[Location, structure and mechanism of action of peripheral arterial chemoreceptors].
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Chemoreceptor Cells↗
Biomedical subjects
A Honig
Publications and source records attributed to A Honig.
The stalemate position.
The psychosurgical operation of stereotactic subcaudate tractotomy can be a highly effective treatment for chronic and intractable affective disorders. We have lately given increasing attention to cases where the depressed mood appears to lift although there is little improvement in social function. In these cases there has been a failure of rehabilitation and the complexities of this process post-operatively are discussed. In addition, relatives report in some 10% of cases "personality changes" after the operation which are not perceived in this way by an independent medical assessor and these observations seem to depend upon relatives mis-interpreting the resumption of pre-morbid personality function after long illnesses as undesirable side-effects. Case histories illustrating the problems are described. Treatment and rehabilitation strategies are outlined.
Depressive Disorder↗
Problem analysis: an instrument in the rehabilitation of chronic psychiatric patients in the community.
In the light of governmental policy in European countries to enhance and reinforce community psychiatric services, the need to introduce a more systematic approach in the treatment of chronic psychiatric patients by the community psychiatric services is currently being stressed. In this paper the problem analysis (P.A.) is described. It is a practical, treatment-oriented instrument which methodically compiles information on chronic patients and their systems. The systematic acquisition and examination of such information provide clues to a rational rehabilitation plan, one that can be carried out by a multidisciplinary community psychiatric service. Such an approach has the added advantage of making education and research in the field feasible.
Chronic Disease↗
Suppression of the plasma aldosterone to renin activity ratio in anaesthetized cats after pharmacological stimulation of the peripheral arterial chemoreceptors with almitrine bismesylate.
In chloralosed, non-vagotomized, spontaneously breathing cats the peripheral arterial chemoreceptors were stimulated by intravenous infusion of almitrine bismesylate (Vectarion, 0.20 mg/kg). Within 5 h after administration of the drug, a decline of both the mean systemic arterial blood pressure and the effective renal plasma flow, as well as an increase of the plasma renin activity (PRA) and the plasma aldosterone concentration (PAC) was observed. But as the PAC increase was less than that of PRA, a highly significant suppression of the PAC to PRA ratio was noted. The results indicate that not only whole body altitude hypoxia, but also stimulation of the peripheral arterial chemoreceptors in normoxic animals lowers the PAC-to-PRA ratio. It remains to be verified experimentally whether there exists a specific reflex influence of the peripheral arterial chemoreceptors on the renin-aldosterone relationship.
Aldosterone↗
Influence of infusion of deoxycorticosterone acetate on the responses of kidney function elicited by stimulation of the peripheral arterial chemoreceptors with almitrine bismesylate in anaesthetized rats.
In two groups of male, normotensive, spontaneously breathing rats in chloralose-urethane anaesthesia the peripheral arterial chemoreceptors were stimulated by intravenous infusion of almitrine bismesylate (0.25 mg/kg). The experiments were carried out in moderate osmotic diuresis. In one series desoxycorticosterone acetate (DOCA) was infused at a rate of 35-40 ng/min.100 g body weight. Urine was collected via a bladder catheter. Kidney hemodynamics as well as tubular and excretory function were determined using the clearance-technique. In both groups of animals administration of almitrine caused an increase of breathing rate as well as an increase of the oxygen tensions and the pH-values in the arterial blood. Mean systemic arterial blood pressure, effective renal plasma flow and glomerular filtration rate decreased slowly with the time of the experiments, whereas renal hemodynamic resistance tended to increase both in the control and in the DOCA treated group. In both groups of animals intravenous infusion of almitrine was followed by an inhibition of renal tubular sodium reabsorption and an increase of both the absolute and the fractional salt excretion. The data indicate that arterial chemoreceptor stimulation in rats causes an inhibition of renal tubular sodium reabsorption which does not result from a reduced tubular action of mineralocorticoid hormones.
Almitrine↗
Plasma vasopressin levels in healthy young men in response to stimulation of the peripheral arterial chemoreceptors by almitrine bismesylate.
The plasma arginine vasopressin (AVP) concentration, the plasma osmolality as well as the systemic arterial blood pressure, the heart rate, and the minute ventilation were determined in four healthy, normotensive, normoxic young men undergoing moderate osmotic diuresis. Each subject was measured in two experiments, both lasting from 7:30 a.m. to 6:00 p.m.. In one of them they obtained 50 mg almitrine bismesylate (Vectarion) at 12:00 o'clock, whereas the other test served as control experiment. There were only negligible changes of the parameters measured in the control experiments and also only weak responses of the cardiorespiratory values in the almitrine treated group. Compared with the data obtained 30 min before administration of the drug, measurements carried out 90 min after the ingestion showed a decrease of plasma AVP in all four subjects through plasma osmolality was increased in three of the four cases. A comparison of the mean values of all data obtained in the morning, i.e. before the oral administration of the drug, with those determined in the afternoon revealed that three out of four subjects had responded to almitrine with a fall of plasma AVP regardless of an increase of plasma osmolality in all these three cases. One person did not react to almitrine ingestion, neither with plasma AVP nor with plasma osmolality. In the control experiments the corresponding reaction pattern was uncharacteristic. The data do not support the assumption that arterial chemoreceptor stimulation increases plasma AVP. They rather indicate that excitation of these pO2-sensors in normoxic humans suppresses plasma AVP by mechanisms so far unknown.
Adult↗
Spin-lattice relaxation of very pure solid o-D2.
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Journal Article↗
Carotid body volumes of spontaneously hypertensive rats (SHR) growing up in hypobaric hypoxia.
Chronically hypoxic spontaneously hypertensive rats (SHR) developed 4-5 times bigger carotid bodies in relation to age-matched normoxic control SHR. When compared with the effects of chronic hypoxic hypoxia the influences of different levels of the systemic arterial blood pressure on carotid body volume were rather small. The data indicate that the carotid bodies of young SHR react to chronic arterial hypoxia in the same way as the glomera carotici of normotensive Wistar rats.
Altitude↗
Blood pressure adjustment, left ventricular weight and carotid body size in young spontaneously hypertensive rats growing up in hypoxia.
Spontaneously hypertensive rats (SHR) of the Okamoto-Aoki strain grew up in low pressure chambers at a simulated altitude of 4000 m from their 5th to their 18th week of age. Both the sea-level control rats and the hypoxic rats were divided into groups with and without additional hypertonic salt solution. Due to chronic hypoxia the development of systemic hypertension and the left ventricular hypertrophy were diminished in young SHR. In contrast to adult SHR, these effects were attenuated but not abolished by addition of salt. Independently of the salt availability, exposure to long-lasting hypoxia increases the carotid body volume significantly. The data indicate that chronic hypoxia has a stronger effect on carotid body enlargement than different levels of the systemic arterial blood pressure.
Animals↗
Influence of age on the carotid bodies of spontaneously hypertensive (SHR) and normotensive rats. II. Alterations of the vascular wall.
The carotid bodies of spontaneously hypertensive rats (SHR) of the Okamoto-Aoki-strain and of age-matched normotensive Wistar rats (NWR) were studied with respect to their size and the histological appearance of their arterial vessels. The animals were aged 3-6 d, and 5-6, 15-20, 30-40 and 50-70 weeks. The development of hypertension in the SHR started at an age of 5-6 weeks and was fully established at 15-20 weeks (mean systemic arterial blood pressure at about 160 mm Hg). When compared with the age-matched normotensive control rats (NWR) the SHR in the established phase of hypertension showed enlarged carotid bodies, an increase of the thickness of the media of the carotid body artery and circumscript pad-like thickening of the vascular wall within the carotid bodies. Repeatedly in particular in the old SHR, also a hyalinosis of the small branches of the glomic artery was found. These pathological changes regularly narrowed the lumen of the vessels seized; sometimes to a considerable extent. Such vascular alterations were never found in the newborn (3-6 d old) SHR and were also not demonstrable in the NWR. Thus these vascular alterations in the carotid body vessels of the adult SHR are supposed to be the result of the high systemic arterial blood pressure. The data indicate that long-lasting high systemic arterial blood pressure leads to changes of the wall of the arterial vessels of the carotid and presumably also the aortic bodies thus inducing an ischemic hypoxia of the specific chemoreceptive tissue and a chronic stimulation of the arterial chemoreceptors.
Aging↗
Ventricular size, the dexamethasone suppression test and outcome of severe endogenous depression following psychosurgery.
To assess the possible significance of cerebral ventricular size and the dexamethasone suppression test (DST) in the outcome of severe endogenous depression, 28 patients were followed up and reviewed 1 year after stereotactic subcaudate tractotomy. Neither ventricular size nor the dexamethasone suppression test predicted either a good or poor outcome. There was no relationship between ventricular size and the DST results.
Bipolar Disorder↗
Kidney function during arterial chemoreceptor stimulation. III. Long-lasting inhibition of renal tubular sodium reabsorption due to pharmacologic stimulation of the peripheral arterial chemoreceptors with almitrine bismesylate.
The reactions of the mean systemic arterial blood pressure, arterial acid-base balance kidney function (clearance-technique), and plasma aldosterone concentration (radio-immunoassay) elicited by stimulation of the peripheral arterial chemoreceptors with almitrine bismesylate were determined in chloralosed, non-vagotomized, spontaneously breathing cats in moderate mannitol-saline diuresis. The left renal nerves were cut; urine was collected separately from both the innervated and denervated kidneys. Intravenous injection of 0.2 mg/kg of the drug caused the expected long-lasting increase of the pO2 and pH and a decrease of pCO2 in the arterial blood, whereas the mean systemic arterial blood pressure slightly rose by an average of 2-4 mm Hg in the first hour of chemoreceptor stimulation but afterwards considerably decreased below the pre-injection values. The renal responses were characterized by a moderate vasoconstriction particularly in the innervated kidneys and a pronounced increase of sodium and urine excretion especially in the denervated kidneys. The inhibition of renal tubular sodium reabsorption underlying these natriuretic and diuretic reactions was fully demonstrable even at the end of the experiments, i. e. 4 h after the administration of the agent. Plasma aldosterone increased with the time of the experiments but did not show any clear relationships to the activity of the arterial chemoreceptors. The results show that the intravenous injection of almitrine bismesylate is connected with a renal response pattern which is typical for an excitation of the peripheral arterial chemoreceptors, i. e. moderate vasoconstriction (efferently mediated by the renal nerves) and an inhibition of renal tubular sodium reabsorption (efferently mediated by hormonal mechanisms). Furthermore, the data suggest that, on the one hand, under certain conditions these reactions of the kidney function could play the role of undesirable side effects but, on the other hand, the inhibition of renal tubular sodium reabsorption caused by almitrine bismesylate might possibly be used to treat diseases that are connected with a reduced ability of the kidneys to sufficiently excrete sodium.
Aldosterone↗
Kidney function during common carotid artery occlusion in anaesthetized cats: influence of vagotomy, constant ventilation, blood pressure stabilization, and carotid body chemoreceptor inactivation.
The reactions of kidney function elicited by bilateral common carotid artery occlusion were studied in six groups of chloralosed cats in which the Nn. vagi, the breathing reaction, the increase of the mean systemic arterial blood pressure, and the carotid body chemoreceptors were excluded successively. Carotid occlusion in the control animals caused a rise of the mean systemic arterial blood pressure, hyperventilation, and an increase in renal sodium and water excretion, resulting from an inhibition of tubular reabsorption. Bilateral cervical vagotomy, relaxation and constant artificial ventilation only slightly modified this renal response. Inactivation of the carotid body chemoreceptors in vagotomized and constantly ventilated cats attenuated the natriuresis due to carotid occlusion regardless of the behaviour of the renal perfusion pressure. On the other hand, keeping the mean arterial blood pressure during carotid occlusion constant by the bleeding technique also reduced the natriuretic reaction. Cats with both inactivated carotid body chemoreceptors and constant renal perfusion pressure exhibited an antinatriuretic reaction during carotid clamping. From these data it is concluded that in narcotized cats the natriuretic response during carotid occlusion is the result of both a stimulation of the carotid body chemoreceptors and the rise of the renal perfusion pressure. In contrast, in dogs this so-called carotid-sinus-polyuria seems to be induced solely by the increase of the systemic arterial blood pressure. The findings additionally indicated that the arterial chemoreceptors may be involved in the physiological daily control of renal sodium excretion already at normal arterial oxygen tension under sea-level conditions.
Anesthesia↗
Kidney function during arterial chemoreceptor stimulation. I. Influence of unilateral renal nerve section, bilateral cervical vagotomy, constant artificial ventilation, and carotid body chemoreceptor inactivation.
The reactions of renal hemodynamics and excretory function elicited by perfusion of the vascularly isolated carotid bodies with venous blood were studied in four groups of chloralosed cats in which the Nn. vagi, the breathing reactions, and the carotid body chemoreceptors were excluded successively. The kidney function was determined using clearance-techniques in both the innervated right and denervated left kidneys. In the animals with intact carotid chemoreceptors perfusion of the carotid bifurcations with venous blood caused a weak (4-6 mm Hg on the average) and transient increase of the mean systemic arterial blood pressure as well as a vasoconstriction and a fall of the blood flow and glomerular filtration rate in the innervated kidneys. In the spontaneously breathing animals carotid body chemoreceptor stimulation effected a rise of fractional sodium excretion only in the denervated kidneys whereas the relaxed and constantly ventilated cats showed a natriuretic response both at the innervated and denervated side. The reactions of renal excretory function did not correlate with those of renal hemodynamics. Vagotomy, relaxation, and constant artificial ventilation failed to abolish the responses elicited by stimulation of the chemoreceptors. Inactivation of the carotid body chemoreceptors by injecting acetic acid into the vascularly isolated carotid sinuses prevented both the hemodynamic and tubular reactions due to hypoxic-hypercapnic perfusion of the carotid bodies. The findings suggest that the arterial chemoreceptors control kidney function by specific reflex mechanisms. The influence of the carotid body chemoreceptors on kidney vasculature is mediated by the efferent renal nerves, whereas the control of renal tubular sodium reabsorption requires hormone action.
Animals↗
Kidney function during arterial chemoreceptor stimulation. II. Suppression of plasma aldosterone concentration due to hypoxic-hypercapnic perfusion of the carotid bodies in anaesthetized cats.
The reactions of the mean systemic arterial blood pressure, kidney function (clearance technique) and plasma aldosterone concentration (radio-immuno-assay) elicited by perfusion of the vascularly isolated carotid bodies with venous blood were studied in two series of chloralosed, vagotomized, relaxed, and constantly ventilated cats undergoing saline diuresis. In one group of animals the carotid body chemoreceptors were left intact; in the other one, they were abolished by injecting acetic acid into the glomera carotici. In the cats with intact chemoreceptors perfusion of the carotid bodies with venous blood immediately caused a small and transient increase of the blood pressure, whereas renal plasma flow tended to fall despite continuous chemoreceptor stimulation. Renal fractional sodium excretion already increased in the first 25 min of chemoreceptor stimulation, whereas plasma aldosterone concentration showed a significant decrease only after 45 min of venous perfusion of the glomera carotici. Plasma electrolytes changed only little at that time. No clear relationships between the responses of plasma aldosterone and those of the other parameters measured could be obtained. On subsequent perfusion of the carotid bodies with arterial blood plasma aldosterone returned to the values determined before chemoreceptor stimulation. Inactivation of the carotid body chemoreceptors per se already enhanced plasma aldosterone concentration. Perfusion of the glomera carotici with venous blood in the cats with abolished chemoreceptors did not suppress plasma aldosterone content. The data show that plasma aldosterone changes are not involved in the development of the initial phase (first hour) of the inhibition of renal tubular sodium reabsorption provoked by arterial chemoreceptor stimulation, but during long-lasting chemoreceptor stimulation they might contribute to the maintenance of this type of natriuresis. Furthermore the experiments suggest that the decrease of plasma aldosterone repeatedly observed during exposure of mammals to acute hypoxic hypoxia is possibly the reflex result of the stimulation of the arterial chemoreceptors.
Aldosterone↗
Influence of age on the carotid bodies of spontaneously hypertensive (SHR) and normotensive rats. I. Arterial blood supply.
In normotensive Wistar rats (NWR) of a random-bred strain and spontaneously hypertensive rats (SHR) of the OKAMOTO-AOKI-strain origin, course, and histological features of the carotid body arteries were examined. The studies were carried out in animals aging 3 d up to 70 weeks using serial sections and light microscopic methods. In both strains of animals the single carotid body was supplied by only one artery. In the NWR the glomic artery originated in nearly equal numbers from the occipital and the external carotid artery usually far distally from the carotid bifurcation. In the SHR in most cases the glomic artery arose from the external carotid artery near the carotid bifurcation and only seldom also from the occipital artery. In both strains of rats only in a few cases the carotid body artery originated from the internal carotid artery. In the normotensive animals in all age-groups at the origin of the glomic artery almost regularly intra-arterial, circular cushions were found. In contrast, in the spontaneously hypertensive rats (SHR) these cushions were often not demonstrable or flat and dumpy. In such cases the origin of the carotid body artery looked funnelled. The functional meaning of these structures as well as the influence of systemic arterial hypertension on them is briefly discussed.
Aging↗
A neuroendocrine study of stereotactic sub-caudate tractotomy.
The growth hormone and hypotensive responses to clonidine have been measured in six drug free severely depressed patients before, and at two weeks after, the surgical procedure of stereotactic sub-caudate tractotomy. The responses were unaltered two weeks after operation, by which time a small clinical improvement was evident. These findings are discussed in relation to central alpha adrenoceptor functions in depression, and the effect upon this of antidepressant treatment.
Aged↗
Arteriovenous anastomoses at the carotid bodies of rats.
In 2 out of 390 carotid bodies of rats arteriovenous anastomoses (AVA) have been found. Both cases belonged to a group of 12 glomera carotici which were prepared using the semithin section technique. The AVA were found in the course of branches of the glomic arteries leaving the main vessel before its entrance into the carotid body tissue. Thus the AVA were placed near but outside of the carotid bodies. Histologically they showed a distinct extension of the tunica media caused by epitheloidly modified smooth muscle cells. Functionally these AVA could act as shunt vessels (Sperrarterien) that would be able to control the blood flow and/or flow distribution through their carotid bodies.
Animals↗