Sustained complete autonomic blockade

Halmagyi, D; Neering, I. R.; Varga, D.; Pullin, Joy

doi:10.1111/j.1476-5381.1969.tb07986.x

Cited by 3 publications

(3 citation statements)

References 13 publications

(8 reference statements)

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“…In fact, at 40 C amphetamine administration elicited a marked hypothermia (Table 3). To determine whether a peripheral action of amphetamine may be involved in raising body temperature, the drug was administered to rats 1 h after ganglionic blockade with chlorisondamine hydrochloride (10 mg/kg intraperitoneally) or after " complete autonomic blockade " (Trendelenburg, 1967;Steinberg & Hilton, 1967;Halmagyi, Neering, Varga & Pullin, 1969) previously, respectively. Table 5 shows that chlorisondamine alone did not alter the effects of amphetamine on 5-HIAA levels and body temperature. "…”

Section: Resultsmentioning

confidence: 99%

Turnover rate of brain 5‐hydroxytryptamine increased by D‐amphetamine

Reid

Derr

1970

British J Pharmacology

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Summary1. Administration of two doses of amphetamine HCl (5 mg/kg intraperitoneally) 45 min apart raised body temperature of rats by an average of 3.40 C and increased the turnover rate of brain 5-hydroxytryptamine (5-HT) by almost one-half. 2. Both effects were blocked by exposure to 40 C or by pretreatment with the B-blocker Ko 592 (1-(2-methylphenoxy)-3-isopropylamino-2-propanol), but not by the administration of the ganglionic blocker chlorisondamine combined with atropine. 3. Since it has previously been shown that hyperthermia per se increases the turnover rate of brain 5-HT, and that amphetamine does not directly affect the uptake and release of 5-HT in brain slices, it is concluded that the amphetamineinduced increase in 5-HT turnover may be secondary to the rise in temperature produced by the drug.

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Section: Resultsmentioning

confidence: 99%

Turnover rate of brain 5‐hydroxytryptamine increased by D‐amphetamine

Reid

Derr

1970

British J Pharmacology

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“…Blood was sampled and analyzed for measurement of PNE with an assay. Atropine (0.4 mg•kg −1 ) was infused via the forearm venous line to block vagal effects during the protocol (Halmagyi et al, 1969).…”

Section: Measurementmentioning

confidence: 99%

Analytic and Integrative Framework for Understanding Human Sympathetic Arterial Baroreflex Function: Equilibrium Diagram of Arterial Pressure and Plasma Norepinephrine Level

Yamasaki

Sato²,

Satō

et al. 2021

Front. Neurosci.

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BackgroundThe sympathetic arterial baroreflex is a closed-loop feedback system for stabilizing arterial pressure (AP). Identification of unique functions of the closed system in humans is a challenge. Here we propose an analytic and integrative framework for identifying a static operating point and open-loop gain to characterize sympathetic arterial baroreflex in humans.Methods and ResultsAn equilibrium diagram with two crossing functions of mechanoneural (MN) and neuromechanical (NM) arcs was analyzed during graded tilt maneuvers in seven healthy subjects. AP and plasma norepinephrine level (PNE), as a surrogate for sympathetic nerve activity, and were recorded after vagal modulation of heart function was blocked by atropine. The MN-arc curve was described as a locus of operating points during –7, 0, 15, and 60° head-up tilting (HUT) on a PNE-AP plane. The NM-arc curve was drawn as a line between operating points before and after ganglionic blockade (trimethaphan, 0.1 mg⋅ml–1⋅kg–1) during 0° or 15° HUT. Gain values were estimated from the slopes of these functional curves. Finally, an open-loop gain, which is a most important index for performance of arterial baroreflex, was given by a product of the gain values of MN (GMN) and NM arcs (GNM). Gain values of MN was 8.92 ± 3.07 pg⋅ml−1⋅mmHg−1; and GNM at 0° and 15° HUT were 0.61 ± 0.08 and 0.36 ± 0.05 mmHg⋅ml⋅pg–1, respectively. A postural change from supine to 15° HUT significantly reduced the open-loop gain from 5.62 ± 0.98 to 3.75 ± 0.62. The effects of HUT on the NM arc and open-loop gain seemed to be similar to those of blood loss observed in our previous animal studies.ConclusionAn equilibrium-diagram analysis contributes to a quantitative and integrative understanding of function of human sympathetic arterial baroreflex.

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“…Complete ganglionic blockade causes by it self irreversible shock [11]; suppression of NE release by surgical or chemical sympathectomy diminishes the resistance to hemorrhage. In contrast, combined blockade of the a+fi adrenergic receptors is beneficial [8,10].…”

Section: Effect Of Hemorrhage On Bretylium-medicated Sheepmentioning

confidence: 99%