Splanchnic hemodynamics in portal hypertensive dogs with portal fibrosis

Splanchnic hemodynamics and portal systemic shunting were measured in eight dogs with experimentally induced portal fibrosis and splenomegaly and in six normal dogs by the radioactive microsphere technique. Portal fibrosis and splenomegaly were produced by repeated intraportal injections of a mixture of killed nonpathogenic Escherichia coli and dog anti-E. coli serum. All E. coli-treated dogs developed intrahepatic presinusoidal portal hypertension (portal vein pressure 15.8 +/- 5.4 vs. 7.5 +/- 0.9 mmHg in controls, P less than 0.005; intrahepatic pressure 6.8 +/- 2.1 vs. 6.2 +/- 1.4 mmHg in controls, NS) within 2.5 mo, but no portal systemic shunt was demonstrated at this time (2.1 +/- 1.5 vs. 0.7 +/- 0.4%, NS). Portal venous inflow, the total blood flow within the portal system, was increased in the treated dogs (27.6 +/- 6.6 vs. 18.2 +/- 2.5 ml X min-1 X kg body wt-1, P less than 0.005). Total splanchnic arterial vascular resistance was reduced in these dogs (26.0 +/- 10.4 vs. 40.9 +/- 4.6 dyn X s X cm-5 X 10(3), P less than 0.01) as a result of reduced arteriolar resistance in the spleen, jejunum and ileum, colon, and omentum, in all of which blood flow increased. In these animals both portal venous flow (27.0 +/- 6.5 vs. 18.1 +/- 2.5 ml X min-1 X kg body wt-1, P less than 0.005) and intrahepatic portal vascular resistance (1.9 +/- 0.7 vs. 0.7 +/- 0.3 dyn X s X cm-5 X 10(3), P less than 0.005) were increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Extraocular muscles in the microphthalmic rat

The extraocular muscles in a mutant microphthalmic strain of rat were studied. The eyeball of this strain of rat is reduced to about a third in diameter of that of the normal rat. Nevertheless, in the orbit of the mutant rat, every one of the extraocular muscles was identified; their origins and courses were the same as in the normal rat, but differences existed in the insertions. These insertions could be classified into three groups: Group A (retractor bulbi): like normal insertion into the eyeball. Group B (superior rectus and superior oblique): attachment of tendonlike insertions to each other; these muscles come from opposite directions and form a loop. Group C (lateral, medial, and inferior rectus and inferior oblique): insertion into connective tissue surrounding the reduced eyeball. The volume of each muscle of the mutant rat was smaller than that of the normal rat; moreover, significant differences existed in the degree of reduction in the volume of each muscle group classified according to the change of insertion. In the group A muscle the volume was only 33% of the normal volume, whereas group B was 74% and group C was about half of normal.

Neurons of the ventral lateral geniculate nucleus of the hereditary microphthalmic rat: a Golgi study

Neurons of the lateral part of the ventral lateral geniculate nucleus in the microphthalmic rat were examined by the Golgi-Cox method. These neurons were divided into the same three types as normal neurons. However, the number of branches and the length of primary dendrites of these neurons were fewer and shorter, and the size of their perikarya was smaller, compared with normal cases.

Uncrossed retino-geniculate and retino-tectal projections in the hereditary unilaterally microphthalmic rats

The dorsal lateral geniculate nucleus (CGLd) of the hereditary unilaterally microphthalmic rats showed a diminution of volume and an increase of neuronal density on the contralateral side of the vestigial eye without the optic nerve (about 60 and 160% of the normal, respectively; P less than 0.001). No significant changes were observed in the ipsilateral CGLd. Uncrossed retino-CGLd and -tectal projections were studied using the anterograde axonal transport of HRP in adult rats with the congenital unilateral microphthalmia. Aberrant expansions of the uncrossed retinal projection widely covered CGLd and the superficial layers of the superior colliculus (SCS). The distribution pattern of expanded uncrossed retinal pathway in the mutant was essentially similar to that of neonatally one-eyed rats.

Quantitative analysis of the oculomotor nuclei in the mutant microphthalmic rat

A quantitative analysis of the oculomotor, trochlear, and abducens nuclei was carried out in the mutant microphthalmic rat. In this strain of rat, the eyeball is reduced to about one-third in diameter, and there is no optic nerve. Nevertheless, this strain possesses all the types of extraocular muscles; however, the volume of these muscles is reduced from 33 to 74% of the normal values. The oculomotor, trochlear, and abducens nuclei in this mutant rat were found in the same location as in the normal ones. Moreover, the neurons in these nuclei in the microphthalmic rat did not appear to be any different from those in the controls. The neuronal population of these nuclei was reduced by 63% (oculomotor), 50% (trochlear), and 61% (abducens) of normal values, respectively. The long axis of all neurons of these nuclei in the microphthalmic and normal rats was measured. In all three nuclei of both strains, the size histograms showed a unimodal distribution ranging from 10 to 35 micron, with peaks at 20 to 25 micron. There was no significant difference between the normal and mutant strains. Consequently, the only influence of the shrinkage of the muscles which they supply was seen in the reduction of the cell populations of these nuclei.

Uncrossed retinal projection to the medial terminal nucleus of the accessory optic system in the hereditary unilaterally microphthalmic rat

The uncrossed optic projection to the medial terminal nucleus of the accessory optic system was studied in adult rats with hereditary unilateral microphthalmia. The vestigial eye of the mutant completely lacks the optic nerve. After injection of HRP into the remaining eye the ipsilateral labeled fibers of the accessory optic system via the superior fasciculus distinctly covered the three terminal nuclei. No ipsilateral inferior fasciculus of the accessory optic system was labeled. Aberrant expansion of the uncrossed superior fasciculus fibers was observed in the medial terminal nucleus.

Geniculotectal neurons of the lateral part of the ventral lateral geniculate nucleus in the hereditary microphthalmic rat: a retrograde WGA-HRP study

The distribution and morphological characteristics of the geniculotectal neurons from the lateral part of the ventral lateral geniculate nucleus in the hereditary microphthalmic rat were examined by the WGA-HRP method. Unilateral injection of the tracer into the microphthalmic superior colliculus showed that WGA-HRP-positive neurons were present in the ipsilateral lateral part of the ventral lateral geniculate nucleus. However, the number of labeled geniculotectal neurons of the microphthalmia was about 50% that of the normal rats. Furthermore, the size of labeled geniculotectal neurons of the microphthalmia was smaller and their dendrites were shorter than those of normal rats. These results demonstrated that, although geniculotectal neurons of the microphthalmic lateral part of the ventral lateral geniculate nucleus could differentiate just as in the normal rat, the size and number of microphthalmic geniculotectal neurons were remarkably smaller and fewer than those of normal rats. Moreover, the dendrites of microphthalmic geniculotectal neurons were less branched than usual.

Neurons of the dorsal lateral geniculate nucleus of the hereditary microphthalmic rat: a Golgi study

Neurons of the dorsal lateral geniculate nucleus (LGNd) in the microphthalmic rat were examined by the Golgi-Cox method. LGNd neurons in the microphthalmic rat were classified into the multipolar (I) and bipolar (II) types as in the normal rat. The multipolar type was further divided into two subclasses (Ia and Ib) on the basis of their dendritic patterns. The proximal portion of their primary dendrites was thinner than in normal LGNd neurons. The Ia cells had 6-7 primary dendrites extending radially, while the Ib cells had 3-4 primary dendrites spreading primarily parallel to the optic tract. Type II cells had two or three primary dendrites emerging from the cell bodies. In both types, primary dendrites were shorter in length or less branched than usual. These results suggested that LGNd neurons in the microphthalmic rat had smaller dendritic fields than those in the normal rat.

Liver function in moderate obesity--study in 534 moderately obese subjects among 4613 male company employees

The influence of moderate obesity on the liver was assessed in 4613 male company employees including 534 moderately obese subjects (30-50 percent overweight). Serum levels of transaminases and gammaglutamyl transferase activities were significantly higher in moderately obese male non-drinkers than in non-obese non-drinkers. Twenty-four percent of male non-drinkers with moderate obesity had abnormal levels of sGPT and 47 percent of moderately obese male non-drinkers had significant hepatic steatosis as assessed by computed tomography. Although most previous studies on this subject were concerned with morbid obesity accompanying only those of more than 50 percent overweight or those who required surgery, the results of this study clearly indicate that moderately obese subjects also have frequent liver dysfunction.

Clinical utility of pulsed Doppler flowmetry in patients with portal hypertension

The recently developed Doppler flowmetry system that consists of an electronic sector and a pulsed Doppler flowmeter, is capable of determining the direction of blood flow in large veins visible by ultrasonography and measuring blood flow. It is noninvasive and can be performed in patients on ambulatory basis at the time of routine ultrasound examination. In this communication, clinical utility of pulsed Doppler flowmetry was tested in 20 patients with portal hypertension. Doppler flowmetry proved useful in differential diagnosis of splenorenal shunt and cystic disease, diagnosis of arterioportal shunt, diagnosis of portal vein occlusion, demonstration of hepatofugal flow in the splenic vein, and prediction of esophageal varices by the demonstration of hepatofugal flow in an enlarged left gastric vein.

Determination of amoxapine and its metabolites in human serum by high-performance liquid chromatography

The simultaneous quantitative determination of amoxapine, 7-hydroxyamoxapine and 8-hydroxyamoxapine in human serum was established, with good recoveries, using reversed-phase high-performance liquid chromatography (HPLC). Prior to analysis by high-performance liquid chromatography, the enzymic hydrolysis with beta-glucuronidase/arylsulphatase of sera from healthy volunteers receiving the drug showed that each conjugate of two hydroxyamoxapines was 75-90% of the amount determined by the present method. The concentrations of amoxapine and its hydroxylated metabolites were measured against time in sera from the volunteers who were given the antidepressant orally for 2 weeks. The serum levels of 8-OH-amoxapine were markedly higher than the drug itself and the 7-OH-derivative. Whereas the levels of the drug were little increased during the continuous administration, the levels of 8-OH-amoxapine were linearly increased until the fourth day after the administration was started. In addition, the ratio of each hydroxylated metabolite to the drug and the time-course of their serum levels varied interindividually.

Quantitative morphological changes in the superior colliculus and the parabigeminal nucleus in the bilaterally microphthalmic rat

Quantitative morphological changes in the superior colliculus (SC) and the parabigeminal nucleus (PB) were studied in hereditary bilaterally microphthalmic rat, which lacks the optic nerve completely. Volumes of the retinorecipient superficial collicular layers of SC (SCS) to the central gray matter were decreased by 35% with respect to the normal. However, the cell density in SCS was increased as much as 150% of the normal. The stratum griseum superficiale was packed densely and irregularly with small-sized round nerve cells. The stratum opticum of the mutant rat appeared as a narrow band with few fiber components, but it contained some medium-sized polygonal neurons. No significant changes were found in the deeper layers of the microphthalmic SC. Bilaterally microphthalmic PB reduced both its volume and cellular density per unit area (about 30 and 75% of the normal, respectively). Furthermore, in contrast to the normal rat, the mutant PB could not be subdivided into the dorsal, middle and ventral subgroups.

Distribution of the tecto-thalamic projection neurons in the hereditary microphthalmic rat

Tecto-thalamic projections in the hereditary bilaterally microphthalmic rat were studied by means of WGA-HRP injection into the dorsal lateral geniculate nucleus (LGNd) and the lateroposterior thalamic nucleus (LP). Histological study in the mutant rats showed that whereas LGNd and superficial layers of the superior colliculus (SC) suffered from a remarkable reduction in size, LP had no histological changes as compared to the normal animals. Unilateral injection of the tracer into the microphthalmic LGNd showed that WGA-HRP positive neurons were present mostly in the ipsilateral str. griseum superficiale (SGS) of the SC. However, the number of labeled SGS neurons of the microphthalmic animals was about 3% of the normal. Although cell bodies of the normal tecto-LGNd neurons in the SGS were spindle-form in shape and issued one or two proximal dendrites from each pole, the microphthalmic tecto-LGNd neurons showed an irregular contour and their dendrites were not so intensively labeled. Unilateral injections of WGA-HRP into the LP revealed that the tecto-LP neurons were mainly distributed in the ipsilateral str. opticum of the colliculus (SO) in both normal and microphthalmic animals. However, the number of labeled SO cells in the microphthalmic rat was about one-half of the normal. Furthermore, the size of labeled tecto-LP neurons was smaller than that of the normal ones, and they showed irregular round to oval cell bodies with equivocally labeled dendrites, in contrast to the normal tecto-LP neurons with polygonal cell bodies extending three or more dendrites in a radial fashion. These results indicate that there exist the tecto-LGNd and -LP projection neurons in the microphthalmic rat and that their laminally segregated projection is fundamentally preserved. However, the number of the tecto-thalamic projection neurons, especially of the tecto-LGNd cells, was markedly diminished in the mutant tectum compared to normals.

The reciprocal connections of the suprageniculate nucleus and the superior colliculus in the rat

Reciprocally bilateral connections between the superior colliculus and the suprageniculate nucleus have been studied in the rat, using the anterograde and retrograde transport techniques of HRP. In those cases where the HRP deposit was restricted to the superficial layers of the colliculus, anterogradely labeled fibers and retrogradely labeled neurons were observed in the ipsilateral suprageniculate nucleus. However, upon HRP injection extended into the intermediate layers of the colliculus, the number of labeled fibers and neurons was not only increased ipsilaterally but were also observed in the contralateral suprageniculate nucleus. The density of the labeled fibers and the number of labeled neurons was always greater in the ipsilateral side. These results show that the suprageniculate nucleus and the superior colliculus are connected reciprocally and bilaterally, with an ipsilateral dominance.

The organization of neurons in the nucleus of the lateral lemniscus projecting to the superior and inferior colliculi in the rat

The topographic organization of neurons in the dorsal nucleus of the lateral lemniscus (DNLL) which project to the superior and inferior colliculi was studied using the retrograde horseradish peroxidase (HRP) and the fluorescent double labeling methods. Neurons projecting to the superior colliculus (SC) are situated in the rostral portion of the DNLL, whereas those to the inferior colliculus (IC) are found in the caudal area of this nucleus. These two portions are completely separated from each other and no neurons projecting to both the SC and the IC are observed. In the dorsolateral part of the rostral portion of the DNLL, neurons projecting to the ipsilateral SC are found, whereas neurons projecting to the contralateral SC are located in the central to medial part of the nucleus, but no neurons sending collateral axons to both sides of the SC were observed. Neurons located in the central part of the caudal area of the DNLL project to the ipsilateral IC and neurons in the lateral and medial parts project contralaterally to the IC. Some of the neurons in the caudal part of the DNLL have divergent axonal branching projecting to both sides of the IC. In the ventral nucleus of the lateral lemniscus, labeled neurons were observed only when the HRP was injected into the ipsilateral IC.

Effects of propranolol on portal hemodynamics in patients with chronic liver disease

To elucidate the mechanism by which propranolol reportedly affects portal hemodynamics, we investigated the effect of propranolol on systemic and splanchnic hemodynamics in 15 patients with portal hypertension and esophageal varices by simultaneous catheterization of the portal vein and the right hepatic vein and measurement of portal venous flow using an ultrasound doppler system. Infusion of 5 mg of propranolol significantly decreased pulse rate (-12.6%), cardiac output (-24.5%), portal venous flow (-22.3%), portal venous pressure (-13.3%), and gradient between portal venous pressure and free hepatic venous pressure (-24.8%). Thus, propranolol seems to decrease portal venous pressure by reducing portal venous flow, at least in part, as a result of reduction of cardiac output due to its beta 1 adrenergic receptor blocking action.

Ascending projections to the lateral thalamic nuclei from the substantia grisea centralis in the rat: a retrograde WGA-HRP study

Ascending projections to the lateral thalamic nuclear group from the substantia grisea centralis (SGC) were studied by injections of wheat germ agglutinin-conjugated with HRP (WGA-HRP) into the laterodorsal (LD) and lateroposterior (LP) thalamic nuclei. The present study demonstrated that the pars ventralis of the SGC at the levels of the intercollicular region and of the locus ceruleus sent fibers to both the LD and LP on both sides with homolateral predominance. Distribution pattern and morphological characteristics of the LD-projection neurons in the SGC were similar to those of SGC-LP projection cells. WGA-HRP injections into the LD or LP labeled also a considerable number of neurons in the dorsal raphe nucleus and the dorsal tegmental nucleus bilaterally with homolateral predominance, but the nucleus of Darkschewitsch contained labeled neurons only after the LD injection.