescent↗
PubMed1976

Adenosine 3',5'-cyclic monophosphate in perfused rat hearts exposed to isoprenaline and dopamine.

Isoprenaline and dopamine increased cyclic AMP (cAMP) content and contractile activity of isolated perfused rat hearts. The changes of cAMP levels depended on the mode of drug administration. Isoprenaline (4 x 10(-10) mol) administered to the perfused heart as a relatively concentrated bolus, caused a substantial, rapid and transient increase of cAMP. Isoprenaline (2 x 10(-10) mol and 4 x 10(-10) mol) and dopamine (10(-7) mol) diluted in 40 ml of perfusate which was continuously recirculated through the heart, caused a gradual increase of cAMP content which approached an apparent steady state. cAMP accumulation occurred at isoprenaline concentrations above 10(-9) M and at dopamine concentrations above 10(-6) M. Both agents also increased cAMP labelling from 14C-adenine in the perfusate, probably indicating increased cAMP synthesis. Isoprenaline at 2 x 10(-8) M and 10(-7) M increased labelling more than content of cAMP. Isoprenaline and dopamine also increased phosphorylase a activity. An association between increased cAMP contents and increased contractile activity was revealed by both the time-response and the dose-response curves of hearts exposed to isoprenaline and dopamine. Since both agents stimulate adrenergic beta-receptors in cardiac muscle, the results are concordant with the hypothesis that cAMP is involved as a mediator of the inotropic response to adrenergic beta-stimulation.

Adenine↗
PubMed1975

Role of cyclic adenosine 3',5'-monophosphate in the isoprenaline-induced relaxation of the oestrogen dominated rabbit uterus.

1. The role of cyclic adenosine 3',5'-monophosphate (cyclic AMP) in the relaxation produced by isoprenaline in muscle strips from the oestrogen dominated rabbit uterus has been investigated. 2. Isoprenaline 2 times 10- minus 8 M produced an inhibition of the mechanical activity but no increase in cyclic AMP. Isoprenaline 2 times 10- minus 6 M produced both inhibition of mechanical activity and increase in cyclic AMP. 3. The increase in cyclic AMP, but not the inhibition of mechanical activity, was blocked by propranolol 3.4 X 10-MINUS 6 M. 4. Dibutyryl-ccylic AMP produced a relaxation which mimicked that produced by isoprenaline, in that the longitudinal strips were more sensitive than the circular ones. 5. It is concluded that cyclic AMP may be a mediator of the beta-adrenergic effect in the oestrogen dominated rabbit myometrium. However, it seems not to be an obligatory link between stimulation of beta-adrenoceptors and relaxation. Other mechanisms may also exist.

Animals↗
PubMed1975

Relationship between cyclic AMP metabolism and inotropic response of perfused rat hearts to phenylephrine and other adrenergic amines.

A positive correlation between inotropic response and increment of cyclic AMP levels and labeling (from 14-C-adenine in the perfusate) was found after isoprenaline, dopamine, and phenylephrine alone, and after isoprenaline in the presence of chlorpromazine. 2. a lack of correlation between contractile activity and cyclic AMP levels and labeling was found when the hearts were exposed to phenylephrine in the presence of propranolol. The contractile activity increased, but the parameters for cyclic AMP did not change. These resuls together with findings by other workers indicate that the inotropic response to beta-stimulation always is associated with cyclic AMP accumulation, while the inotropic response to alpha-stimulation (when present) is not correlated to cyclic AMP elevation. Other differences between alpha- and beta-adrenergic effects on heart (course of development of the inotropic response, effect of theophylline on the response, effects on relaxing processes, action potential, and on refractory period) also indicate different mechanisms of action. On the basis of the available data we suggest as a conclusion that the inotropic response after alpha-adrenergic stimulation does not involve cyclic AMP as a mediator whereas beta-adrenergic effects are mediated by cyclic AMP. This means that the naturally occurring adrenergic amines norepinephrine and epinephrine, both of which are able to stimulate both alpha and beta myocardial receptors (twenzel and Su, 1966), elicit the inotropic response through two different mechanisms. Usually the beta-adrenergic effect on the heart is the more important. The contribution from alpha-stimulation, however, may increase under certain conditions: hypothyroidism or proplythiouracil treatment per se (Nakashima et al., 1971) or hypothermia (Kunos and Szentiványi, 1968; Buckley and Jordan. 1970; Benfey et al., 1973; Kunos, Yong, and Nickerson, 1973; Nickerson, 1973). Thus a single physiologic response may be mediated by more than one mechanism. Multiple mechanisms of action for one agent might have more general biologic significance; e.g., they may serve to maintain the responsiveness of a tissue under various conditions.

Animals↗