Observations on the intrahepatic flow interactions of the hepatic artery and portal vein

Grayson, J.; Mendel, David

doi:10.1113/jphysiol.1957.sp005884

Cited by 17 publications

(5 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The present results are not essentially different from the measurements in rats, as reported by Grayson and Mendel (20). There have been many observations (7,8,16,(21)(22)(23)25) on the distribution and the properties of cholinergic receptors on the circulation beds of HA and PV.…”

Section: Discussionsupporting

confidence: 68%

Factors Producing Various Responses to Acetylcholine in Dog Hepatic Circulation

Yamamoto

1976

Japanese Journal of Pharmacology

View full text Add to dashboard Cite

Abstract-Effect of acetylcholine on hepatic circulation was investigated in 33 mongrel dogs. Mean arterial blood pressure, hepatic artery flow, portal vein pressure and portal vein flow were determined after laparotomy under nembutal anesthesia. In order to analyse the complicated responses in hepatic blood (lows to 3 ,'g of acetylcholine hydrochloride, the peripheral resistance of each vascular system was observed in hy potensive dogs, in vascular obliteration dogs and in portal vein shunting dogs. Ob servation under a hypotensive condition produced by exsanguination revealed that hepatic artery resistance responded to decrease in hepatic artery pressure in different ways depending on whether the systemic blood pressure was above or below 90 mmHg. Experiments in which the hepatic artery or portal vein were obliterated disclosed that there was a certain regularity in the induction of resistance change in the non-injected one of the two hepatic vessels. The result of shunting the portal vein suggested that the complicated change above mentioned would be the expression of the overlapping two sequential responses. Since these results are difficult to explain merely by the direct response of vascular smooth muscle to acetycholine, the possibility that the hypo thetical communication between the hepatic artery and portal vein might be a cholinergic system was discussed.It has long been observed that the hemodynamics of the liver, which is supplied by the two vascular systems, the hepatic artery and portal vein, are somewhat different from those of any other organ (1-7, 10-24). Many authors have discussed the presence or absence of a blood flow regulation mechanism specific to the liver and have estimated the related pro perties, yet did not reach any definite conclusion.On the other hand, the physiologic functions of adrenergic and cholinergic receptors, which are considered to be distributed on the vascular perfusion beds, that is, their phar macologic reactions to noradrenaline, isoproterenol and acetylcholine were also studied by many investigators (6,7,8,15,(21)(22)(23). The diversity among the reports on the distribution and the function of cholinergic receptors in the liver has also attracted the attention of many workers. It has been confirmed that the administraction of a rather large dose of acetyl choline often produced different responses. (8) termed the responses as atypical and discussed the mode of manifestation of the atypical responses. The present author attempted to elucidate the diversity in physiologic roles of cholinergic receptors distributed on the hepatic vascular wall by exploring the mechanism of these various responses to acetylcholine. MATERIALS AND METHODSThirty-three male and female mongrel dogs, weighing 13.0-36.0 kg, were fasted 24 hr prior to the experiment, and were then anesthetized with pentobarital sodium (30 mg/kg,

show abstract

Section: Discussionsupporting

confidence: 68%

Factors Producing Various Responses to Acetylcholine in Dog Hepatic Circulation

Yamamoto

1976

Japanese Journal of Pharmacology

View full text Add to dashboard Cite

show abstract

“…The simplified photographic recording method described by Grayson & Mendel (1957) was used, giving automatic temperature and conductivity readings at intervals of 41 sec. The cold junction was protected by a fine Polythene sleeve and situated in the abdomen alongside the portal vein.…”

Section: Insulin On Liver Blood Flow and Metabolism 53mentioning

confidence: 99%

Vascular and metabolic responses of the liver to insulin

Grayson¹,

Kinnear²

1958

The Journal of Physiology

Self Cite

View full text Add to dashboard Cite

By means of the bromsulphalein method it has been shown in man that insulin hypoglycaemia is accompanied by an increase in liver blood flow (Bearn, Billing & Sherlock, 1952). These experiments, however, threw little direct light on the relative importance of hepatic artery and portal vein, nor could they really be regarded as conclusive in regard to the importance of nervous or endocrine factors.The first object of the present work was, therefore, to apply the method of 'internal calorimetry', a heated thermocouple technique which depends on the measurement of thermal conductivity (Grayson, 1952; Hensel, Ruef & Golenhofen, 1954), to the fuller investigation of this phenomenon in rats and baboons.The present work has had, too, a subsidiary object, namely, to determine changes in hepatic heat production after giving insulin. METHODSWistar strain albino rats (200-250 g) of either sex were used. Many of the experiments were carried out on the conscious animal. In these experiments liver recorders were implanted under ether anaesthesia, usually on the previous day. The leads from the animals were soldered to the leads from the apparatus. No restraint other than the animal's usual cage was used, the leads from the apparatus hanging freely from above.In other experiments the rats were anaesthetized with pentobarbitone sodium (Nembutal, Abbott Laboratories; 60 mg/kg intraperitoneally). Polythene cannulae were inserted into the trachea, a carotid artery, a femoral artery and, usually, an external jugular vein, after heparinization (Liquemin, Roche Products, 100 ug/kg intraperitoneally). Liver blood-flow recorders were inserted through a mid-line abdominal incision. Baboons (Papio anubos) were anaesthetized by ethyl chloride induction followed by open ether and intraperitoneal pentobarbitone sodium (75 mg/kg).Liver blood flow. The technique of internal calorimetry fully described elsewhere (Birnie & Grayson, 1952;Grayson, 1952) was employed for assessment of liver blood flow. This technique depends on a thermo-electric measurement of liver thermal conductivity. It has been shown elsewhere (Grayson, 1952) that conductivity increment (i.e. thermal conductivity of living liver less the thermal conductivity of dead liver) is an approximately linear function of blood flow.

show abstract

“…It depends on the thermo-electric measurement of thermal conductivity by means of a heated thermocouple, to the heater circuit of which current is supplied in cyclic fashion as follows (Grayson & Mendel, 1957): 0-200 mA2 for 24 sec, 0-600 mA2 for 17 sec, 0-315 mA2 for 24 sec, no current for 17 sec. This cycle is continuously repeated by means of a cam-operated switch.…”

Section: Methodsmentioning

confidence: 99%

The measurement of metabolic and vascular responses in the thyroid gland with observations on its responses to insulin, glucose and adrenaline

Dosekun¹

1961

The Journal of Physiology

View full text Add to dashboard Cite

Grayson & Kinnear (1958) have extended the technique of internal calorimetry (Grayson, 1952; Carlyle & Grayson, 1956) to investigate problems of blood flow and metabolic heat production in solid organs. Dosekun, Grayson & Mendel (1960) have reported further investigations on human liver and rat skeletal muscle in which the validity of the technique of internal calorimetry in the determination of metabolic heat production was established.The purpose of the present work was to apply this technique to the investigation of blood flow and heat production in the thyroid gland with particular reference to its carbohydrate metabolism. METHODSThe technique of internal calorimetry has been previously described (Grayson, 1952; Dosekun et al. 1960). It depends on the thermo-electric measurement of thermal conductivity by means of a heated thermocouple, to the heater circuit of which current is supplied in cyclic fashion as follows (Grayson & Mendel, 1957): 0-200 mA2 for 24 sec, 0-600 mA2 for 17 sec, 0-315 mA2 for 24 sec, no current for 17 sec. This cycle is continuously repeated by means of a cam-operated switch. The temperature changes induced in the thermocouple by this procedure were recorded using a Cambridge D'Arsonval galvanometer, a light source and a recording camera. In all experiments the 'cold junction' was in the aorta. The calculation of thermal conductivity (8k) from the record has been fully described elsewhere (Dosekun et al. 1960). It has been shown previously that the difference between the thermal conductivity of living and dead tissue is a linear function of blood flow and in these experiments the function Sk has been taken to represent blood flow.Calculation of metabolic heat production. The temperatures of a heated thermocouple through which currents of 0-200 mA2 and 0-315 mA2 are passing are called lower equilibrium and upper equilibrium temperatures respectively. As already reported (Dosekun et al. 1960), the lower equilibrium temperature could be measured from the bottom of the paper to the lower point of inflexion on the photographic trace. Changes in lower equilibrium temperature may be brought about by alterations in blood flow or by alterations in the temperature of the afferent blood; they may be brought about by alterations in local conditions of heat loss or they may be the result of changes in local heat production.In the present experiments the 'cold junction' was situated in the aorta and changes in blood temperature were thus automatically compensated. The experiments were carried out

show abstract

Observations on the intrahepatic flow interactions of the hepatic artery and portal vein

Cited by 17 publications

References 6 publications

Factors Producing Various Responses to Acetylcholine in Dog Hepatic Circulation

Factors Producing Various Responses to Acetylcholine in Dog Hepatic Circulation

Vascular and metabolic responses of the liver to insulin

The measurement of metabolic and vascular responses in the thyroid gland with observations on its responses to insulin, glucose and adrenaline

Contact Info

Product

Resources

About